db/update: convert to OO API

Move global variables into the new classes.  That may allow multiple
update threads for multiple databases one day.

1 files changed, 463 insertions, 0 deletions

diff --git a/src/db/update/Walk.cxx b/src/db/update/Walk.cxx
new file mode 100644
index 000000000..5a799d8f7
--- /dev/null
+++ b/src/db/update/Walk.cxx
@@ -0,0 +1,463 @@
+/*
+ * 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" /* must be first for large file support */
+#include "Walk.hxx"
+#include "UpdateIO.hxx"
+#include "Editor.hxx"
+#include "UpdateDomain.hxx"
+#include "db/DatabaseLock.hxx"
+#include "db/DatabaseSimple.hxx"
+#include "db/Directory.hxx"
+#include "db/Song.hxx"
+#include "db/PlaylistVector.hxx"
+#include "db/Uri.hxx"
+#include "playlist/PlaylistRegistry.hxx"
+#include "Mapper.hxx"
+#include "ExcludeList.hxx"
+#include "config/ConfigGlobal.hxx"
+#include "config/ConfigOption.hxx"
+#include "fs/AllocatedPath.hxx"
+#include "fs/Traits.hxx"
+#include "fs/FileSystem.hxx"
+#include "fs/DirectoryReader.hxx"
+#include "util/Alloc.hxx"
+#include "util/UriUtil.hxx"
+#include "Log.hxx"
+
+#include <assert.h>
+#include <sys/stat.h>
+#include <string.h>
+#include <stdlib.h>
+#include <errno.h>
+
+UpdateWalk::UpdateWalk(EventLoop &_loop)
+	:editor(_loop)
+{
+#ifndef WIN32
+	follow_inside_symlinks =
+		config_get_bool(CONF_FOLLOW_INSIDE_SYMLINKS,
+				DEFAULT_FOLLOW_INSIDE_SYMLINKS);
+
+	follow_outside_symlinks =
+		config_get_bool(CONF_FOLLOW_OUTSIDE_SYMLINKS,
+				DEFAULT_FOLLOW_OUTSIDE_SYMLINKS);
+#endif
+}
+
+static void
+directory_set_stat(Directory &dir, const struct stat *st)
+{
+	dir.inode = st->st_ino;
+	dir.device = st->st_dev;
+	dir.have_stat = true;
+}
+
+inline void
+UpdateWalk::RemoveExcludedFromDirectory(Directory &directory,
+					const ExcludeList &exclude_list)
+{
+	db_lock();
+
+	Directory *child, *n;
+	directory_for_each_child_safe(child, n, directory) {
+		const auto name_fs = AllocatedPath::FromUTF8(child->GetName());
+
+		if (name_fs.IsNull() || exclude_list.Check(name_fs)) {
+			editor.DeleteDirectory(child);
+			modified = true;
+		}
+	}
+
+	Song *song, *ns;
+	directory_for_each_song_safe(song, ns, directory) {
+		assert(song->parent == &directory);
+
+		const auto name_fs = AllocatedPath::FromUTF8(song->uri);
+		if (name_fs.IsNull() || exclude_list.Check(name_fs)) {
+			editor.DeleteSong(directory, song);
+			modified = true;
+		}
+	}
+
+	db_unlock();
+}
+
+inline void
+UpdateWalk::PurgeDeletedFromDirectory(Directory &directory)
+{
+	Directory *child, *n;
+	directory_for_each_child_safe(child, n, directory) {
+		if (directory_exists(*child))
+			continue;
+
+		db_lock();
+		editor.DeleteDirectory(child);
+		db_unlock();
+
+		modified = true;
+	}
+
+	Song *song, *ns;
+	directory_for_each_song_safe(song, ns, directory) {
+		const auto path = map_song_fs(*song);
+		if (path.IsNull() || !FileExists(path)) {
+			db_lock();
+			editor.DeleteSong(directory, song);
+			db_unlock();
+
+			modified = true;
+		}
+	}
+
+	for (auto i = directory.playlists.begin(),
+		     end = directory.playlists.end();
+	     i != end;) {
+		if (!directory_child_is_regular(directory, i->name.c_str())) {
+			db_lock();
+			i = directory.playlists.erase(i);
+			db_unlock();
+		} else
+			++i;
+	}
+}
+
+#ifndef WIN32
+static int
+update_directory_stat(Directory &directory)
+{
+	struct stat st;
+	if (stat_directory(directory, &st) < 0)
+		return -1;
+
+	directory_set_stat(directory, &st);
+	return 0;
+}
+#endif
+
+static int
+find_inode_ancestor(Directory *parent, ino_t inode, dev_t device)
+{
+#ifndef WIN32
+	while (parent) {
+		if (!parent->have_stat && update_directory_stat(*parent) < 0)
