--- /dev/null
+/*
+ * Copyright (C) 2009-2010 Andy Spencer <andy753421@gmail.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/**
+ * SECTION:gis-http
+ * @short_description: Hyper Text Transfer Protocol
+ *
+ * #GisHttp is a small wrapper around libsoup to provide data access using the
+ * Hyper Text Transfer Protocol. Each #GisHttp should be associated with a
+ * particular server or dataset, all the files downloaded for this dataset will
+ * be cached together in $HOME.cache/libgis/
+ */
+
+#include <config.h>
+#include <glib.h>
+#include <glib/gstdio.h>
+#include <libsoup/soup.h>
+
+#include "gis-http.h"
+
+gchar *_get_cache_path(GisHttp *http, const gchar *local)
+{
+ return g_build_filename(g_get_user_cache_dir(), PACKAGE,
+ http->prefix, local, NULL);
+}
+
+/**
+ * gis_http_new:
+ * @prefix: The prefix in the cache to store the downloaded files.
+ * For example: * "/nexrad/level2/".
+ *
+ * Create a new #GisHttp for the given prefix
+ *
+ * Returns: the new #GisHttp
+ */
+GisHttp *gis_http_new(const gchar *prefix)
+{
+ g_debug("GisHttp: new - %s", prefix);
+ GisHttp *http = g_new0(GisHttp, 1);
+ http->soup = soup_session_sync_new();
+ http->prefix = g_strdup(prefix);
+ g_object_set(http->soup, "user-agent", PACKAGE_STRING, NULL);
+ return http;
+}
+
+/**
+ * gis_http_free:
+ * @http: the #GisHttp to free
+ *
+ * Frees resources used by @http and cancels any pending requests.
+ */
+void gis_http_free(GisHttp *http)
+{
+ g_debug("GisHttp: free - %s", http->prefix);
+ soup_session_abort(http->soup);
+ g_object_unref(http->soup);
+ g_free(http->prefix);
+ g_free(http);
+}
+
+/* For passing data to the chunck callback */
+struct _CacheInfo {
+ FILE *fp;
+ gchar *path;
+ GisChunkCallback callback;
+ gpointer user_data;
+};
+struct _CacheInfoMain {
+ gchar *path;
+ GisChunkCallback callback;
+ gpointer user_data;
+ goffset cur, total;
+};
+
+/* call the user callback from the main thread,
+ * since it's usually UI updates */
+static gboolean _chunk_main_cb(gpointer _infomain)
+{
+ struct _CacheInfoMain *infomain = _infomain;
+ infomain->callback(infomain->path,
+ infomain->cur, infomain->total,
+ infomain->user_data);
+ g_free(infomain);
+ return FALSE;
+}
+
+/**
+ * Append data to the file and call the users callback if they supplied one.
+ */
+static void _chunk_cb(SoupMessage *message, SoupBuffer *chunk, gpointer _info)
+{
+ struct _CacheInfo *info = _info;
+
+ if (!SOUP_STATUS_IS_SUCCESSFUL(message->status_code)) {
+ g_warning("GisHttp: _chunk_cb - soup failed with %d",
+ message->status_code);
+ return;
+ }
+
+ if (!fwrite(chunk->data, chunk->length, 1, info->fp))
+ g_error("GisHttp: _chunk_cb - Unable to write data");
+
+ if (info->callback) {
+ struct _CacheInfoMain *infomain = g_new0(struct _CacheInfoMain, 1);
+ infomain->path = info->path;
+ infomain->callback = info->callback;
+ infomain->user_data = info->user_data;
+ infomain->cur = ftell(info->fp);
+ goffset st=0, end=0;
+ soup_message_headers_get_content_range(message->response_headers,
+ &st, &end, &infomain->total);
+ g_idle_add(_chunk_main_cb, infomain);
+ }
+
+}
+
+/**
+ * gis_http_fetch:
+ * @http: the #GisHttp connection to use
+ * @uri: the URI to fetch
+ * @local: the local name to give to the file
+ * @mode: the update type to use when fetching data
+ * @callback: callback to call when a chunk of data is received
+ * @user_data: user data to pass to the callback
+ *
+ * Fetch a file from the cache. Whether the file is actually loaded from the
+ * remote server depends on the value of @mode.
