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Diffstat (limited to 'libs/libevent/include/event2/rpc.h')
| -rw-r--r-- | libs/libevent/include/event2/rpc.h | 596 |
1 files changed, 0 insertions, 596 deletions
diff --git a/libs/libevent/include/event2/rpc.h b/libs/libevent/include/event2/rpc.h deleted file mode 100644 index dd43df266a..0000000000 --- a/libs/libevent/include/event2/rpc.h +++ /dev/null @@ -1,596 +0,0 @@ -/* - * Copyright (c) 2006-2007 Niels Provos <provos@citi.umich.edu> - * Copyright (c) 2007-2012 Niels Provos and Nick Mathewson - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * 1. Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * 2. 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. - * 3. The name of the author may not be used to endorse or promote products - * derived from this software without specific prior written permission. - * - * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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. - */ -#ifndef EVENT2_RPC_H_INCLUDED_ -#define EVENT2_RPC_H_INCLUDED_ - -#ifdef __cplusplus -extern "C" { -#endif - -/** @file rpc.h - * - * This header files provides basic support for an RPC server and client. - * - * To support RPCs in a server, every supported RPC command needs to be - * defined and registered. - * - * EVRPC_HEADER(SendCommand, Request, Reply); - * - * SendCommand is the name of the RPC command. - * Request is the name of a structure generated by event_rpcgen.py. - * It contains all parameters relating to the SendCommand RPC. The - * server needs to fill in the Reply structure. - * Reply is the name of a structure generated by event_rpcgen.py. It - * contains the answer to the RPC. - * - * To register an RPC with an HTTP server, you need to first create an RPC - * base with: - * - * struct evrpc_base *base = evrpc_init(http); - * - * A specific RPC can then be registered with - * - * EVRPC_REGISTER(base, SendCommand, Request, Reply, FunctionCB, arg); - * - * when the server receives an appropriately formatted RPC, the user callback - * is invoked. The callback needs to fill in the reply structure. - * - * void FunctionCB(EVRPC_STRUCT(SendCommand)* rpc, void *arg); - * - * To send the reply, call EVRPC_REQUEST_DONE(rpc); - * - * See the regression test for an example. - */ - -/** - Determines if the member has been set in the message - - @param msg the message to inspect - @param member the member variable to test for presences - @return 1 if it's present or 0 otherwise. -*/ -#define EVTAG_HAS(msg, member) \ - ((msg)->member##_set == 1) - -#ifndef EVENT2_RPC_COMPAT_H_INCLUDED_ - -/** - Assigns a value to the member in the message. - - @param msg the message to which to assign a value - @param member the name of the member variable - @param value the value to assign -*/ -#define EVTAG_ASSIGN(msg, member, value) \ - (*(msg)->base->member##_assign)((msg), (value)) -/** - Assigns a value to the member in the message. - - @param msg the message to which to assign a value - @param member the name of the member variable - @param value the value to assign - @param len the length of the value -*/ -#define EVTAG_ASSIGN_WITH_LEN(msg, member, value, len) \ - (*(msg)->base->member##_assign)((msg), (value), (len)) -/** - Returns the value for a member. - - @param msg the message from which to get the value - @param member the name of the member variable - @param pvalue a pointer to the variable to hold the value - @return 0 on success, -1 otherwise. -*/ -#define EVTAG_GET(msg, member, pvalue) \ - (*(msg)->base->member##_get)((msg), (pvalue)) -/** - Returns the value for a member. - - @param msg the message from which to get the value - @param member the name of the member variable - @param pvalue a pointer to the variable to hold the value - @param plen a pointer to the length of the value - @return 0 on success, -1 otherwise. -*/ -#define EVTAG_GET_WITH_LEN(msg, member, pvalue, plen) \ - (*(msg)->base->member##_get)((msg), (pvalue), (plen)) - -#endif /* EVENT2_RPC_COMPAT_H_INCLUDED_ */ - -/** - Adds a value to an array. -*/ -#define EVTAG_ARRAY_ADD_VALUE(msg, member, value) \ - (*(msg)->base->member##_add)((msg), (value)) -/** - Allocates a new entry in the array and returns it. -*/ -#define EVTAG_ARRAY_ADD(msg, member) \ - (*(msg)->base->member##_add)(msg) -/** - Gets a variable at the specified offset from the array. -*/ -#define EVTAG_ARRAY_GET(msg, member, offset, pvalue) \ - (*(msg)->base->member##_get)((msg), (offset), (pvalue)) -/** - Returns the number of entries in the array. -*/ -#define EVTAG_ARRAY_LEN(msg, member) ((msg)->member##_length) - - -struct evbuffer; -struct event_base; -struct evrpc_req_generic; -struct evrpc_request_wrapper; -struct evrpc; - -/** The type of a specific RPC Message - * - * @param rpcname the name of the RPC message - */ -#define EVRPC_STRUCT(rpcname) struct evrpc_req__##rpcname - -struct evhttp_request; -struct evrpc_status; -struct evrpc_hook_meta; - -/** Creates the definitions and prototypes for an RPC - * - * You need to use EVRPC_HEADER to create structures and function prototypes - * needed by the server and client implementation. The structures have to be - * defined in an .rpc file and converted to source code via event_rpcgen.py - * - * @param rpcname the name of the RPC - * @param reqstruct the name of the RPC request structure - * @param replystruct the name of the RPC reply structure - * @see EVRPC_GENERATE() - */ -#define EVRPC_HEADER(rpcname, reqstruct, rplystruct) \ -EVRPC_STRUCT(rpcname) { \ - struct evrpc_hook_meta *hook_meta; \ - struct reqstruct* request; \ - struct rplystruct* reply; \ - struct evrpc* rpc; \ - struct evhttp_request* http_req; \ - struct evbuffer* rpc_data; \ -}; \ -int evrpc_send_request_##rpcname(struct evrpc_pool *, \ - struct reqstruct *, struct rplystruct *, \ - void (*)(struct evrpc_status *, \ - struct reqstruct *, struct rplystruct *, void *cbarg), \ - void *); - -struct evrpc_pool; - -/** use EVRPC_GENERATE instead */ -struct evrpc_request_wrapper *evrpc_make_request_ctx( - struct evrpc_pool *pool, void *request, void *reply, - const char *rpcname, - void (*req_marshal)(struct evbuffer*, void *), - void (*rpl_clear)(void *), - int (*rpl_unmarshal)(void *, struct evbuffer *), - void (*cb)(struct evrpc_status *, void *, void *, void *), - void *cbarg); - -/** Creates a context structure that contains rpc specific information. - * - * EVRPC_MAKE_CTX is used to populate a RPC specific context that - * contains information about marshaling the RPC data types. - * - * @param rpcname the name of the RPC - * @param reqstruct the name of the RPC request structure - * @param replystruct the name of the RPC reply structure - * @param pool the evrpc_pool over which to make the request - * @param request a pointer to the RPC request structure object - * @param reply a pointer to the RPC reply structure object - * @param cb the callback function to call when the RPC has completed - * @param cbarg the argument to supply to the callback - */ -#define EVRPC_MAKE_CTX(rpcname, reqstruct, rplystruct, \ - pool, request, reply, cb, cbarg) \ - evrpc_make_request_ctx(pool, request, reply, \ - #rpcname, \ - (void (*)(struct evbuffer *, void *))reqstruct##_marshal, \ - (void (*)(void *))rplystruct##_clear, \ - (int (*)(void *, struct evbuffer *))rplystruct##_unmarshal, \ - (void (*)(struct evrpc_status *, void *, void *, void *))cb, \ - cbarg) - -/** Generates the code for receiving and sending an RPC message - * - * EVRPC_GENERATE is used to create the code corresponding to sending - * and receiving a particular RPC message - * - * @param rpcname the name of the RPC - * @param reqstruct the name of the RPC request structure - * @param replystruct the name of the RPC reply structure - * @see EVRPC_HEADER() - */ -#define EVRPC_GENERATE(rpcname, reqstruct, rplystruct) \ - int evrpc_send_request_##rpcname(struct evrpc_pool *pool, \ - struct reqstruct *request, struct rplystruct *reply, \ - void (*cb)(struct evrpc_status *, \ - struct reqstruct *, struct rplystruct *, void *cbarg), \ - void *cbarg) { \ - return evrpc_send_request_generic(pool, request, reply, \ - (void (*)(struct evrpc_status *, void *, void *, void *))cb, \ - cbarg, \ - #rpcname, \ - (void (*)(struct evbuffer *, void *))reqstruct##_marshal, \ - (void (*)(void *))rplystruct##_clear, \ - (int (*)(void *, struct evbuffer *))rplystruct##_unmarshal); \ -} - -/** Provides access to the HTTP request object underlying an RPC - * - * Access to the underlying http object; can be used to look at headers or - * for getting the remote ip address - * - * @param rpc_req the rpc request structure provided to the server callback - * @return an struct evhttp_request object that can be inspected for - * HTTP headers or sender information. - */ -#define EVRPC_REQUEST_HTTP(rpc_req) (rpc_req)->http_req - -/** completes the server response to an rpc request */ -void evrpc_request_done(struct evrpc_req_generic *req); - -/** accessors for request and reply */ -void *evrpc_get_request(struct evrpc_req_generic *req); -void *evrpc_get_reply(struct evrpc_req_generic *req); - -/** Creates the reply to an RPC request - * - * EVRPC_REQUEST_DONE is used to answer a request; the reply is expected - * to have been filled in. The request and reply pointers become invalid - * after this call has finished. - * - * @param rpc_req the rpc request structure provided to the server callback - */ -#define EVRPC_REQUEST_DONE(rpc_req) do { \ - struct evrpc_req_generic *req_ = (struct evrpc_req_generic *)(rpc_req); \ - evrpc_request_done(req_); \ -} while (0) - - -struct evrpc_base; -struct evhttp; - -/* functions to start up the rpc system */ - -/** Creates a new rpc base from which RPC requests can be received - * - * @param server a pointer to an existing HTTP server - * @return a newly allocated evrpc_base struct - * @see evrpc_free() - */ -struct evrpc_base *evrpc_init(struct evhttp *server); - -/** - * Frees the evrpc base - * - * For now, you are responsible for making sure that no rpcs are ongoing. - * - * @param base the evrpc_base object to be freed - * @see evrpc_init - */ -void evrpc_free(struct evrpc_base *base); - -/** register RPCs with the HTTP Server - * - * registers a new RPC with the HTTP server, each RPC needs to have - * a unique name under which it can be identified. - * - * @param base the evrpc_base structure in which the RPC should be - * registered. - * @param name the name of the RPC - * @param request the name of the RPC request structure - * @param reply the name of the RPC reply structure - * @param callback the callback that should be invoked when the RPC - * is received. The callback has the following prototype - * void (*callback)(EVRPC_STRUCT(Message)* rpc, void *arg) - * @param cbarg an additional parameter that can be passed to the callback. - * The parameter can be used to carry around state. - */ -#define EVRPC_REGISTER(base, name, request, reply, callback, cbarg) \ - evrpc_register_generic(base, #name, \ - (void (*)(struct evrpc_req_generic *, void *))callback, cbarg, \ - (void *(*)(void *))request##_new, NULL, \ - (void (*)(void *))request##_free, \ - (int (*)(void *, struct evbuffer *))request##_unmarshal, \ - (void *(*)(void *))reply##_new, NULL, \ - (void (*)(void *))reply##_free, \ - (int (*)(void *))reply##_complete, \ - (void (*)(struct evbuffer *, void *))reply##_marshal) - -/** - Low level function for registering an RPC with a server. - - Use EVRPC_REGISTER() instead. - - @see EVRPC_REGISTER() -*/ -int evrpc_register_rpc(struct evrpc_base *, struct evrpc *, - void (*)(struct evrpc_req_generic*, void *), void *); - -/** - * Unregisters an already registered RPC - * - * @param base the evrpc_base object from which to unregister an RPC - * @param name the name of the rpc to unregister - * @return -1 on error or 0 when successful. - * @see EVRPC_REGISTER() - */ -#define EVRPC_UNREGISTER(base, name) evrpc_unregister_rpc((base), #name) - -int evrpc_unregister_rpc(struct evrpc_base *base, const char *name); - -/* - * Client-side RPC support - */ - -struct evhttp_connection; -struct evrpc_status; - -/** launches an RPC and sends it to the server - * - * EVRPC_MAKE_REQUEST() is used by the client to send an RPC to the server. - * - * @param name the name of the RPC - * @param pool the evrpc_pool that contains the connection objects over which - * the request should be