summaryrefslogtreecommitdiff
path: root/src/db/plugins/simple/DatabaseSave.cxx
blob: d2953b048f54d26fca1b41628785772f2fca8ebb (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
/*
 * Copyright (C) 2003-2015 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 "DatabaseSave.hxx"
#include "db/DatabaseLock.hxx"
#include "db/DatabaseError.hxx"
#include "Directory.hxx"
#include "DirectorySave.hxx"
#include "fs/io/BufferedOutputStream.hxx"
#include "fs/io/TextFile.hxx"
#include "tag/Tag.hxx"
#include "tag/Settings.hxx"
#include "fs/Charset.hxx"
#include "util/StringUtil.hxx"
#include "util/Error.hxx"
#include "Log.hxx"

#include <string.h>
#include <stdlib.h>

#define DIRECTORY_INFO_BEGIN "info_begin"
#define DIRECTORY_INFO_END "info_end"
#define DB_FORMAT_PREFIX "format: "
#define DIRECTORY_MPD_VERSION "mpd_version: "
#define DIRECTORY_FS_CHARSET "fs_charset: "
#define DB_TAG_PREFIX "tag: "

static constexpr unsigned DB_FORMAT = 2;

/**
 * The oldest database format understood by this MPD version.
 */
static constexpr unsigned OLDEST_DB_FORMAT = 1;

void
db_save_internal(BufferedOutputStream &os, const Directory &music_root)
{
	os.Format("%s\n", DIRECTORY_INFO_BEGIN);
	os.Format(DB_FORMAT_PREFIX "%u\n", DB_FORMAT);
	os.Format("%s%s\n", DIRECTORY_MPD_VERSION, VERSION);
	os.Format("%s%s\n", DIRECTORY_FS_CHARSET, GetFSCharset());

	for (unsigned i = 0; i < TAG_NUM_OF_ITEM_TYPES; ++i)
		if (IsTagEnabled(i))
			os.Format(DB_TAG_PREFIX "%s\n", tag_item_names[i]);

	os.Format("%s\n", DIRECTORY_INFO_END);

	directory_save(os, music_root);
}

bool
db_load_internal(TextFile &file, Directory &music_root, Error &error)
{
	char *line;
	unsigned format = 0;
	bool found_charset = false, found_version = false;
	bool success;
	bool tags[TAG_NUM_OF_ITEM_TYPES];

	/* get initial info */
	line = file.ReadLine();
	if (line == nullptr || strcmp(DIRECTORY_INFO_BEGIN, line) != 0) {
		error.Set(db_domain, "Database corrupted");
		return false;
	}

	memset(tags, false, sizeof(tags));

	while ((line = file.ReadLine()) != nullptr &&
	       strcmp(line, DIRECTORY_INFO_END) != 0) {
		if (StringStartsWith(line, DB_FORMAT_PREFIX)) {
			format = atoi(line + sizeof(DB_FORMAT_PREFIX) - 1);
		} else if (StringStartsWith(line, DIRECTORY_MPD_VERSION)) {
			if (found_version) {
				error.Set(db_domain, "Duplicate version line");
				return false;
			}

			found_version = true;
		} else if (StringStartsWith(line, DIRECTORY_FS_CHARSET)) {
			const char *new_charset;

			if (found_charset) {
				error.Set(db_domain, "Duplicate charset line");
				return false;
			}

			found_charset = true;

			new_charset = line + sizeof(DIRECTORY_FS_CHARSET) - 1;
			const char *const old_charset = GetFSCharset();
			if (*old_charset != 0
			    && strcmp(new_charset, old_charset) != 0) {
				error.Format(db_domain,
					     "Existing database has charset "
					     "\"%s\" instead of \"%s\"; "
					     "discarding database file",
					     new_charset, old_charset);
				return false;
			}
		} else if (StringStartsWith(line, DB_TAG_PREFIX)) {
			const char *name = line + sizeof(DB_TAG_PREFIX) - 1;
			TagType tag = tag_name_parse(name);
			if (tag == TAG_NUM_OF_ITEM_TYPES) {
				error.Format(db_domain,
					     "Unrecognized tag '%s', "
					     "discarding database file",
					     name);
				return false;
			}

			tags[tag] = true;
		} else {
			error.Format(db_domain, "Malformed line: %s", line);
			return false;
		}
	}

	if (format < OLDEST_DB_FORMAT || format > DB_FORMAT) {
		error.Set(db_domain,
			  "Database format mismatch, "
			  "discarding database file");
		return false;
	}

	for (unsigned i = 0; i < TAG_NUM_OF_ITEM_TYPES; ++i) {
		if (IsTagEnabled(i) && !tags[i]) {
			error.Set(db_domain,
				  "Tag list mismatch, "
				  "discarding database file");
			return false;
		}
	}

	LogDebug(db_domain, "reading DB");

	db_lock();
	success = directory_load(file, music_root, error);
	db_unlock();

	return success;
}