libaxolotl doesn't exist anymore, it's renamed to libsignal

3 files changed, 4612 insertions, 0 deletions

diff --git a/libs/libsignal/src/protobuf-c/CMakeLists.txt b/libs/libsignal/src/protobuf-c/CMakeLists.txt
new file mode 100644
index 0000000000..1af25df194
--- /dev/null
+++ b/libs/libsignal/src/protobuf-c/CMakeLists.txt
@@ -0,0 +1,25 @@
+IF(CMAKE_COMPILER_IS_GNUCC OR CMAKE_C_COMPILER_ID MATCHES "Clang")
+  SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-shadow")
+ENDIF(CMAKE_COMPILER_IS_GNUCC OR CMAKE_C_COMPILER_ID MATCHES "Clang")
+
+IF(CMAKE_COMPILER_IS_GNUCC)
+	SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-sign-compare")
+	IF(GCC_WARN_SIGN_CONVERSION)
+		SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-sign-conversion")
+	ENDIF(GCC_WARN_SIGN_CONVERSION)
+ENDIF(CMAKE_COMPILER_IS_GNUCC)
+
+IF(CMAKE_C_COMPILER_ID MATCHES "Clang")
+  SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-shorten-64-to-32")
+ENDIF(CMAKE_C_COMPILER_ID MATCHES "Clang")
+
+set(protobuf_SRCS
+	protobuf-c.c
+)
+
+add_library(protobuf-c OBJECT ${protobuf_SRCS})
+
+# Add -fPIC flag
+if(BUILD_SHARED_LIBS)
+	set_property(TARGET protobuf-c PROPERTY POSITION_INDEPENDENT_CODE ON)
+endif()
diff --git a/libs/libsignal/src/protobuf-c/protobuf-c.c b/libs/libsignal/src/protobuf-c/protobuf-c.c
new file mode 100644
index 0000000000..4f2f5bcc73
--- /dev/null
+++ b/libs/libsignal/src/protobuf-c/protobuf-c.c
@@ -0,0 +1,3490 @@
+/*
+ * Copyright (c) 2008-2015, Dave Benson and the protobuf-c authors.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/*! \file
+ * Support library for `protoc-c` generated code.
+ *
+ * This file implements the public API used by the code generated
+ * by `protoc-c`.
+ *
+ * \authors Dave Benson and the protobuf-c authors
+ *
+ * \copyright 2008-2014. Licensed under the terms of the [BSD-2-Clause] license.
+ */
+
+/**
+ * \todo 64-BIT OPTIMIZATION: certain implementations use 32-bit math
+ * even on 64-bit platforms (uint64_size, uint64_pack, parse_uint64).
+ *
+ * \todo Use size_t consistently.
+ */
+
+#include <stdlib.h>	/* for malloc, free */
+#include <string.h>	/* for strcmp, strlen, memcpy, memmove, memset */
+
+#include "protobuf-c.h"
+
+#define TRUE				1
+#define FALSE				0
+
+#define PROTOBUF_C__ASSERT_NOT_REACHED() assert(0)
+
+/* Workaround for Microsoft compilers. */
+#ifdef _MSC_VER
+# define inline __inline
+#endif
+
+/**
+ * \defgroup internal Internal functions and macros
+ *
+ * These are not exported by the library but are useful to developers working
+ * on `libprotobuf-c` itself.
+ */
+
+/**
+ * \defgroup macros Utility macros for manipulating structures
+ *
+ * Macros and constants used to manipulate the base "classes" generated by
+ * `protobuf-c`. They also define limits and check correctness.
+ *
+ * \ingroup internal
+ * @{
+ */
+
+/** The maximum length of a 64-bit integer in varint encoding. */
+#define MAX_UINT64_ENCODED_SIZE		10
+
+#ifndef PROTOBUF_C_UNPACK_ERROR
+# define PROTOBUF_C_UNPACK_ERROR(...)
+#endif
+
+/**
+ * Internal `ProtobufCMessage` manipulation macro.
+ *
+ * Base macro for manipulating a `ProtobufCMessage`. Used by STRUCT_MEMBER() and
+ * STRUCT_MEMBER_PTR().
+ */
+#define STRUCT_MEMBER_P(struct_p, struct_offset) \
+    ((void *) ((uint8_t *) (struct_p) + (struct_offset)))
+
+/**
+ * Return field in a `ProtobufCMessage` based on offset.
+ *
+ * Take a pointer to a `ProtobufCMessage` and find the field at the offset.
+ * Cast it to the passed type.
+ */
+#define STRUCT_MEMBER(member_type, struct_p, struct_offset) \
+    (*(member_type *) STRUCT_MEMBER_P((struct_p), (struct_offset)))
+
+/**
+ * Return field in a `ProtobufCMessage` based on offset.
+ *
+ * Take a pointer to a `ProtobufCMessage` and find the field at the offset. Cast
+ * it to a pointer to the passed type.
+ */
+#define STRUCT_MEMBER_PTR(member_type, struct_p, struct_offset) \
+    ((member_type *) STRUCT_MEMBER_P((struct_p), (struct_offset)))
+
+/* Assertions for magic numbers. */
+
+#define ASSERT_IS_ENUM_DESCRIPTOR(desc) \
+	assert((desc)->magic == PROTOBUF_C__ENUM_DESCRIPTOR_MAGIC)
+
+#define ASSERT_IS_MESSAGE_DESCRIPTOR(desc) \
+	assert((desc)->magic == PROTOBUF_C__MESSAGE_DESCRIPTOR_MAGIC)
+
+#define ASSERT_IS_MESSAGE(message) \
+	ASSERT_IS_MESSAGE_DESCRIPTOR((message)->descriptor)
+
+#define ASSERT_IS_SERVICE_DESCRIPTOR(desc) \
+	assert((desc)->magic == PROTOBUF_C__SERVICE_DESCRIPTOR_MAGIC)
+
+/**@}*/
+
+/* --- version --- */
+
+const char *
+protobuf_c_version(void)
+{
+	return PROTOBUF_C_VERSION;
+}
+
+uint32_t
+protobuf_c_version_number(void)
+{
+	return PROTOBUF_C_VERSION_NUMBER;
+}
+
+/* --- allocator --- */
+
+static void *
+system_alloc(void *allocator_data, size_t size)
+{
+	return malloc(size);
+}
+
+static void
+system_free(void *allocator_data, void *data)
+{
+	free(data);
+}
+
+static inline void *
+do_alloc(ProtobufCAllocator *allocator, size_t size)
+{
+	return allocator->alloc(allocator->allocator_data, size);
+}
+
+static inline void
+do_free(ProtobufCAllocator *allocator, void *data)
+{
+	if (data != NULL)
+		allocator->free(allocator->allocator_data, data);
+}
+
+/*
+ * This allocator uses the system's malloc() and free(). It is the default
+ * allocator used if NULL is passed as the ProtobufCAllocator to an exported
+ * function.
+ */
+static ProtobufCAllocator protobuf_c__allocator = {
+	&system_alloc,
+	&system_free,
+	NULL
+};
+
+/* === buffer-simple === */
+
+void
+protobuf_c_buffer_simple_append(ProtobufCBuffer *buffer,
+				size_t len, const uint8_t *data)
+{
+	ProtobufCBufferSimple *simp = (ProtobufCBufferSimple *) buffer;
+	size_t new_len = simp->len + len;
+
+	if (new_len > simp->alloced) {
+		ProtobufCAllocator *allocator = simp->allocator;
+		size_t new_alloced = simp->alloced * 2;
+		uint8_t *new_data;
+
+		if (allocator == NULL)
+			allocator = &protobuf_c__allocator;
+		while (new_alloced < new_len)
+			new_alloced += new_alloced;
+		new_data = do_alloc(allocator, new_alloced);
+		if (!new_data)
+			return;
+		memcpy(new_data, simp->data, simp->len);
+		if (simp->must_free_data)
+			do_free(allocator, simp->data);
+		else
+			simp->must_free_data = TRUE;
+		simp->data = new_data;
+		simp->alloced = new_alloced;
+	}
+	memcpy(simp->data + simp->len, data, len);
+	simp->len = new_len;
+}
+
+/**
+ * \defgroup packedsz protobuf_c_message_get_packed_size() implementation
+ *
+ * Routines mainly used by protobuf_c_message_get_packed_size().
+ *
+ * \ingroup internal
+ * @{
+ */
+
+/**
+ * Return the number of bytes required to store the tag for the field. Includes
+ * 3 bits for the wire-type, and a single bit that denotes the end-of-tag.
+ *
+ * \param number
+ *      Field tag to encode.
+ * \return
+ *      Number of bytes required.
+ */
+static inline size_t
+get_tag_size(unsigned number)
+{
+	if (number < (1 << 4)) {
+		return 1;
+	} else if (number < (1 << 11)) {
+		return 2;
+	} else if (number < (1 << 18)) {
+		return 3;
+	} else if (number < (1 << 25)) {
+		return 4;
+	} else {
+		return 5;
+	}
+}
+
+/**
+ * Return the number of bytes required to store a variable-length unsigned
+ * 32-bit integer in base-128 varint encoding.
+ *
+ * \param v
+ *      Value to encode.
+ * \return
+ *      Number of bytes required.
+ */
+static inline size_t
+uint32_size(uint32_t v)
+{
+	if (v < (1 << 7)) {
+		return 1;
+	} else if (v < (1 << 14)) {
+		return 2;
+	} else if (v < (1 << 21)) {
+		return 3;
+	} else if (v < (1 << 28)) {
+		return 4;
+	} else {
+		return 5;
+	}
+}
+
+/**
+ * Return the number of bytes required to store a variable-length signed 32-bit
+ * integer in base-128 varint encoding.
+ *
+ * \param v
+ *      Value to encode.
+ * \return
+ *      Number of bytes required.
+ */
+static inline size_t
+int32_size(int32_t v)
+{
+	if (v < 0) {
+		return 10;
+	} else if (v < (1 << 7)) {
+		return 1;
+	} else if (v < (1 << 14)) {
+		return 2;
+	} else if (v < (1 << 21)) {
+		return 3;
+	} else if (v < (1 << 28)) {
+		return 4;
+	} else {
+		return 5;
+	}
+}
+
+/**
+ * Return the ZigZag-encoded 32-bit unsigned integer form of a 32-bit signed
+ * integer.
+ *
+ * \param v
+ *      Value to encode.
+ * \return
+ *      ZigZag encoded integer.
+ */
+static inline uint32_t
+zigzag32(int32_t v)
+{
+	if (v < 0)
+		return ((uint32_t) (-v)) * 2 - 1;
+	else
+		return v * 2;
+}
+
+/**
+ * Return the number of bytes required to store a signed 32-bit integer,
+ * converted to an unsigned 32-bit integer with ZigZag encoding, using base-128
+ * varint encoding.
+ *
+ * \param v
+ *      Value to encode.
+ * \return
+ *      Number of bytes required.
+ */
+static inline size_t
+sint32_size(int32_t v)
+{
+	return uint32_size(zigzag32(v));
+}
+
+/**
+ * Return the number of bytes required to store a 64-bit unsigned integer in
+ * base-128 varint encoding.
+ *
+ * \param v
+ *      Value to encode.
+ * \return
+ *      Number of bytes required.
+ */
+static inline size_t
+uint64_size(uint64_t v)
+{
+	uint32_t upper_v = (uint32_t) (v >> 32);
+
+	if (upper_v == 0) {
+		return uint32_size((uint32_t) v);
+	} else if (upper_v < (1 << 3)) {
+		return 5;
+	} else if (upper_v < (1 << 10)) {
+		return 6;
+	} else if (upper_v < (1 << 17)) {
+		return 7;
+	} else if (upper_v < (1 << 24)) {
+		return 8;
+	} else if (upper_v < (1U << 31)) {
+		return 9;
+	} else {
+		return 10;
+	}
+}
+
+/**
+ * Return the ZigZag-encoded 64-bit unsigned integer form of a 64-bit signed
+ * integer.
+ *
+ * \param v
+ *      Value to encode.
+ * \return
+ *      ZigZag encoded integer.
+ */
+static inline uint64_t
+zigzag64(int64_t v)
+{
+	if (v < 0)
+		return ((uint64_t) (-v)) * 2 - 1;
+	else
+		return v * 2;
+}
+
+/**
+ * Return the number of bytes required to store a signed 64-bit integer,
+ * converted to an unsigned 64-bit integer with ZigZag encoding, using base-128
+ * varint encoding.
+ *
+ * \param v
+ *      Value to encode.
+ * \return
+ *      Number of bytes required.
+ */
+static inline size_t
+sint64_size(int64_t v)
+{
+	return uint64_size(zigzag64(v));
+}
+
+/**
+ * Calculate the serialized size of a single required message field, including
+ * the space needed by the preceding tag.
+ *
+ * \param field
+ *      Field descriptor for member.
+ * \param member
+ *      Field to encode.
+ * \return
+ *      Number of bytes required.
+ */
+static size_t
+required_field_get_packed_size(const ProtobufCFieldDescriptor *field,
+			       const void *member)
+{
+	size_t rv = get_tag_size(field->id);
+
+	switch (field->type) {
+	case PROTOBUF_C_TYPE_SINT32:
+		return rv + sint32_size(*(const int32_t *) member);
+	case PROTOBUF_C_TYPE_INT32:
+		return rv + int32_size(*(const uint32_t *) member);
+	case PROTOBUF_C_TYPE_UINT32:
+		return rv + uint32_size(*(const uint32_t *) member);
+	case PROTOBUF_C_TYPE_SINT64:
+		return rv + sint64_size(*(const int64_t *) member);
+	case PROTOBUF_C_TYPE_INT64:
+	case PROTOBUF_C_TYPE_UINT64:
+		return rv + uint64_size(*(const uint64_t *) member);
+	case PROTOBUF_C_TYPE_SFIXED32:
+	case PROTOBUF_C_TYPE_FIXED32:
+		return rv + 4;
+	case PROTOBUF_C_TYPE_SFIXED64:
+	case PROTOBUF_C_TYPE_FIXED64:
+		return rv + 8;
+	case PROTOBUF_C_TYPE_BOOL:
+		return rv + 1;
+	case PROTOBUF_C_TYPE_FLOAT:
+		return rv + 4;
+	case PROTOBUF_C_TYPE_DOUBLE:
+		return rv + 8;
+	case PROTOBUF_C_TYPE_ENUM:
+		/* \todo Is this correct for negative-valued enums? */
+		return rv + uint32_size(*(const uint32_t *) member);
+	case PROTOBUF_C_TYPE_STRING: {
+		const char *str = *(char * const *) member;
+		size_t len = str ? strlen(str) : 0;
+		return rv + uint32_size(len) + len;
+	}
+	case PROTOBUF_C_TYPE_BYTES: {
+		size_t len = ((const ProtobufCBinaryData *) member)->len;
+		return rv + uint32_size(len) + len;
+	}
+	case PROTOBUF_C_TYPE_MESSAGE: {
+		const ProtobufCMessage *msg = *(ProtobufCMessage * const *) member;
+		size_t subrv = msg ? protobuf_c_message_get_packed_size(msg) : 0;
+		return rv + uint32_size(subrv) + subrv;
+	}
+	}
+	PROTOBUF_C__ASSERT_NOT_REACHED();
+	return 0;
+}
+
+/**
+ * Calculate the serialized size of a single oneof message field, including
+ * the space needed by the preceding tag. Returns 0 if the oneof field isn't
+ * selected or is not set.
+ *
+ * \param field
+ *      Field descriptor for member.
+ * \param oneof_case
+ *      A pointer to the case enum that selects the field in the oneof.
+ * \param member
+ *      Field to encode.
+ * \return
+ *      Number of bytes required.
+ */
+static size_t
+oneof_field_get_packed_size(const ProtobufCFieldDescriptor *field,
+			    const uint32_t *oneof_case,
+			    const void *member)
+{
+	if (*oneof_case == field->id) {
+		if (field->type == PROTOBUF_C_TYPE_MESSAGE ||
+		    field->type == PROTOBUF_C_TYPE_STRING)
+		{
+			const void *ptr = *(const void * const *) member;
+			if (ptr == NULL || ptr == field->default_value)
+				return 0;
+		}
+	} else {
+		return 0;
+	}
+	return required_field_get_packed_size(field, member);
+}
+
+/**
+ * Calculate the serialized size of a single optional message field, including
+ * the space needed by the preceding tag. Returns 0 if the optional field isn't
+ * set.
+ *
+ * \param field
+ *      Field descriptor for member.
+ * \param has
+ *      True if the field exists, false if not.
+ * \param member
+ *      Field to encode.
+ * \return
+ *      Number of bytes required.
+ */
+static size_t
+optional_field_get_packed_size(const ProtobufCFieldDescriptor *field,
+			       const protobuf_c_boolean *has,
+			       const void *member)
+{
+	if (field->type == PROTOBUF_C_TYPE_MESSAGE ||
+	    field->type == PROTOBUF_C_TYPE_STRING)
+	{
+		const void *ptr = *(const void * const *) member;
+		if (ptr == NULL || ptr == field->default_value)
+			return 0;
+	} else {
+		if (!*has)
+			return 0;
+	}
+	return required_field_get_packed_size(field, member);
+}
+
+/**
+ * Calculate the serialized size of repeated message fields, which may consist
+ * of any number of values (including 0). Includes the space needed by the
+ * preceding tags (as needed).
+ *
+ * \param field
+ *      Field descriptor for member.
+ * \param count
+ *      Number of repeated field members.
+ * \param member
+ *      Field to encode.
+ * \return
+ *      Number of bytes required.
+ */
+static size_t
+repeated_field_get_packed_size(const ProtobufCFieldDescriptor *field,
+			       size_t count, const void *member)
+{
+	size_t header_size;
+	size_t rv = 0;
+	unsigned i;
+	void *array = *(void * const *) member;
+
+	if (count == 0)
+		return 0;
+	header_size = get_tag_size(field->id);
+	if (0 == (field->flags & PROTOBUF_C_FIELD_FLAG_PACKED))
+		header_size *= count;
+
+	switch (field->type) {
+	case PROTOBUF_C_TYPE_SINT32:
+		for (i = 0; i < count; i++)
+			rv += sint32_size(((int32_t *) array)[i]);
+		break;
+	case PROTOBUF_C_TYPE_INT32:
+		for (i = 0; i < count; i++)
+			rv += int32_size(((uint32_t *) array)[i]);
+		break;
+	case PROTOBUF_C_TYPE_UINT32:
+	case PROTOBUF_C_TYPE_ENUM:
+		for (i = 0; i < count; i++)
+			rv += uint32_size(((uint32_t *) array)[i]);
+		break;
+	case PROTOBUF_C_TYPE_SINT64:
+		for (i = 0; i < count; i++)
+			rv += sint64_size(((int64_t *) array)[i]);
+		break;
+	case PROTOBUF_C_TYPE_INT64:
+	case PROTOBUF_C_TYPE_UINT64:
+		for (i = 0; i < count; i++)
+			rv += uint64_size(((uint64_t *) array)[i]);
+		break;
+	case PROTOBUF_C_TYPE_SFIXED32:
+	case PROTOBUF_C_TYPE_FIXED32:
+	case PROTOBUF_C_TYPE_FLOAT:
+		rv += 4 * count;
+		break;
+	case PROTOBUF_C_TYPE_SFIXED64:
+	case PROTOBUF_C_TYPE_FIXED64:
+	case PROTOBUF_C_TYPE_DOUBLE:
+		rv += 8 * count;
+		break;
+	case PROTOBUF_C_TYPE_BOOL:
+		rv += count;
+		break;
+	case PROTOBUF_C_TYPE_STRING:
+		for (i = 0; i < count; i++) {
+			size_t len = strlen(((char **) array)[i]);
+			rv += uint32_size(len) + len;
+		}
+		break;
+	case PROTOBUF_C_TYPE_BYTES:
+		for (i = 0; i < count; i++) {
+			size_t len = ((ProtobufCBinaryData *) array)[i].len;
+			rv += uint32_size(len) + len;
+		}
+		break;
+	case PROTOBUF_C_TYPE_MESSAGE:
+		for (i = 0; i < count; i++) {
+			size_t len = protobuf_c_message_get_packed_size(
+				((ProtobufCMessage **) array)[i]);
+			rv += uint32_size(len) + len;
+		}
+		break;
+	}
+
+	if (0 != (field->flags & PROTOBUF_C_FIELD_FLAG_PACKED))
+		header_size += uint32_size(rv);
+	return header_size + rv;
+}
+
+/**
+ * Calculate the serialized size of an unknown field, i.e. one that is passed
+ * through mostly uninterpreted. This is required for forward compatibility if
+ * new fields are added to the message descriptor.