+			return -1;
+
+		if (parent->inode == inode && parent->device == device) {
+			LogDebug(update_domain, "recursive directory found");
+			return 1;
+		}
+
+		parent = parent->parent;
+	}
+#else
+	(void)parent;
+	(void)inode;
+	(void)device;
+#endif
+
+	return 0;
+}
+
+inline bool
+UpdateWalk::UpdatePlaylistFile(Directory &directory,
+			       const char *name, const char *suffix,
+			       const struct stat *st)
+{
+	if (!playlist_suffix_supported(suffix))
+		return false;
+
+	PlaylistInfo pi(name, st->st_mtime);
+
+	db_lock();
+	if (directory.playlists.UpdateOrInsert(std::move(pi)))
+		modified = true;
+	db_unlock();
+	return true;
+}
+
+inline bool
+UpdateWalk::UpdateRegularFile(Directory &directory,
+			      const char *name, const struct stat *st)
+{
+	const char *suffix = uri_get_suffix(name);
+	if (suffix == nullptr)
+		return false;
+
+	return UpdateSongFile(directory, name, suffix, st) ||
+		UpdateArchiveFile(directory, name, suffix, st) ||
+		UpdatePlaylistFile(directory, name, suffix, st);
+}
+
+void
+UpdateWalk::UpdateDirectoryChild(Directory &directory,
+				 const char *name, const struct stat *st)
+{
+	assert(strchr(name, '/') == nullptr);
+
+	if (S_ISREG(st->st_mode)) {
+		UpdateRegularFile(directory, name, st);
+	} else if (S_ISDIR(st->st_mode)) {
+		if (find_inode_ancestor(&directory, st->st_ino, st->st_dev))
+			return;
+
+		db_lock();
+		Directory *subdir = directory.MakeChild(name);
+		db_unlock();
+
+		assert(&directory == subdir->parent);
+
+		if (!UpdateDirectory(*subdir, st)) {
+			db_lock();
+			editor.DeleteDirectory(subdir);
+			db_unlock();
+		}
+	} else {
+		FormatDebug(update_domain,
+			    "%s is not a directory, archive or music", name);
+	}
+}
+
+/* we don't look at "." / ".." nor files with newlines in their name */
+gcc_pure
+static bool skip_path(Path path_fs)
+{
+	const char *path = path_fs.c_str();
+	return (path[0] == '.' && path[1] == 0) ||
+		(path[0] == '.' && path[1] == '.' && path[2] == 0) ||
+		strchr(path, '\n') != nullptr;
+}
+
+gcc_pure
+bool
+UpdateWalk::SkipSymlink(const Directory *directory,
+			const char *utf8_name) const
+{
+#ifndef WIN32
+	const auto path_fs = map_directory_child_fs(*directory, utf8_name);
+	if (path_fs.IsNull())
+		return true;
+
+	const auto target = ReadLink(path_fs);
+	if (target.IsNull())
+		/* don't skip if this is not a symlink */
+		return errno != EINVAL;
+
+	if (!follow_inside_symlinks && !follow_outside_symlinks) {
+		/* ignore all symlinks */
+		return true;
+	} else if (follow_inside_symlinks && follow_outside_symlinks) {
+		/* consider all symlinks */
+		return false;
+	}
+
+	const char *target_str = target.c_str();
+
+	if (PathTraitsFS::IsAbsolute(target_str)) {
+		/* if the symlink points to an absolute path, see if
+		   that path is inside the music directory */
+		const char *relative = map_to_relative_path(target_str);
+		return relative > target_str
+			? !follow_inside_symlinks
+			: !follow_outside_symlinks;
+	}
+
+	const char *p = target_str;
+	while (*p == '.') {
+		if (p[1] == '.' && PathTraitsFS::IsSeparator(p[2])) {
+			/* "../" moves to parent directory */
+			directory = directory->parent;
+			if (directory == nullptr) {
+				/* we have moved outside the music
+				   directory - skip this symlink
+				   if such symlinks are not allowed */
+				return !follow_outside_symlinks;
+			}
+			p += 3;
+		} else if (PathTraitsFS::IsSeparator(p[1]))
+			/* eliminate "./" */
+			p += 2;
+		else
+			break;
+	}
+
+	/* we are still in the music directory, so this symlink points
+	   to a song which is already in the database - skip according
+	   to the follow_inside_symlinks param*/
