input/Plugin: add attribute `prefixes`

src/input/InputPlugin.cxx

+/*
+ * Copyright 2003-2018 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * 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 2 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, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "InputPlugin.hxx"
+#include "util/StringCompare.hxx"
+
+#include <assert.h>
+
+bool
+InputPlugin::SupportsUri(const char *uri) const noexcept
+{
+	assert(prefixes != nullptr);
+
+	for (auto i = prefixes; *i != nullptr; ++i)
+		if (StringStartsWithIgnoreCase(uri, *i))
+			return true;
+
+	return false;
+}

src/input/InputPlugin.hxx

 /*
- * Copyright 2003-2017 The Music Player Daemon Project
+ * Copyright 2003-2018 The Music Player Daemon Project
  * http://www.musicpd.org
  *
  * This program is free software; you can redistribute it and/or modify
@@ -21,6 +21,7 @@
 #define MPD_INPUT_PLUGIN_HXX
 
 #include "Ptr.hxx"
+#include "util/Compiler.h"
 
 struct ConfigBlock;
 class Mutex;
@@ -32,6 +33,12 @@ struct InputPlugin {
 	const char *name;
 
 	/**
+	 * A nullptr-terminated list of URI prefixes handled by this
+	 * plugin.  This is usually a string in the form "scheme://".
+	 */
+	const char *const*prefixes;
+
+	/**
 	 * Global initialization.  This method is called when MPD starts.
 	 *
 	 * Throws #PluginUnavailable if the plugin is not available
@@ -66,6 +73,9 @@ struct InputPlugin {
 	 */
 	std::unique_ptr<RemoteTagScanner> (*scan_tags)(const char *uri,
 						       RemoteTagHandler &handler) = nullptr;
+
+	gcc_pure
+	bool SupportsUri(const char *uri) const noexcept;
 };
 
 #endif

src/input/Open.cxx

@@ -38,6 +38,9 @@ InputStream::Open(const char *url, Mutex &mutex)
 	}
 
 	input_plugins_for_each_enabled(plugin) {
+		if (!plugin->SupportsUri(url))
+			continue;
+
 		auto is = plugin->open(url, mutex);
 		if (is != nullptr)
 			return input_rewind_open(std::move(is));

src/input/ScanTags.cxx

@@ -27,7 +27,7 @@ std::unique_ptr<RemoteTagScanner>
 InputScanTags(const char *uri, RemoteTagHandler &handler)
 {
 	input_plugins_for_each_enabled(plugin) {
-		if (plugin->scan_tags == nullptr)
+		if (plugin->scan_tags == nullptr || !plugin->SupportsUri(uri))
 			continue;
 
 		auto scanner = plugin->scan_tags(uri, handler);

src/input/meson.build

 input_api = static_library(
   'input_api',
   'Error.cxx',
+  'InputPlugin.cxx',
   'InputStream.cxx',
   'ThreadInputStream.cxx',
   'AsyncInputStream.cxx',

src/input/plugins/AlsaInputPlugin.cxx

@@ -409,8 +409,14 @@ alsa_input_open(const char *uri, Mutex &mutex)
 				       mutex);
 }
 
+static constexpr const char *alsa_prefixes[] = {
+	"alsa://",
+	nullptr
+};
+
 const struct InputPlugin input_plugin_alsa = {
 	"alsa",
+	alsa_prefixes,
 	alsa_input_init,
 	nullptr,
 	alsa_input_open,

src/input/plugins/CdioParanoiaInputPlugin.cxx

@@ -357,8 +357,14 @@ CdioParanoiaInputStream::IsEOF() noexcept
 	return lsn_from + lsn_relofs > lsn_to;
 }
 
+static constexpr const char *cdio_paranoia_prefixes[] = {
+	"cdda://",
+	nullptr
+};
+
 const InputPlugin input_plugin_cdio_paranoia = {
 	"cdio_paranoia",
+	cdio_paranoia_prefixes,
 	input_cdio_init,
 	nullptr,
 	input_cdio_open,

src/input/plugins/CurlInputPlugin.cxx

@@ -473,8 +473,15 @@ input_curl_open(const char *url, Mutex &mutex)
 	return CurlInputStream::Open(url, {}, mutex);
 }
 
