aboutsummaryrefslogtreecommitdiffstats
path: root/src/db/SimpleDatabasePlugin.cxx
blob: 7ba86fb384fff3a4f691dd64013bac96ec4cd104 (plain) (blame)
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
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
/*
 * Copyright (C) 2003-2011 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 "SimpleDatabasePlugin.hxx"
#include "DatabaseSelection.hxx"
#include "DatabaseHelpers.hxx"
#include "Directory.hxx"
#include "SongFilter.hxx"
#include "DatabaseSave.hxx"
#include "DatabaseLock.hxx"
#include "DatabaseError.hxx"
#include "TextFile.hxx"
#include "ConfigData.hxx"
#include "fs/FileSystem.hxx"
#include "util/Error.hxx"
#include "util/Domain.hxx"

#include <sys/types.h>
#include <errno.h>

static constexpr Domain simple_db_domain("simple_db");

Database *
SimpleDatabase::Create(const config_param &param, Error &error)
{
	SimpleDatabase *db = new SimpleDatabase();
	if (!db->Configure(param, error)) {
		delete db;
		db = NULL;
	}

	return db;
}

bool
SimpleDatabase::Configure(const config_param &param, Error &error)
{
	path = param.GetBlockPath("path", error);
	if (path.IsNull()) {
		if (!error.IsDefined())
			error.Set(simple_db_domain,
				  "No \"path\" parameter specified");
		return false;
	}

	path_utf8 = path.ToUTF8();

	return true;
}

bool
SimpleDatabase::Check(Error &error) const
{
	assert(!path.IsNull());
	assert(!path.empty());

	/* Check if the file exists */
	if (!CheckAccess(path, F_OK)) {
		/* If the file doesn't exist, we can't check if we can write
		 * it, so we are going to try to get the directory path, and
		 * see if we can write a file in that */
		const Path dirPath = path.GetDirectoryName();

		/* Check that the parent part of the path is a directory */
		struct stat st;
		if (!StatFile(dirPath, st)) {
			error.FormatErrno("Couldn't stat parent directory of db file "
					  "\"%s\"",
					  path_utf8.c_str());
			return false;
		}

		if (!S_ISDIR(st.st_mode)) {
			error.Format(simple_db_domain,
				     "Couldn't create db file \"%s\" because the "
				     "parent path is not a directory",
				     path_utf8.c_str());
			return false;
		}

		/* Check if we can write to the directory */
		if (!CheckAccess(dirPath, X_OK | W_OK)) {
			const int e = errno;
			const std::string dirPath_utf8 = dirPath.ToUTF8();
			error.FormatErrno(e, "Can't create db file in \"%s\"",
					  dirPath_utf8.c_str());
			return false;
		}

		return true;
	}

	/* Path exists, now check if it's a regular file */
	struct stat st;
	if (!StatFile(path, st)) {
		error.FormatErrno("Couldn't stat db file \"%s\"",
				  path_utf8.c_str());
		return false;
	}

	if (!S_ISREG(st.st_mode)) {
		error.Format(simple_db_domain,
			     "db file \"%s\" is not a regular file",
			     path_utf8.c_str());
		return false;
	}

	/* And check that we can write to it */
	if (!CheckAccess(path, R_OK | W_OK)) {
		error.FormatErrno("Can't open db file \"%s\" for reading/writing",
				  path_utf8.c_str());
		return false;
	}

	return true;
}

bool
SimpleDatabase::Load(Error &error)
{
	assert(!path.empty());
	assert(root != NULL);

	TextFile file(path);
	if (file.HasFailed()) {
		error.FormatErrno("Failed to open database file \"%s\"",
				  path_utf8.c_str());
		return false;
	}

	if (!db_load_internal(file, root, error))
		return false;

	struct stat st;
	if (StatFile(path, st))
		mtime = st.st_mtime;

	return true;
}

bool
SimpleDatabase::Open(Error &error)
{
	root = Directory::NewRoot();
	mtime = 0;

#ifndef NDEBUG
	borrowed_song_count = 0;
#endif

	if (!Load(error)) {
		root->Free();

		g_warning("Failed to load database: %s", error.GetMessage());
		error.Clear();

		if (!Check(error))
			return false;

		root = Directory::NewRoot();
	}

	return true;
}

void
SimpleDatabase::Close()
{
	assert(root != NULL);
	assert(borrowed_song_count == 0);

	root->Free();
}

Song *
SimpleDatabase::GetSong(const char *uri, Error &error) const
{
	assert(root != NULL);

	db_lock();
	Song *song = root->LookupSong(uri);
	db_unlock();
	if (song == NULL)
		error.Format(db_domain, DB_NOT_FOUND,
			     "No such song: %s", uri);
#ifndef NDEBUG
	else
		++const_cast<unsigned &>(borrowed_song_count);
#endif

	return song;
}

void
SimpleDatabase::ReturnSong(gcc_unused Song *song) const
{
	assert(song != nullptr);

#ifndef NDEBUG
	assert(borrowed_song_count > 0);
	--const_cast<unsigned &>(borrowed_song_count);
#endif
}

gcc_pure
const Directory *
SimpleDatabase::LookupDirectory(const char *uri) const
{
	assert(root != NULL);
	assert(uri != NULL);

	ScopeDatabaseLock protect;
	return root->LookupDirectory(uri);
}

bool
SimpleDatabase::Visit(const DatabaseSelection &selection,
		      VisitDirectory visit_directory,
		      VisitSong visit_song,
		      VisitPlaylist visit_playlist,
		      Error &error) const
{
	ScopeDatabaseLock protect;

	const Directory *directory = root->LookupDirectory(selection.uri);
	if (directory == NULL) {
		if (visit_song) {
			Song *song = root->LookupSong(selection.uri);
			if (song != nullptr)
				return !selection.Match(*song) ||
					visit_song(*song, error);
		}

		error.Set(db_domain, DB_NOT_FOUND, "No such directory");
		return false;
	}

	if (selection.recursive && visit_directory &&
	    !visit_directory(*directory, error))
		return false;

	return directory->Walk(selection.recursive, selection.filter,
			       visit_directory, visit_song, visit_playlist,
			       error);
}

bool
SimpleDatabase::VisitUniqueTags(const DatabaseSelection &selection,
				enum tag_type tag_type,
				VisitString visit_string,
				Error &error) const
{
	return ::VisitUniqueTags(*this, selection, tag_type, visit_string,
				 error);
}

bool
SimpleDatabase::GetStats(const DatabaseSelection &selection,
			 DatabaseStats &stats, Error &error) const
{
	return ::GetStats(*this, selection, stats, error);
}

bool
SimpleDatabase::Save(Error &error)
{
	db_lock();

	g_debug("removing empty directories from DB");
	root->PruneEmpty();

	g_debug("sorting DB");
	root->Sort();

	db_unlock();

	g_debug("writing DB");

	FILE *fp = FOpen(path, FOpenMode::WriteText);
	if (!fp) {
		error.FormatErrno("unable to write to db file \"%s\"",
				  path_utf8.c_str());
		return false;
	}

	db_save_internal(fp, root);

	if (ferror(fp)) {
		error.SetErrno("Failed to write to database file");
		fclose(fp);
		return false;
	}

	fclose(fp);

	struct stat st;
	if (StatFile(path, st))
		mtime = st.st_mtime;

	return true;
}

const DatabasePlugin simple_db_plugin = {
	"simple",
	SimpleDatabase::Create,
};