+ *
+ * \param field
+ *      Unknown field type.
+ * \return
+ *      Number of bytes required.
+ */
+static inline size_t
+unknown_field_get_packed_size(const ProtobufCMessageUnknownField *field)
+{
+	return get_tag_size(field->tag) + field->len;
+}
+
+/**@}*/
+
+/*
+ * Calculate the serialized size of the message.
+ */
+size_t protobuf_c_message_get_packed_size(const ProtobufCMessage *message)
+{
+	unsigned i;
+	size_t rv = 0;
+
+	ASSERT_IS_MESSAGE(message);
+	for (i = 0; i < message->descriptor->n_fields; i++) {
+		const ProtobufCFieldDescriptor *field =
+			message->descriptor->fields + i;
+		const void *member =
+			((const char *) message) + field->offset;
+		const void *qmember =
+			((const char *) message) + field->quantifier_offset;
+
+		if (field->label == PROTOBUF_C_LABEL_REQUIRED) {
+			rv += required_field_get_packed_size(field, member);
+		} else if (field->label == PROTOBUF_C_LABEL_OPTIONAL) {
+			if (0 != (field->flags & PROTOBUF_C_FIELD_FLAG_ONEOF))
+				rv += oneof_field_get_packed_size(field, qmember, member);
+			else
+				rv += optional_field_get_packed_size(field, qmember, member);
+		} else {
+			rv += repeated_field_get_packed_size(
+				field,
+				*(const size_t *) qmember,
+				member
+			);
+		}
+	}
+	for (i = 0; i < message->n_unknown_fields; i++)
+		rv += unknown_field_get_packed_size(&message->unknown_fields[i]);
+	return rv;
+}
+
+/**
+ * \defgroup pack protobuf_c_message_pack() implementation
+ *
+ * Routines mainly used by protobuf_c_message_pack().
+ *
+ * \ingroup internal
+ * @{
+ */
+
+/**
+ * Pack an unsigned 32-bit integer in base-128 varint encoding and return the
+ * number of bytes written, which must be 5 or less.
+ *
+ * \param value
+ *      Value to encode.
+ * \param[out] out
+ *      Packed value.
+ * \return
+ *      Number of bytes written to `out`.
+ */
+static inline size_t
+uint32_pack(uint32_t value, uint8_t *out)
+{
+	unsigned rv = 0;
+
+	if (value >= 0x80) {
+		out[rv++] = value | 0x80;
+		value >>= 7;
+		if (value >= 0x80) {
+			out[rv++] = value | 0x80;
+			value >>= 7;
+			if (value >= 0x80) {
+				out[rv++] = value | 0x80;
+				value >>= 7;
+				if (value >= 0x80) {
+					out[rv++] = value | 0x80;
+					value >>= 7;
+				}
+			}
+		}
+	}
+	/* assert: value<128 */
+	out[rv++] = value;
+	return rv;
+}
+
+/**
+ * Pack a signed 32-bit integer and return the number of bytes written.
+ * Negative numbers are encoded as two's complement 64-bit integers.
+ *
+ * \param value
+ *      Value to encode.
+ * \param[out] out
+ *      Packed value.
+ * \return
+ *      Number of bytes written to `out`.
+ */
+static inline size_t
+int32_pack(int32_t value, uint8_t *out)
+{
+	if (value < 0) {
+		out[0] = value | 0x80;
+		out[1] = (value >> 7) | 0x80;
+		out[2] = (value >> 14) | 0x80;
+		out[3] = (value >> 21) | 0x80;
+		out[4] = (value >> 28) | 0x80;
+		out[5] = out[6] = out[7] = out[8] = 0xff;
+		out[9] = 0x01;
+		return 10;
+	} else {
+		return uint32_pack(value, out);
+	}
+}
+
+/**
+ * Pack a signed 32-bit integer using ZigZag encoding and return the number of
+ * bytes written.
+ *
+ * \param value
+ *      Value to encode.
+ * \param[out] out
+ *      Packed value.
+ * \return
+ *      Number of bytes written to `out`.
+ */
+static inline size_t
+sint32_pack(int32_t value, uint8_t *out)
+{
+	return uint32_pack(zigzag32(value), out);
+}
+
+/**
+ * Pack a 64-bit unsigned integer using base-128 varint encoding and return the
+ * number of bytes written.
+ *
+ * \param value
+ *      Value to encode.
+ * \param[out] out
+ *      Packed value.
+ * \return
+ *      Number of bytes written to `out`.
+ */
+static size_t
+uint64_pack(uint64_t value, uint8_t *out)
+{
+	uint32_t hi = (uint32_t) (value >> 32);
+	uint32_t lo = (uint32_t) value;
+	unsigned rv;
+
+	if (hi == 0)
+		return uint32_pack((uint32_t) lo, out);
+	out[0] = (lo) | 0x80;
+	out[1] = (lo >> 7) | 0x80;
+	out[2] = (lo >> 14) | 0x80;
+	out[3] = (lo >> 21) | 0x80;
+	if (hi < 8) {
+		out[4] = (hi << 4) | (lo >> 28);
+		return 5;
+	} else {
+		out[4] = ((hi & 7) << 4) | (lo >> 28) | 0x80;
+		hi >>= 3;
+	}
+	rv = 5;
+	while (hi >= 128) {
+		out[rv++] = hi | 0x80;
+		hi >>= 7;
+	}
+	out[rv++] = hi;
+	return rv;
+}
+
+/**
+ * Pack a 64-bit signed integer in ZigZag encoding and return the number of
+ * bytes written.
+ *
+ * \param value
+ *      Value to encode.
+ * \param[out] out
+ *      Packed value.
+ * \return
+ *      Number of bytes written to `out`.
+ */
+static inline size_t
+sint64_pack(int64_t value, uint8_t *out)
+{
+	return uint64_pack(zigzag64(value), out);
+}
+
+/**
+ * Pack a 32-bit quantity in little-endian byte order. Used for protobuf wire
+ * types fixed32, sfixed32, float. Similar to "htole32".
+ *
+ * \param value
+ *      Value to encode.
+ * \param[out] out
+ *      Packed value.
+ * \return
+ *      Number of bytes written to `out`.
+ */
+static inline size_t
+fixed32_pack(uint32_t value, void *out)
+{
+#if !defined(WORDS_BIGENDIAN)
+	memcpy(out, &value, 4);
+#else
+	uint8_t *buf = out;
+
+	buf[0] = value;
+	buf[1] = value >> 8;
+	buf[2] = value >> 16;
+	buf[3] = value >> 24;
+#endif
+	return 4;
+}
+
+/**
+ * Pack a 64-bit quantity in little-endian byte order. Used for protobuf wire
+ * types fixed64, sfixed64, double. Similar to "htole64".
+ *
+ * \todo The big-endian impl is really only good for 32-bit machines, a 64-bit
+ * version would be appreciated, plus a way to decide to use 64-bit math where
+ * convenient.
+ *
+ * \param value
+ *      Value to encode.
+ * \param[out] out
+ *      Packed value.
+ * \return
+ *      Number of bytes written to `out`.
+ */
+static inline size_t
+fixed64_pack(uint64_t value, void *out)
+{
+#if !defined(WORDS_BIGENDIAN)
+	memcpy(out, &value, 8);
+#else
+	fixed32_pack(value, out);
+	fixed32_pack(value >> 32, ((char *) out) + 4);
+#endif
+	return 8;
+}
+
+/**
+ * Pack a boolean value as an integer and return the number of bytes written.
+ *
+ * \todo Perhaps on some platforms *out = !!value would be a better impl, b/c
+ * that is idiomatic C++ in some STL implementations.
+ *
+ * \param value
+ *      Value to encode.
+ * \param[out] out
+ *      Packed value.
+ * \return
+ *      Number of bytes written to `out`.
+ */
+static inline size_t
+boolean_pack(protobuf_c_boolean value, uint8_t *out)
+{
+	*out = value ? TRUE : FALSE;
+	return 1;
+}
+
+/**
+ * Pack a NUL-terminated C string and return the number of bytes written. The
+ * output includes a length delimiter.
+ *
+ * The NULL pointer is treated as an empty string. This isn't really necessary,
+ * but it allows people to leave required strings blank. (See Issue #13 in the
+ * bug tracker for a little more explanation).
+ *
+ * \param str
+ *      String to encode.
+ * \param[out] out
+ *      Packed value.
+ * \return
+ *      Number of bytes written to `out`.
+ */
+static inline size_t
+string_pack(const char *str, uint8_t *out)
+{
+	if (str == NULL) {
+		out[0] = 0;
+		return 1;
+	} else {
+		size_t len = strlen(str);
+		size_t rv = uint32_pack(len, out);
+		memcpy(out + rv, str, len);
+		return rv + len;
+	}
+}
+
+/**
+ * Pack a ProtobufCBinaryData and return the number of bytes written. The output
+ * includes a length delimiter.
+ *
+ * \param bd
+ *      ProtobufCBinaryData to encode.
+ * \param[out] out
+ *      Packed value.
+ * \return
+ *      Number of bytes written to `out`.
+ */
+static inline size_t
+binary_data_pack(const ProtobufCBinaryData *bd, uint8_t *out)
+{
+	size_t len = bd->len;
+	size_t rv = uint32_pack(len, out);
+	memcpy(out + rv, bd->data, len);
+	return rv + len;
+}
+
+/**
+ * Pack a ProtobufCMessage and return the number of bytes written. The output
+ * includes a length delimiter.
+ *
+ * \param message
+ *      ProtobufCMessage object to pack.
+ * \param[out] out
+ *      Packed message.
+ * \return
+ *      Number of bytes written to `out`.
+ */
+static inline size_t
+prefixed_message_pack(const ProtobufCMessage *message, uint8_t *out)
+{
+	if (message == NULL) {
+		out[0] = 0;
+		return 1;
+	} else {
+		size_t rv = protobuf_c_message_pack(message, out + 1);
+		uint32_t rv_packed_size = uint32_size(rv);
+		if (rv_packed_size != 1)
+			memmove(out + rv_packed_size, out + 1, rv);
+		return uint32_pack(rv, out) + rv;
+	}
+}
+
+/**
+ * Pack a field tag.
+ *
+ * Wire-type will be added in required_field_pack().
+ *
+ * \todo Just call uint64_pack on 64-bit platforms.
+ *
+ * \param id
+ *      Tag value to encode.
+ * \param[out] out
+ *      Packed value.
+ * \return
+ *      Number of bytes written to `out`.
+ */
+static size_t
+tag_pack(uint32_t id, uint8_t *out)
+{
+	if (id < (1 << (32 - 3)))
+		return uint32_pack(id << 3, out);
+	else
+		return uint64_pack(((uint64_t) id) << 3, out);
+}
+
+/**
+ * Pack a required field and return the number of bytes written.
+ *
+ * \param field
+ *      Field descriptor.
+ * \param member
+ *      The field member.
+ * \param[out] out
+ *      Packed value.
+ * \return
+ *      Number of bytes written to `out`.
+ */
+static size_t
+required_field_pack(const ProtobufCFieldDescriptor *field,
+		    const void *member, uint8_t *out)
+{
+	size_t rv = tag_pack(field->id, out);
+
+	switch (field->type) {
+	case PROTOBUF_C_TYPE_SINT32:
+		out[0] |= PROTOBUF_C_WIRE_TYPE_VARINT;
+		return rv + sint32_pack(*(const int32_t *) member, out + rv);
+	case PROTOBUF_C_TYPE_INT32:
+		out[0] |= PROTOBUF_C_WIRE_TYPE_VARINT;
+		return rv + int32_pack(*(const uint32_t *) member, out + rv);
+	case PROTOBUF_C_TYPE_UINT32:
+	case PROTOBUF_C_TYPE_ENUM:
+		out[0] |= PROTOBUF_C_WIRE_TYPE_VARINT;
+		return rv + uint32_pack(*(const uint32_t *) member, out + rv);
+	case PROTOBUF_C_TYPE_SINT64:
+		out[0] |= PROTOBUF_C_WIRE_TYPE_VARINT;
+		return rv + sint64_pack(*(const int64_t *) member, out + rv);
+	case PROTOBUF_C_TYPE_INT64:
+	case PROTOBUF_C_TYPE_UINT64:
+		out[0] |= PROTOBUF_C_WIRE_TYPE_VARINT;
+		return rv + uint64_pack(*(const uint64_t *) member, out + rv);
+	case PROTOBUF_C_TYPE_SFIXED32:
+	case PROTOBUF_C_TYPE_FIXED32:
+	case PROTOBUF_C_TYPE_FLOAT:
+		out[0] |= PROTOBUF_C_WIRE_TYPE_32BIT;
+		return rv + fixed32_pack(*(const uint32_t *) member, out + rv);
+	case PROTOBUF_C_TYPE_SFIXED64:
+	case PROTOBUF_C_TYPE_FIXED64:
+	case PROTOBUF_C_TYPE_DOUBLE:
+		out[0] |= PROTOBUF_C_WIRE_TYPE_64BIT;
+		return rv + fixed64_pack(*(const uint64_t *) member, out + rv);
+	case PROTOBUF_C_TYPE_BOOL:
+		out[0] |= PROTOBUF_C_WIRE_TYPE_VARINT;
+		return rv + boolean_pack(*(const protobuf_c_boolean *) member, out + rv);
+	case PROTOBUF_C_TYPE_STRING:
+		out[0] |= PROTOBUF_C_WIRE_TYPE_LENGTH_PREFIXED;
+		return rv + string_pack(*(char *const *) member, out + rv);
+	case PROTOBUF_C_TYPE_BYTES:
+		out[0] |= PROTOBUF_C_WIRE_TYPE_LENGTH_PREFIXED;
+		return rv + binary_data_pack((const ProtobufCBinaryData *) member, out + rv);
+	case PROTOBUF_C_TYPE_MESSAGE:
+		out[0] |= PROTOBUF_C_WIRE_TYPE_LENGTH_PREFIXED;
+		return rv + prefixed_message_pack(*(ProtobufCMessage * const *) member, out + rv);
+	}
+	PROTOBUF_C__ASSERT_NOT_REACHED();
+	return 0;
+}
+
+/**
+ * Pack a oneof field and return the number of bytes written. Only packs the
+ * field that is selected by the case enum.
+ *
+ * \param field
+ *      Field descriptor.
+ * \param oneof_case
+ *      A pointer to the case enum that selects the field in the oneof.
+ * \param member
+ *      The field member.
+ * \param[out] out
+ *      Packed value.
+ * \return
+ *      Number of bytes written to `out`.
+ */
+static size_t
+oneof_field_pack(const ProtobufCFieldDescriptor *field,
+		 const uint32_t *oneof_case,
+		 const void *member, uint8_t *out)
+{
+	if (*oneof_case == field->id) {
+		if (field->type == PROTOBUF_C_TYPE_MESSAGE ||
+		    field->type == PROTOBUF_C_TYPE_STRING)
+		{
+			const void *ptr = *(const void * const *) member;
+			if (ptr == NULL || ptr == field->default_value)
+				return 0;
+		}
+	} else {
+		return 0;
+	}
+	return required_field_pack(field, member, out);
+}
+
+/**
+ * Pack an optional field and return the number of bytes written.
+ *
+ * \param field
+ *      Field descriptor.
+ * \param has
+ *      Whether the field is set.
+ * \param member
+ *      The field member.
+ * \param[out] out
+ *      Packed value.
+ * \return
+ *      Number of bytes written to `out`.
+ */
+static size_t
+optional_field_pack(const ProtobufCFieldDescriptor *field,
+		    const protobuf_c_boolean *has,
+		    const void *member, uint8_t *out)
+{
+	if (field->type == PROTOBUF_C_TYPE_MESSAGE ||
+	    field->type == PROTOBUF_C_TYPE_STRING)
+	{
+		const void *ptr = *(const void * const *) member;
+		if (ptr == NULL || ptr == field->default_value)
+			return 0;
+	} else {
+		if (!*has)
+			return 0;
+	}
+	return required_field_pack(field, member, out);
+}
+
+/**
+ * Given a field type, return the in-memory size.
+ *
+ * \todo Implement as a table lookup.
+ *
+ * \param type
+ *      Field type.
+ * \return
+ *      Size of the field.
+ */
+static inline size_t
+sizeof_elt_in_repeated_array(ProtobufCType type)
+{
+	switch (type) {
+	case PROTOBUF_C_TYPE_SINT32:
+	case PROTOBUF_C_TYPE_INT32:
+	case PROTOBUF_C_TYPE_UINT32:
+	case PROTOBUF_C_TYPE_SFIXED32:
+	case PROTOBUF_C_TYPE_FIXED32:
+	case PROTOBUF_C_TYPE_FLOAT:
+	case PROTOBUF_C_TYPE_ENUM:
+		return 4;
+	case PROTOBUF_C_TYPE_SINT64:
+	case PROTOBUF_C_TYPE_INT64:
+	case PROTOBUF_C_TYPE_UINT64:
+	case PROTOBUF_C_TYPE_SFIXED64:
+	case PROTOBUF_C_TYPE_FIXED64:
+	case PROTOBUF_C_TYPE_DOUBLE:
+		return 8;
+	case PROTOBUF_C_TYPE_BOOL:
+		return sizeof(protobuf_c_boolean);
+	case PROTOBUF_C_TYPE_STRING:
+	case PROTOBUF_C_TYPE_MESSAGE:
+		return sizeof(void *);
+	case PROTOBUF_C_TYPE_BYTES:
+		return sizeof(ProtobufCBinaryData);
+	}
+	PROTOBUF_C__ASSERT_NOT_REACHED();
+	return 0;
+}
+
+/**
+ * Pack an array of 32-bit quantities.
+ *
+ * \param[out] out
+ *      Destination.
+ * \param[in] in
+ *      Source.
+ * \param[in] n
+ *      Number of elements in the source array.
+ */
+static void
+copy_to_little_endian_32(void *out, const void *in, const unsigned n)
+{
+#if !defined(WORDS_BIGENDIAN)
+	memcpy(out, in, n * 4);
+#else
+	unsigned i;
+	const uint32_t *ini = in;
+	for (i = 0; i < n; i++)
+		fixed32_pack(ini[i], (uint32_t *) out + i);
+#endif
+}
+
+/**
+ * Pack an array of 64-bit quantities.
+ *
+ * \param[out] out
+ *      Destination.
+ * \param[in] in
+ *      Source.
+ * \param[in] n
+ *      Number of elements in the source array.
+ */
+static void
+copy_to_little_endian_64(void *out, const void *in, const unsigned n)
+{
+#if !defined(WORDS_BIGENDIAN)
+	memcpy(out, in, n * 8);
+#else
+	unsigned i;
+	const uint64_t *ini = in;
+	for (i = 0; i < n; i++)
+		fixed64_pack(ini[i], (uint64_t *) out + i);
+#endif
+}
+
+/**
+ * Get the minimum number of bytes required to pack a field value of a
+ * particular type.
+ *
+ * \param type
+ *      Field type.
+ * \return
+ *      Number of bytes.
+ */
+static unsigned
+get_type_min_size(ProtobufCType type)
+{
+	if (type == PROTOBUF_C_TYPE_SFIXED32 ||
+	    type == PROTOBUF_C_TYPE_FIXED32 ||
+	    type == PROTOBUF_C_TYPE_FLOAT)
+	{
+		return 4;
+	}
+	if (type == PROTOBUF_C_TYPE_SFIXED64 ||
+	    type == PROTOBUF_C_TYPE_FIXED64 ||
+	    type == PROTOBUF_C_TYPE_DOUBLE)
+	{
+		return 8;
+	}
+	return 1;
+}
+
+/**
+ * Packs the elements of a repeated field and returns the serialised field and
+ * its length.