+static constexpr const char *curl_prefixes[] = {
+	"http://",
+	"https://",
+	nullptr
+};
+
 const struct InputPlugin input_plugin_curl = {
 	"curl",
+	curl_prefixes,
 	input_curl_init,
 	input_curl_finish,
 	input_curl_open,

src/input/plugins/FfmpegInputPlugin.cxx

@@ -85,14 +85,6 @@ static InputStreamPtr
 input_ffmpeg_open(const char *uri,
 		  Mutex &mutex)
 {
-	if (!StringStartsWithCaseASCII(uri, "gopher://") &&
-	    !StringStartsWithCaseASCII(uri, "rtp://") &&
-	    !StringStartsWithCaseASCII(uri, "rtsp://") &&
-	    !StringStartsWithCaseASCII(uri, "rtmp://") &&
-	    !StringStartsWithCaseASCII(uri, "rtmpt://") &&
-	    !StringStartsWithCaseASCII(uri, "rtmps://"))
-		return nullptr;
-
 	AVIOContext *h;
 	auto result = avio_open(&h, uri, AVIO_FLAG_READ);
 	if (result != 0)
@@ -146,8 +138,19 @@ FfmpegInputStream::Seek(offset_type new_offset)
 	eof = false;
 }
 
+static constexpr const char *ffmpeg_prefixes[] = {
+	"gopher://",
+	"rtp://",
+	"rtsp://",
+	"rtmp://",
+	"rtmpt://",
+	"rtmps://",
+	nullptr
+};
+
 const InputPlugin input_plugin_ffmpeg = {
 	"ffmpeg",
+	ffmpeg_prefixes,
 	input_ffmpeg_init,
 	nullptr,
 	input_ffmpeg_open,

src/input/plugins/MmsInputPlugin.cxx

@@ -72,12 +72,6 @@ static InputStreamPtr
 input_mms_open(const char *url,
 	       Mutex &mutex)
 {
-	if (!StringStartsWithCaseASCII(url, "mms://") &&
-	    !StringStartsWithCaseASCII(url, "mmsh://") &&
-	    !StringStartsWithCaseASCII(url, "mmst://") &&
-	    !StringStartsWithCaseASCII(url, "mmsu://"))
-		return nullptr;
-
 	auto m = std::make_unique<MmsInputStream>(url, mutex);
 	m->Start();
 	return m;
@@ -103,8 +97,17 @@ MmsInputStream::ThreadRead(void *ptr, size_t read_size)
 	return (size_t)nbytes;
 }
 
+static constexpr const char *mms_prefixes[] = {
+	"mms://",
+	"mmsh://",
+	"mmst://",
+	"mmsu://",
+	nullptr
+};
+
 const InputPlugin input_plugin_mms = {
 	"mms",
+	mms_prefixes,
 	nullptr,
 	nullptr,
 	input_mms_open,

src/input/plugins/NfsInputPlugin.cxx

@@ -217,16 +217,19 @@ static InputStreamPtr
 input_nfs_open(const char *uri,
 	       Mutex &mutex)
 {
-	if (!StringStartsWithCaseASCII(uri, "nfs://"))
-		return nullptr;
-
 	auto is = std::make_unique<NfsInputStream>(uri, mutex);
 	is->Open();
 	return is;
 }
 
+static constexpr const char *nfs_prefixes[] = {
+	"nfs://",
+	nullptr
+};
+
 const InputPlugin input_plugin_nfs = {
 	"nfs",
+	nfs_prefixes,
 	input_nfs_init,
 	input_nfs_finish,
 	input_nfs_open,

src/input/plugins/QobuzInputPlugin.cxx

@@ -209,8 +209,14 @@ ScanQobuzTags(const char *uri, RemoteTagHandler &handler)
 						 handler);
 }
 
+static constexpr const char *qobuz_prefixes[] = {
+	"qobuz://",
+	nullptr
+};
+
 const InputPlugin qobuz_input_plugin = {
 	"qobuz",
+	qobuz_prefixes,
 	InitQobuzInput,
 	FinishQobuzInput,
 	OpenQobuzInput,

src/input/plugins/SmbclientInputPlugin.cxx

@@ -87,9 +87,6 @@ static InputStreamPtr
 input_smbclient_open(const char *uri,
 		     Mutex &mutex)
 {
-	if (!StringStartsWithCaseASCII(uri, "smb://"))
-		return nullptr;
-
 	const std::lock_guard<Mutex> protect(smbclient_mutex);
 
 	SMBCCTX *ctx = smbc_new_context();
@@ -158,8 +155,14 @@ SmbclientInputStream::Seek(offset_type new_offset)
 	offset = result;
 }
 
