cue_parser: convert to C++

src/cue/CueParser.cxx

@@ -0,0 +1,322 @@
+/*
+ * Copyright (C) 2003-2013 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 "config.h"
+#include "CueParser.hxx"
+#include "string_util.h"
+#include "song.h"
+#include "tag.h"
+
+#include <glib.h>
+
+#include <assert.h>
+#include <stdlib.h>
+
+CueParser::CueParser()
+	:state(HEADER), tag(tag_new()),
+	 filename(nullptr),
+	 current(nullptr),
+	 previous(nullptr),
+	 finished(nullptr),
+	 end(false) {}
+
+CueParser::~CueParser()
+{
+	tag_free(tag);
+	g_free(filename);
+
+	if (current != nullptr)
+		song_free(current);
+
+	if (previous != nullptr)
+		song_free(previous);
+
+	if (finished != nullptr)
+		song_free(finished);
+}
+
+static const char *
+cue_next_word(char *p, char **pp)
+{
+	assert(p >= *pp);
+	assert(!g_ascii_isspace(*p));
+
+	const char *word = p;
+	while (*p != 0 && !g_ascii_isspace(*p))
+		++p;
+
+	*p = 0;
+	*pp = p + 1;
+	return word;
+}
+
+static const char *
+cue_next_quoted(char *p, char **pp)
+{
+	assert(p >= *pp);
+	assert(p[-1] == '"');
+
+	char *end = strchr(p, '"');
+	if (end == nullptr) {
+		/* syntax error - ignore it silently */
+		*pp = p + strlen(p);
+		return p;
+	}
+
+	*end = 0;
+	*pp = end + 1;
+
+	return p;
+}
+
+static const char *
+cue_next_token(char **pp)
+{
+	char *p = strchug_fast(*pp);
+	if (*p == 0)
+		return nullptr;
+
+	return cue_next_word(p, pp);
+}
+
+static const char *
+cue_next_value(char **pp)
+{
+	char *p = strchug_fast(*pp);
+	if (*p == 0)
+		return nullptr;
+
+	if (*p == '"')
+		return cue_next_quoted(p + 1, pp);
+	else
+		return cue_next_word(p, pp);
+}
+
+static void
+cue_add_tag(struct tag *tag, enum tag_type type, char *p)
+{
+	const char *value = cue_next_value(&p);
+	if (value != nullptr)
+		tag_add_item(tag, type, value);
+
+}
+
+static void
+cue_parse_rem(char *p, struct tag *tag)
+{
+	const char *type = cue_next_token(&p);
+	if (type == nullptr)
+		return;
+
+	enum tag_type type2 = tag_name_parse_i(type);
+	if (type2 != TAG_NUM_OF_ITEM_TYPES)
+		cue_add_tag(tag, type2, p);
+}
+
+struct tag *
+CueParser::GetCurrentTag()
+{
+	if (state == HEADER)
+		return tag;
+	else if (state == TRACK)
+		return current->tag;
+	else
+		return nullptr;
+}
+
+static int
+cue_parse_position(const char *p)
+{
+	char *endptr;
+	unsigned long minutes = strtoul(p, &endptr, 10);
+	if (endptr == p || *endptr != ':')
+		return -1;
+
+	p = endptr + 1;
+	unsigned long seconds = strtoul(p, &endptr, 10);
+	if (endptr == p || *endptr != ':')
+		return -1;
+
+	p = endptr + 1;
+	unsigned long frames = strtoul(p, &endptr, 10);
+	if (endptr == p || *endptr != 0)
+		return -1;
+
+	return minutes * 60000 + seconds * 1000 + frames * 1000 / 75;
+}
+
+void
+CueParser::Commit()
+{
+	/* the caller of this library must call cue_parser_get() often
+	   enough */
+	assert(finished == nullptr);
+	assert(!end);
+
+	if (current == nullptr)
+		return;
+
+	finished = previous;
+	previous = current;
+	current = nullptr;
+}
+
+void
+CueParser::Feed2(char *p)
+{
+	assert(!end);
+	assert(p != nullptr);
+
+	const char *command = cue_next_token(&p);
+	if (command == nullptr)
+		return;