+ *
+ * \param field
+ *      Field descriptor.
+ * \param count
+ *      Number of elements in the repeated field array.
+ * \param member
+ *      Pointer to the elements for this repeated field.
+ * \param[out] out
+ *      Serialised representation of the repeated field.
+ * \return
+ *      Number of bytes serialised to `out`.
+ */
+static size_t
+repeated_field_pack(const ProtobufCFieldDescriptor *field,
+		    size_t count, const void *member, uint8_t *out)
+{
+	void *array = *(void * const *) member;
+	unsigned i;
+
+	if (0 != (field->flags & PROTOBUF_C_FIELD_FLAG_PACKED)) {
+		unsigned header_len;
+		unsigned len_start;
+		unsigned min_length;
+		unsigned payload_len;
+		unsigned length_size_min;
+		unsigned actual_length_size;
+		uint8_t *payload_at;
+
+		if (count == 0)
+			return 0;
+		header_len = tag_pack(field->id, out);
+		out[0] |= PROTOBUF_C_WIRE_TYPE_LENGTH_PREFIXED;
+		len_start = header_len;
+		min_length = get_type_min_size(field->type) * count;
+		length_size_min = uint32_size(min_length);
+		header_len += length_size_min;
+		payload_at = out + header_len;
+
+		switch (field->type) {
+		case PROTOBUF_C_TYPE_SFIXED32:
+		case PROTOBUF_C_TYPE_FIXED32:
+		case PROTOBUF_C_TYPE_FLOAT:
+			copy_to_little_endian_32(payload_at, array, count);
+			payload_at += count * 4;
+			break;
+		case PROTOBUF_C_TYPE_SFIXED64:
+		case PROTOBUF_C_TYPE_FIXED64:
+		case PROTOBUF_C_TYPE_DOUBLE:
+			copy_to_little_endian_64(payload_at, array, count);
+			payload_at += count * 8;
+			break;
+		case PROTOBUF_C_TYPE_INT32: {
+			const int32_t *arr = (const int32_t *) array;
+			for (i = 0; i < count; i++)
+				payload_at += int32_pack(arr[i], payload_at);
+			break;
+		}
+		case PROTOBUF_C_TYPE_SINT32: {
+			const int32_t *arr = (const int32_t *) array;
+			for (i = 0; i < count; i++)
+				payload_at += sint32_pack(arr[i], payload_at);
+			break;
+		}
+		case PROTOBUF_C_TYPE_SINT64: {
+			const int64_t *arr = (const int64_t *) array;
+			for (i = 0; i < count; i++)
+				payload_at += sint64_pack(arr[i], payload_at);
+			break;
+		}
+		case PROTOBUF_C_TYPE_ENUM:
+		case PROTOBUF_C_TYPE_UINT32: {
+			const uint32_t *arr = (const uint32_t *) array;
+			for (i = 0; i < count; i++)
+				payload_at += uint32_pack(arr[i], payload_at);
+			break;
+		}
+		case PROTOBUF_C_TYPE_INT64:
+		case PROTOBUF_C_TYPE_UINT64: {
+			const uint64_t *arr = (const uint64_t *) array;
+			for (i = 0; i < count; i++)
+				payload_at += uint64_pack(arr[i], payload_at);
+			break;
+		}
+		case PROTOBUF_C_TYPE_BOOL: {
+			const protobuf_c_boolean *arr = (const protobuf_c_boolean *) array;
+			for (i = 0; i < count; i++)
+				payload_at += boolean_pack(arr[i], payload_at);
+			break;
+		}
+		default:
+			PROTOBUF_C__ASSERT_NOT_REACHED();
+		}
+
+		payload_len = payload_at - (out + header_len);
+		actual_length_size = uint32_size(payload_len);
+		if (length_size_min != actual_length_size) {
+			assert(actual_length_size == length_size_min + 1);
+			memmove(out + header_len + 1, out + header_len,
+				payload_len);
+			header_len++;
+		}
+		uint32_pack(payload_len, out + len_start);
+		return header_len + payload_len;
+	} else {
+		/* not "packed" cased */
+		/* CONSIDER: optimize this case a bit (by putting the loop inside the switch) */
+		size_t rv = 0;
+		unsigned siz = sizeof_elt_in_repeated_array(field->type);
+
+		for (i = 0; i < count; i++) {
+			rv += required_field_pack(field, array, out + rv);
+			array = (char *)array + siz;
+		}
+		return rv;
+	}
+}
+
+static size_t
+unknown_field_pack(const ProtobufCMessageUnknownField *field, uint8_t *out)
+{
+	size_t rv = tag_pack(field->tag, out);
+	out[0] |= field->wire_type;
+	memcpy(out + rv, field->data, field->len);
+	return rv + field->len;
+}
+
+/**@}*/
+
+size_t
+protobuf_c_message_pack(const ProtobufCMessage *message, uint8_t *out)
+{
+	unsigned i;
+	size_t rv = 0;
+
+	ASSERT_IS_MESSAGE(message);
+	for (i = 0; i < message->descriptor->n_fields; i++) {
+		const ProtobufCFieldDescriptor *field =
+			message->descriptor->fields + i;
+		const void *member = ((const char *) message) + field->offset;
+
+		/*
+		 * It doesn't hurt to compute qmember (a pointer to the
+		 * quantifier field of the structure), but the pointer is only
+		 * valid if the field is:
+		 *  - a repeated field, or
+		 *  - a field that is part of a oneof
+		 *  - an optional field that isn't a pointer type
+		 * (Meaning: not a message or a string).
+		 */
+		const void *qmember =
+			((const char *) message) + field->quantifier_offset;
+
+		if (field->label == PROTOBUF_C_LABEL_REQUIRED) {
+			rv += required_field_pack(field, member, out + rv);
+		} else if (field->label == PROTOBUF_C_LABEL_OPTIONAL) {
+			if (0 != (field->flags & PROTOBUF_C_FIELD_FLAG_ONEOF))
+				rv += oneof_field_pack (field, qmember, member, out + rv);
+			else
+				rv += optional_field_pack(field, qmember, member, out + rv);
+		} else {
+			rv += repeated_field_pack(field, *(const size_t *) qmember,
+				member, out + rv);
+		}
+	}
+	for (i = 0; i < message->n_unknown_fields; i++)
+		rv += unknown_field_pack(&message->unknown_fields[i], out + rv);
+	return rv;
+}
+
+/**
+ * \defgroup packbuf protobuf_c_message_pack_to_buffer() implementation
+ *
+ * Routines mainly used by protobuf_c_message_pack_to_buffer().
+ *
+ * \ingroup internal
+ * @{
+ */
+
+/**
+ * Pack a required field to a virtual buffer.
+ *
+ * \param field
+ *      Field descriptor.
+ * \param member
+ *      The element to be packed.
+ * \param[out] buffer
+ *      Virtual buffer to append data to.
+ * \return
+ *      Number of bytes packed.
+ */
+static size_t
+required_field_pack_to_buffer(const ProtobufCFieldDescriptor *field,
+			      const void *member, ProtobufCBuffer *buffer)
+{
+	size_t rv;
+	uint8_t scratch[MAX_UINT64_ENCODED_SIZE * 2];
+
+	rv = tag_pack(field->id, scratch);
+	switch (field->type) {
+	case PROTOBUF_C_TYPE_SINT32:
+		scratch[0] |= PROTOBUF_C_WIRE_TYPE_VARINT;
+		rv += sint32_pack(*(const int32_t *) member, scratch + rv);
+		buffer->append(buffer, rv, scratch);
+		break;
+	case PROTOBUF_C_TYPE_INT32:
+		scratch[0] |= PROTOBUF_C_WIRE_TYPE_VARINT;
+		rv += int32_pack(*(const uint32_t *) member, scratch + rv);
+		buffer->append(buffer, rv, scratch);
+		break;
+	case PROTOBUF_C_TYPE_UINT32:
+	case PROTOBUF_C_TYPE_ENUM:
+		scratch[0] |= PROTOBUF_C_WIRE_TYPE_VARINT;
+		rv += uint32_pack(*(const uint32_t *) member, scratch + rv);
+		buffer->append(buffer, rv, scratch);
+		break;
+	case PROTOBUF_C_TYPE_SINT64:
+		scratch[0] |= PROTOBUF_C_WIRE_TYPE_VARINT;
+		rv += sint64_pack(*(const int64_t *) member, scratch + rv);
+		buffer->append(buffer, rv, scratch);
+		break;
+	case PROTOBUF_C_TYPE_INT64:
+	case PROTOBUF_C_TYPE_UINT64:
+		scratch[0] |= PROTOBUF_C_WIRE_TYPE_VARINT;
+		rv += uint64_pack(*(const uint64_t *) member, scratch + rv);
+		buffer->append(buffer, rv, scratch);
+		break;
+	case PROTOBUF_C_TYPE_SFIXED32:
+	case PROTOBUF_C_TYPE_FIXED32:
+	case PROTOBUF_C_TYPE_FLOAT:
+		scratch[0] |= PROTOBUF_C_WIRE_TYPE_32BIT;
+		rv += fixed32_pack(*(const uint32_t *) member, scratch + rv);
+		buffer->append(buffer, rv, scratch);
+		break;
+	case PROTOBUF_C_TYPE_SFIXED64:
+	case PROTOBUF_C_TYPE_FIXED64:
+	case PROTOBUF_C_TYPE_DOUBLE:
+		scratch[0] |= PROTOBUF_C_WIRE_TYPE_64BIT;
+		rv += fixed64_pack(*(const uint64_t *) member, scratch + rv);
+		buffer->append(buffer, rv, scratch);
+		break;
+	case PROTOBUF_C_TYPE_BOOL:
+		scratch[0] |= PROTOBUF_C_WIRE_TYPE_VARINT;
+		rv += boolean_pack(*(const protobuf_c_boolean *) member, scratch + rv);
+		buffer->append(buffer, rv, scratch);
+		break;
+	case PROTOBUF_C_TYPE_STRING: {
+		const char *str = *(char *const *) member;
+		size_t sublen = str ? strlen(str) : 0;
+
+		scratch[0] |= PROTOBUF_C_WIRE_TYPE_LENGTH_PREFIXED;
+		rv += uint32_pack(sublen, scratch + rv);
+		buffer->append(buffer, rv, scratch);
+		buffer->append(buffer, sublen, (const uint8_t *) str);
+		rv += sublen;
+		break;
+	}
+	case PROTOBUF_C_TYPE_BYTES: {
+		const ProtobufCBinaryData *bd = ((const ProtobufCBinaryData *) member);
+		size_t sublen = bd->len;
+
+		scratch[0] |= PROTOBUF_C_WIRE_TYPE_LENGTH_PREFIXED;
+		rv += uint32_pack(sublen, scratch + rv);
+		buffer->append(buffer, rv, scratch);
+		buffer->append(buffer, sublen, bd->data);
+		rv += sublen;
+		break;
+	}
+	case PROTOBUF_C_TYPE_MESSAGE: {
+		uint8_t simple_buffer_scratch[256];
+		size_t sublen;
+		const ProtobufCMessage *msg = *(ProtobufCMessage * const *) member;
+		ProtobufCBufferSimple simple_buffer =
+			PROTOBUF_C_BUFFER_SIMPLE_INIT(simple_buffer_scratch);
+
+		scratch[0] |= PROTOBUF_C_WIRE_TYPE_LENGTH_PREFIXED;
+		if (msg == NULL)
+			sublen = 0;
+		else
+			sublen = protobuf_c_message_pack_to_buffer(msg, &simple_buffer.base);
+		rv += uint32_pack(sublen, scratch + rv);
+		buffer->append(buffer, rv, scratch);
+		buffer->append(buffer, sublen, simple_buffer.data);
+		rv += sublen;
+		PROTOBUF_C_BUFFER_SIMPLE_CLEAR(&simple_buffer);
+		break;
+	}
+	default:
+		PROTOBUF_C__ASSERT_NOT_REACHED();
+	}
+	return rv;
+}
+
+/**
+ * Pack a oneof field to a buffer. Only packs the field that is selected by the case enum.
+ *
+ * \param field
+ *      Field descriptor.
+ * \param oneof_case
+ *      A pointer to the case enum that selects the field in the oneof.
+ * \param member
+ *      The element to be packed.
+ * \param[out] buffer
+ *      Virtual buffer to append data to.
+ * \return
+ *      Number of bytes serialised to `buffer`.
+ */
+static size_t
+oneof_field_pack_to_buffer(const ProtobufCFieldDescriptor *field,
+			   const uint32_t *oneof_case,
+			   const void *member, ProtobufCBuffer *buffer)
+{
+	if (*oneof_case == field->id) {
+		if (field->type == PROTOBUF_C_TYPE_MESSAGE ||
+		    field->type == PROTOBUF_C_TYPE_STRING)
+		{
+			const void *ptr = *(const void *const *) member;
+			if (ptr == NULL || ptr == field->default_value)
+				return 0;
+		}
+	} else {
+		return 0;
+	}
+	return required_field_pack_to_buffer(field, member, buffer);
+}
+
+/**
+ * Pack an optional field to a buffer.
+ *
+ * \param field
+ *      Field descriptor.
+ * \param has
+ *      Whether the field is set.
+ * \param member
+ *      The element to be packed.
+ * \param[out] buffer
+ *      Virtual buffer to append data to.
+ * \return
+ *      Number of bytes serialised to `buffer`.
+ */
+static size_t
+optional_field_pack_to_buffer(const ProtobufCFieldDescriptor *field,
+			      const protobuf_c_boolean *has,
+			      const void *member, ProtobufCBuffer *buffer)
+{
+	if (field->type == PROTOBUF_C_TYPE_MESSAGE ||
+	    field->type == PROTOBUF_C_TYPE_STRING)
+	{
+		const void *ptr = *(const void *const *) member;
+		if (ptr == NULL || ptr == field->default_value)
+			return 0;
+	} else {
+		if (!*has)
+			return 0;
+	}
+	return required_field_pack_to_buffer(field, member, buffer);
+}
+
+/**
+ * Get the packed size of an array of same field type.
+ *
+ * \param field
+ *      Field descriptor.
+ * \param count
+ *      Number of elements of this type.
+ * \param array
+ *      The elements to get the size of.
+ * \return
+ *      Number of bytes required.
+ */
+static size_t
+get_packed_payload_length(const ProtobufCFieldDescriptor *field,
+			  unsigned count, const void *array)
+{
+	unsigned rv = 0;
+	unsigned i;
+
+	switch (field->type) {
+	case PROTOBUF_C_TYPE_SFIXED32:
+	case PROTOBUF_C_TYPE_FIXED32:
+	case PROTOBUF_C_TYPE_FLOAT:
+		return count * 4;
+	case PROTOBUF_C_TYPE_SFIXED64:
+	case PROTOBUF_C_TYPE_FIXED64:
+	case PROTOBUF_C_TYPE_DOUBLE:
+		return count * 8;
+	case PROTOBUF_C_TYPE_INT32: {
+		const int32_t *arr = (const int32_t *) array;
+		for (i = 0; i < count; i++)
+			rv += int32_size(arr[i]);
+		break;
+	}
+	case PROTOBUF_C_TYPE_SINT32: {
+		const int32_t *arr = (const int32_t *) array;
+		for (i = 0; i < count; i++)
+			rv += sint32_size(arr[i]);
+		break;
+	}
+	case PROTOBUF_C_TYPE_ENUM:
+	case PROTOBUF_C_TYPE_UINT32: {
+		const uint32_t *arr = (const uint32_t *) array;
+		for (i = 0; i < count; i++)
+			rv += uint32_size(arr[i]);
+		break;
+	}
+	case PROTOBUF_C_TYPE_SINT64: {
+		const int64_t *arr = (const int64_t *) array;
+		for (i = 0; i < count; i++)
+			rv += sint64_size(arr[i]);
+		break;
+	}
+	case PROTOBUF_C_TYPE_INT64:
+	case PROTOBUF_C_TYPE_UINT64: {
+		const uint64_t *arr = (const uint64_t *) array;
+		for (i = 0; i < count; i++)
+			rv += uint64_size(arr[i]);
+		break;
+	}
+	case PROTOBUF_C_TYPE_BOOL:
+		return count;
+	default:
+		PROTOBUF_C__ASSERT_NOT_REACHED();
+	}
+	return rv;
+}
+
+/**
+ * Pack an array of same field type to a virtual buffer.
+ *
+ * \param field
+ *      Field descriptor.
+ * \param count
+ *      Number of elements of this type.
+ * \param array
+ *      The elements to get the size of.
+ * \param[out] buffer
+ *      Virtual buffer to append data to.
+ * \return
+ *      Number of bytes packed.
