db/simple: create dedicated directory

src/db/plugins/simple/DatabaseSave.cxx

@@ -0,0 +1,159 @@
+/*
+ * Copyright (C) 2003-2014 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/TextFile.hxx"
+#include "tag/Tag.hxx"
+#include "tag/TagSettings.h"
+#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(FILE *fp, const Directory &music_root)
+{
+	fprintf(fp, "%s\n", DIRECTORY_INFO_BEGIN);
+	fprintf(fp, DB_FORMAT_PREFIX "%u\n", DB_FORMAT);
+	fprintf(fp, "%s%s\n", DIRECTORY_MPD_VERSION, VERSION);
+	fprintf(fp, "%s%s\n", DIRECTORY_FS_CHARSET, GetFSCharset());
+
+	for (unsigned i = 0; i < TAG_NUM_OF_ITEM_TYPES; ++i)
+		if (!ignore_tag_items[i])
+			fprintf(fp, DB_TAG_PREFIX "%s\n", tag_item_names[i]);
+
+	fprintf(fp, "%s\n", DIRECTORY_INFO_END);
+
+	directory_save(fp, 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 (!ignore_tag_items[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;
+}