+ *
+ * Returns: The local path to the complete file
+ */
+/* TODO: use .part extentions and continue even when using GIS_ONCE */
+gchar *gis_http_fetch(GisHttp *http, const gchar *uri, const char *local,
+ GisCacheType mode, GisChunkCallback callback, gpointer user_data)
+{
+ g_debug("GisHttp: fetch - %s mode=%d", local, mode);
+ gchar *path = _get_cache_path(http, local);
+
+ /* Unlink the file if we're refreshing it */
+ if (mode == GIS_REFRESH)
+ g_remove(path);
+
+ /* Do the cache if necessasairy */
+ if (!(mode == GIS_ONCE && g_file_test(path, G_FILE_TEST_EXISTS)) &&
+ mode != GIS_LOCAL) {
+ g_debug("GisHttp: fetch - Caching file %s", local);
+
+ /* Open the file for writting */
+ gchar *part = path;
+ if (!g_file_test(path, G_FILE_TEST_EXISTS))
+ part = g_strdup_printf("%s.part", path);
+ FILE *fp = fopen_p(part, "ab");
+ fseek(fp, 0, SEEK_END); // "a" is broken on Windows, twice
+
+ /* Make temp data */
+ struct _CacheInfo info = {
+ .fp = fp,
+ .path = path,
+ .callback = callback,
+ .user_data = user_data,
+ };
+
+ /* Download the file */
+ SoupMessage *message = soup_message_new("GET", uri);
+ if (message == NULL)
+ g_error("message is null, cannot parse uri");
+ g_signal_connect(message, "got-chunk", G_CALLBACK(_chunk_cb), &info);
+ soup_message_headers_set_range(message->request_headers, ftell(fp), -1);
+ soup_session_send_message(http->soup, message);
+
+ /* Close file */
+ fclose(fp);
+ if (path != part && SOUP_STATUS_IS_SUCCESSFUL(message->status_code)) {
+ g_rename(part, path);
+ g_free(part);
+ }
+
+ /* Finished */
+ if (message->status_code == 416) {
+ /* Range unsatisfiable, file already complete */
+ } else if (!SOUP_STATUS_IS_SUCCESSFUL(message->status_code)) {
+ g_warning("GisHttp: done_cb - error copying file, status=%d\n"
+ "\tsrc=%s\n"
+ "\tdst=%s",
+ message->status_code, uri, path);
+ return NULL;
+ }
+ }
+
+
+ /* TODO: free everything.. */
+ return path;
+}
+
+/**
+ * gis_http_available:
+ * @http: the #GisHttp connection to use
+ * @filter: filter used to extract files from the index, or NULL
+ * For example: "href=\"([^"]*)\""
+ * @cache: path to the local cache, or NULL to not search the cache
+ * @extract: regex used to extract filenames from the page, should match the
+ * filename as $1, or NULL to use /http="([^"])"/
+ * @index: path to the index page, or NULL to not search online
+ *
+ * Look through the cache and an HTTP index page for a list of available files.
+ * The name of each file that matches the filter is added to the returned list.
+ *
+ * The list as well as the strings contained in it should be freed afterwards.
+ *
+ * Returns the list of matching filenames
+ */
+GList *gis_http_available(GisHttp *http,
+ gchar *filter, gchar *cache,
+ gchar *extract, gchar *index)
+{
+ g_debug("GisHttp: available - %s~=%s %s~=%s",
+ filter, cache, extract, index);
+ GRegex *filter_re = g_regex_new(filter, 0, 0, NULL);
+ GList *files = NULL;
+
+ /* Add cached files */
+ if (cache) {
+ const gchar *file;
+ gchar *path = _get_cache_path(http, cache);
+ GDir *dir = g_dir_open(path, 0, NULL);
+ while ((file = g_dir_read_name(dir)))
+ if (g_regex_match(filter_re, file, 0, NULL))
+ files = g_list_prepend(files, g_strdup(file));
+ g_free(path);
+ g_dir_close(dir);
+ }
+
+ /* Add online files if online */
+ if (index) {
+ gchar tmp[32];
+ g_snprintf(tmp, sizeof(tmp), ".index.%x", g_random_int());
+ gchar *path = gis_http_fetch(http, index, tmp,
+ GIS_REFRESH, NULL, NULL);
+ if (!path)
+ return files;
+ gchar *html;
+ g_file_get_contents(path, &html, NULL, NULL);
+ if (!html)
+ return files;
+
+ /* Match hrefs by default, this regex is not very accurate */
+ GRegex *extract_re = g_regex_new(
+ extract ?: "href=\"([^\"]*)\"", 0, 0, NULL);
+ GMatchInfo *info;
+ g_regex_match(extract_re, html, 0, &info);
+ while (g_match_info_matches(info)) {
+ gchar *file = g_match_info_fetch(info, 1);
+ if (file) {
+ if (g_regex_match(filter_re, file, 0, NULL))
+ files = g_list_prepend(files, file);
+ else
+ g_free(file);
+ }
+ g_match_info_next(info, NULL);
+ }
+
+ g_regex_unref(extract_re);
+ g_match_info_free(info);
+ g_unlink(path);
+ g_free(path);
+ g_free(html);
+ }
+
+ g_regex_unref(filter_re);
+
+ return files;
+}
projects / grits / blobdiff