common: llama_load_model_from_url using --model-url (#6098)

* common: llama_load_model_from_url with libcurl dependency

Co-authored-by: Georgi Gerganov <ggerganov@gmail.com>

1 files changed, 237 insertions, 1 deletions

diff --git a/common/common.cpp b/common/common.cpp
index 1b0ba849..2f5d965d 100644
--- a/common/common.cpp
+++ b/common/common.cpp
@@ -37,6 +37,9 @@
 #include <sys/stat.h>
 #include <unistd.h>
 #endif
+#if defined(LLAMA_USE_CURL)
+#include <curl/curl.h>
+#endif
 
 #if defined(_MSC_VER)
 #pragma warning(disable: 4244 4267) // possible loss of data
@@ -50,6 +53,18 @@
 #define GGML_USE_CUBLAS_SYCL_VULKAN
 #endif
 
+#if defined(LLAMA_USE_CURL)
+#ifdef __linux__
+#include <linux/limits.h>
+#elif defined(_WIN32)
+#define PATH_MAX MAX_PATH
+#else
+#include <sys/syslimits.h>
+#endif
+#define LLAMA_CURL_MAX_PATH_LENGTH PATH_MAX
+#define LLAMA_CURL_MAX_HEADER_LENGTH 256
+#endif // LLAMA_USE_CURL
+
 int32_t get_num_physical_cores() {
 #ifdef __linux__
     // enumerate the set of thread siblings, num entries is num cores
@@ -644,6 +659,13 @@ bool gpt_params_parse_ex(int argc, char ** argv, gpt_params & params) {
             }
             params.model = argv[i];
         }
+        if (arg == "-mu" || arg == "--model-url") {
+            if (++i >= argc) {
+                invalid_param = true;
+                break;
+            }
+            params.model_url = argv[i];
+        }
         if (arg == "-md" || arg == "--model-draft") {
             arg_found = true;
             if (++i >= argc) {
@@ -1368,6 +1390,8 @@ void gpt_print_usage(int /*argc*/, char ** argv, const gpt_params & params) {
     printf("                        layer range to apply the control vector(s) to, start and end inclusive\n");
     printf("  -m FNAME, --model FNAME\n");
     printf("                        model path (default: %s)\n", params.model.c_str());
+    printf("  -mu MODEL_URL, --model-url MODEL_URL\n");
+    printf("                        model download url (default: %s)\n", params.model_url.c_str());
     printf("  -md FNAME, --model-draft FNAME\n");
     printf("                        draft model for speculative decoding\n");
     printf("  -ld LOGDIR, --logdir LOGDIR\n");
@@ -1613,10 +1637,222 @@ void llama_batch_add(
     batch.n_tokens++;
 }
 
