Add bt_plugin_create_from_name()

[babeltrace.git] / lib / plugin / plugin.c

diff --git a/lib/plugin/plugin.c b/lib/plugin/plugin.c
index ce3a866f18935d0e4f803980a06dbdc249adf020..0e62889030a63f229a08d7811191caa42e9efb9c 100644 (file)
--- a/lib/plugin/plugin.c
+++ b/lib/plugin/plugin.c
@@ -29,6 +29,7 @@
 
 #include <babeltrace/compiler.h>
 #include <babeltrace/ref.h>
+#include <babeltrace/common-internal.h>
 #include <babeltrace/plugin/plugin-internal.h>
 #include <babeltrace/plugin/plugin-so-internal.h>
 #include <glib.h>
@@ -180,6 +181,139 @@ end:
        return plugins;
 }
 
+static void destroy_gstring(void *data)
+{
+       g_string_free(data, TRUE);
+}
+
+void free_plugins(struct bt_plugin **plugins) {
+       if (plugins) {
+               struct bt_plugin **cur_plugin = plugins;
+
+               while (*cur_plugin) {
+                       bt_put(*cur_plugin);
+                       cur_plugin++;
+               }
+
+               free(plugins);
+       }
+}
+
+struct bt_plugin *bt_plugin_create_from_name(const char *plugin_name)
+{
+       const char *system_plugin_dir;
+       char *home_plugin_dir = NULL;
+       const char *envvar;
+       struct bt_plugin *plugin = NULL;
+       struct bt_plugin **plugins = NULL;
+       struct bt_plugin **cur_plugin;
+       GPtrArray *dirs = NULL;
+       int ret;
+       size_t i;
+
+       if (!plugin_name) {
+               goto end;
+       }
+
+       dirs = g_ptr_array_new_with_free_func((GDestroyNotify) destroy_gstring);
+       if (!dirs) {
+               goto end;
+       }
+
+       /*
+        * Search order is:
+        *
+        * 1. BABELTRACE_PLUGIN_PATH environment variable
+        *    (colon-separated list of directories)
+        * 2. ~/.local/lib/babeltrace/plugins
+        * 3. Default system directory for Babeltrace plugins, usually
+        *    /usr/lib/babeltrace/plugins or
+        *    /usr/local/lib/babeltrace/plugins if installed
+        *    locally
+        * 4. Built-in plugins (static)
+        *
+        * Directories are searched non-recursively.
+        */
+       envvar = getenv("BABELTRACE_PLUGIN_PATH");
+       if (envvar) {
+               ret = bt_common_append_plugin_path_dirs(envvar, dirs);
+               if (ret) {
+                       goto end;
+               }
+       }
+
+       home_plugin_dir = bt_common_get_home_plugin_path();
+       if (home_plugin_dir) {
+               GString *home_plugin_dir_str =
+                       g_string_new(home_plugin_dir);
+
+               if (!home_plugin_dir_str) {
+                       goto end;
+               }
+
+               g_ptr_array_add(dirs, home_plugin_dir_str);
+       }
+
+       system_plugin_dir = bt_common_get_system_plugin_path();
+       if (system_plugin_dir) {
+               GString *system_plugin_dir_str =
+                       g_string_new(system_plugin_dir);
+
+               if (!system_plugin_dir_str) {
+                       goto end;
+               }
+
+               g_ptr_array_add(dirs, system_plugin_dir_str);
+       }
+
+       for (i = 0; i < dirs->len; i++) {
+               GString *dir = g_ptr_array_index(dirs, i);
+
+               printf_verbose("Trying to load plugins from directory `%s`\n",
+                       dir->str);
+               free_plugins(plugins);
+               plugins = bt_plugin_create_all_from_dir(dir->str, false);
+               if (!plugins) {
+                       continue;
+               }
+
+               cur_plugin = plugins;
+
+               while (*cur_plugin) {
+                       if (strcmp(bt_plugin_get_name(*cur_plugin), plugin_name)
+                                       == 0) {
+                               plugin = bt_get(*cur_plugin);
+                               goto end;
+                       }
+
+                       cur_plugin++;
+               }
+       }
+
+       free_plugins(plugins);
+       plugins = bt_plugin_create_all_from_static();
+       cur_plugin = plugins;
+
+       while (*cur_plugin) {
+               if (strcmp(bt_plugin_get_name(*cur_plugin), plugin_name) == 0) {
+                       plugin = bt_get(*cur_plugin);
+                       goto end;
+               }
+
+               cur_plugin++;
+       }
+
+end:
+       free(home_plugin_dir);
+       free_plugins(plugins);
+
+       if (dirs) {
+               g_ptr_array_free(dirs, TRUE);
+       }
+
+       return plugin;
+}
+
 /* Allocate dirent as recommended by READDIR(3), NOTES on readdir_r */
 static
 struct dirent *alloc_dirent(const char *path)