+ */
+static size_t
+pack_buffer_packed_payload(const ProtobufCFieldDescriptor *field,
+			   unsigned count, const void *array,
+			   ProtobufCBuffer *buffer)
+{
+	uint8_t scratch[16];
+	size_t rv = 0;
+	unsigned i;
+
+	switch (field->type) {
+	case PROTOBUF_C_TYPE_SFIXED32:
+	case PROTOBUF_C_TYPE_FIXED32:
+	case PROTOBUF_C_TYPE_FLOAT:
+#if !defined(WORDS_BIGENDIAN)
+		rv = count * 4;
+		goto no_packing_needed;
+#else
+		for (i = 0; i < count; i++) {
+			unsigned len = fixed32_pack(((uint32_t *) array)[i], scratch);
+			buffer->append(buffer, len, scratch);
+			rv += len;
+		}
+		break;
+#endif
+	case PROTOBUF_C_TYPE_SFIXED64:
+	case PROTOBUF_C_TYPE_FIXED64:
+	case PROTOBUF_C_TYPE_DOUBLE:
+#if !defined(WORDS_BIGENDIAN)
+		rv = count * 8;
+		goto no_packing_needed;
+#else
+		for (i = 0; i < count; i++) {
+			unsigned len = fixed64_pack(((uint64_t *) array)[i], scratch);
+			buffer->append(buffer, len, scratch);
+			rv += len;
+		}
+		break;
+#endif
+	case PROTOBUF_C_TYPE_INT32:
+		for (i = 0; i < count; i++) {
+			unsigned len = int32_pack(((int32_t *) array)[i], scratch);
+			buffer->append(buffer, len, scratch);
+			rv += len;
+		}
+		break;
+	case PROTOBUF_C_TYPE_SINT32:
+		for (i = 0; i < count; i++) {
+			unsigned len = sint32_pack(((int32_t *) array)[i], scratch);
+			buffer->append(buffer, len, scratch);
+			rv += len;
+		}
+		break;
+	case PROTOBUF_C_TYPE_ENUM:
+	case PROTOBUF_C_TYPE_UINT32:
+		for (i = 0; i < count; i++) {
+			unsigned len = uint32_pack(((uint32_t *) array)[i], scratch);
+			buffer->append(buffer, len, scratch);
+			rv += len;
+		}
+		break;
+	case PROTOBUF_C_TYPE_SINT64:
+		for (i = 0; i < count; i++) {
+			unsigned len = sint64_pack(((int64_t *) array)[i], scratch);
+			buffer->append(buffer, len, scratch);
+			rv += len;
+		}
+		break;
+	case PROTOBUF_C_TYPE_INT64:
+	case PROTOBUF_C_TYPE_UINT64:
+		for (i = 0; i < count; i++) {
+			unsigned len = uint64_pack(((uint64_t *) array)[i], scratch);
+			buffer->append(buffer, len, scratch);
+			rv += len;
+		}
+		break;
+	case PROTOBUF_C_TYPE_BOOL:
+		for (i = 0; i < count; i++) {
+			unsigned len = boolean_pack(((protobuf_c_boolean *) array)[i], scratch);
+			buffer->append(buffer, len, scratch);
+			rv += len;
+		}
+		return count;
+	default:
+		PROTOBUF_C__ASSERT_NOT_REACHED();
+	}
+	return rv;
+
+no_packing_needed:
+	buffer->append(buffer, rv, array);
+	return rv;
+}
+
+static size_t
+repeated_field_pack_to_buffer(const ProtobufCFieldDescriptor *field,
+			      unsigned count, const void *member,
+			      ProtobufCBuffer *buffer)
+{
+	char *array = *(char * const *) member;
+
+	if (count == 0)
+		return 0;
+	if (0 != (field->flags & PROTOBUF_C_FIELD_FLAG_PACKED)) {
+		uint8_t scratch[MAX_UINT64_ENCODED_SIZE * 2];
+		size_t rv = tag_pack(field->id, scratch);
+		size_t payload_len = get_packed_payload_length(field, count, array);
+		size_t tmp;
+
+		scratch[0] |= PROTOBUF_C_WIRE_TYPE_LENGTH_PREFIXED;
+		rv += uint32_pack(payload_len, scratch + rv);
+		buffer->append(buffer, rv, scratch);
+		tmp = pack_buffer_packed_payload(field, count, array, buffer);
+		assert(tmp == payload_len);
+		return rv + payload_len;
+	} else {
+		size_t siz;
+		unsigned i;
+		/* CONSIDER: optimize this case a bit (by putting the loop inside the switch) */
+		unsigned rv = 0;
+
+		siz = sizeof_elt_in_repeated_array(field->type);
+		for (i = 0; i < count; i++) {
+			rv += required_field_pack_to_buffer(field, array, buffer);
+			array += siz;
+		}
+		return rv;
+	}
+}
+
+static size_t
+unknown_field_pack_to_buffer(const ProtobufCMessageUnknownField *field,
+			     ProtobufCBuffer *buffer)
+{
+	uint8_t header[MAX_UINT64_ENCODED_SIZE];
+	size_t rv = tag_pack(field->tag, header);
+
+	header[0] |= field->wire_type;
+	buffer->append(buffer, rv, header);
+	buffer->append(buffer, field->len, field->data);
+	return rv + field->len;
+}
+
+/**@}*/
+
+size_t
+protobuf_c_message_pack_to_buffer(const ProtobufCMessage *message,
+				  ProtobufCBuffer *buffer)
+{
+	unsigned i;
+	size_t rv = 0;
+
+	ASSERT_IS_MESSAGE(message);
+	for (i = 0; i < message->descriptor->n_fields; i++) {
+		const ProtobufCFieldDescriptor *field =
+			message->descriptor->fields + i;
+		const void *member =
+			((const char *) message) + field->offset;
+		const void *qmember =
+			((const char *) message) + field->quantifier_offset;
+
+		if (field->label == PROTOBUF_C_LABEL_REQUIRED) {
+			rv += required_field_pack_to_buffer(field, member, buffer);
+		} else if (field->label == PROTOBUF_C_LABEL_OPTIONAL) {
+			if (0 != (field->flags & PROTOBUF_C_FIELD_FLAG_ONEOF)) {
+				rv += oneof_field_pack_to_buffer(
+					field,
+					qmember,
+					member,
+					buffer
+					);
+			} else {
+				rv += optional_field_pack_to_buffer(
+					field,
+					qmember,
+					member,
+					buffer
+					);
+			}
+		} else {
+			rv += repeated_field_pack_to_buffer(
+				field,
+				*(const size_t *) qmember,
+				member,
+				buffer
+			);
+		}
+	}
+	for (i = 0; i < message->n_unknown_fields; i++)
+		rv += unknown_field_pack_to_buffer(&message->unknown_fields[i], buffer);
+
+	return rv;
+}
+
+/**
+ * \defgroup unpack unpacking implementation
+ *
+ * Routines mainly used by the unpacking functions.
+ *
+ * \ingroup internal
+ * @{
+ */
+
+static inline int
+int_range_lookup(unsigned n_ranges, const ProtobufCIntRange *ranges, int value)
+{
+	unsigned n;
+	unsigned start;
+
+	if (n_ranges == 0)
+		return -1;
+	start = 0;
+	n = n_ranges;
+	while (n > 1) {
+		unsigned mid = start + n / 2;
+
+		if (value < ranges[mid].start_value) {
+			n = mid - start;
+		} else if (value >= ranges[mid].start_value +
+			   (int) (ranges[mid + 1].orig_index -
+				  ranges[mid].orig_index))
+		{
+			unsigned new_start = mid + 1;
+			n = start + n - new_start;
+			start = new_start;
+		} else
+			return (value - ranges[mid].start_value) +
+			    ranges[mid].orig_index;
+	}
+	if (n > 0) {
+		unsigned start_orig_index = ranges[start].orig_index;
+		unsigned range_size =
+			ranges[start + 1].orig_index - start_orig_index;
+
+		if (ranges[start].start_value <= value &&
+		    value < (int) (ranges[start].start_value + range_size))
+		{
+			return (value - ranges[start].start_value) +
+			    start_orig_index;
+		}
+	}
+	return -1;
+}
+
+static size_t
+parse_tag_and_wiretype(size_t len,
+		       const uint8_t *data,
+		       uint32_t *tag_out,
+		       ProtobufCWireType *wiretype_out)
+{
+	unsigned max_rv = len > 5 ? 5 : len;
+	uint32_t tag = (data[0] & 0x7f) >> 3;
+	unsigned shift = 4;
+	unsigned rv;
+
+	*wiretype_out = data[0] & 7;
+	if ((data[0] & 0x80) == 0) {
+		*tag_out = tag;
+		return 1;
+	}
+	for (rv = 1; rv < max_rv; rv++) {
+		if (data[rv] & 0x80) {
+			tag |= (data[rv] & 0x7f) << shift;
+			shift += 7;
+		} else {
+			tag |= data[rv] << shift;
+			*tag_out = tag;
+			return rv + 1;
+		}
+	}
+	return 0; /* error: bad header */
+}
+
+/* sizeof(ScannedMember) must be <= (1<<BOUND_SIZEOF_SCANNED_MEMBER_LOG2) */
+#define BOUND_SIZEOF_SCANNED_MEMBER_LOG2 5
+typedef struct _ScannedMember ScannedMember;
+/** Field as it's being read. */
+struct _ScannedMember {
+	uint32_t tag;              /**< Field tag. */
+	uint8_t wire_type;         /**< Field type. */
+	uint8_t length_prefix_len; /**< Prefix length. */
+	const ProtobufCFieldDescriptor *field; /**< Field descriptor. */
+	size_t len;                /**< Field length. */
+	const uint8_t *data;       /**< Pointer to field data. */
+};
+
+static inline uint32_t
+scan_length_prefixed_data(size_t len, const uint8_t *data,
+			  size_t *prefix_len_out)
+{
+	unsigned hdr_max = len < 5 ? len : 5;
+	unsigned hdr_len;
+	uint32_t val = 0;
+	unsigned i;
+	unsigned shift = 0;
+
+	for (i = 0; i < hdr_max; i++) {
+		val |= (data[i] & 0x7f) << shift;
+		shift += 7;
+		if ((data[i] & 0x80) == 0)
+			break;
+	}
+	if (i == hdr_max) {
+		PROTOBUF_C_UNPACK_ERROR("error parsing length for length-prefixed data");
+		return 0;
+	}
+	hdr_len = i + 1;
+	*prefix_len_out = hdr_len;
+	if (hdr_len + val > len) {
+		PROTOBUF_C_UNPACK_ERROR("data too short after length-prefix of %u", val);
+		return 0;
+	}
+	return hdr_len + val;
+}
+
+static size_t
+max_b128_numbers(size_t len, const uint8_t *data)
+{
+	size_t rv = 0;
+	while (len--)
+		if ((*data++ & 0x80) == 0)
+			++rv;
+	return rv;
+}
+
+/**@}*/
+
+/**
+ * Merge earlier message into a latter message.
+ *
+ * For numeric types and strings, if the same value appears multiple
+ * times, the parser accepts the last value it sees. For embedded
+ * message fields, the parser merges multiple instances of the same
+ * field. That is, all singular scalar fields in the latter instance
+ * replace those in the former, singular embedded messages are merged,
+ * and repeated fields are concatenated.
+ *
+ * The earlier message should be freed after calling this function, as
+ * some of its fields may have been reused and changed to their default
+ * values during the merge.
+ */
+static protobuf_c_boolean
+merge_messages(ProtobufCMessage *earlier_msg,
+	       ProtobufCMessage *latter_msg,
+	       ProtobufCAllocator *allocator)
+{
+	unsigned i;
+	const ProtobufCFieldDescriptor *fields =
+		latter_msg->descriptor->fields;
+	for (i = 0; i < latter_msg->descriptor->n_fields; i++) {
+		if (fields[i].label == PROTOBUF_C_LABEL_REPEATED) {
+			size_t *n_earlier =
+				STRUCT_MEMBER_PTR(size_t, earlier_msg,
+						  fields[i].quantifier_offset);
+			uint8_t **p_earlier =
+				STRUCT_MEMBER_PTR(uint8_t *, earlier_msg,
+						  fields[i].offset);
+			size_t *n_latter =
+				STRUCT_MEMBER_PTR(size_t, latter_msg,
+						  fields[i].quantifier_offset);
+			uint8_t **p_latter =
+				STRUCT_MEMBER_PTR(uint8_t *, latter_msg,
+						  fields[i].offset);
+
+			if (*n_earlier > 0) {
+				if (*n_latter > 0) {
+					/* Concatenate the repeated field */
+					size_t el_size =
+						sizeof_elt_in_repeated_array(fields[i].type);
+					uint8_t *new_field;
+
+					new_field = do_alloc(allocator,
+						(*n_earlier + *n_latter) * el_size);
+					if (!new_field)
+						return FALSE;
+
+					memcpy(new_field, *p_earlier,
+					       *n_earlier * el_size);
+					memcpy(new_field +
+					       *n_earlier * el_size,
+					       *p_latter,
+					       *n_latter * el_size);
+
+					do_free(allocator, *p_latter);
+					do_free(allocator, *p_earlier);
+					*p_latter = new_field;
+					*n_latter = *n_earlier + *n_latter;
+				} else {
+					/* Zero copy the repeated field from the earlier message */
+					*n_latter = *n_earlier;
+					*p_latter = *p_earlier;
+				}
+				/* Make sure the field does not get double freed */
+				*n_earlier = 0;
+				*p_earlier = 0;
+			}
+		} else if (fields[i].label == PROTOBUF_C_LABEL_OPTIONAL) {
+			const ProtobufCFieldDescriptor *field;
+			uint32_t *earlier_case_p = STRUCT_MEMBER_PTR(uint32_t,
+								     earlier_msg,
+								     fields[i].
+								     quantifier_offset);
+			uint32_t *latter_case_p = STRUCT_MEMBER_PTR(uint32_t,
+								    latter_msg,
+								    fields[i].
+								    quantifier_offset);
+			protobuf_c_boolean need_to_merge = FALSE;
+			void *earlier_elem;
+			void *latter_elem;
+			const void *def_val;
+
+			if (fields[i].flags & PROTOBUF_C_FIELD_FLAG_ONEOF) {
+				if (*latter_case_p == 0) {
+					/* lookup correct oneof field */
+					int field_index =
+						int_range_lookup(
+							latter_msg->descriptor
+							->n_field_ranges,
+							latter_msg->descriptor
+							->field_ranges,
+							*earlier_case_p);
+					field = latter_msg->descriptor->fields +
+						field_index;
+				} else {
+					/* Oneof is present in the latter message, move on */
+					continue;
+				}
+			} else {
+				field = &fields[i];
+			}
+
+
+			earlier_elem =
+				STRUCT_MEMBER_P(earlier_msg, field->offset);
+			latter_elem =
+				STRUCT_MEMBER_P(latter_msg, field->offset);
+			def_val = field->default_value;
+
+			switch (field->type) {
+			case PROTOBUF_C_TYPE_MESSAGE: {
+				ProtobufCMessage *em = *(ProtobufCMessage **) earlier_elem;
+				ProtobufCMessage *lm = *(ProtobufCMessage **) latter_elem;
+				if (em != NULL) {
+					if (lm != NULL) {
+						if (!merge_messages(em, lm, allocator))
+							return FALSE;
+						/* Already merged */
+						need_to_merge = FALSE;
+					} else {
+						/* Zero copy the message */
+						need_to_merge = TRUE;
+					}
+				}
+				break;
+			}
+			case PROTOBUF_C_TYPE_BYTES: {
+				uint8_t *e_data =
+					((ProtobufCBinaryData *) earlier_elem)->data;
+				uint8_t *l_data =
+					((ProtobufCBinaryData *) latter_elem)->data;
+				const ProtobufCBinaryData *d_bd =
+					(ProtobufCBinaryData *) def_val;
+
+				need_to_merge =
+					(e_data != NULL &&
+					 (d_bd == NULL ||
+					  e_data != d_bd->data)) &&
+					(l_data == NULL ||
+					 (d_bd != NULL &&
+					  l_data == d_bd->data));
+				break;
+			}
+			case PROTOBUF_C_TYPE_STRING: {
+				char *e_str = *(char **) earlier_elem;
+				char *l_str = *(char **) latter_elem;
+				const char *d_str = def_val;
+
+				need_to_merge = e_str != d_str && l_str == d_str;
+				break;
+			}
+			default: {
+				/* Could be has field or case enum, the logic is
+				 * equivalent, since 0 (FALSE) means not set for
+				 * oneof */
+				need_to_merge = (*earlier_case_p != 0) &&
+						(*latter_case_p == 0);
+				break;
+			}
+			}
+
+			if (need_to_merge) {
+				size_t el_size =
+					sizeof_elt_in_repeated_array(field->type);
+				memcpy(latter_elem, earlier_elem, el_size);
+				/*
+				 * Reset the element from the old message to 0
+				 * to make sure earlier message deallocation
+				 * doesn't corrupt zero-copied data in the new
+				 * message, earlier message will be freed after
+				 * this function is called anyway
+				 */
+				memset(earlier_elem, 0, el_size);
+
+				if (field->quantifier_offset != 0) {
+					/* Set the has field or the case enum,
+					 * if applicable */
+					*latter_case_p = *earlier_case_p;
+					*earlier_case_p = 0;
+				}
+			}
+		}
+	}
+	return TRUE;
+}
+
+/**
+ * Count packed elements.
+ *
+ * Given a raw slab of packed-repeated values, determine the number of
+ * elements. This function detects certain kinds of errors but not
+ * others; the remaining error checking is done by
+ * parse_packed_repeated_member().