sent. - * @param request a pointer to the RPC request structure - it contains the - * data to be sent to the server. - * @param reply a pointer to the RPC reply structure. It is going to be filled - * if the request was answered successfully - * @param cb the callback to invoke when the RPC request has been answered - * @param cbarg an additional argument to be passed to the client - * @return 0 on success, -1 on failure - */ -#define EVRPC_MAKE_REQUEST(name, pool, request, reply, cb, cbarg) \ - evrpc_send_request_##name((pool), (request), (reply), (cb), (cbarg)) - -/** - Makes an RPC request based on the provided context. - - This is a low-level function and should not be used directly - unless a custom context object is provided. Use EVRPC_MAKE_REQUEST() - instead. - - @param ctx a context from EVRPC_MAKE_CTX() - @returns 0 on success, -1 otherwise. - @see EVRPC_MAKE_REQUEST(), EVRPC_MAKE_CTX() -*/ -int evrpc_make_request(struct evrpc_request_wrapper *ctx); - -/** creates an rpc connection pool - * - * a pool has a number of connections associated with it. - * rpc requests are always made via a pool. - * - * @param base a pointer to an struct event_based object; can be left NULL - * in singled-threaded applications - * @return a newly allocated struct evrpc_pool object - * @see evrpc_pool_free() - */ -struct evrpc_pool *evrpc_pool_new(struct event_base *base); -/** frees an rpc connection pool - * - * @param pool a pointer to an evrpc_pool allocated via evrpc_pool_new() - * @see evrpc_pool_new() - */ -void evrpc_pool_free(struct evrpc_pool *pool); - -/** - * Adds a connection over which rpc can be dispatched to the pool. - * - * The connection object must have been newly created. - * - * @param pool the pool to which to add the connection - * @param evcon the connection to add to the pool. - */ -void evrpc_pool_add_connection(struct evrpc_pool *pool, - struct evhttp_connection *evcon); - -/** - * Removes a connection from the pool. - * - * The connection object must have been newly created. - * - * @param pool the pool from which to remove the connection - * @param evcon the connection to remove from the pool. - */ -void evrpc_pool_remove_connection(struct evrpc_pool *pool, - struct evhttp_connection *evcon); - -/** - * Sets the timeout in secs after which a request has to complete. The - * RPC is completely aborted if it does not complete by then. Setting - * the timeout to 0 means that it never timeouts and can be used to - * implement callback type RPCs. - * - * Any connection already in the pool will be updated with the new - * timeout. Connections added to the pool after set_timeout has be - * called receive the pool timeout only if no timeout has been set - * for the connection itself. - * - * @param pool a pointer to a struct evrpc_pool object - * @param timeout_in_secs the number of seconds after which a request should - * timeout and a failure be returned to the callback. - */ -void evrpc_pool_set_timeout(struct evrpc_pool *pool, int timeout_in_secs); - -/** - * Hooks for changing the input and output of RPCs; this can be used to - * implement compression, authentication, encryption, ... - */ - -enum EVRPC_HOOK_TYPE { - EVRPC_INPUT, /**< apply the function to an input hook */ - EVRPC_OUTPUT /**< apply the function to an output hook */ -}; - -#ifndef _WIN32 -/** Deprecated alias for EVRPC_INPUT. Not available on windows, where it - * conflicts with platform headers. */ -#define INPUT EVRPC_INPUT -/** Deprecated alias for EVRPC_OUTPUT. Not available on windows, where it - * conflicts with platform headers. */ -#define OUTPUT EVRPC_OUTPUT -#endif - -/** - * Return value from hook processing functions - */ - -enum EVRPC_HOOK_RESULT { - EVRPC_TERMINATE = -1, /**< indicates the rpc should be terminated */ - EVRPC_CONTINUE = 0, /**< continue processing the rpc */ - EVRPC_PAUSE = 1 /**< pause processing request until resumed */ -}; - -/** adds a processing hook to either an rpc base or rpc pool - * - * If a hook returns TERMINATE, the processing is aborted. On CONTINUE, - * the request is immediately processed after the hook returns. If the - * hook returns