1 /*
2  * Copyright 2003-2021 The Music Player Daemon Project
3  * http://www.musicpd.org
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License as published by
7  * the Free Software Foundation; either version 2 of the License, or
8  * (at your option) any later version.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License along
16  * with this program; if not, write to the Free Software Foundation, Inc.,
17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
18  */
19 
20 /*
21  * Saving and loading the playlist to/from the state file.
22  *
23  */
24 
25 #include "PlaylistState.hxx"
26 #include "PlaylistError.hxx"
27 #include "Playlist.hxx"
28 #include "SingleMode.hxx"
29 #include "StateFileConfig.hxx"
30 #include "queue/QueueSave.hxx"
31 #include "io/LineReader.hxx"
32 #include "io/BufferedOutputStream.hxx"
33 #include "player/Control.hxx"
34 #include "util/CharUtil.hxx"
35 #include "util/StringAPI.hxx"
36 #include "util/StringCompare.hxx"
37 #include "util/NumberParser.hxx"
38 #include "Log.hxx"
39 
40 #include <string.h>
41 #include <stdlib.h>
42 
43 #define PLAYLIST_STATE_FILE_STATE		"state: "
44 #define PLAYLIST_STATE_FILE_RANDOM		"random: "
45 #define PLAYLIST_STATE_FILE_REPEAT		"repeat: "
46 #define PLAYLIST_STATE_FILE_SINGLE		"single: "
47 #define PLAYLIST_STATE_FILE_CONSUME		"consume: "
48 #define PLAYLIST_STATE_FILE_CURRENT		"current: "
49 #define PLAYLIST_STATE_FILE_TIME		"time: "
50 #define PLAYLIST_STATE_FILE_CROSSFADE		"crossfade: "
51 #define PLAYLIST_STATE_FILE_MIXRAMPDB		"mixrampdb: "
52 #define PLAYLIST_STATE_FILE_MIXRAMPDELAY	"mixrampdelay: "
53 #define PLAYLIST_STATE_FILE_PLAYLIST_BEGIN	"playlist_begin"
54 #define PLAYLIST_STATE_FILE_PLAYLIST_END	"playlist_end"
55 
56 #define PLAYLIST_STATE_FILE_STATE_PLAY		"play"
57 #define PLAYLIST_STATE_FILE_STATE_PAUSE		"pause"
58 #define PLAYLIST_STATE_FILE_STATE_STOP		"stop"
59 
60 void
playlist_state_save(BufferedOutputStream & os,const struct playlist & playlist,PlayerControl & pc)61 playlist_state_save(BufferedOutputStream &os, const struct playlist &playlist,
62 		    PlayerControl &pc)
63 {
64 	const auto player_status = pc.LockGetStatus();
65 
66 	os.Write(PLAYLIST_STATE_FILE_STATE);
67 
68 	if (playlist.playing) {
69 		switch (player_status.state) {
70 		case PlayerState::PAUSE:
71 			os.Write(PLAYLIST_STATE_FILE_STATE_PAUSE "\n");
72 			break;
73 		default:
74 			os.Write(PLAYLIST_STATE_FILE_STATE_PLAY "\n");
75 		}
76 		os.Format(PLAYLIST_STATE_FILE_CURRENT "%i\n",
77 			  playlist.queue.OrderToPosition(playlist.current));
78 		os.Format(PLAYLIST_STATE_FILE_TIME "%f\n",
79 			  player_status.elapsed_time.ToDoubleS());
80 	} else {
81 		os.Write(PLAYLIST_STATE_FILE_STATE_STOP "\n");
82 
83 		if (playlist.current >= 0)
84 			os.Format(PLAYLIST_STATE_FILE_CURRENT "%i\n",
85 				playlist.queue.OrderToPosition(playlist.current));
86 	}
87 
88 	os.Format(PLAYLIST_STATE_FILE_RANDOM "%i\n", playlist.queue.random);
89 	os.Format(PLAYLIST_STATE_FILE_REPEAT "%i\n", playlist.queue.repeat);
90 	os.Format(PLAYLIST_STATE_FILE_SINGLE "%i\n",
91 			  (int)playlist.queue.single);
92 	os.Format(PLAYLIST_STATE_FILE_CONSUME "%i\n", playlist.queue.consume);
93 	os.Format(PLAYLIST_STATE_FILE_CROSSFADE "%i\n",
94 		  (int)pc.GetCrossFade().count());
95 	os.Format(PLAYLIST_STATE_FILE_MIXRAMPDB "%f\n",
96 		  (double)pc.GetMixRampDb());
97 	os.Format(PLAYLIST_STATE_FILE_MIXRAMPDELAY "%f\n",
98 		  pc.GetMixRampDelay().count());
99 	os.Write(PLAYLIST_STATE_FILE_PLAYLIST_BEGIN "\n");
100 	queue_save(os, playlist.queue);
101 	os.Write(PLAYLIST_STATE_FILE_PLAYLIST_END "\n");
102 }
103 
104 static void
playlist_state_load(LineReader & file,const SongLoader & song_loader,struct playlist & playlist)105 playlist_state_load(LineReader &file, const SongLoader &song_loader,
106 		    struct playlist &playlist)
107 {
108 	const char *line = file.ReadLine();
109 	if (line == nullptr) {
110 		LogWarning(playlist_domain, "No playlist in state file");
111 		return;
112 	}
113 
114 	while (!StringStartsWith(line, PLAYLIST_STATE_FILE_PLAYLIST_END)) {
115 		queue_load_song(file, song_loader, line, playlist.queue);
116 
117 		line = file.ReadLine();
118 		if (line == nullptr) {
119 			LogWarning(playlist_domain,
120 				   "'" PLAYLIST_STATE_FILE_PLAYLIST_END
121 				   "' not found in state file");
122 			break;
123 		}
124 	}
125 