+ */
+static protobuf_c_boolean
+count_packed_elements(ProtobufCType type,
+		      size_t len, const uint8_t *data, size_t *count_out)
+{
+	switch (type) {
+	case PROTOBUF_C_TYPE_SFIXED32:
+	case PROTOBUF_C_TYPE_FIXED32:
+	case PROTOBUF_C_TYPE_FLOAT:
+		if (len % 4 != 0) {
+			PROTOBUF_C_UNPACK_ERROR("length must be a multiple of 4 for fixed-length 32-bit types");
+			return FALSE;
+		}
+		*count_out = len / 4;
+		return TRUE;
+	case PROTOBUF_C_TYPE_SFIXED64:
+	case PROTOBUF_C_TYPE_FIXED64:
+	case PROTOBUF_C_TYPE_DOUBLE:
+		if (len % 8 != 0) {
+			PROTOBUF_C_UNPACK_ERROR("length must be a multiple of 8 for fixed-length 64-bit types");
+			return FALSE;
+		}
+		*count_out = len / 8;
+		return TRUE;
+	case PROTOBUF_C_TYPE_INT32:
+	case PROTOBUF_C_TYPE_SINT32:
+	case PROTOBUF_C_TYPE_ENUM:
+	case PROTOBUF_C_TYPE_UINT32:
+	case PROTOBUF_C_TYPE_INT64:
+	case PROTOBUF_C_TYPE_SINT64:
+	case PROTOBUF_C_TYPE_UINT64:
+		*count_out = max_b128_numbers(len, data);
+		return TRUE;
+	case PROTOBUF_C_TYPE_BOOL:
+		*count_out = len;
+		return TRUE;
+	case PROTOBUF_C_TYPE_STRING:
+	case PROTOBUF_C_TYPE_BYTES:
+	case PROTOBUF_C_TYPE_MESSAGE:
+	default:
+		PROTOBUF_C_UNPACK_ERROR("bad protobuf-c type %u for packed-repeated", type);
+		return FALSE;
+	}
+}
+
+static inline uint32_t
+parse_uint32(unsigned len, const uint8_t *data)
+{
+	uint32_t rv = data[0] & 0x7f;
+	if (len > 1) {
+		rv |= ((uint32_t) (data[1] & 0x7f) << 7);
+		if (len > 2) {
+			rv |= ((uint32_t) (data[2] & 0x7f) << 14);
+			if (len > 3) {
+				rv |= ((uint32_t) (data[3] & 0x7f) << 21);
+				if (len > 4)
+					rv |= ((uint32_t) (data[4]) << 28);
+			}
+		}
+	}
+	return rv;
+}
+
+static inline uint32_t
+parse_int32(unsigned len, const uint8_t *data)
+{
+	return parse_uint32(len, data);
+}
+
+static inline int32_t
+unzigzag32(uint32_t v)
+{
+	if (v & 1)
+		return -(v >> 1) - 1;
+	else
+		return v >> 1;
+}
+
+static inline uint32_t
+parse_fixed_uint32(const uint8_t *data)
+{
+#if !defined(WORDS_BIGENDIAN)
+	uint32_t t;
+	memcpy(&t, data, 4);
+	return t;
+#else
+	return data[0] |
+		((uint32_t) (data[1]) << 8) |
+		((uint32_t) (data[2]) << 16) |
+		((uint32_t) (data[3]) << 24);
+#endif
+}
+
+static uint64_t
+parse_uint64(unsigned len, const uint8_t *data)
+{
+	unsigned shift, i;
+	uint64_t rv;
+
+	if (len < 5)
+		return parse_uint32(len, data);
+	rv = ((uint64_t) (data[0] & 0x7f)) |
+		((uint64_t) (data[1] & 0x7f) << 7) |
+		((uint64_t) (data[2] & 0x7f) << 14) |
+		((uint64_t) (data[3] & 0x7f) << 21);
+	shift = 28;
+	for (i = 4; i < len; i++) {
+		rv |= (((uint64_t) (data[i] & 0x7f)) << shift);
+		shift += 7;
+	}
+	return rv;
+}
+
+static inline int64_t
+unzigzag64(uint64_t v)
+{
+	if (v & 1)
+		return -(v >> 1) - 1;
+	else
+		return v >> 1;
+}
+
+static inline uint64_t
+parse_fixed_uint64(const uint8_t *data)
+{
+#if !defined(WORDS_BIGENDIAN)
+	uint64_t t;
+	memcpy(&t, data, 8);
+	return t;
+#else
+	return (uint64_t) parse_fixed_uint32(data) |
+		(((uint64_t) parse_fixed_uint32(data + 4)) << 32);
+#endif
+}
+
+static protobuf_c_boolean
+parse_boolean(unsigned len, const uint8_t *data)
+{
+	unsigned i;
+	for (i = 0; i < len; i++)
+		if (data[i] & 0x7f)
+			return TRUE;
+	return FALSE;
+}
+
+static protobuf_c_boolean
+parse_required_member(ScannedMember *scanned_member,
+		      void *member,
+		      ProtobufCAllocator *allocator,
+		      protobuf_c_boolean maybe_clear)
+{
+	unsigned len = scanned_member->len;
+	const uint8_t *data = scanned_member->data;
+	ProtobufCWireType wire_type = scanned_member->wire_type;
+
+	switch (scanned_member->field->type) {
+	case PROTOBUF_C_TYPE_INT32:
+		if (wire_type != PROTOBUF_C_WIRE_TYPE_VARINT)
+			return FALSE;
+		*(uint32_t *) member = parse_int32(len, data);
+		return TRUE;
+	case PROTOBUF_C_TYPE_UINT32:
+		if (wire_type != PROTOBUF_C_WIRE_TYPE_VARINT)
+			return FALSE;
+		*(uint32_t *) member = parse_uint32(len, data);
+		return TRUE;
+	case PROTOBUF_C_TYPE_SINT32:
+		if (wire_type != PROTOBUF_C_WIRE_TYPE_VARINT)
+			return FALSE;
+		*(int32_t *) member = unzigzag32(parse_uint32(len, data));
+		return TRUE;
+	case PROTOBUF_C_TYPE_SFIXED32:
+	case PROTOBUF_C_TYPE_FIXED32:
+	case PROTOBUF_C_TYPE_FLOAT:
+		if (wire_type != PROTOBUF_C_WIRE_TYPE_32BIT)
+			return FALSE;
+		*(uint32_t *) member = parse_fixed_uint32(data);
+		return TRUE;
+	case PROTOBUF_C_TYPE_INT64:
+	case PROTOBUF_C_TYPE_UINT64:
+		if (wire_type != PROTOBUF_C_WIRE_TYPE_VARINT)
+			return FALSE;
+		*(uint64_t *) member = parse_uint64(len, data);
+		return TRUE;
+	case PROTOBUF_C_TYPE_SINT64:
+		if (wire_type != PROTOBUF_C_WIRE_TYPE_VARINT)
+			return FALSE;
+		*(int64_t *) member = unzigzag64(parse_uint64(len, data));
+		return TRUE;
+	case PROTOBUF_C_TYPE_SFIXED64:
+	case PROTOBUF_C_TYPE_FIXED64:
+	case PROTOBUF_C_TYPE_DOUBLE:
+		if (wire_type != PROTOBUF_C_WIRE_TYPE_64BIT)
+			return FALSE;
+		*(uint64_t *) member = parse_fixed_uint64(data);
+		return TRUE;
+	case PROTOBUF_C_TYPE_BOOL:
+		*(protobuf_c_boolean *) member = parse_boolean(len, data);
+		return TRUE;
+	case PROTOBUF_C_TYPE_ENUM:
+		if (wire_type != PROTOBUF_C_WIRE_TYPE_VARINT)
+			return FALSE;
+		*(uint32_t *) member = parse_uint32(len, data);
+		return TRUE;
+	case PROTOBUF_C_TYPE_STRING: {
+		char **pstr = member;
+		unsigned pref_len = scanned_member->length_prefix_len;
+
+		if (wire_type != PROTOBUF_C_WIRE_TYPE_LENGTH_PREFIXED)
+			return FALSE;
+
+		if (maybe_clear && *pstr != NULL) {
+			const char *def = scanned_member->field->default_value;
+			if (*pstr != NULL && *pstr != def)
+				do_free(allocator, *pstr);
+		}
+		*pstr = do_alloc(allocator, len - pref_len + 1);
+		if (*pstr == NULL)
+			return FALSE;
+		memcpy(*pstr, data + pref_len, len - pref_len);
+		(*pstr)[len - pref_len] = 0;
+		return TRUE;
+	}
+	case PROTOBUF_C_TYPE_BYTES: {
+		ProtobufCBinaryData *bd = member;
+		const ProtobufCBinaryData *def_bd;
+		unsigned pref_len = scanned_member->length_prefix_len;
+
+		if (wire_type != PROTOBUF_C_WIRE_TYPE_LENGTH_PREFIXED)
+			return FALSE;
+
+		def_bd = scanned_member->field->default_value;
+		if (maybe_clear &&
+		    bd->data != NULL &&
+		    (def_bd == NULL || bd->data != def_bd->data))
+		{
+			do_free(allocator, bd->data);
+		}
+		if (len - pref_len > 0) {
+			bd->data = do_alloc(allocator, len - pref_len);
+			if (bd->data == NULL)
+				return FALSE;
+			memcpy(bd->data, data + pref_len, len - pref_len);
+		} else {
+			bd->data = NULL;
+		}
+		bd->len = len - pref_len;
+		return TRUE;
+	}
+	case PROTOBUF_C_TYPE_MESSAGE: {
+		ProtobufCMessage **pmessage = member;
+		ProtobufCMessage *subm;
+		const ProtobufCMessage *def_mess;
+		protobuf_c_boolean merge_successful = TRUE;
+		unsigned pref_len = scanned_member->length_prefix_len;
+
+		if (wire_type != PROTOBUF_C_WIRE_TYPE_LENGTH_PREFIXED)
+			return FALSE;
+
+		def_mess = scanned_member->field->default_value;
+		subm = protobuf_c_message_unpack(scanned_member->field->descriptor,
+						 allocator,
+						 len - pref_len,
+						 data + pref_len);
+
+		if (maybe_clear &&
+		    *pmessage != NULL &&
+		    *pmessage != def_mess)
+		{
+			if (subm != NULL)
+				merge_successful = merge_messages(*pmessage, subm, allocator);
+			/* Delete the previous message */
+			protobuf_c_message_free_unpacked(*pmessage, allocator);
+		}
+		*pmessage = subm;
+		if (subm == NULL || !merge_successful)
+			return FALSE;
+		return TRUE;
+	}
+	}
+	return FALSE;
+}
+
+static protobuf_c_boolean
+parse_oneof_member (ScannedMember *scanned_member,
+		    void *member,
+		    ProtobufCMessage *message,
+		    ProtobufCAllocator *allocator)
+{
+	uint32_t *oneof_case = STRUCT_MEMBER_PTR(uint32_t, message,
+					       scanned_member->field->quantifier_offset);
+
+	/* If we have already parsed a member of this oneof, free it. */
+	if (*oneof_case != 0) {
+		/* lookup field */
+		int field_index =
+			int_range_lookup(message->descriptor->n_field_ranges,
+					 message->descriptor->field_ranges,
+					 *oneof_case);
+		const ProtobufCFieldDescriptor *old_field =
+			message->descriptor->fields + field_index;
+		size_t el_size;
+
+		switch (old_field->type) {
+	        case PROTOBUF_C_TYPE_STRING: {
+			char **pstr = member;
+			const char *def = old_field->default_value;
+			if (*pstr != NULL && *pstr != def)
+				do_free(allocator, *pstr);
+			break;
+	        }
+		case PROTOBUF_C_TYPE_BYTES: {
+			ProtobufCBinaryData *bd = member;
+			const ProtobufCBinaryData *def_bd = old_field->default_value;
+			if (bd->data != NULL &&
+			   (def_bd == NULL || bd->data != def_bd->data))
+			{
+				do_free(allocator, bd->data);
+			}
+			break;
+	        }
+		case PROTOBUF_C_TYPE_MESSAGE: {
+			ProtobufCMessage **pmessage = member;
+			const ProtobufCMessage *def_mess = old_field->default_value;
+			if (*pmessage != NULL && *pmessage != def_mess)
+				protobuf_c_message_free_unpacked(*pmessage, allocator);
+			break;
+	        }
+		default:
+			break;
+		}
+
+		el_size = sizeof_elt_in_repeated_array(old_field->type);
+		memset (member, 0, el_size);
+	}
+	if (!parse_required_member (scanned_member, member, allocator, TRUE))
+		return FALSE;
+
+	*oneof_case = scanned_member->tag;
+	return TRUE;
+}
+
+
+static protobuf_c_boolean
+parse_optional_member(ScannedMember *scanned_member,
+		      void *member,
+		      ProtobufCMessage *message,
+		      ProtobufCAllocator *allocator)
+{
+	if (!parse_required_member(scanned_member, member, allocator, TRUE))
+		return FALSE;
+	if (scanned_member->field->quantifier_offset != 0)
+		STRUCT_MEMBER(protobuf_c_boolean,
+			      message,
+			      scanned_member->field->quantifier_offset) = TRUE;
+	return TRUE;
+}
+
+static protobuf_c_boolean
+parse_repeated_member(ScannedMember *scanned_member,
+		      void *member,
+		      ProtobufCMessage *message,
+		      ProtobufCAllocator *allocator)
+{
+	const ProtobufCFieldDescriptor *field = scanned_member->field;
+	size_t *p_n = STRUCT_MEMBER_PTR(size_t, message, field->quantifier_offset);
+	size_t siz = sizeof_elt_in_repeated_array(field->type);
+	char *array = *(char **) member;
+
+	if (!parse_required_member(scanned_member, array + siz * (*p_n),
+				   allocator, FALSE))
+	{
+		return FALSE;
+	}
+	*p_n += 1;
+	return TRUE;
+}
+
+static unsigned
+scan_varint(unsigned len, const uint8_t *data)
+{
+	unsigned i;
+	if (len > 10)
+		len = 10;
+	for (i = 0; i < len; i++)
+		if ((data[i] & 0x80) == 0)
+			break;
+	if (i == len)
+		return 0;
+	return i + 1;
+}
+
+static protobuf_c_boolean
+parse_packed_repeated_member(ScannedMember *scanned_member,
+			     void *member,
+			     ProtobufCMessage *message)
+{
+	const ProtobufCFieldDescriptor *field = scanned_member->field;
+	size_t *p_n = STRUCT_MEMBER_PTR(size_t, message, field->quantifier_offset);
+	size_t siz = sizeof_elt_in_repeated_array(field->type);
+	void *array = *(char **) member + siz * (*p_n);
+	const uint8_t *at = scanned_member->data + scanned_member->length_prefix_len;
+	size_t rem = scanned_member->len - scanned_member->length_prefix_len;
+	size_t count = 0;
+	unsigned i;
+
+	switch (field->type) {
+	case PROTOBUF_C_TYPE_SFIXED32:
+	case PROTOBUF_C_TYPE_FIXED32:
+	case PROTOBUF_C_TYPE_FLOAT:
+		count = (scanned_member->len - scanned_member->length_prefix_len) / 4;
+#if !defined(WORDS_BIGENDIAN)
+		goto no_unpacking_needed;
+#else
+		for (i = 0; i < count; i++) {
+			((uint32_t *) array)[i] = parse_fixed_uint32(at);
+			at += 4;
+		}
+		break;
+#endif
+	case PROTOBUF_C_TYPE_SFIXED64:
+	case PROTOBUF_C_TYPE_FIXED64:
+	case PROTOBUF_C_TYPE_DOUBLE:
+		count = (scanned_member->len - scanned_member->length_prefix_len) / 8;
+#if !defined(WORDS_BIGENDIAN)
+		goto no_unpacking_needed;
+#else
+		for (i = 0; i < count; i++) {
+			((uint64_t *) array)[i] = parse_fixed_uint64(at);
+			at += 8;
+		}
+		break;
+#endif
+	case PROTOBUF_C_TYPE_INT32:
+		while (rem > 0) {
+			unsigned s = scan_varint(rem, at);
+			if (s == 0) {
+				PROTOBUF_C_UNPACK_ERROR("bad packed-repeated int32 value");
+				return FALSE;
+			}
+			((int32_t *) array)[count++] = parse_int32(s, at);
+			at += s;
+			rem -= s;
+		}
+		break;
+	case PROTOBUF_C_TYPE_SINT32:
+		while (rem > 0) {
+			unsigned s = scan_varint(rem, at);
+			if (s == 0) {
+				PROTOBUF_C_UNPACK_ERROR("bad packed-repeated sint32 value");
+				return FALSE;
+			}
+			((int32_t *) array)[count++] = unzigzag32(parse_uint32(s, at));
+			at += s;
+			rem -= s;
+		}
+		break;
+	case PROTOBUF_C_TYPE_ENUM:
+	case PROTOBUF_C_TYPE_UINT32:
+		while (rem > 0) {
+			unsigned s = scan_varint(rem, at);
+			if (s == 0) {
+				PROTOBUF_C_UNPACK_ERROR("bad packed-repeated enum or uint32 value");
+				return FALSE;
+			}
+			((uint32_t *) array)[count++] = parse_uint32(s, at);
+			at += s;
+			rem -= s;
+		}
+		break;
+
+	case PROTOBUF_C_TYPE_SINT64:
+		while (rem > 0) {
+			unsigned s = scan_varint(rem, at);
+			if (s == 0) {
+				PROTOBUF_C_UNPACK_ERROR("bad packed-repeated sint64 value");
+				return FALSE;
+			}
+			((int64_t *) array)[count++] = unzigzag64(parse_uint64(s, at));
+			at += s;
+			rem -= s;
+		}
+		break;
+	case PROTOBUF_C_TYPE_INT64:
+	case PROTOBUF_C_TYPE_UINT64:
+		while (rem > 0) {
+			unsigned s = scan_varint(rem, at);
+			if (s == 0) {
+				PROTOBUF_C_UNPACK_ERROR("bad packed-repeated int64/uint64 value");
+				return FALSE;
+			}
+			((int64_t *) array)[count++] = parse_uint64(s, at);
+			at += s;
+			rem -= s;
+		}
+		break;
+	case PROTOBUF_C_TYPE_BOOL:
+		count = rem;
+		for (i = 0; i < count; i++) {
+			if (at[i] > 1) {
+				PROTOBUF_C_UNPACK_ERROR("bad packed-repeated boolean value");
+				return FALSE;
+			}
+			((protobuf_c_boolean *) array)[i] = at[i];
+		}
+		break;
+	default:
+		PROTOBUF_C__ASSERT_NOT_REACHED();
+	}
+	*p_n += count;
+	return TRUE;
+
+#if !defined(WORDS_BIGENDIAN)
+no_unpacking_needed:
+	memcpy(array, at, count * siz);
+	*p_n += count;
+	return TRUE;
+#endif
+}
+
+static protobuf_c_boolean
+is_packable_type(ProtobufCType type)
+{
+	return
+		type != PROTOBUF_C_TYPE_STRING &&
+		type != PROTOBUF_C_TYPE_BYTES &&
+		type != PROTOBUF_C_TYPE_MESSAGE;
+}
+
+static protobuf_c_boolean
+parse_member(ScannedMember *scanned_member,
+	     ProtobufCMessage *message,
+	     ProtobufCAllocator *allocator)
+{
+	const ProtobufCFieldDescriptor *field = scanned_member->field;
+	void *member;
+
+	if (field == NULL) {
+		ProtobufCMessageUnknownField *ufield =
+			message->unknown_fields +
+			(message->n_unknown_fields++);
+		ufield->tag = scanned_member->tag;
+		ufield->wire_type = scanned_member->wire_type;
+		ufield->len = scanned_member->len;
+		ufield->data = do_alloc(allocator, scanned_member->len);
+		if (ufield->data == NULL)
+			return FALSE;
+		memcpy(ufield->data, scanned_member->data, ufield->len);
+		return TRUE;
+	}
+	member = (char *) message + field->offset;
+	switch (field->label) {
+	case PROTOBUF_C_LABEL_REQUIRED:
+		return parse_required_member(scanned_member, member,
+					     allocator, TRUE);
+	case PROTOBUF_C_LABEL_OPTIONAL:
+		if (0 != (field->flags & PROTOBUF_C_FIELD_FLAG_ONEOF)) {
+			return parse_oneof_member(scanned_member, member,
+						  message, allocator);
+		} else {
+			return parse_optional_member(scanned_member, member,
+						     message, allocator);
+		}
+	case PROTOBUF_C_LABEL_REPEATED:
+		if (scanned_member->wire_type ==
+		    PROTOBUF_C_WIRE_TYPE_LENGTH_PREFIXED &&
+		    (0 != (field->flags & PROTOBUF_C_FIELD_FLAG_PACKED) ||
+		     is_packable_type(field->type)))
+		{
+			return parse_packed_repeated_member(scanned_member,
+							    member, message);
+		} else {
+			return parse_repeated_member(scanned_member,
+						     member, message,
+						     allocator);
+		}
+	}
+	PROTOBUF_C__ASSERT_NOT_REACHED();
+	return 0;
+}
+
+/**
+ * Initialise messages generated by old code.
+ *
+ * This function is used if desc->message_init == NULL (which occurs
+ * for old code, and which would be useful to support allocating
+ * descriptors dynamically).
+ */
+static void
+message_init_generic(const ProtobufCMessageDescriptor *desc,
+		     ProtobufCMessage *message)
+{
+	unsigned i;
+
+	memset(message, 0, desc->sizeof_message);
+	message->descriptor = desc;
+	for (i = 0; i < desc->n_fields; i++) {
+		if (desc->fields[i].default_value != NULL &&
+		    desc->fields[i].label != PROTOBUF_C_LABEL_REPEATED)
+		{
+			void *field =
+				STRUCT_MEMBER_P(message, desc->fields[i].offset);
+			const void *dv = desc->fields[i].default_value;
+
+			switch (desc->fields[i].type) {
+			case PROTOBUF_C_TYPE_INT32:
+			case PROTOBUF_C_TYPE_SINT32:
+			case PROTOBUF_C_TYPE_SFIXED32:
+			case PROTOBUF_C_TYPE_UINT32:
+			case PROTOBUF_C_TYPE_FIXED32:
+			case PROTOBUF_C_TYPE_FLOAT:
+			case PROTOBUF_C_TYPE_ENUM:
+				memcpy(field, dv, 4);
+				break;
+			case PROTOBUF_C_TYPE_INT64:
+			case PROTOBUF_C_TYPE_SINT64:
+			case PROTOBUF_C_TYPE_SFIXED64:
+			case PROTOBUF_C_TYPE_UINT64:
+			case PROTOBUF_C_TYPE_FIXED64:
+			case PROTOBUF_C_TYPE_DOUBLE:
+				memcpy(field, dv, 8);
+				break;
+			case PROTOBUF_C_TYPE_BOOL:
+				memcpy(field, dv, sizeof(protobuf_c_boolean));
+				break;
+			case PROTOBUF_C_TYPE_BYTES:
+				memcpy(field, dv, sizeof(ProtobufCBinaryData));
+				break;
+
+			case PROTOBUF_C_TYPE_STRING:
+			case PROTOBUF_C_TYPE_MESSAGE:
+				/*
+				 * The next line essentially implements a cast
+				 * from const, which is totally unavoidable.
+				 */
+				*(const void **) field = dv;
+				break;
+			}
+		}
+	}
+}
+
+/**@}*/
+
+/*
+ * ScannedMember slabs (an unpacking implementation detail). Before doing real
+ * unpacking, we first scan through the elements to see how many there are (for
+ * repeated fields), and which field to use (for non-repeated fields given
+ * twice).
+ *
+ * In order to avoid allocations for small messages, we keep a stack-allocated
+ * slab of ScannedMembers of size FIRST_SCANNED_MEMBER_SLAB_SIZE (16). After we
+ * fill that up, we allocate each slab twice as large as the previous one.
+ */
+#define FIRST_SCANNED_MEMBER_SLAB_SIZE_LOG2 4
+
+/*
+ * The number of slabs, including the stack-allocated ones; choose the number so
+ * that we would overflow if we needed a slab larger than provided.
+ */
+#define MAX_SCANNED_MEMBER_SLAB			\
+  (sizeof(unsigned int)*8 - 1			\
+   - BOUND_SIZEOF_SCANNED_MEMBER_LOG2		\
+   - FIRST_SCANNED_MEMBER_SLAB_SIZE_LOG2)
+
+#define REQUIRED_FIELD_BITMAP_SET(index)	\
+	(required_fields_bitmap[(index)/8] |= (1<<((index)%8)))
+
+#define REQUIRED_FIELD_BITMAP_IS_SET(index)	\
+	(required_fields_bitmap[(index)/8] & (1<<((index)%8)))
+
+ProtobufCMessage *
+protobuf_c_message_unpack(const ProtobufCMessageDescriptor *desc,
+			  ProtobufCAllocator *allocator,
+			  size_t len, const uint8_t *data)
+{
+	ProtobufCMessage *rv;
+	size_t rem = len;
+	const uint8_t *at = data;
+	const ProtobufCFieldDescriptor *last_field = desc->fields + 0;
+	ScannedMember first_member_slab[1 <<
+					FIRST_SCANNED_MEMBER_SLAB_SIZE_LOG2];
+
+	/*
+	 * scanned_member_slabs[i] is an array of arrays of ScannedMember.
+	 * The first slab (scanned_member_slabs[0] is just a pointer to
+	 * first_member_slab), above. All subsequent slabs will be allocated
+	 * using the allocator.
