command: "lsinfo" and "readcomments" allowed for remote files

NEWS

 ver 0.19 (not yet released)
 * protocol
   - new commands "addtagid", "cleartagid"
+  - "lsinfo" and "readcomments" allowed for remote files
 * archive
   - read tags from songs in an archive
 * input

doc/protocol.xml

@@ -1618,6 +1618,10 @@ OK
               deprecated; use "listplaylists" instead.
             </para>
             <para>
+              This command may be used to list metadata of remote
+              files (e.g. URI beginning with "http://" or "smb://").
+            </para>
+            <para>
               Clients that are connected via UNIX domain socket may
               use this command to read the tags of an arbitrary local
               file (URI beginning with "file:///").
@@ -1639,6 +1643,10 @@ OK
               "file:///foo/bar.ogg".
             </para>
             <para>
+              This command may be used to list metadata of remote
+              files (e.g. URI beginning with "http://" or "smb://").
+            </para>
+            <para>
               The response consists of lines in the form "KEY: VALUE".
               Comments with suspicious characters (e.g. newlines) are
               ignored silently.

src/Song.hxx

@@ -130,6 +130,7 @@ struct Song {
 
 	bool UpdateFile();
 	bool UpdateFileInArchive();
+	bool UpdateStream();
 
 	/**
 	 * Returns the URI of the song in UTF-8 encoding, including its

src/SongUpdate.cxx

@@ -132,3 +132,17 @@ Song::UpdateFileInArchive()
 	tag = tag_builder.Commit();
 	return true;
 }
+
+bool
+Song::UpdateStream()
+{
+	assert(!IsFile());
+
+	TagBuilder tag_builder;
+	if (!tag_stream_scan(uri, full_tag_handler, &tag_builder))
+		return false;
+
+	delete tag;
+	tag = tag_builder.Commit();
+	return true;
+}

src/command/FileCommands.cxx

@@ -25,13 +25,16 @@
 #include "ClientFile.hxx"
 #include "Client.hxx"
 #include "util/CharUtil.hxx"
+#include "util/UriUtil.hxx"
 #include "util/Error.hxx"
 #include "tag/TagHandler.hxx"
 #include "tag/ApeTag.hxx"
 #include "tag/TagId3.hxx"
+#include "TagStream.hxx"
 #include "TagFile.hxx"
 #include "Mapper.hxx"
 #include "fs/AllocatedPath.hxx"
+#include "ls.hxx"
 
 #include <assert.h>
 
@@ -80,6 +83,25 @@ static constexpr tag_handler print_comment_handler = {
 	print_pair,
 };
 
+static CommandResult
+read_stream_comments(Client &client, const char *uri)
+{
+	if (!uri_supported_scheme(uri)) {
+		command_error(client, ACK_ERROR_NO_EXIST,
+			      "unsupported URI scheme");
+		return CommandResult::ERROR;
+	}
+
+	if (!tag_stream_scan(uri, print_comment_handler, &client)) {
+		command_error(client, ACK_ERROR_NO_EXIST,
+			      "Failed to load file");
+		return CommandResult::ERROR;
+	}
+
+	return CommandResult::OK;
+
+}
+
 CommandResult
 handle_read_comments(Client &client, gcc_unused int argc, char *argv[])
 {
@@ -102,6 +124,8 @@ handle_read_comments(Client &client, gcc_unused int argc, char *argv[])
 		Error error;
 		if (!client_allow_file(client, path_fs, error))
 			return print_error(client, error);
+	} else if (uri_has_scheme(uri)) {
+		return read_stream_comments(client, uri);
 	} else if (*uri != '/') {
 		path_fs = map_uri_fs(uri);
 		if (path_fs.IsNull()) {

src/command/OtherCommands.cxx

@@ -136,6 +136,26 @@ handle_lsinfo(Client &client, int argc, char *argv[])
 		return CommandResult::OK;
 	}
 
+	if (uri_has_scheme(uri)) {
+		if (!uri_supported_scheme(uri)) {
+			command_error(client, ACK_ERROR_NO_EXIST,
+				      "unsupported URI scheme");
+			return CommandResult::ERROR;
+		}
+
+		Song *song = Song::NewRemote(uri);
+		if (!song->UpdateStream()) {
+			song->Free();
+			command_error(client, ACK_ERROR_NO_EXIST,
+				      "No such file");
+			return CommandResult::ERROR;
+		}
+
+		song_print_info(client, *song);
+		song->Free();
+		return CommandResult::OK;
+	}
+
 	CommandResult result = handle_lsinfo2(client, argc, argv);
 	if (result != CommandResult::OK)
 		return result;