+static constexpr const char *smbclient_prefixes[] = {
+	"smb://",
+	nullptr
+};
+
 const InputPlugin input_plugin_smbclient = {
 	"smbclient",
+	smbclient_prefixes,
 	input_smbclient_init,
 	nullptr,
 	input_smbclient_open,

src/input/plugins/TidalInputPlugin.cxx

@@ -239,8 +239,14 @@ ScanTidalTags(const char *uri, RemoteTagHandler &handler)
 						 track_id, handler);
 }
 
+static constexpr const char *tidal_prefixes[] = {
+	"tidal://",
+	nullptr
+};
+
 const InputPlugin tidal_input_plugin = {
 	"tidal",
+	tidal_prefixes,
 	InitTidalInput,
 	FinishTidalInput,
 	OpenTidalInput,

src/ls.cxx

 /*
- * Copyright 2003-2017 The Music Player Daemon Project
+ * Copyright 2003-2018 The Music Player Daemon Project
  * http://www.musicpd.org
  *
  * This program is free software; you can redistribute it and/or modify
@@ -19,94 +19,42 @@
 
 #include "config.h"
 #include "ls.hxx"
+#include "input/Registry.hxx"
+#include "input/InputPlugin.hxx"
 #include "client/Response.hxx"
 #include "util/ASCII.hxx"
 #include "util/UriUtil.hxx"
 
 #include <assert.h>
 
-/**
-  * file:// is not included in remoteUrlPrefixes, the connection method
-  * is detected at runtime and displayed as a urlhandler if the client is
-  * connected by IPC socket.
-  */
-static const char *const remoteUrlPrefixes[] = {
-#if defined(ENABLE_CURL)
-	"http://",
-	"https://",
-#endif
-#ifdef ENABLE_MMS
-	"mms://",
-	"mmsh://",
-	"mmst://",
-	"mmsu://",
-#endif
-#ifdef ENABLE_FFMPEG
-	"gopher://",
-	"rtp://",
-	"rtsp://",
-	"rtmp://",
-	"rtmpt://",
-	"rtmps://",
-#endif
-#ifdef ENABLE_SMBCLIENT
-	"smb://",
-#endif
-#ifdef ENABLE_NFS
-	"nfs://",
-#endif
-#ifdef ENABLE_CDIO_PARANOIA
-	"cdda://",
-#endif
-#ifdef ENABLE_ALSA
-	"alsa://",
-#endif
-#ifdef ENABLE_QOBUZ
-	"qobuz://",
-#endif
-#ifdef ENABLE_TIDAL
-	"tidal://",
-#endif
-	NULL
-};
-
 void print_supported_uri_schemes_to_fp(FILE *fp)
 {
-	const char *const*prefixes = remoteUrlPrefixes;
-
 #ifdef HAVE_UN
 	fprintf(fp, " file://");
 #endif
-	while (*prefixes) {
-		fprintf(fp, " %s", *prefixes);
-		prefixes++;
-	}
+	input_plugins_for_each(plugin)
+		for (auto i = plugin->prefixes; *i != nullptr; ++i)
+			fprintf(fp, " %s", *i);
 	fprintf(fp,"\n");
 }
 
 void
 print_supported_uri_schemes(Response &r)
 {
-	const char *const *prefixes = remoteUrlPrefixes;
-
-	while (*prefixes) {
-		r.Format("handler: %s\n", *prefixes);
-		prefixes++;
-	}
+	input_plugins_for_each_enabled(plugin)
+		for (auto i = plugin->prefixes; *i != nullptr; ++i)
+			r.Format("handler: %s\n", *i);
 }
 
 bool
 uri_supported_scheme(const char *uri) noexcept
 {
-	const char *const*urlPrefixes = remoteUrlPrefixes;
-
 	assert(uri_has_scheme(uri));
 
-	while (*urlPrefixes) {
-		if (StringStartsWithCaseASCII(uri, *urlPrefixes))
+	input_plugins_for_each_enabled(plugin)
+		for (auto i = plugin->prefixes; *i != nullptr; ++i)
+			if (StringStartsWithCaseASCII(uri, *i))
 				return true;
-		urlPrefixes++;
-	}
 
 	return false;
 }

src/ls.hxx

 /*
- * Copyright 2003-2017 The Music Player Daemon Project
+ * Copyright 2003-2018 The Music Player Daemon Project
  * http://www.musicpd.org
  *
  * This program is free software; you can redistribute it and/or modify