+	 */
+	ScannedMember *scanned_member_slabs[MAX_SCANNED_MEMBER_SLAB + 1];
+	unsigned which_slab = 0; /* the slab we are currently populating */
+	unsigned in_slab_index = 0; /* number of members in the slab */
+	size_t n_unknown = 0;
+	unsigned f;
+	unsigned j;
+	unsigned i_slab;
+	unsigned last_field_index = 0;
+	unsigned required_fields_bitmap_len;
+	unsigned char required_fields_bitmap_stack[16];
+	unsigned char *required_fields_bitmap = required_fields_bitmap_stack;
+	protobuf_c_boolean required_fields_bitmap_alloced = FALSE;
+
+	ASSERT_IS_MESSAGE_DESCRIPTOR(desc);
+
+	if (allocator == NULL)
+		allocator = &protobuf_c__allocator;
+
+	rv = do_alloc(allocator, desc->sizeof_message);
+	if (!rv)
+		return (NULL);
+	scanned_member_slabs[0] = first_member_slab;
+
+	required_fields_bitmap_len = (desc->n_fields + 7) / 8;
+	if (required_fields_bitmap_len > sizeof(required_fields_bitmap_stack)) {
+		required_fields_bitmap = do_alloc(allocator, required_fields_bitmap_len);
+		if (!required_fields_bitmap) {
+			do_free(allocator, rv);
+			return (NULL);
+		}
+		required_fields_bitmap_alloced = TRUE;
+	}
+	memset(required_fields_bitmap, 0, required_fields_bitmap_len);
+
+	/*
+	 * Generated code always defines "message_init". However, we provide a
+	 * fallback for (1) users of old protobuf-c generated-code that do not
+	 * provide the function, and (2) descriptors constructed from some other
+	 * source (most likely, direct construction from the .proto file).
+	 */
+	if (desc->message_init != NULL)
+		protobuf_c_message_init(desc, rv);
+	else
+		message_init_generic(desc, rv);
+
+	while (rem > 0) {
+		uint32_t tag;
+		ProtobufCWireType wire_type;
+		size_t used = parse_tag_and_wiretype(rem, at, &tag, &wire_type);
+		const ProtobufCFieldDescriptor *field;
+		ScannedMember tmp;
+
+		if (used == 0) {
+			PROTOBUF_C_UNPACK_ERROR("error parsing tag/wiretype at offset %u",
+						(unsigned) (at - data));
+			goto error_cleanup_during_scan;
+		}
+		/*
+		 * \todo Consider optimizing for field[1].id == tag, if field[1]
+		 * exists!
+		 */
+		if (last_field == NULL || last_field->id != tag) {
+			/* lookup field */
+			int field_index =
+			    int_range_lookup(desc->n_field_ranges,
+					     desc->field_ranges,
+					     tag);
+			if (field_index < 0) {
+				field = NULL;
+				n_unknown++;
+			} else {
+				field = desc->fields + field_index;
+				last_field = field;
+				last_field_index = field_index;
+			}
+		} else {
+			field = last_field;
+		}
+
+		if (field != NULL && field->label == PROTOBUF_C_LABEL_REQUIRED)
+			REQUIRED_FIELD_BITMAP_SET(last_field_index);
+
+		at += used;
+		rem -= used;
+		tmp.tag = tag;
+		tmp.wire_type = wire_type;
+		tmp.field = field;
+		tmp.data = at;
+		tmp.length_prefix_len = 0;
+
+		switch (wire_type) {
+		case PROTOBUF_C_WIRE_TYPE_VARINT: {
+			unsigned max_len = rem < 10 ? rem : 10;
+			unsigned i;
+
+			for (i = 0; i < max_len; i++)
+				if ((at[i] & 0x80) == 0)
+					break;
+			if (i == max_len) {
+				PROTOBUF_C_UNPACK_ERROR("unterminated varint at offset %u",
+							(unsigned) (at - data));
+				goto error_cleanup_during_scan;
+			}
+			tmp.len = i + 1;
+			break;
+		}
+		case PROTOBUF_C_WIRE_TYPE_64BIT:
+			if (rem < 8) {
+				PROTOBUF_C_UNPACK_ERROR("too short after 64bit wiretype at offset %u",
+							(unsigned) (at - data));
+				goto error_cleanup_during_scan;
+			}
+			tmp.len = 8;
+			break;
+		case PROTOBUF_C_WIRE_TYPE_LENGTH_PREFIXED: {
+			size_t pref_len;
+
+			tmp.len = scan_length_prefixed_data(rem, at, &pref_len);
+			if (tmp.len == 0) {
+				/* NOTE: scan_length_prefixed_data calls UNPACK_ERROR */
+				goto error_cleanup_during_scan;
+			}
+			tmp.length_prefix_len = pref_len;
+			break;
+		}
+		case PROTOBUF_C_WIRE_TYPE_32BIT:
+			if (rem < 4) {
+				PROTOBUF_C_UNPACK_ERROR("too short after 32bit wiretype at offset %u",
+					      (unsigned) (at - data));
+				goto error_cleanup_during_scan;
+			}
+			tmp.len = 4;
+			break;
+		default:
+			PROTOBUF_C_UNPACK_ERROR("unsupported tag %u at offset %u",
+						wire_type, (unsigned) (at - data));
+			goto error_cleanup_during_scan;
+		}
+
+		if (in_slab_index == (1U <<
+			(which_slab + FIRST_SCANNED_MEMBER_SLAB_SIZE_LOG2)))
+		{
+			size_t size;
+
+			in_slab_index = 0;
+			if (which_slab == MAX_SCANNED_MEMBER_SLAB) {
+				PROTOBUF_C_UNPACK_ERROR("too many fields");
+				goto error_cleanup_during_scan;
+			}
+			which_slab++;
+			size = sizeof(ScannedMember)
+				<< (which_slab + FIRST_SCANNED_MEMBER_SLAB_SIZE_LOG2);
+			scanned_member_slabs[which_slab] = do_alloc(allocator, size);
+			if (scanned_member_slabs[which_slab] == NULL)
+				goto error_cleanup_during_scan;
+		}
+		scanned_member_slabs[which_slab][in_slab_index++] = tmp;
+
+		if (field != NULL && field->label == PROTOBUF_C_LABEL_REPEATED) {
+			size_t *n = STRUCT_MEMBER_PTR(size_t, rv,
+						      field->quantifier_offset);
+			if (wire_type == PROTOBUF_C_WIRE_TYPE_LENGTH_PREFIXED &&
+			    (0 != (field->flags & PROTOBUF_C_FIELD_FLAG_PACKED) ||
+			     is_packable_type(field->type)))
+			{
+				size_t count;
+				if (!count_packed_elements(field->type,
+							   tmp.len -
+							   tmp.length_prefix_len,
+							   tmp.data +
+							   tmp.length_prefix_len,
+							   &count))
+				{
+					PROTOBUF_C_UNPACK_ERROR("counting packed elements");
+					goto error_cleanup_during_scan;
+				}
+				*n += count;
+			} else {
+				*n += 1;
+			}
+		}
+
+		at += tmp.len;
+		rem -= tmp.len;
+	}
+
+	/* allocate space for repeated fields, also check that all required fields have been set */
+	for (f = 0; f < desc->n_fields; f++) {
+		const ProtobufCFieldDescriptor *field = desc->fields + f;
+		if (field->label == PROTOBUF_C_LABEL_REPEATED) {
+			size_t siz =
+			    sizeof_elt_in_repeated_array(field->type);
+			size_t *n_ptr =
+			    STRUCT_MEMBER_PTR(size_t, rv,
+					      field->quantifier_offset);
+			if (*n_ptr != 0) {
+                void *a = 0;
+				unsigned n = *n_ptr;
+				*n_ptr = 0;
+				assert(rv->descriptor != NULL);
+#define CLEAR_REMAINING_N_PTRS()                                              \
+              for(f++;f < desc->n_fields; f++)                                \
+                {                                                             \
+                  field = desc->fields + f;                                   \
+                  if (field->label == PROTOBUF_C_LABEL_REPEATED)              \
+                    STRUCT_MEMBER (size_t, rv, field->quantifier_offset) = 0; \
+                }
+				a = do_alloc(allocator, siz * n);
+				if (!a) {
+					CLEAR_REMAINING_N_PTRS();
+					goto error_cleanup;
+				}
+				STRUCT_MEMBER(void *, rv, field->offset) = a;
+			}
+		} else if (field->label == PROTOBUF_C_LABEL_REQUIRED) {
+			if (field->default_value == NULL &&
+			    !REQUIRED_FIELD_BITMAP_IS_SET(f))
+			{
+				CLEAR_REMAINING_N_PTRS();
+				PROTOBUF_C_UNPACK_ERROR("message '%s': missing required field '%s'",
+							desc->name, field->name);
+				goto error_cleanup;
+			}
+		}
+	}
+#undef CLEAR_REMAINING_N_PTRS
+
+	/* allocate space for unknown fields */
+	if (n_unknown) {
+		rv->unknown_fields = do_alloc(allocator,
+					      n_unknown * sizeof(ProtobufCMessageUnknownField));
+		if (rv->unknown_fields == NULL)
+			goto error_cleanup;
+	}
+
+	/* do real parsing */
+	for (i_slab = 0; i_slab <= which_slab; i_slab++) {
+		unsigned max = (i_slab == which_slab) ?
+			in_slab_index : (1U << (i_slab + 4));
+		ScannedMember *slab = scanned_member_slabs[i_slab];
+		unsigned j;
+
+		for (j = 0; j < max; j++) {
+			if (!parse_member(slab + j, rv, allocator)) {
+				PROTOBUF_C_UNPACK_ERROR("error parsing member %s of %s",
+							slab->field ? slab->field->name : "*unknown-field*",
+					desc->name);
+				goto error_cleanup;
+			}
+		}
+	}
+
+	/* cleanup */
+	for (j = 1; j <= which_slab; j++)
+		do_free(allocator, scanned_member_slabs[j]);
+	if (required_fields_bitmap_alloced)
+		do_free(allocator, required_fields_bitmap);
+	return rv;
+
+error_cleanup:
+	protobuf_c_message_free_unpacked(rv, allocator);
+	for (j = 1; j <= which_slab; j++)
+		do_free(allocator, scanned_member_slabs[j]);
+	if (required_fields_bitmap_alloced)
+		do_free(allocator, required_fields_bitmap);
+	return NULL;
+
+error_cleanup_during_scan:
+	do_free(allocator, rv);
+	for (j = 1; j <= which_slab; j++)
+		do_free(allocator, scanned_member_slabs[j]);
+	if (required_fields_bitmap_alloced)
+		do_free(allocator, required_fields_bitmap);
+	return NULL;
+}
+
+void
+protobuf_c_message_free_unpacked(ProtobufCMessage *message,
+				 ProtobufCAllocator *allocator)
+{
+	const ProtobufCMessageDescriptor *desc;
+	unsigned f;
+	
+	if (message == NULL)
+		return;
+
+	desc = message->descriptor;
+	
+	ASSERT_IS_MESSAGE(message);
+
+	if (allocator == NULL)
+		allocator = &protobuf_c__allocator;
+	message->descriptor = NULL;
+	for (f = 0; f < desc->n_fields; f++) {
+		if (0 != (desc->fields[f].flags & PROTOBUF_C_FIELD_FLAG_ONEOF) &&
+		    desc->fields[f].id !=
+		    STRUCT_MEMBER(uint32_t, message, desc->fields[f].quantifier_offset))
+		{
+			/* This is not the selected oneof, skip it */
+			continue;
+		}
+
+		if (desc->fields[f].label == PROTOBUF_C_LABEL_REPEATED) {
+			size_t n = STRUCT_MEMBER(size_t,
+						 message,
+						 desc->fields[f].quantifier_offset);
+			void *arr = STRUCT_MEMBER(void *,
+						  message,
+						  desc->fields[f].offset);
+
+			if (arr != NULL) {
+				if (desc->fields[f].type == PROTOBUF_C_TYPE_STRING) {
+					unsigned i;
+					for (i = 0; i < n; i++)
+						do_free(allocator, ((char **) arr)[i]);
+				} else if (desc->fields[f].type == PROTOBUF_C_TYPE_BYTES) {
+					unsigned i;
+					for (i = 0; i < n; i++)
+						do_free(allocator, ((ProtobufCBinaryData *) arr)[i].data);
+				} else if (desc->fields[f].type == PROTOBUF_C_TYPE_MESSAGE) {
+					unsigned i;
+					for (i = 0; i < n; i++)
+						protobuf_c_message_free_unpacked(
+							((ProtobufCMessage **) arr)[i],
+							allocator
+						);
+				}
+				do_free(allocator, arr);
+			}
+		} else if (desc->fields[f].type == PROTOBUF_C_TYPE_STRING) {
+			char *str = STRUCT_MEMBER(char *, message,
+						  desc->fields[f].offset);
+
+			if (str && str != desc->fields[f].default_value)
+				do_free(allocator, str);
+		} else if (desc->fields[f].type == PROTOBUF_C_TYPE_BYTES) {
+			void *data = STRUCT_MEMBER(ProtobufCBinaryData, message,
+						   desc->fields[f].offset).data;
+			const ProtobufCBinaryData *default_bd;
+
+			default_bd = desc->fields[f].default_value;
+			if (data != NULL &&
+			    (default_bd == NULL ||
+			     default_bd->data != data))
+			{
+				do_free(allocator, data);
+			}
+		} else if (desc->fields[f].type == PROTOBUF_C_TYPE_MESSAGE) {
+			ProtobufCMessage *sm;
+
+			sm = STRUCT_MEMBER(ProtobufCMessage *, message,
+					   desc->fields[f].offset);
+			if (sm && sm != desc->fields[f].default_value)
+				protobuf_c_message_free_unpacked(sm, allocator);
+		}
+	}
+
+	for (f = 0; f < message->n_unknown_fields; f++)
+		do_free(allocator, message->unknown_fields[f].data);
+	if (message->unknown_fields != NULL)
+		do_free(allocator, message->unknown_fields);
+
+	do_free(allocator, message);
+}
+
+void
+protobuf_c_message_init(const ProtobufCMessageDescriptor * descriptor,
+			void *message)
+{
+	descriptor->message_init((ProtobufCMessage *) (message));
+}
+
+protobuf_c_boolean
+protobuf_c_message_check(const ProtobufCMessage *message)
+{
+	unsigned i;
+	if (!message ||
+	    !message->descriptor ||
+	    message->descriptor->magic != PROTOBUF_C__MESSAGE_DESCRIPTOR_MAGIC)
+	{
+		return FALSE;
+	}
+
+	for (i = 0; i < message->descriptor->n_fields; i++) {
+		const ProtobufCFieldDescriptor *f = message->descriptor->fields + i;
+		ProtobufCType type = f->type;
+		ProtobufCLabel label = f->label;
+		void *field = STRUCT_MEMBER_P (message, f->offset);
+
+		if (label == PROTOBUF_C_LABEL_REPEATED) {
+			size_t *quantity = STRUCT_MEMBER_P (message, f->quantifier_offset);
+
+			if (*quantity > 0 && *(void **) field == NULL) {
+				return FALSE;
+			}
+
+			if (type == PROTOBUF_C_TYPE_MESSAGE) {
+				ProtobufCMessage **submessage = *(ProtobufCMessage ***) field;
+				unsigned j;
+				for (j = 0; j < *quantity; j++) {
+					if (!protobuf_c_message_check(submessage[j]))
+						return FALSE;
+				}
+			} else if (type == PROTOBUF_C_TYPE_STRING) {
+				char **string = *(char ***) field;
+				unsigned j;
+				for (j = 0; j < *quantity; j++) {
+					if (!string[j])
+						return FALSE;
+				}
+			} else if (type == PROTOBUF_C_TYPE_BYTES) {
+				ProtobufCBinaryData *bd = *(ProtobufCBinaryData **) field;
+				unsigned j;
+				for (j = 0; j < *quantity; j++) {
+					if (bd[j].len > 0 && bd[j].data == NULL)
+						return FALSE;
+				}
+			}
+
+		} else { /* PROTOBUF_C_LABEL_REQUIRED or PROTOBUF_C_LABEL_OPTIONAL */
+
+			if (type == PROTOBUF_C_TYPE_MESSAGE) {
+				ProtobufCMessage *submessage = *(ProtobufCMessage **) field;
+				if (label == PROTOBUF_C_LABEL_REQUIRED || submessage != NULL) {
+					if (!protobuf_c_message_check(submessage))
+						return FALSE;
+				}
+			} else if (type == PROTOBUF_C_TYPE_STRING) {
+				char *string = *(char **) field;
+				if (label == PROTOBUF_C_LABEL_REQUIRED && string == NULL)
+					return FALSE;
+			} else if (type == PROTOBUF_C_TYPE_BYTES) {
+				protobuf_c_boolean *has = STRUCT_MEMBER_P (message, f->quantifier_offset);
+				ProtobufCBinaryData *bd = field;
+				if (label == PROTOBUF_C_LABEL_REQUIRED || *has == TRUE) {
+					if (bd->len > 0 && bd->data == NULL)
+						return FALSE;
+				}
+			}
+		}
+	}
+
+	return TRUE;
+}
+
+/* === services === */
+
+typedef void (*GenericHandler) (void *service,
+				const ProtobufCMessage *input,
+				ProtobufCClosure closure,
+				void *closure_data);
+void
+protobuf_c_service_invoke_internal(ProtobufCService *service,
+				   unsigned method_index,
+				   const ProtobufCMessage *input,
+				   ProtobufCClosure closure,
+				   void *closure_data)
+{
+	GenericHandler *handlers;
+	GenericHandler handler;
+
+	/*
+	 * Verify that method_index is within range. If this fails, you are
+	 * likely invoking a newly added method on an old service. (Although
+	 * other memory corruption bugs can cause this assertion too.)
+	 */
+	assert(method_index < service->descriptor->n_methods);
+
+	/*
+	 * Get the array of virtual methods (which are enumerated by the
+	 * generated code).
+	 */
+	handlers = (GenericHandler *) (service + 1);
+
+	/*
+	 * Get our method and invoke it.
+	 * \todo Seems like handler == NULL is a situation that needs handling.