PAUSE, request processing stops until evrpc_resume_request() - * has been called. - * - * The add functions return handles that can be used for removing hooks. - * - * @param vbase a pointer to either struct evrpc_base or struct evrpc_pool - * @param hook_type either INPUT or OUTPUT - * @param cb the callback to call when the hook is activated - * @param cb_arg an additional argument for the callback - * @return a handle to the hook so it can be removed later - * @see evrpc_remove_hook() - */ -void *evrpc_add_hook(void *vbase, - enum EVRPC_HOOK_TYPE hook_type, - int (*cb)(void *, struct evhttp_request *, struct evbuffer *, void *), - void *cb_arg); - -/** removes a previously added hook - * - * @param vbase a pointer to either struct evrpc_base or struct evrpc_pool - * @param hook_type either INPUT or OUTPUT - * @param handle a handle returned by evrpc_add_hook() - * @return 1 on success or 0 on failure - * @see evrpc_add_hook() - */ -int evrpc_remove_hook(void *vbase, - enum EVRPC_HOOK_TYPE hook_type, - void *handle); - -/** resume a paused request - * - * @param vbase a pointer to either struct evrpc_base or struct evrpc_pool - * @param ctx the context pointer provided to the original hook call - */ -int -evrpc_resume_request(void *vbase, void *ctx, enum EVRPC_HOOK_RESULT res); - -/** adds meta data to request - * - * evrpc_hook_add_meta() allows hooks to add meta data to a request. for - * a client request, the meta data can be inserted by an outgoing request hook - * and retrieved by the incoming request hook. - * - * @param ctx the context provided to the hook call - * @param key a NUL-terminated c-string - * @param data the data to be associated with the key - * @param data_size the size of the data - */ -void evrpc_hook_add_meta(void *ctx, const char *key, - const void *data, size_t data_size); - -/** retrieves meta data previously associated - * - * evrpc_hook_find_meta() can be used to retrieve meta data associated to a - * request by a previous hook. - * @param ctx the context provided to the hook call - * @param key a NUL-terminated c-string - * @param data pointer to a data pointer that will contain the retrieved data - * @param data_size pointer to the size of the data - * @return 0 on success or -1 on failure - */ -int evrpc_hook_find_meta(void *ctx, const char *key, - void **data, size_t *data_size); - -/** - * returns the connection object associated with the request - * - * @param ctx the context provided to the hook call - * @return a pointer to the evhttp_connection object - */ -struct evhttp_connection *evrpc_hook_get_connection(void *ctx); - -/** - Function for sending a generic RPC request. - - Do not call this function directly, use EVRPC_MAKE_REQUEST() instead. - - @see EVRPC_MAKE_REQUEST() - */ -int evrpc_send_request_generic(struct evrpc_pool *pool, - void *request, void *reply, - void (*cb)(struct evrpc_status *, void *, void *, void *), - void *cb_arg, - const char *rpcname, - void (*req_marshal)(struct evbuffer *, void *), - void (*rpl_clear)(void *), - int (*rpl_unmarshal)(void *, struct evbuffer *)); - -/** - Function for registering a generic RPC with the RPC base. - - Do not call this function directly, use EVRPC_REGISTER() instead. - - @see EVRPC_REGISTER() - */ -int -evrpc_register_generic(struct evrpc_base *base, const char *name, - void (*callback)(struct evrpc_req_generic *, void *), void *cbarg, - void *(*req_new)(void *), void *req_new_arg, void (*req_free)(void *), - int (*req_unmarshal)(void *, struct evbuffer *), - void *(*rpl_new)(void *), void *rpl_new_arg, void (*rpl_free)(void *), - int (*rpl_complete)(void *), - void (*rpl_marshal)(struct evbuffer *, void *)); - -/** accessors for obscure and undocumented functionality */ -struct evrpc_pool* evrpc_request_get_pool(struct evrpc_request_wrapper *ctx); -void evrpc_request_set_pool(struct evrpc_request_wrapper *ctx, - struct evrpc_pool *pool); -void evrpc_request_set_cb(struct evrpc_request_wrapper *ctx, - void (*cb)(struct evrpc_status*, void *request, void *reply, void *arg), - void *cb_arg); - -#ifdef __cplusplus -} -#endif - -#endif /* EVENT2_RPC_H_INCLUDED_ */ |