+
+	if (strcmp(command, "REM") == 0) {
+		struct tag *current_tag = GetCurrentTag();
+		if (current_tag != nullptr)
+			cue_parse_rem(p, current_tag);
+	} else if (strcmp(command, "PERFORMER") == 0) {
+		/* MPD knows a "performer" tag, but it is not a good
+		   match for this CUE tag; from the Hydrogenaudio
+		   Knowledgebase: "At top-level this will specify the
+		   CD artist, while at track-level it specifies the
+		   track artist." */
+
+		enum tag_type type = state == TRACK
+			? TAG_ARTIST
+			: TAG_ALBUM_ARTIST;
+
+		struct tag *current_tag = GetCurrentTag();
+		if (current_tag != nullptr)
+			cue_add_tag(current_tag, type, p);
+	} else if (strcmp(command, "TITLE") == 0) {
+		if (state == HEADER)
+			cue_add_tag(tag, TAG_ALBUM, p);
+		else if (state == TRACK)
+			cue_add_tag(current->tag, TAG_TITLE, p);
+	} else if (strcmp(command, "FILE") == 0) {
+		Commit();
+
+		const char *new_filename = cue_next_value(&p);
+		if (new_filename == nullptr)
+			return;
+
+		const char *type = cue_next_token(&p);
+		if (type == nullptr)
+			return;
+
+		if (strcmp(type, "WAVE") != 0 &&
+		    strcmp(type, "MP3") != 0 &&
+		    strcmp(type, "AIFF") != 0) {
+			state = IGNORE_FILE;
+			return;
+		}
+
+		state = WAVE;
+		g_free(filename);
+		filename = g_strdup(new_filename);
+	} else if (state == IGNORE_FILE) {
+		return;
+	} else if (strcmp(command, "TRACK") == 0) {
+		Commit();
+
+		const char *nr = cue_next_token(&p);
+		if (nr == nullptr)
+			return;
+
+		const char *type = cue_next_token(&p);
+		if (type == nullptr)
+			return;
+
+		if (strcmp(type, "AUDIO") != 0) {
+			state = IGNORE_TRACK;
+			return;
+		}
+
+		state = TRACK;
+		current = song_remote_new(filename);
+		assert(current->tag == nullptr);
+		current->tag = tag_dup(tag);
+		tag_add_item(current->tag, TAG_TRACK, nr);
+		last_updated = false;
+	} else if (state == IGNORE_TRACK) {
+		return;
+	} else if (state == TRACK && strcmp(command, "INDEX") == 0) {
+		const char *nr = cue_next_token(&p);
+		if (nr == nullptr)
+			return;
+
+		const char *position = cue_next_token(&p);
+		if (position == nullptr)
+			return;
+
+		int position_ms = cue_parse_position(position);
+		if (position_ms < 0)
+			return;
+
+		if (!last_updated && previous != nullptr &&
+		    previous->start_ms < (unsigned)position_ms) {
+			last_updated = true;
+			previous->end_ms = position_ms;
+			previous->tag->time =
+				(previous->end_ms - previous->start_ms + 500) / 1000;
+		}
+
+		current->start_ms = position_ms;
+	}
+}
+
+void
+CueParser::Feed(const char *line)
+{
+	assert(!end);
+	assert(line != nullptr);
+
+	char *allocated = g_strdup(line);
+	Feed2(allocated);
+	g_free(allocated);
+}
+
+void
+CueParser::Finish()
+{
+	if (end)
+		/* has already been called, ignore */
+		return;
+
+	Commit();
+	end = true;
+}
+
+struct song *
+CueParser::Get()
+{
+	if (finished == nullptr && end) {
+		/* cue_parser_finish() has been called already:
+		   deliver all remaining (partial) results */
+		assert(current == nullptr);
+
+		finished = previous;
+		previous = nullptr;
+	}
+
+	struct song *song = finished;
+	finished = nullptr;
+	return song;
+}