+	 */
+	handler = handlers[method_index];
+	(*handler)(service, input, closure, closure_data);
+}
+
+void
+protobuf_c_service_generated_init(ProtobufCService *service,
+				  const ProtobufCServiceDescriptor *descriptor,
+				  ProtobufCServiceDestroy destroy)
+{
+	ASSERT_IS_SERVICE_DESCRIPTOR(descriptor);
+	service->descriptor = descriptor;
+	service->destroy = destroy;
+	service->invoke = protobuf_c_service_invoke_internal;
+	memset(service + 1, 0, descriptor->n_methods * sizeof(GenericHandler));
+}
+
+void protobuf_c_service_destroy(ProtobufCService *service)
+{
+	service->destroy(service);
+}
+
+/* --- querying the descriptors --- */
+
+const ProtobufCEnumValue *
+protobuf_c_enum_descriptor_get_value_by_name(const ProtobufCEnumDescriptor *desc,
+					     const char *name)
+{
+	unsigned start = 0;
+	unsigned count = desc->n_value_names;
+
+	while (count > 1) {
+		unsigned mid = start + count / 2;
+		int rv = strcmp(desc->values_by_name[mid].name, name);
+		if (rv == 0)
+			return desc->values + desc->values_by_name[mid].index;
+		else if (rv < 0) {
+			count = start + count - (mid + 1);
+			start = mid + 1;
+		} else
+			count = mid - start;
+	}
+	if (count == 0)
+		return NULL;
+	if (strcmp(desc->values_by_name[start].name, name) == 0)
+		return desc->values + desc->values_by_name[start].index;
+	return NULL;
+}
+
+const ProtobufCEnumValue *
+protobuf_c_enum_descriptor_get_value(const ProtobufCEnumDescriptor *desc,
+				     int value)
+{
+	int rv = int_range_lookup(desc->n_value_ranges, desc->value_ranges, value);
+	if (rv < 0)
+		return NULL;
+	return desc->values + rv;
+}
+
+const ProtobufCFieldDescriptor *
+protobuf_c_message_descriptor_get_field_by_name(const ProtobufCMessageDescriptor *desc,
+						const char *name)
+{
+	unsigned start = 0;
+	unsigned count = desc->n_fields;
+	const ProtobufCFieldDescriptor *field;
+
+	while (count > 1) {
+		unsigned mid = start + count / 2;
+		int rv;
+		field = desc->fields + desc->fields_sorted_by_name[mid];
+		rv = strcmp(field->name, name);
+		if (rv == 0)
+			return field;
+		else if (rv < 0) {
+			count = start + count - (mid + 1);
+			start = mid + 1;
+		} else
+			count = mid - start;
+	}
+	if (count == 0)
+		return NULL;
+	field = desc->fields + desc->fields_sorted_by_name[start];
+	if (strcmp(field->name, name) == 0)
+		return field;
+	return NULL;
+}
+
+const ProtobufCFieldDescriptor *
+protobuf_c_message_descriptor_get_field(const ProtobufCMessageDescriptor *desc,
+					unsigned value)
+{
+	int rv = int_range_lookup(desc->n_field_ranges,desc->field_ranges, value);
+	if (rv < 0)
+		return NULL;
+	return desc->fields + rv;
+}
+
+const ProtobufCMethodDescriptor *
+protobuf_c_service_descriptor_get_method_by_name(const ProtobufCServiceDescriptor *desc,
+						 const char *name)
+{
+	unsigned start = 0;
+	unsigned count = desc->n_methods;
+
+	while (count > 1) {
+		unsigned mid = start + count / 2;
+		unsigned mid_index = desc->method_indices_by_name[mid];
+		const char *mid_name = desc->methods[mid_index].name;
+		int rv = strcmp(mid_name, name);
+
+		if (rv == 0)
+			return desc->methods + desc->method_indices_by_name[mid];
+		if (rv < 0) {
+			count = start + count - (mid + 1);
+			start = mid + 1;
+		} else {
+			count = mid - start;
+		}
+	}
+	if (count == 0)
+		return NULL;
+	if (strcmp(desc->methods[desc->method_indices_by_name[start]].name, name) == 0)
+		return desc->methods + desc->method_indices_by_name[start];
+	return NULL;
+}
diff --git a/libs/libsignal/src/protobuf-c/protobuf-c.h b/libs/libsignal/src/protobuf-c/protobuf-c.h
new file mode 100644
index 0000000000..705a1f7003
--- /dev/null
+++ b/libs/libsignal/src/protobuf-c/protobuf-c.h
@@ -0,0 +1,1097 @@
+/*
+ * Copyright (c) 2008-2014, Dave Benson and the protobuf-c authors.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/*! \file
+ * \mainpage Introduction
+ *
+ * This is [protobuf-c], a C implementation of [Protocol Buffers].
+ *
+ * This file defines the public API for the `libprotobuf-c` support library.
+ * This API includes interfaces that can be used directly by client code as well
+ * as the interfaces used by the code generated by the `protoc-c` compiler.
+ *
+ * The `libprotobuf-c` support library performs the actual serialization and
+ * deserialization of Protocol Buffers messages. It interacts with structures,
+ * definitions, and metadata generated by the `protoc-c` compiler from .proto
+ * files.
+ *
+ * \authors Dave Benson and the `protobuf-c` authors.
+ *
+ * \copyright 2008-2014. Licensed under the terms of the [BSD-2-Clause] license.
+ *
+ * [protobuf-c]:       https://github.com/protobuf-c/protobuf-c
+ * [Protocol Buffers]: https://developers.google.com/protocol-buffers/
+ * [BSD-2-Clause]:     http://opensource.org/licenses/BSD-2-Clause
+ *
+ * \page gencode Generated Code
+ *
+ * For each enum, we generate a C enum. For each message, we generate a C
+ * structure which can be cast to a `ProtobufCMessage`.
+ *
+ * For each enum and message, we generate a descriptor object that allows us to
+ * implement a kind of reflection on the structures.
+ *
+ * First, some naming conventions:
+ *
+ * - The name of the type for enums and messages and services is camel case
+ *   (meaning WordsAreCrammedTogether) except that double underscores are used
+ *   to delimit scopes. For example, the following `.proto` file:
+ *
+~~~{.proto}
+        package foo.bar;
+        message BazBah {
+            optional int32 val = 1;
+        }
+~~~
+ *
+ * would generate a C type `Foo__Bar__BazBah`.
+ *
+ * - Identifiers for functions and globals are all lowercase, with camel case
+ *   words separated by single underscores. For example, one of the function
+ *   prototypes generated by `protoc-c` for the above example:
+ *
+~~~{.c}
+Foo__Bar__BazBah *
+       foo__bar__baz_bah__unpack
+                     (ProtobufCAllocator  *allocator,
+                      size_t               len,
+                      const uint8_t       *data);
+~~~
+ *
+ * - Identifiers for enum values contain an uppercase prefix which embeds the
+ *   package name and the enum type name.
+ *
+ * - A double underscore is used to separate further components of identifier
+ *   names.
+ *
+ * For example, in the name of the unpack function above, the package name
+ * `foo.bar` has become `foo__bar`, the message name BazBah has become
+ * `baz_bah`, and the method name is `unpack`. These are all joined with double
+ * underscores to form the C identifier `foo__bar__baz_bah__unpack`.
+ *
+ * We also generate descriptor objects for messages and enums. These are
+ * declared in the `.pb-c.h` files:
+ *
+~~~{.c}
+extern const ProtobufCMessageDescriptor foo__bar__baz_bah__descriptor;
+~~~
+ *
+ * The message structures all begin with `ProtobufCMessageDescriptor *` which is
+ * sufficient to allow them to be cast to `ProtobufCMessage`.
+ *
+ * For each message defined in a `.proto` file, we generate a number of
+ * functions and macros. Each function name contains a prefix based on the
+ * package name and message name in order to make it a unique C identifier.
+ *
+ * - `INIT`. Statically initializes a message object, initializing its
+ *   descriptor and setting its fields to default values. Uninitialized
+ *   messages cannot be processed by the protobuf-c library.
+ *
+~~~{.c}
+#define FOO__BAR__BAZ_BAH__INIT \
+ { PROTOBUF_C_MESSAGE_INIT (&foo__bar__baz_bah__descriptor), 0 }
+~~~
+ * - `init()`. Initializes a message object, initializing its descriptor and
+ *   setting its fields to default values. Uninitialized messages cannot be
+ *   processed by the protobuf-c library.
+ *
+~~~{.c}
+void foo__bar__baz_bah__init
+                     (Foo__Bar__BazBah *message);
+~~~
+ * - `unpack()`. Unpacks data for a particular message format. Note that the
+ *   `allocator` parameter is usually `NULL` to indicate that the system's
+ *   `malloc()` and `free()` functions should be used for dynamically allocating
+ *   memory.
+ *
+~~~{.c}
+Foo__Bar__BazBah *
+       foo__bar__baz_bah__unpack
+                     (ProtobufCAllocator  *allocator,
+                      size_t               len,
+                      const uint8_t       *data);
+~~~
+ *
+ * - `free_unpacked()`. Frees a message object obtained with the `unpack()`
+ *   method.
+ *
+~~~{.c}
+void   foo__bar__baz_bah__free_unpacked
+                     (Foo__Bar__BazBah *message,
+                      ProtobufCAllocator *allocator);
+~~~
+ *
+ * - `get_packed_size()`. Calculates the length in bytes of the serialized
+ *   representation of the message object.
+ *
+~~~{.c}
+size_t foo__bar__baz_bah__get_packed_size
+                     (const Foo__Bar__BazBah   *message);
+~~~
+ *
+ * - `pack()`. Pack a message object into a preallocated buffer. Assumes that
+ *   the buffer is large enough. (Use `get_packed_size()` first.)
+ *
+~~~{.c}
+size_t foo__bar__baz_bah__pack
+                     (const Foo__Bar__BazBah   *message,
+                      uint8_t             *out);
+~~~
+ *
+ * - `pack_to_buffer()`. Packs a message into a "virtual buffer". This is an
+ *   object which defines an "append bytes" callback to consume data as it is
+ *   serialized.
+ *
+~~~{.c}
+size_t foo__bar__baz_bah__pack_to_buffer
+                     (const Foo__Bar__BazBah   *message,
+                      ProtobufCBuffer     *buffer);
+~~~
+ *
+ * \page pack Packing and unpacking messages
+ *
+ * To pack a message, first compute the packed size of the message with
+ * protobuf_c_message_get_packed_size(), then allocate a buffer of at least
+ * that size, then call protobuf_c_message_pack().
+ *
+ * Alternatively, a message can be serialized without calculating the final size
+ * first. Use the protobuf_c_message_pack_to_buffer() function and provide a
+ * ProtobufCBuffer object which implements an "append" method that consumes
+ * data.
+ *
+ * To unpack a message, call the protobuf_c_message_unpack() function. The
+ * result can be cast to an object of the type that matches the descriptor for
+ * the message.
+ *
+ * The result of unpacking a message should be freed with
+ * protobuf_c_message_free_unpacked().
+ */
+
+#ifndef PROTOBUF_C_H
+#define PROTOBUF_C_H
+
+#include <assert.h>
+#include <limits.h>
+#include <stddef.h>
+#include <stdint.h>
+
+#ifdef __cplusplus
+# define PROTOBUF_C__BEGIN_DECLS	extern "C" {
+# define PROTOBUF_C__END_DECLS		}
+#else
+# define PROTOBUF_C__BEGIN_DECLS
+# define PROTOBUF_C__END_DECLS
+#endif
+
+PROTOBUF_C__BEGIN_DECLS
+
+#if defined(_WIN32) && defined(PROTOBUF_C_USE_SHARED_LIB)
+# ifdef PROTOBUF_C_EXPORT
+#  define PROTOBUF_C__API __declspec(dllexport)
+# else
+#  define PROTOBUF_C__API __declspec(dllimport)
+# endif
+#else
+# define PROTOBUF_C__API
+#endif
+
+#if !defined(PROTOBUF_C__NO_DEPRECATED) && \
+	((__GNUC__ > 3) || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1))
+# define PROTOBUF_C__DEPRECATED __attribute__((__deprecated__))
+#else
+# define PROTOBUF_C__DEPRECATED
+#endif
+
+#ifndef PROTOBUF_C__FORCE_ENUM_TO_BE_INT_SIZE
+ #define PROTOBUF_C__FORCE_ENUM_TO_BE_INT_SIZE(enum_name) \
+  , _##enum_name##_IS_INT_SIZE = INT_MAX
+#endif
+
+#define PROTOBUF_C__SERVICE_DESCRIPTOR_MAGIC    0x14159bc3
+#define PROTOBUF_C__MESSAGE_DESCRIPTOR_MAGIC    0x28aaeef9
+#define PROTOBUF_C__ENUM_DESCRIPTOR_MAGIC       0x114315af
+
+/**
+ * \defgroup api Public API
+ *
+ * This is the public API for `libprotobuf-c`. These interfaces are stable and
+ * subject to Semantic Versioning guarantees.
+ *
+ * @{
+ */
+
+/**
+ * Values for the `flags` word in `ProtobufCFieldDescriptor`.
+ */
+typedef enum {
+	/** Set if the field is repeated and marked with the `packed` option. */
+	PROTOBUF_C_FIELD_FLAG_PACKED		= (1 << 0),
+
+	/** Set if the field is marked with the `deprecated` option. */
+	PROTOBUF_C_FIELD_FLAG_DEPRECATED	= (1 << 1),
+
+	/** Set if the field is a member of a oneof (union). */
+	PROTOBUF_C_FIELD_FLAG_ONEOF		= (1 << 2),
+} ProtobufCFieldFlag;
+
+/**
+ * Message field rules.
+ *
+ * \see [Defining A Message Type] in the Protocol Buffers documentation.
+ *
+ * [Defining A Message Type]:
+ *      https://developers.google.com/protocol-buffers/docs/proto#simple
+ */
+typedef enum {
+	/** A well-formed message must have exactly one of this field. */
+	PROTOBUF_C_LABEL_REQUIRED,
+
+	/**
+	 * A well-formed message can have zero or one of this field (but not
+	 * more than one).
+	 */
+	PROTOBUF_C_LABEL_OPTIONAL,
+
+	/**
+	 * This field can be repeated any number of times (including zero) in a
+	 * well-formed message. The order of the repeated values will be
+	 * preserved.
+	 */
+	PROTOBUF_C_LABEL_REPEATED,
+} ProtobufCLabel;
+
+/**
+ * Field value types.
+ *
+ * \see [Scalar Value Types] in the Protocol Buffers documentation.
+ *
+ * [Scalar Value Types]:
+ *      https://developers.google.com/protocol-buffers/docs/proto#scalar
+ */
+typedef enum {
+	PROTOBUF_C_TYPE_INT32,      /**< int32 */
+	PROTOBUF_C_TYPE_SINT32,     /**< signed int32 */
+	PROTOBUF_C_TYPE_SFIXED32,   /**< signed int32 (4 bytes) */
+	PROTOBUF_C_TYPE_INT64,      /**< int64 */
+	PROTOBUF_C_TYPE_SINT64,     /**< signed int64 */
+	PROTOBUF_C_TYPE_SFIXED64,   /**< signed int64 (8 bytes) */
+	PROTOBUF_C_TYPE_UINT32,     /**< unsigned int32 */
+	PROTOBUF_C_TYPE_FIXED32,    /**< unsigned int32 (4 bytes) */
+	PROTOBUF_C_TYPE_UINT64,     /**< unsigned int64 */
+	PROTOBUF_C_TYPE_FIXED64,    /**< unsigned int64 (8 bytes) */
+	PROTOBUF_C_TYPE_FLOAT,      /**< float */
+	PROTOBUF_C_TYPE_DOUBLE,     /**< double */
+	PROTOBUF_C_TYPE_BOOL,       /**< boolean */
+	PROTOBUF_C_TYPE_ENUM,       /**< enumerated type */
+	PROTOBUF_C_TYPE_STRING,     /**< UTF-8 or ASCII string */
+	PROTOBUF_C_TYPE_BYTES,      /**< arbitrary byte sequence */
+	PROTOBUF_C_TYPE_MESSAGE,    /**< nested message */
+} ProtobufCType;
+
+/**
+ * Field wire types.
+ *
+ * \see [Message Structure] in the Protocol Buffers documentation.
+ *
+ * [Message Structure]:
+ *      https://developers.google.com/protocol-buffers/docs/encoding#structure
+ */
+typedef enum {
+	PROTOBUF_C_WIRE_TYPE_VARINT = 0,
+	PROTOBUF_C_WIRE_TYPE_64BIT = 1,
+	PROTOBUF_C_WIRE_TYPE_LENGTH_PREFIXED = 2,
+	/* "Start group" and "end group" wire types are unsupported. */
+	PROTOBUF_C_WIRE_TYPE_32BIT = 5,
+} ProtobufCWireType;
+
+struct ProtobufCAllocator;
+struct ProtobufCBinaryData;
+struct ProtobufCBuffer;
+struct ProtobufCBufferSimple;
+struct ProtobufCEnumDescriptor;
+struct ProtobufCEnumValue;
+struct ProtobufCEnumValueIndex;
+struct ProtobufCFieldDescriptor;
+struct ProtobufCIntRange;
+struct ProtobufCMessage;
+struct ProtobufCMessageDescriptor;
+struct ProtobufCMessageUnknownField;
+struct ProtobufCMethodDescriptor;
+struct ProtobufCService;
+struct ProtobufCServiceDescriptor;
+
+typedef struct ProtobufCAllocator ProtobufCAllocator;
+typedef struct ProtobufCBinaryData ProtobufCBinaryData;
+typedef struct ProtobufCBuffer ProtobufCBuffer;
+typedef struct ProtobufCBufferSimple ProtobufCBufferSimple;
+typedef struct ProtobufCEnumDescriptor ProtobufCEnumDescriptor;
+typedef struct ProtobufCEnumValue ProtobufCEnumValue;
+typedef struct ProtobufCEnumValueIndex ProtobufCEnumValueIndex;
+typedef struct ProtobufCFieldDescriptor ProtobufCFieldDescriptor;
+typedef struct ProtobufCIntRange ProtobufCIntRange;
+typedef struct ProtobufCMessage ProtobufCMessage;
+typedef struct ProtobufCMessageDescriptor ProtobufCMessageDescriptor;
+typedef struct ProtobufCMessageUnknownField ProtobufCMessageUnknownField;
+typedef struct ProtobufCMethodDescriptor ProtobufCMethodDescriptor;
+typedef struct ProtobufCService ProtobufCService;
+typedef struct ProtobufCServiceDescriptor ProtobufCServiceDescriptor;
+
+/** Boolean type. */
+typedef int protobuf_c_boolean;
+
+typedef void (*ProtobufCClosure)(const ProtobufCMessage *, void *closure_data);
+typedef void (*ProtobufCMessageInit)(ProtobufCMessage *);
+typedef void (*ProtobufCServiceDestroy)(ProtobufCService *);
+
+/**
+ * Structure for defining a custom memory allocator.
+ */
+struct ProtobufCAllocator {
+	/** Function to allocate memory. */
+	void		*(*alloc)(void *allocator_data, size_t size);
+
+	/** Function to free memory. */
+	void		(*free)(void *allocator_data, void *pointer);
+
+	/** Opaque pointer passed to `alloc` and `free` functions. */
+	void		*allocator_data;
+};
+
+/**
+ * Structure for the protobuf `bytes` scalar type.
+ *
+ * The data contained in a `ProtobufCBinaryData` is an arbitrary sequence of
+ * bytes. It may contain embedded `NUL` characters and is not required to be
+ * `NUL`-terminated.
+ */
+struct ProtobufCBinaryData {
+	size_t	len;        /**< Number of bytes in the `data` field. */
+	uint8_t	*data;      /**< Data bytes. */
+};
+
+/**
+ * Structure for defining a virtual append-only buffer. Used by
+ * protobuf_c_message_pack_to_buffer() to abstract the consumption of serialized
+ * bytes.
+ *
+ * `ProtobufCBuffer` "subclasses" may be defined on the stack. For example, to
+ * write to a `FILE` object:
+ *
+~~~{.c}
+typedef struct {
+        ProtobufCBuffer base;
+        FILE *fp;
+} BufferAppendToFile;
+
+static void
+my_buffer_file_append(ProtobufCBuffer *buffer,
+                      size_t len,
+                      const uint8_t *data)
+{
+        BufferAppendToFile *file_buf = (BufferAppendToFile *) buffer;
+        fwrite(data, len, 1, file_buf->fp); // XXX: No error handling!
+}
+~~~
+ *
+ * To use this new type of ProtobufCBuffer, it could be called as follows:
+ *
+~~~{.c}
+...
+BufferAppendToFile tmp = {0};
+tmp.base.append = my_buffer_file_append;
+tmp.fp = fp;
+protobuf_c_message_pack_to_buffer(&message, &tmp);
+...
+~~~
+ */
+struct ProtobufCBuffer {
+	/** Append function. Consumes the `len` bytes stored at `data`. */
+	void		(*append)(ProtobufCBuffer *buffer,
+				  size_t len,
+				  const uint8_t *data);
+};
+
+/**
+ * Simple buffer "subclass" of `ProtobufCBuffer`.
+ *
+ * A `ProtobufCBufferSimple` object is declared on the stack and uses a
+ * scratch buffer provided by the user for the initial allocation. It performs
+ * exponential resizing, using dynamically allocated memory. A
+ * `ProtobufCBufferSimple` object can be created and used as follows:
+ *
+~~~{.c}
+uint8_t pad[128];
+ProtobufCBufferSimple simple = PROTOBUF_C_BUFFER_SIMPLE_INIT(pad);
+ProtobufCBuffer *buffer = (ProtobufCBuffer *) &simple;
+~~~
+ *
+ * `buffer` can now be used with `protobuf_c_message_pack_to_buffer()`. Once a
+ * message has been serialized to a `ProtobufCBufferSimple` object, the
+ * serialized data bytes can be accessed from the `.data` field.
