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Diffstat (limited to 'src/db/plugins/simple/SimpleDatabasePlugin.cxx')
| -rw-r--r-- | src/db/plugins/simple/SimpleDatabasePlugin.cxx | 541 |
1 files changed, 541 insertions, 0 deletions
diff --git a/src/db/plugins/simple/SimpleDatabasePlugin.cxx b/src/db/plugins/simple/SimpleDatabasePlugin.cxx new file mode 100644 index 000000000..7b1886f1c --- /dev/null +++ b/src/db/plugins/simple/SimpleDatabasePlugin.cxx @@ -0,0 +1,541 @@ +/* + * 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 "SimpleDatabasePlugin.hxx" +#include "PrefixedLightSong.hxx" +#include "db/DatabasePlugin.hxx" +#include "db/Selection.hxx" +#include "db/Helpers.hxx" +#include "db/UniqueTags.hxx" +#include "db/LightDirectory.hxx" +#include "Directory.hxx" +#include "Song.hxx" +#include "SongFilter.hxx" +#include "DatabaseSave.hxx" +#include "db/DatabaseLock.hxx" +#include "db/DatabaseError.hxx" +#include "fs/io/TextFile.hxx" +#include "fs/io/BufferedOutputStream.hxx" +#include "fs/io/FileOutputStream.hxx" +#include "config/ConfigData.hxx" +#include "fs/FileSystem.hxx" +#include "util/CharUtil.hxx" +#include "util/Error.hxx" +#include "util/Domain.hxx" +#include "Log.hxx" + +#ifdef HAVE_ZLIB +#include "fs/io/GzipOutputStream.hxx" +#endif + +#include <errno.h> + +static constexpr Domain simple_db_domain("simple_db"); + +inline SimpleDatabase::SimpleDatabase() + :Database(simple_db_plugin), + path(AllocatedPath::Null()), +#ifdef HAVE_ZLIB + compress(true), +#endif + cache_path(AllocatedPath::Null()), + prefixed_light_song(nullptr) {} + +inline SimpleDatabase::SimpleDatabase(AllocatedPath &&_path, +#ifndef HAVE_ZLIB + gcc_unused +#endif + bool _compress) + :Database(simple_db_plugin), + path(std::move(_path)), + path_utf8(path.ToUTF8()), +#ifdef HAVE_ZLIB + compress(_compress), +#endif + cache_path(AllocatedPath::Null()), + prefixed_light_song(nullptr) { +} + +Database * +SimpleDatabase::Create(gcc_unused EventLoop &loop, + gcc_unused DatabaseListener &listener, + const config_param ¶m, Error &error) +{ + SimpleDatabase *db = new SimpleDatabase(); + if (!db->Configure(param, error)) { + delete db; + db = nullptr; + } + + return db; +} + +bool +SimpleDatabase::Configure(const config_param ¶m, 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(); + + cache_path = param.GetBlockPath("cache_directory", error); + if (path.IsNull() && error.IsDefined()) + return false; + +#ifdef HAVE_ZLIB + compress = param.GetBlockValue("compress", compress); +#endif + + return true; +} + +bool +SimpleDatabase::Check(Error &error) const +{ + assert(!path.IsNull()); + + /* Check if the file exists */ + if (!CheckAccess(path)) { + /* 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 auto 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; + } + +#ifndef WIN32 + /* 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; + } +#endif + 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; + } + +#ifndef WIN32 + /* 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; + } +#endif + + return true; +} + +bool +SimpleDatabase::Load(Error &error) +{ + assert(!path.IsNull()); + assert(root != nullptr); + + TextFile file(path, error); + if (file.HasFailed()) + return false; + + if (!db_load_internal(file, *root, error) || !file.Check(error)) + return false; + + struct stat st; + if (StatFile(path, st)) + mtime = st.st_mtime; + + return true; +} + +bool +SimpleDatabase::Open(Error &error) +{ + assert(prefixed_light_song == nullptr); + + root = Directory::NewRoot(); + mtime = 0; + +#ifndef NDEBUG + borrowed_song_count = 0; +#endif + + if (!Load(error)) { + delete root; + + LogError(error); + error.Clear(); + + if (!Check(error)) + return false; + + root = Directory::NewRoot(); + } + + return true; +} + +void +SimpleDatabase::Close() +{ + assert(root != nullptr); + assert(prefixed_light_song == nullptr); + assert(borrowed_song_count == 0); + + delete root; +} + +const LightSong * +SimpleDatabase::GetSong(const char *uri, Error &error) const +{ + assert(root != nullptr); + assert(prefixed_light_song == nullptr); + assert(borrowed_song_count == 0); + + db_lock(); + + auto r = root->LookupDirectory(uri); + + if (r.directory->IsMount()) { + /* pass the request to the mounted database */ + db_unlock(); + + const LightSong *song = + r.directory->mounted_database->GetSong(r.uri, error); + if (song == nullptr) + return nullptr; + + prefixed_light_song = + new PrefixedLightSong(*song, r.directory->GetPath()); + return prefixed_light_song; + } + + if (r.uri == nullptr) { + /* it's a directory */ + db_unlock(); + error.Format(db_domain, DB_NOT_FOUND, + "No such song: %s", uri); + return nullptr; + } + + if (strchr(r.uri, '/') != nullptr) { + /* refers to a URI "below" the actual song */ + db_unlock(); + error.Format(db_domain, DB_NOT_FOUND, + "No such song: %s", uri); + return nullptr; + } + + const Song *song = r.directory->FindSong(r.uri); + db_unlock(); + if (song == nullptr) { + error.Format(db_domain, DB_NOT_FOUND, + "No such song: %s", uri); + return nullptr; + } + + light_song = song->Export(); + +#ifndef NDEBUG + ++borrowed_song_count; +#endif + + return &light_song; +} + +void +SimpleDatabase::ReturnSong(gcc_unused const LightSong *song) const +{ + assert(song != nullptr); + assert(song == &light_song || song == prefixed_light_song); + + delete prefixed_light_song; + prefixed_light_song = nullptr; + +#ifndef NDEBUG + if (song == &light_song) { + assert(borrowed_song_count > 0); + --borrowed_song_count; + } +#endif +} + +bool +SimpleDatabase::Visit(const DatabaseSelection &selection, + VisitDirectory visit_directory, + VisitSong visit_song, + VisitPlaylist visit_playlist, + Error &error) const +{ + ScopeDatabaseLock protect; + + auto r = root->LookupDirectory(selection.uri.c_str()); + if (r.uri == nullptr) { + /* it's a directory */ + + if (selection.recursive && visit_directory && + !visit_directory(r.directory->Export(), error)) + return false; + + return r.directory->Walk(selection.recursive, selection.filter, + visit_directory, visit_song, + visit_playlist, + error); + } + + if (strchr(r.uri, '/') == nullptr) { + if (visit_song) { + Song *song = r.directory->FindSong(r.uri); + if (song != nullptr) { + const LightSong song2 = song->Export(); + return !selection.Match(song2) || + visit_song(song2, error); + } + } + } + + error.Set(db_domain, DB_NOT_FOUND, "No such directory"); + return false; +} + +bool +SimpleDatabase::VisitUniqueTags(const DatabaseSelection &selection, + TagType tag_type, uint32_t group_mask, + VisitTag visit_tag, + Error &error) const +{ + return ::VisitUniqueTags(*this, selection, tag_type, group_mask, + visit_tag, + 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(); + + LogDebug(simple_db_domain, "removing empty directories from DB"); + root->PruneEmpty(); + + LogDebug(simple_db_domain, "sorting DB"); + root->Sort(); + + db_unlock(); + + LogDebug(simple_db_domain, "writing DB"); + + FileOutputStream fos(path, error); + if (!fos.IsDefined()) + return false; + + OutputStream *os = &fos; + +#ifdef HAVE_ZLIB + GzipOutputStream *gzip = nullptr; + if (compress) { + gzip = new GzipOutputStream(*os, error); + if (!gzip->IsDefined()) { + delete gzip; + return false; + } + + os = gzip; + } +#endif + + BufferedOutputStream bos(*os); + + db_save_internal(bos, *root); + + if (!bos.Flush(error)) { +#ifdef HAVE_ZLIB + delete gzip; +#endif + return false; + } + +#ifdef HAVE_ZLIB + if (gzip != nullptr) { + bool success = gzip->Flush(error); + delete gzip; + if (!success) + return false; + } +#endif + + if (!fos.Commit(error)) + return false; + + struct stat st; + if (StatFile(path, st)) + mtime = st.st_mtime; + + return true; +} + +bool +SimpleDatabase::Mount(const char *uri, Database *db, Error &error) +{ + assert(uri != nullptr); + assert(*uri != 0); + assert(db != nullptr); + + ScopeDatabaseLock protect; + + auto r = root->LookupDirectory(uri); + if (r.uri == nullptr) { + error.Format(db_domain, DB_CONFLICT, + "Already exists: %s", uri); + return nullptr; + } + + if (strchr(r.uri, '/') != nullptr) { + error.Format(db_domain, DB_NOT_FOUND, + "Parent not found: %s", uri); + return nullptr; + } + + Directory *mnt = r.directory->CreateChild(r.uri); + mnt->mounted_database = db; + return true; +} + +static constexpr bool +IsSafeChar(char ch) +{ + return IsAlphaNumericASCII(ch) || ch == '-' || ch == '_' || ch == '%'; +} + +static constexpr bool +IsUnsafeChar(char ch) +{ + return !IsSafeChar(ch); +} + +bool +SimpleDatabase::Mount(const char *local_uri, const char *storage_uri, + Error &error) +{ + if (cache_path.IsNull()) { + error.Format(db_domain, DB_NOT_FOUND, + "No 'cache_directory' configured"); + return nullptr; + } + + std::string name(storage_uri); + std::replace_if(name.begin(), name.end(), IsUnsafeChar, '_'); + +#ifndef HAVE_ZLIB + constexpr bool compress = false; +#endif + auto db = new SimpleDatabase(AllocatedPath::Build(cache_path, + name.c_str()), + compress); + if (!db->Open(error)) { + delete db; + return false; + } + + // TODO: update the new database instance? + + if (!Mount(local_uri, db, error)) { + db->Close(); + delete db; + return false; + } + + return true; +} + +Database * +SimpleDatabase::LockUmountSteal(const char *uri) +{ + ScopeDatabaseLock protect; + + auto r = root->LookupDirectory(uri); + if (r.uri != nullptr || !r.directory->IsMount()) + return nullptr; + + Database *db = r.directory->mounted_database; + r.directory->mounted_database = nullptr; + r.directory->Delete(); + + return db; +} + +bool +SimpleDatabase::Unmount(const char *uri) +{ + Database *db = LockUmountSteal(uri); + if (db == nullptr) + return false; + + db->Close(); + delete db; + return true; +} + +const DatabasePlugin simple_db_plugin = { + "simple", + DatabasePlugin::FLAG_REQUIRE_STORAGE, + SimpleDatabase::Create, +}; |