archive/List: add option to disable archive plugins in mpd.conf

Closes https://github.com/MusicPlayerDaemon/MPD/issues/1384

NEWS

@@ -2,6 +2,8 @@ ver 0.24 (not yet released)
 * protocol
   - "playlistfind"/"playlistsearch" have "sort" and "window" parameters
   - filter "prio" (for "playlistfind"/"playlistsearch")
+* archive
+  - add option to disable archive plugins in mpd.conf
 * player
   - add option "mixramp_analyzer" to scan MixRamp tags on-the-fly
 * tags

doc/plugins.rst

@@ -1395,6 +1395,8 @@ xspf
 Reads XSPF playlist files. 
 
 
+.. _archive_plugins:
+
 Archive plugins
 ===============
 

doc/user.rst

@@ -341,6 +341,35 @@ The following table lists the input options valid for all plugins:
 
 More information can be found in the :ref:`input_plugins` reference.
 
+Configuring archive plugins
+---------------------------
+
+To configure an archive plugin, add an :code:`archive_plugin` block to
+:file:`mpd.conf`:
+
+.. code-block:: none
+
+    archive_plugin {
+        name "zzip"
+        enabled "no"
+    }
+
+The following table lists the input options valid for all plugins:
+
+.. list-table::
+   :widths: 20 80
+   :header-rows: 1
+
+   * - Name
+     - Description
+   * - **name**
+     - The name of the plugin
+   * - **enabled yes|no**
+     - Allows you to disable a plugin without recompiling.  By
+       default, all plugins are enabled.
+
+More information can be found in the :ref:`archive_plugins` reference.
+
 .. _input_cache:
 
 Configuring the Input Cache

src/Main.cxx

@@ -385,7 +385,7 @@ MainConfigured(const CommandLineOptions &options,
 	initPermissions(raw_config);
 	spl_global_init(raw_config);
 #ifdef ENABLE_ARCHIVE
-	const ScopeArchivePluginsInit archive_plugins_init;
+	const ScopeArchivePluginsInit archive_plugins_init{raw_config};
 #endif
 
 	pcm_convert_global_init(raw_config);

src/archive/ArchiveList.cxx

@@ -20,6 +20,8 @@
 #include "ArchiveList.hxx"
 #include "ArchivePlugin.hxx"
 #include "archive/Features.h"
+#include "config/Data.hxx"
+#include "config/Block.hxx"
 #include "util/StringUtil.hxx"
 #include "plugins/Bzip2ArchivePlugin.hxx"
 #include "plugins/Iso9660ArchivePlugin.hxx"
@@ -74,10 +76,21 @@ archive_plugin_from_name(const char *name) noexcept
 	return nullptr;
 }
 
-void archive_plugin_init_all()
+void
+archive_plugin_init_all(const ConfigData &config)
 {
+	ConfigBlock empty;
+
 	for (unsigned i = 0; archive_plugins[i] != nullptr; ++i) {
 		const auto &plugin = *archive_plugins[i];
+
+		const auto *param =
+			config.FindBlock(ConfigBlockOption::ARCHIVE_PLUGIN,
+					 "name", plugin.name);
+		if (param != nullptr && !param->GetBlockValue("enabled", true))
+			/* the plugin is disabled in mpd.conf */
+			continue;
+
 		if (plugin.init == nullptr || plugin.init())
 			archive_plugins_enabled[i] = true;
 	}
@@ -86,8 +99,9 @@ void archive_plugin_init_all()
 void
 archive_plugin_deinit_all() noexcept
 {
+	unsigned i = 0;
 	archive_plugins_for_each_enabled(plugin)
-		if (plugin->finish != nullptr)
+		if (archive_plugins_enabled[i++] && plugin->finish != nullptr)
 			plugin->finish();
 }
 

src/archive/ArchiveList.hxx

@@ -22,6 +22,7 @@
 
 #include <string_view>
 
+struct ConfigData;
 struct ArchivePlugin;
 
 extern const ArchivePlugin *const archive_plugins[];
@@ -42,7 +43,7 @@ archive_plugin_from_name(const char *name) noexcept;
 
 /* this is where we "load" all the "plugins" ;-) */
 void
-archive_plugin_init_all();
+archive_plugin_init_all(const ConfigData &config);
 
 /* this is where we "unload" all the "plugins" */
 void
@@ -50,8 +51,8 @@ archive_plugin_deinit_all() noexcept;
 
 class ScopeArchivePluginsInit {
 public:
-	ScopeArchivePluginsInit() {
-		archive_plugin_init_all();
+	explicit ScopeArchivePluginsInit(const ConfigData &config) {
+		archive_plugin_init_all(config);
 	}
 
 	~ScopeArchivePluginsInit() noexcept {

src/config/Option.hxx

@@ -91,6 +91,7 @@ enum class ConfigBlockOption {
 	DECODER,
 	INPUT,
 	INPUT_CACHE,
+	ARCHIVE_PLUGIN,
 	PLAYLIST_PLUGIN,
 	RESAMPLER,
 	AUDIO_FILTER,

src/config/Templates.cxx

@@ -90,6 +90,7 @@ const ConfigTemplate config_block_templates[] = {
 	{ "decoder", true },
 	{ "input", true },
 	{ "input_cache" },
+	{ "archive_plugin", true },
 	{ "playlist_plugin", true },
 	{ "resampler" },
 	{ "filter", true },

test/dump_text_file.cxx

@@ -41,7 +41,7 @@ class GlobalInit {
 	EventThread io_thread;
 
 #ifdef ENABLE_ARCHIVE
-	const ScopeArchivePluginsInit archive_plugins_init;
+	const ScopeArchivePluginsInit archive_plugins_init{config};
 #endif
 
 	const ScopeInputPluginsInit input_plugins_init{config, io_thread.GetEventLoop()};

test/run_input.cxx

@@ -137,7 +137,7 @@ class GlobalInit {
 	EventThread io_thread;
 
 #ifdef ENABLE_ARCHIVE
-	const ScopeArchivePluginsInit archive_plugins_init;
+	const ScopeArchivePluginsInit archive_plugins_init{config};
 #endif
 
 	const ScopeInputPluginsInit input_plugins_init{config, io_thread.GetEventLoop()};

test/visit_archive.cxx

@@ -41,7 +41,7 @@ class GlobalInit {
 	EventThread io_thread;
 
 #ifdef ENABLE_ARCHIVE
-	const ScopeArchivePluginsInit archive_plugins_init;
+	const ScopeArchivePluginsInit archive_plugins_init{config};
 #endif
 
 	const ScopeInputPluginsInit input_plugins_init{config, io_thread.GetEventLoop()};