+	return !follow_inside_symlinks;
+#else
+	/* no symlink checking on WIN32 */
+
+	(void)directory;
+	(void)utf8_name;
+
+	return false;
+#endif
+}
+
+bool
+UpdateWalk::UpdateDirectory(Directory &directory, const struct stat *st)
+{
+	assert(S_ISDIR(st->st_mode));
+
+	directory_set_stat(directory, st);
+
+	const auto path_fs = map_directory_fs(directory);
+	if (path_fs.IsNull())
+		return false;
+
+	DirectoryReader reader(path_fs);
+	if (reader.HasFailed()) {
+		int error = errno;
+		const auto path_utf8 = path_fs.ToUTF8();
+		FormatErrno(update_domain, error,
+			    "Failed to open directory %s",
+			    path_utf8.c_str());
+		return false;
+	}
+
+	ExcludeList exclude_list;
+	exclude_list.LoadFile(AllocatedPath::Build(path_fs, ".mpdignore"));
+
+	if (!exclude_list.IsEmpty())
+		RemoveExcludedFromDirectory(directory, exclude_list);
+
+	PurgeDeletedFromDirectory(directory);
+
+	while (reader.ReadEntry()) {
+		std::string utf8;
+		struct stat st2;
+
+		const auto entry = reader.GetEntry();
+
+		if (skip_path(entry) || exclude_list.Check(entry))
+			continue;
+
+		utf8 = entry.ToUTF8();
+		if (utf8.empty())
+			continue;
+
+		if (SkipSymlink(&directory, utf8.c_str())) {
+			modified |= editor.DeleteNameIn(directory, utf8.c_str());
+			continue;
+		}
+
+		if (stat_directory_child(directory, utf8.c_str(), &st2) == 0)
+			UpdateDirectoryChild(directory, utf8.c_str(), &st2);
+		else
+			modified |= editor.DeleteNameIn(directory, utf8.c_str());
+	}
+
+	directory.mtime = st->st_mtime;
+
+	return true;
+}
+
+inline Directory *
+UpdateWalk::DirectoryMakeChildChecked(Directory &parent, const char *name_utf8)
+{
+	db_lock();
+	Directory *directory = parent.FindChild(name_utf8);
+	db_unlock();
+
+	if (directory != nullptr)
+		return directory;
+
+	struct stat st;
+	if (stat_directory_child(parent, name_utf8, &st) < 0 ||
+	    find_inode_ancestor(&parent, st.st_ino, st.st_dev))
+		return nullptr;
+
+	if (SkipSymlink(&parent, name_utf8))
+		return nullptr;
+
+	/* if we're adding directory paths, make sure to delete filenames
+	   with potentially the same name */
+	db_lock();
+	Song *conflicting = parent.FindSong(name_utf8);
+	if (conflicting)
+		editor.DeleteSong(parent, conflicting);
+
+	directory = parent.CreateChild(name_utf8);
+	db_unlock();
+
+	directory_set_stat(*directory, &st);
+	return directory;
+}
+
+inline Directory *
+UpdateWalk::DirectoryMakeUriParentChecked(const char *uri)
+{
+	Directory *directory = db_get_root();
+	char *duplicated = xstrdup(uri);
+	char *name_utf8 = duplicated, *slash;
+
+	while ((slash = strchr(name_utf8, '/')) != nullptr) {
+		*slash = 0;
+
+		if (*name_utf8 == 0)
+			continue;
+
+		directory = DirectoryMakeChildChecked(*directory,
+						      name_utf8);
+		if (directory == nullptr)
+			break;
+
+		name_utf8 = slash + 1;
+	}
+
+	free(duplicated);
+	return directory;
+}
+
+inline void
+UpdateWalk::UpdateUri(const char *uri)
+{
+	Directory *parent = DirectoryMakeUriParentChecked(uri);
+	if (parent == nullptr)
+		return;
+
+	const char *name = PathTraitsUTF8::GetBase(uri);
+
+	struct stat st;
+	if (!SkipSymlink(parent, name) &&
+	    stat_directory_child(*parent, name, &st) == 0)
+		UpdateDirectoryChild(*parent, name, &st);
+	else
+		modified |= editor.DeleteNameIn(*parent, name);
+}
+
+bool
+UpdateWalk::Walk(const char *path, bool discard)
+{
+	walk_discard = discard;
+	modified = false;
+
+	if (path != nullptr && !isRootDirectory(path)) {
+		UpdateUri(path);
+	} else {
+		Directory *directory = db_get_root();
+		struct stat st;
+
+		if (stat_directory(*directory, &st) == 0)
+			UpdateDirectory(*directory, &st);
+	}
+
+	return modified;
+}