+#ifdef LLAMA_USE_CURL
+
+struct llama_model * llama_load_model_from_url(const char * model_url, const char * path_model,
+                                              struct llama_model_params params) {
+    // Basic validation of the model_url
+    if (!model_url || strlen(model_url) == 0) {
+        fprintf(stderr, "%s: invalid model_url\n", __func__);
+        return NULL;
+    }
+
+    // Initialize libcurl globally
+    auto curl = curl_easy_init();
+
+    if (!curl) {
+        fprintf(stderr, "%s: error initializing libcurl\n", __func__);
+        return NULL;
+    }
+
+    // Set the URL, allow to follow http redirection
+    curl_easy_setopt(curl, CURLOPT_URL, model_url);
+    curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);
+#if defined(_WIN32)
+    // CURLSSLOPT_NATIVE_CA tells libcurl to use standard certificate store of
+    //   operating system. Currently implemented under MS-Windows.
+    curl_easy_setopt(curl, CURLOPT_SSL_OPTIONS, CURLSSLOPT_NATIVE_CA);
+#endif
+
+    // Check if the file already exists locally
+    struct stat model_file_info;
+    auto file_exists = (stat(path_model, &model_file_info) == 0);
+
+    // If the file exists, check for ${path_model}.etag or ${path_model}.lastModified files
+    char etag[LLAMA_CURL_MAX_HEADER_LENGTH] = {0};
+    char etag_path[LLAMA_CURL_MAX_PATH_LENGTH] = {0};
+    snprintf(etag_path, sizeof(etag_path), "%s.etag", path_model);
+
+    char last_modified[LLAMA_CURL_MAX_HEADER_LENGTH] = {0};
+    char last_modified_path[LLAMA_CURL_MAX_PATH_LENGTH] = {0};
+    snprintf(last_modified_path, sizeof(last_modified_path), "%s.lastModified", path_model);
+
+    if (file_exists) {
+        auto * f_etag = fopen(etag_path, "r");
+        if (f_etag) {
+            if (!fgets(etag, sizeof(etag), f_etag)) {
+                fprintf(stderr, "%s: unable to read file %s\n", __func__, etag_path);
+            } else {
+                fprintf(stderr, "%s: previous model file found %s: %s\n", __func__, etag_path, etag);
+            }
+            fclose(f_etag);
+        }
+
+        auto * f_last_modified = fopen(last_modified_path, "r");
+        if (f_last_modified) {
+            if (!fgets(last_modified, sizeof(last_modified), f_last_modified)) {
+                fprintf(stderr, "%s: unable to read file %s\n", __func__, last_modified_path);
+            } else {
+                fprintf(stderr, "%s: previous model file found %s: %s\n", __func__, last_modified_path,
+                        last_modified);
+            }
+            fclose(f_last_modified);
+        }
+    }
+
+    // Send a HEAD request to retrieve the etag and last-modified headers
+    struct llama_load_model_from_url_headers {
+        char etag[LLAMA_CURL_MAX_HEADER_LENGTH] = {0};
+        char last_modified[LLAMA_CURL_MAX_HEADER_LENGTH] = {0};
+    };
+    llama_load_model_from_url_headers headers;
+    {
+        typedef size_t(*CURLOPT_HEADERFUNCTION_PTR)(char *, size_t, size_t, void *);
+        auto header_callback = [](char * buffer, size_t /*size*/, size_t n_items, void * userdata) -> size_t {
+            llama_load_model_from_url_headers *headers = (llama_load_model_from_url_headers *) userdata;
+
+            const char * etag_prefix = "etag: ";
+            if (strncmp(buffer, etag_prefix, strlen(etag_prefix)) == 0) {
+                strncpy(headers->etag, buffer + strlen(etag_prefix), n_items - strlen(etag_prefix) - 2); // Remove CRLF
+            }
+
+            const char * last_modified_prefix = "last-modified: ";
+            if (strncmp(buffer, last_modified_prefix, strlen(last_modified_prefix)) == 0) {
+                strncpy(headers->last_modified, buffer + strlen(last_modified_prefix),
+                        n_items - strlen(last_modified_prefix) - 2); // Remove CRLF
+            }
+            return n_items;
+        };
+
+        curl_easy_setopt(curl, CURLOPT_NOBODY, 1L); // will trigger the HEAD verb
+        curl_easy_setopt(curl, CURLOPT_NOPROGRESS, 1L); // hide head request progress
+        curl_easy_setopt(curl, CURLOPT_HEADERFUNCTION, static_cast<CURLOPT_HEADERFUNCTION_PTR>(header_callback));
+        curl_easy_setopt(curl, CURLOPT_HEADERDATA, &headers);
+
+        CURLcode res = curl_easy_perform(curl);
+        if (res != CURLE_OK) {
+            curl_easy_cleanup(curl);
+            fprintf(stderr, "%s: curl_easy_perform() failed: %s\n", __func__, curl_easy_strerror(res));
+            return NULL;
+        }
+
+        long http_code = 0;
+        curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE, &http_code);
+        if (http_code != 200) {
+            // HEAD not supported, we don't know if the file has changed
+            // force trigger downloading
+            file_exists = false;
+            fprintf(stderr, "%s: HEAD invalid http status code received: %ld\n", __func__, http_code);
+        }
+    }
+