126 	playlist.queue.IncrementVersion();
127 }
128 
129 bool
playlist_state_restore(const StateFileConfig & config,const char * line,LineReader & file,const SongLoader & song_loader,struct playlist & playlist,PlayerControl & pc)130 playlist_state_restore(const StateFileConfig &config,
131 		       const char *line, LineReader &file,
132 		       const SongLoader &song_loader,
133 		       struct playlist &playlist, PlayerControl &pc)
134 {
135 	int current = -1;
136 	SongTime seek_time = SongTime::zero();
137 	bool random_mode = false;
138 
139 	line = StringAfterPrefix(line, PLAYLIST_STATE_FILE_STATE);
140 	if (line == nullptr)
141 		return false;
142 
143 	PlayerState state;
144 	if (strcmp(line, PLAYLIST_STATE_FILE_STATE_PLAY) == 0)
145 		state = PlayerState::PLAY;
146 	else if (strcmp(line, PLAYLIST_STATE_FILE_STATE_PAUSE) == 0)
147 		state = PlayerState::PAUSE;
148 	else
149 		state = PlayerState::STOP;
150 
151 	while ((line = file.ReadLine()) != nullptr) {
152 		const char *p;
153 		if ((p = StringAfterPrefix(line, PLAYLIST_STATE_FILE_TIME))) {
154 			seek_time = SongTime::FromS(ParseDouble(p));
155 		} else if ((p = StringAfterPrefix(line, PLAYLIST_STATE_FILE_REPEAT))) {
156 			playlist.SetRepeat(pc, StringIsEqual(p, "1"));
157 		} else if ((p = StringAfterPrefix(line, PLAYLIST_STATE_FILE_SINGLE))) {
158 			playlist.SetSingle(pc, SingleFromString(p));
159 		} else if ((p = StringAfterPrefix(line, PLAYLIST_STATE_FILE_CONSUME))) {
160 			playlist.SetConsume(StringIsEqual(p, "1"));
161 		} else if ((p = StringAfterPrefix(line, PLAYLIST_STATE_FILE_CROSSFADE))) {
162 			pc.SetCrossFade(FloatDuration(atoi(p)));
163 		} else if ((p = StringAfterPrefix(line, PLAYLIST_STATE_FILE_MIXRAMPDB))) {
164 			pc.SetMixRampDb(ParseFloat(p));
165 		} else if ((p = StringAfterPrefix(line, PLAYLIST_STATE_FILE_MIXRAMPDELAY))) {
166 			/* this check discards "nan" which was used
167 			   prior to MPD 0.18 */
168 			if (IsDigitASCII(*p))
169 				pc.SetMixRampDelay(FloatDuration(ParseFloat(p)));
170 		} else if ((p = StringAfterPrefix(line, PLAYLIST_STATE_FILE_RANDOM))) {
171 			random_mode = StringIsEqual(p, "1");
172 		} else if ((p = StringAfterPrefix(line, PLAYLIST_STATE_FILE_CURRENT))) {
173 			current = atoi(p);
174 		} else if (StringStartsWith(line,
175 					    PLAYLIST_STATE_FILE_PLAYLIST_BEGIN)) {
176 			playlist_state_load(file, song_loader, playlist);
177 		}
178 	}
179 
180 	playlist.SetRandom(pc, random_mode);
181 
182 	if (!playlist.queue.IsEmpty()) {
183 		if (!playlist.queue.IsValidPosition(current))
184 			current = 0;
185 
186 		if (state == PlayerState::PLAY && config.restore_paused)
187 			/* the user doesn't want MPD to auto-start
188 			   playback after startup; fall back to
189 			   "pause" */
190 			state = PlayerState::PAUSE;
191 
192 		/* enable all devices for the first time; this must be
193 		   called here, after the audio output states were
194 		   restored, before playback begins */
195 		if (state != PlayerState::STOP)
196 			pc.LockUpdateAudio();
197 
198 		if (state == PlayerState::STOP /* && config_option */)
199 			playlist.current = current;
200 		else if (seek_time.count() == 0) {
201 			try {
202 				playlist.PlayPosition(pc, current);
203 			} catch (...) {
204 				/* TODO: log error? */
205 			}
206 		} else {
207 			try {
208 				playlist.SeekSongPosition(pc, current,
209 							  seek_time);
210 			} catch (...) {
211 				/* TODO: log error? */
212 			}
213 		}
214 
215 		if (state == PlayerState::PAUSE)
216 			pc.LockPause();
217 	}
218 
219 	return true;
220 }
221 
222 unsigned
playlist_state_get_hash(const playlist & playlist,PlayerControl & pc)223 playlist_state_get_hash(const playlist &playlist,
224 			PlayerControl &pc)
225 {
226 	const auto player_status = pc.LockGetStatus();
227 
228 	return playlist.queue.version ^
229 		(player_status.state != PlayerState::STOP
230 		 ? (player_status.elapsed_time.ToS() << 8)
231 		 : 0) ^
232 		(playlist.current >= 0
233 		 ? (playlist.queue.OrderToPosition(playlist.current) << 16)
234 		 : 0) ^
235 		((int)pc.GetCrossFade().count() << 20) ^
236 		(unsigned(player_status.state) << 24) ^
237 		/* note that this takes 2 bits */
238 		((int)playlist.queue.single << 25) ^
239 		(playlist.queue.random << 27) ^
240 		(playlist.queue.repeat << 28) ^
241 		(playlist.queue.consume << 30) ^
242 		(playlist.queue.random << 31);
243 }
244