+ *
+ * To free the memory allocated by a `ProtobufCBufferSimple` object, if any,
+ * call PROTOBUF_C_BUFFER_SIMPLE_CLEAR() on the object, for example:
+ *
+~~~{.c}
+PROTOBUF_C_BUFFER_SIMPLE_CLEAR(&simple);
+~~~
+ *
+ * \see PROTOBUF_C_BUFFER_SIMPLE_INIT
+ * \see PROTOBUF_C_BUFFER_SIMPLE_CLEAR
+ */
+struct ProtobufCBufferSimple {
+	/** "Base class". */
+	ProtobufCBuffer		base;
+	/** Number of bytes allocated in `data`. */
+	size_t			alloced;
+	/** Number of bytes currently stored in `data`. */
+	size_t			len;
+	/** Data bytes. */
+	uint8_t			*data;
+	/** Whether `data` must be freed. */
+	protobuf_c_boolean	must_free_data;
+	/** Allocator to use. May be NULL to indicate the system allocator. */
+	ProtobufCAllocator	*allocator;
+};
+
+/**
+ * Describes an enumeration as a whole, with all of its values.
+ */
+struct ProtobufCEnumDescriptor {
+	/** Magic value checked to ensure that the API is used correctly. */
+	uint32_t			magic;
+
+	/** The qualified name (e.g., "namespace.Type"). */
+	const char			*name;
+	/** The unqualified name as given in the .proto file (e.g., "Type"). */
+	const char			*short_name;
+	/** Identifier used in generated C code. */
+	const char			*c_name;
+	/** The dot-separated namespace. */
+	const char			*package_name;
+
+	/** Number elements in `values`. */
+	unsigned			n_values;
+	/** Array of distinct values, sorted by numeric value. */
+	const ProtobufCEnumValue	*values;
+
+	/** Number of elements in `values_by_name`. */
+	unsigned			n_value_names;
+	/** Array of named values, including aliases, sorted by name. */
+	const ProtobufCEnumValueIndex	*values_by_name;
+
+	/** Number of elements in `value_ranges`. */
+	unsigned			n_value_ranges;
+	/** Value ranges, for faster lookups by numeric value. */
+	const ProtobufCIntRange		*value_ranges;
+
+	/** Reserved for future use. */
+	void				*reserved1;
+	/** Reserved for future use. */
+	void				*reserved2;
+	/** Reserved for future use. */
+	void				*reserved3;
+	/** Reserved for future use. */
+	void				*reserved4;
+};
+
+/**
+ * Represents a single value of an enumeration.
+ */
+struct ProtobufCEnumValue {
+	/** The string identifying this value in the .proto file. */
+	const char	*name;
+
+	/** The string identifying this value in generated C code. */
+	const char	*c_name;
+
+	/** The numeric value assigned in the .proto file. */
+	int		value;
+};
+
+/**
+ * Used by `ProtobufCEnumDescriptor` to look up enum values.
+ */
+struct ProtobufCEnumValueIndex {
+	/** Name of the enum value. */
+	const char      *name;
+	/** Index into values[] array. */
+	unsigned        index;
+};
+
+/**
+ * Describes a single field in a message.
+ */
+struct ProtobufCFieldDescriptor {
+	/** Name of the field as given in the .proto file. */
+	const char		*name;
+
+	/** Tag value of the field as given in the .proto file. */
+	uint32_t		id;
+
+	/** Whether the field is `REQUIRED`, `OPTIONAL`, or `REPEATED`. */
+	ProtobufCLabel		label;
+
+	/** The type of the field. */
+	ProtobufCType		type;
+
+	/**
+	 * The offset in bytes of the message's C structure's quantifier field
+	 * (the `has_MEMBER` field for optional members or the `n_MEMBER` field
+	 * for repeated members or the case enum for oneofs).
+	 */
+	unsigned		quantifier_offset;
+
+	/**
+	 * The offset in bytes into the message's C structure for the member
+	 * itself.
+	 */
+	unsigned		offset;
+
+	/**
+	 * A type-specific descriptor.
+	 *
+	 * If `type` is `PROTOBUF_C_TYPE_ENUM`, then `descriptor` points to the
+	 * corresponding `ProtobufCEnumDescriptor`.
+	 *
+	 * If `type` is `PROTOBUF_C_TYPE_MESSAGE`, then `descriptor` points to
+	 * the corresponding `ProtobufCMessageDescriptor`.
+	 *
+	 * Otherwise this field is NULL.
+	 */
+	const void		*descriptor; /* for MESSAGE and ENUM types */
+
+	/** The default value for this field, if defined. May be NULL. */
+	const void		*default_value;
+
+	/**
+	 * A flag word. Zero or more of the bits defined in the
+	 * `ProtobufCFieldFlag` enum may be set.
+	 */
+	uint32_t		flags;
+
+	/** Reserved for future use. */
+	unsigned		reserved_flags;
+	/** Reserved for future use. */
+	void			*reserved2;
+	/** Reserved for future use. */
+	void			*reserved3;
+};
+
+/**
+ * Helper structure for optimizing int => index lookups in the case
+ * where the keys are mostly consecutive values, as they presumably are for
+ * enums and fields.
+ *
+ * The data structures requires that the values in the original array are
+ * sorted.
+ */
+struct ProtobufCIntRange {
+	int             start_value;
+	unsigned        orig_index;
+	/*
+	 * NOTE: the number of values in the range can be inferred by looking
+	 * at the next element's orig_index. A dummy element is added to make
+	 * this simple.
+	 */
+};
+
+/**
+ * An instance of a message.
+ *
+ * `ProtobufCMessage` is a light-weight "base class" for all messages.
+ *
+ * In particular, `ProtobufCMessage` doesn't have any allocation policy
+ * associated with it. That's because it's common to create `ProtobufCMessage`
+ * objects on the stack. In fact, that's what we recommend for sending messages.
+ * If the object is allocated from the stack, you can't really have a memory
+ * leak.
+ *
+ * This means that calls to functions like protobuf_c_message_unpack() which
+ * return a `ProtobufCMessage` must be paired with a call to a free function,
+ * like protobuf_c_message_free_unpacked().
+ */
+struct ProtobufCMessage {
+	/** The descriptor for this message type. */
+	const ProtobufCMessageDescriptor	*descriptor;
+	/** The number of elements in `unknown_fields`. */
+	unsigned				n_unknown_fields;
+	/** The fields that weren't recognized by the parser. */
+	ProtobufCMessageUnknownField		*unknown_fields;
+};
+
+/**
+ * Describes a message.
+ */
+struct ProtobufCMessageDescriptor {
+	/** Magic value checked to ensure that the API is used correctly. */
+	uint32_t			magic;
+
+	/** The qualified name (e.g., "namespace.Type"). */
+	const char			*name;
+	/** The unqualified name as given in the .proto file (e.g., "Type"). */
+	const char			*short_name;
+	/** Identifier used in generated C code. */
+	const char			*c_name;
+	/** The dot-separated namespace. */
+	const char			*package_name;
+
+	/**
+	 * Size in bytes of the C structure representing an instance of this
+	 * type of message.
+	 */
+	size_t				sizeof_message;
+
+	/** Number of elements in `fields`. */
+	unsigned			n_fields;
+	/** Field descriptors, sorted by tag number. */
+	const ProtobufCFieldDescriptor	*fields;
+	/** Used for looking up fields by name. */
+	const unsigned			*fields_sorted_by_name;
+
+	/** Number of elements in `field_ranges`. */
+	unsigned			n_field_ranges;
+	/** Used for looking up fields by id. */
+	const ProtobufCIntRange		*field_ranges;
+
+	/** Message initialisation function. */
+	ProtobufCMessageInit		message_init;
+
+	/** Reserved for future use. */
+	void				*reserved1;
+	/** Reserved for future use. */
+	void				*reserved2;
+	/** Reserved for future use. */
+	void				*reserved3;
+};
+
+/**
+ * An unknown message field.
+ */
+struct ProtobufCMessageUnknownField {
+	/** The tag number. */
+	uint32_t		tag;
+	/** The wire type of the field. */
+	ProtobufCWireType	wire_type;
+	/** Number of bytes in `data`. */
+	size_t			len;
+	/** Field data. */
+	uint8_t			*data;
+};
+
+/**
+ * Method descriptor.
+ */
+struct ProtobufCMethodDescriptor {
+	/** Method name. */
+	const char				*name;
+	/** Input message descriptor. */
+	const ProtobufCMessageDescriptor	*input;
+	/** Output message descriptor. */
+	const ProtobufCMessageDescriptor	*output;
+};
+
+/**
+ * Service.
+ */
+struct ProtobufCService {
+	/** Service descriptor. */
+	const ProtobufCServiceDescriptor *descriptor;
+	/** Function to invoke the service. */
+	void (*invoke)(ProtobufCService *service,
+		       unsigned method_index,
+		       const ProtobufCMessage *input,
+		       ProtobufCClosure closure,
+		       void *closure_data);
+	/** Function to destroy the service. */
+	void (*destroy)(ProtobufCService *service);
+};
+
+/**
+ * Service descriptor.
+ */
+struct ProtobufCServiceDescriptor {
+	/** Magic value checked to ensure that the API is used correctly. */
+	uint32_t			magic;
+
+	/** Service name. */
+	const char			*name;
+	/** Short version of service name. */
+	const char			*short_name;
+	/** C identifier for the service name. */
+	const char			*c_name;
+	/** Package name. */
+	const char			*package;
+	/** Number of elements in `methods`. */
+	unsigned			n_methods;
+	/** Method descriptors, in the order defined in the .proto file. */
+	const ProtobufCMethodDescriptor	*methods;
+	/** Sort index of methods. */
+	const unsigned			*method_indices_by_name;
+};
+
+/**
+ * Get the version of the protobuf-c library. Note that this is the version of
+ * the library linked against, not the version of the headers compiled against.
+ *
+ * \return A string containing the version number of protobuf-c.
+ */
+PROTOBUF_C__API
+const char *
+protobuf_c_version(void);
+
+/**
+ * Get the version of the protobuf-c library. Note that this is the version of
+ * the library linked against, not the version of the headers compiled against.
+ *
+ * \return A 32 bit unsigned integer containing the version number of
+ *      protobuf-c, represented in base-10 as (MAJOR*1E6) + (MINOR*1E3) + PATCH.
+ */
+PROTOBUF_C__API
+uint32_t
+protobuf_c_version_number(void);
+
+/**
+ * The version of the protobuf-c headers, represented as a string using the same
+ * format as protobuf_c_version().
+ */
+#define PROTOBUF_C_VERSION		"1.1.1"
+
+/**
+ * The version of the protobuf-c headers, represented as an integer using the
+ * same format as protobuf_c_version_number().
+ */
+#define PROTOBUF_C_VERSION_NUMBER	1001001
+
+/**
+ * The minimum protoc-c version which works with the current version of the
+ * protobuf-c headers.
+ */
+#define PROTOBUF_C_MIN_COMPILER_VERSION	1000000
+
+/**
+ * Look up a `ProtobufCEnumValue` from a `ProtobufCEnumDescriptor` by name.
+ *
+ * \param desc
+ *      The `ProtobufCEnumDescriptor` object.
+ * \param name
+ *      The `name` field from the corresponding `ProtobufCEnumValue` object to
+ *      match.
+ * \return
+ *      A `ProtobufCEnumValue` object.
+ * \retval NULL
+ *      If not found.
+ */
+PROTOBUF_C__API
+const ProtobufCEnumValue *
+protobuf_c_enum_descriptor_get_value_by_name(
+	const ProtobufCEnumDescriptor *desc,
+	const char *name);
+
+/**
+ * Look up a `ProtobufCEnumValue` from a `ProtobufCEnumDescriptor` by numeric
+ * value.
+ *
+ * \param desc
+ *      The `ProtobufCEnumDescriptor` object.
+ * \param value
+ *      The `value` field from the corresponding `ProtobufCEnumValue` object to
+ *      match.
+ *
+ * \return
+ *      A `ProtobufCEnumValue` object.
+ * \retval NULL
+ *      If not found.
+ */
+PROTOBUF_C__API
+const ProtobufCEnumValue *
+protobuf_c_enum_descriptor_get_value(
+	const ProtobufCEnumDescriptor *desc,
+	int value);
+
+/**
+ * Look up a `ProtobufCFieldDescriptor` from a `ProtobufCMessageDescriptor` by
+ * the name of the field.
+ *
+ * \param desc
+ *      The `ProtobufCMessageDescriptor` object.
+ * \param name
+ *      The name of the field.
+ * \return
+ *      A `ProtobufCFieldDescriptor` object.
+ * \retval NULL
+ *      If not found.
+ */
+PROTOBUF_C__API
+const ProtobufCFieldDescriptor *
+protobuf_c_message_descriptor_get_field_by_name(
+	const ProtobufCMessageDescriptor *desc,
+	const char *name);
+
+/**
+ * Look up a `ProtobufCFieldDescriptor` from a `ProtobufCMessageDescriptor` by
+ * the tag value of the field.
+ *
+ * \param desc
+ *      The `ProtobufCMessageDescriptor` object.
+ * \param value
+ *      The tag value of the field.
+ * \return
+ *      A `ProtobufCFieldDescriptor` object.
+ * \retval NULL
+ *      If not found.
+ */
+PROTOBUF_C__API
+const ProtobufCFieldDescriptor *
+protobuf_c_message_descriptor_get_field(
+	const ProtobufCMessageDescriptor *desc,
+	unsigned value);
+
+/**
+ * Determine the number of bytes required to store the serialised message.
+ *
+ * \param message
+ *      The message object to serialise.
+ * \return
+ *      Number of bytes.
+ */
+PROTOBUF_C__API
+size_t
+protobuf_c_message_get_packed_size(const ProtobufCMessage *message);
+
+/**
+ * Serialise a message from its in-memory representation.
+ *
+ * This function stores the serialised bytes of the message in a pre-allocated
+ * buffer.
+ *
+ * \param message
+ *      The message object to serialise.
+ * \param[out] out
+ *      Buffer to store the bytes of the serialised message. This buffer must
+ *      have enough space to store the packed message. Use
+ *      protobuf_c_message_get_packed_size() to determine the number of bytes
+ *      required.
+ * \return
+ *      Number of bytes stored in `out`.
+ */
+PROTOBUF_C__API
+size_t
+protobuf_c_message_pack(const ProtobufCMessage *message, uint8_t *out);
+
+/**
+ * Serialise a message from its in-memory representation to a virtual buffer.
+ *
+ * This function calls the `append` method of a `ProtobufCBuffer` object to
+ * consume the bytes generated by the serialiser.
+ *
+ * \param message
+ *      The message object to serialise.
+ * \param buffer
+ *      The virtual buffer object.
+ * \return
+ *      Number of bytes passed to the virtual buffer.
+ */
+PROTOBUF_C__API
+size_t
+protobuf_c_message_pack_to_buffer(
+	const ProtobufCMessage *message,
+	ProtobufCBuffer *buffer);
+
+/**
+ * Unpack a serialised message into an in-memory representation.
+ *
+ * \param descriptor
+ *      The message descriptor.
+ * \param allocator
+ *      `ProtobufCAllocator` to use for memory allocation. May be NULL to
+ *      specify the default allocator.
+ * \param len
+ *      Length in bytes of the serialised message.
+ * \param data
+ *      Pointer to the serialised message.
+ * \return
+ *      An unpacked message object.
+ * \retval NULL
+ *      If an error occurred during unpacking.
+ */
+PROTOBUF_C__API
+ProtobufCMessage *
+protobuf_c_message_unpack(
+	const ProtobufCMessageDescriptor *descriptor,
+	ProtobufCAllocator *allocator,
+	size_t len,
+	const uint8_t *data);
+
+/**
+ * Free an unpacked message object.
+ *
+ * This function should be used to deallocate the memory used by a call to
+ * protobuf_c_message_unpack().
+ *
+ * \param message
+ *      The message object to free.
+ * \param allocator
+ *      `ProtobufCAllocator` to use for memory deallocation. May be NULL to
+ *      specify the default allocator.
+ */
+PROTOBUF_C__API
+void
+protobuf_c_message_free_unpacked(
+	ProtobufCMessage *message,
+	ProtobufCAllocator *allocator);
+
+/**
+ * Check the validity of a message object.
+ *
+ * Makes sure all required fields (`PROTOBUF_C_LABEL_REQUIRED`) are present.
+ * Recursively checks nested messages.
+ *
+ * \retval TRUE
+ *      Message is valid.
+ * \retval FALSE
+ *      Message is invalid.
+ */
+PROTOBUF_C__API
+protobuf_c_boolean
+protobuf_c_message_check(const ProtobufCMessage *);
+
+/** Message initialiser. */
+#define PROTOBUF_C_MESSAGE_INIT(descriptor) { descriptor, 0, NULL }
+
+/**
+ * Initialise a message object from a message descriptor.
+ *
+ * \param descriptor
+ *      Message descriptor.
+ * \param message
+ *      Allocated block of memory of size `descriptor->sizeof_message`.
+ */
+PROTOBUF_C__API
+void
+protobuf_c_message_init(
+	const ProtobufCMessageDescriptor *descriptor,
+	void *message);
+
+/**
+ * Free a service.
+ *
+ * \param service
+ *      The service object to free.
+ */
+PROTOBUF_C__API
+void
+protobuf_c_service_destroy(ProtobufCService *service);
+
+/**
+ * Look up a `ProtobufCMethodDescriptor` by name.
+ *
+ * \param desc
+ *      Service descriptor.
+ * \param name
+ *      Name of the method.
+ *
+ * \return
+ *      A `ProtobufCMethodDescriptor` object.
+ * \retval NULL
+ *      If not found.
+ */
+PROTOBUF_C__API
+const ProtobufCMethodDescriptor *
+protobuf_c_service_descriptor_get_method_by_name(
+	const ProtobufCServiceDescriptor *desc,
+	const char *name);
+
+/**
+ * Initialise a `ProtobufCBufferSimple` object.
+ */
+#define PROTOBUF_C_BUFFER_SIMPLE_INIT(array_of_bytes)                   \
+{                                                                       \
+	{ protobuf_c_buffer_simple_append },                            \
+	sizeof(array_of_bytes),                                         \
+	0,                                                              \
+	(array_of_bytes),                                               \
+	0,                                                              \
+	NULL                                                            \
+}
+
+/**
+ * Clear a `ProtobufCBufferSimple` object, freeing any allocated memory.
+ */
+#define PROTOBUF_C_BUFFER_SIMPLE_CLEAR(simp_buf)                        \
+do {                                                                    \
+	if ((simp_buf)->must_free_data) {                               \
+		if ((simp_buf)->allocator != NULL)                      \
+			(simp_buf)->allocator->free(                    \
+				(simp_buf)->allocator,                  \
+				(simp_buf)->data);			\
+		else                                                    \
+			free((simp_buf)->data);                         \
+	}                                                               \
+} while (0)
+
+/**
+ * The `append` method for `ProtobufCBufferSimple`.
+ *
+ * \param buffer
+ *      The buffer object to append to. Must actually be a
+ *      `ProtobufCBufferSimple` object.
+ * \param len
+ *      Number of bytes in `data`.
+ * \param data
+ *      Data to append.
+ */
+PROTOBUF_C__API
+void
+protobuf_c_buffer_simple_append(
+	ProtobufCBuffer *buffer,
+	size_t len,
+	const unsigned char *data);
+
+PROTOBUF_C__API
+void
+protobuf_c_service_generated_init(
+	ProtobufCService *service,
+	const ProtobufCServiceDescriptor *descriptor,
+	ProtobufCServiceDestroy destroy);
+
+PROTOBUF_C__API
+void
+protobuf_c_service_invoke_internal(
+	ProtobufCService *service,
+	unsigned method_index,
+	const ProtobufCMessage *input,
+	ProtobufCClosure closure,
+	void *closure_data);
+
+/**@}*/
+
+PROTOBUF_C__END_DECLS
+
+#endif /* PROTOBUF_C_H */