+    // If the ETag or the Last-Modified headers are different: trigger a new download
+    if (!file_exists || strcmp(etag, headers.etag) != 0 || strcmp(last_modified, headers.last_modified) != 0) {
+        char path_model_temporary[LLAMA_CURL_MAX_PATH_LENGTH] = {0};
+        snprintf(path_model_temporary, sizeof(path_model_temporary), "%s.downloadInProgress", path_model);
+        if (file_exists) {
+            fprintf(stderr, "%s: deleting previous downloaded model file: %s\n", __func__, path_model);
+            if (remove(path_model) != 0) {
+                curl_easy_cleanup(curl);
+                fprintf(stderr, "%s: unable to delete file: %s\n", __func__, path_model);
+                return NULL;
+            }
+        }
+
+        // Set the output file
+        auto * outfile = fopen(path_model_temporary, "wb");
+        if (!outfile) {
+            curl_easy_cleanup(curl);
+            fprintf(stderr, "%s: error opening local file for writing: %s\n", __func__, path_model);
+            return NULL;
+        }
+
+        typedef size_t(*CURLOPT_WRITEFUNCTION_PTR)(void * data, size_t size, size_t nmemb, void * fd);
+        auto write_callback = [](void * data, size_t size, size_t nmemb, void * fd) -> size_t {
+            return fwrite(data, size, nmemb, (FILE *)fd);
+        };
+        curl_easy_setopt(curl, CURLOPT_NOBODY, 0L);
+        curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, static_cast<CURLOPT_WRITEFUNCTION_PTR>(write_callback));
+        curl_easy_setopt(curl, CURLOPT_WRITEDATA, outfile);
+
+        //  display download progress
+        curl_easy_setopt(curl, CURLOPT_NOPROGRESS, 0L);
+
+        // start the download
+        fprintf(stderr, "%s: downloading model from %s to %s (server_etag:%s, server_last_modified:%s)...\n", __func__,
+                model_url, path_model, headers.etag, headers.last_modified);
+        auto res = curl_easy_perform(curl);
+        if (res != CURLE_OK) {
+            fclose(outfile);
+            curl_easy_cleanup(curl);
+            fprintf(stderr, "%s: curl_easy_perform() failed: %s\n", __func__, curl_easy_strerror(res));
+            return NULL;
+        }
+
+        long http_code = 0;
+        curl_easy_getinfo (curl, CURLINFO_RESPONSE_CODE, &http_code);
+        if (http_code < 200 || http_code >= 400) {
+            fclose(outfile);
+            curl_easy_cleanup(curl);
+            fprintf(stderr, "%s: invalid http status code received: %ld\n", __func__, http_code);
+            return NULL;
+        }
+
+        // Clean up
+        fclose(outfile);
+
+        // Write the new ETag to the .etag file
+        if (strlen(headers.etag) > 0) {
+            auto * etag_file = fopen(etag_path, "w");
+            if (etag_file) {
+                fputs(headers.etag, etag_file);
+                fclose(etag_file);
+                fprintf(stderr, "%s: model etag saved %s: %s\n", __func__, etag_path, headers.etag);
+            }
+        }
+
+        // Write the new lastModified to the .etag file
+        if (strlen(headers.last_modified) > 0) {
+            auto * last_modified_file = fopen(last_modified_path, "w");
+            if (last_modified_file) {
+                fputs(headers.last_modified, last_modified_file);
+                fclose(last_modified_file);
+                fprintf(stderr, "%s: model last modified saved %s: %s\n", __func__, last_modified_path,
+                        headers.last_modified);
+            }
+        }
+
+        if (rename(path_model_temporary, path_model) != 0) {
+            curl_easy_cleanup(curl);
+            fprintf(stderr, "%s: unable to rename file: %s to %s\n", __func__, path_model_temporary, path_model);
+            return NULL;
+        }
+    }
+
+    curl_easy_cleanup(curl);
+
+    return llama_load_model_from_file(path_model, params);
+}
+
+#else
+
+struct llama_model * llama_load_model_from_url(const char * /*model_url*/, const char * /*path_model*/,
+                                              struct llama_model_params /*params*/) {
+    fprintf(stderr, "%s: llama.cpp built without libcurl, downloading from an url not supported.\n", __func__);
+    return nullptr;
+}
+
+#endif // LLAMA_USE_CURL
+
 std::tuple<struct llama_model *, struct llama_context *> llama_init_from_gpt_params(gpt_params & params) {
     auto mparams = llama_model_params_from_gpt_params(params);
 
-    llama_model * model  = llama_load_model_from_file(params.model.c_str(), mparams);
+    llama_model * model = nullptr;
+    if (!params.model_url.empty()) {
+        model = llama_load_model_from_url(params.model_url.c_str(), params.model.c_str(), mparams);
+    } else {
+        model = llama_load_model_from_file(params.model.c_str(), mparams);
+    }
     if (model == NULL) {
         fprintf(stderr, "%s: error: failed to load model '%s'\n", __func__, params.model.c_str());
         return std::make_tuple(nullptr, nullptr);