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/*
* Copyright 2003-2017 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.
*/
/*
* Save and load mounts of the compound storage to/from the state file.
*
*/
#include "config.h"
#include "StorageState.hxx"
#include "fs/io/TextFile.hxx"
#include "fs/io/BufferedOutputStream.hxx"
#include "storage/Registry.hxx"
#include "storage/CompositeStorage.hxx"
#include "db/plugins/simple/SimpleDatabasePlugin.hxx"
#include "util/StringCompare.hxx"
#include "util/Domain.hxx"
#include "Instance.hxx"
#include "Log.hxx"
#include <set>
#include <boost/crc.hpp>
#define MOUNT_STATE_BEGIN "mount_begin"
#define MOUNT_STATE_END "mount_end"
#define MOUNT_STATE_STORAGE_URI "uri: "
#define MOUNT_STATE_MOUNTED_URL "mounted_url: "
static constexpr Domain storage_domain("storage");
void
storage_state_save(BufferedOutputStream &os, const Instance &instance)
{
if (instance.storage == nullptr)
return;
const auto visitor = [&os](const char *mount_uri, const Storage &storage) {
std::string uri = storage.MapUTF8("");
if (uri.empty() || StringIsEmpty(mount_uri))
return;
os.Format(
MOUNT_STATE_BEGIN "\n"
MOUNT_STATE_STORAGE_URI "%s\n"
MOUNT_STATE_MOUNTED_URL "%s\n"
MOUNT_STATE_END "\n", mount_uri, uri.c_str());
};
((CompositeStorage*)instance.storage)->VisitMounts(visitor);
}
bool
storage_state_restore(const char *line, TextFile &file, Instance &instance)
{
if (!StringStartsWith(line, MOUNT_STATE_BEGIN))
return false;
std::string url;
std::string uri;
const char* value;
while ((line = file.ReadLine()) != nullptr) {
if (StringStartsWith(line, MOUNT_STATE_END))
break;
if ((value = StringAfterPrefix(line, MOUNT_STATE_MOUNTED_URL)))
url = value;
else if ((value = StringAfterPrefix(line, MOUNT_STATE_STORAGE_URI)))
uri = value;
else
FormatError(storage_domain, "Unrecognized line in mountpoint state: %s", line);
}
if (instance.storage == nullptr)
/* without storage (a CompositeStorage instance), we
cannot mount, and therefore we silently ignore the
state file */
return true;
if (url.empty() || uri.empty()) {
LogError(storage_domain, "Missing value in mountpoint state.");
return true;
}
FormatDebug(storage_domain, "Restoring mount %s => %s", uri.c_str(), url.c_str());
auto &event_loop = instance.io_thread.GetEventLoop();
auto storage = CreateStorageURI(event_loop, url.c_str());
if (storage == nullptr) {
FormatError(storage_domain, "Unrecognized storage URI: %s", url.c_str());
return true;
}
Database *db = instance.database;
if (db != nullptr && db->IsPlugin(simple_db_plugin)) {
try {
((SimpleDatabase *)db)->Mount(uri.c_str(), url.c_str());
} catch (...) {
FormatError(std::current_exception(),
"Failed to restore mount to %s",
url.c_str());
return true;
}
}
((CompositeStorage*)instance.storage)->Mount(uri.c_str(),
storage.release());
return true;
}
unsigned
storage_state_get_hash(const Instance &instance)
{
if (instance.storage == nullptr)
return 0;
std::set<std::string> mounts;
const auto visitor = [&mounts](const char *mount_uri, const Storage &storage) {
mounts.emplace(std::string(mount_uri) + ":" + storage.MapUTF8(""));
};
((CompositeStorage*)instance.storage)->VisitMounts(visitor);
boost::crc_32_type result;
for (auto mount: mounts) {
result.process_bytes(mount.c_str(), mount.length());
}
return result.checksum();
}
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