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-rw-r--r--src/db/update/InotifyUpdate.cxx339
1 files changed, 339 insertions, 0 deletions
diff --git a/src/db/update/InotifyUpdate.cxx b/src/db/update/InotifyUpdate.cxx
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+++ b/src/db/update/InotifyUpdate.cxx
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+/*
+ * 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 "InotifyUpdate.hxx"
+#include "InotifySource.hxx"
+#include "InotifyQueue.hxx"
+#include "InotifyDomain.hxx"
+#include "Mapper.hxx"
+#include "Main.hxx"
+#include "fs/AllocatedPath.hxx"
+#include "fs/FileSystem.hxx"
+#include "util/Error.hxx"
+#include "Log.hxx"
+
+#include <string>
+#include <map>
+#include <forward_list>
+
+#include <assert.h>
+#include <sys/inotify.h>
+#include <sys/stat.h>
+#include <string.h>
+#include <dirent.h>
+
+static constexpr unsigned IN_MASK =
+#ifdef IN_ONLYDIR
+ IN_ONLYDIR|
+#endif
+ IN_ATTRIB|IN_CLOSE_WRITE|IN_CREATE|IN_DELETE|IN_DELETE_SELF
+ |IN_MOVE|IN_MOVE_SELF;
+
+struct WatchDirectory {
+ WatchDirectory *parent;
+
+ AllocatedPath name;
+
+ int descriptor;
+
+ std::forward_list<WatchDirectory> children;
+
+ template<typename N>
+ WatchDirectory(WatchDirectory *_parent, N &&_name,
+ int _descriptor)
+ :parent(_parent), name(std::forward<N>(_name)),
+ descriptor(_descriptor) {}
+
+ WatchDirectory(const WatchDirectory &) = delete;
+ WatchDirectory &operator=(const WatchDirectory &) = delete;
+};
+
+static InotifySource *inotify_source;
+static InotifyQueue *inotify_queue;
+
+static unsigned inotify_max_depth;
+static WatchDirectory *inotify_root;
+static std::map<int, WatchDirectory *> inotify_directories;
+
+static void
+tree_add_watch_directory(WatchDirectory *directory)
+{
+ inotify_directories.insert(std::make_pair(directory->descriptor,
+ directory));
+}
+
+static void
+tree_remove_watch_directory(WatchDirectory *directory)
+{
+ auto i = inotify_directories.find(directory->descriptor);
+ assert(i != inotify_directories.end());
+ inotify_directories.erase(i);
+}
+
+static WatchDirectory *
+tree_find_watch_directory(int wd)
+{
+ auto i = inotify_directories.find(wd);
+ if (i == inotify_directories.end())
+ return nullptr;
+
+ return i->second;
+}
+
+static void
+disable_watch_directory(WatchDirectory &directory)
+{
+ tree_remove_watch_directory(&directory);
+
+ for (WatchDirectory &child : directory.children)
+ disable_watch_directory(child);
+
+ inotify_source->Remove(directory.descriptor);
+}
+
+static void
+remove_watch_directory(WatchDirectory *directory)
+{
+ assert(directory != nullptr);
+
+ if (directory->parent == nullptr) {
+ LogWarning(inotify_domain,
+ "music directory was removed - "
+ "cannot continue to watch it");
+ return;
+ }
+
+ disable_watch_directory(*directory);
+
+ /* remove it from the parent, which effectively deletes it */
+ directory->parent->children.remove_if([directory](const WatchDirectory &child){
+ return &child == directory;
+ });
+}
+
+static AllocatedPath
+watch_directory_get_uri_fs(const WatchDirectory *directory)
+{
+ if (directory->parent == nullptr)
+ return AllocatedPath::Null();
+
+ const auto uri = watch_directory_get_uri_fs(directory->parent);
+ if (uri.IsNull())
+ return directory->name;
+
+ return AllocatedPath::Build(uri, directory->name);
+}
+
+/* we don't look at "." / ".." nor files with newlines in their name */
+static bool skip_path(const char *path)
+{
+ return (path[0] == '.' && path[1] == 0) ||
+ (path[0] == '.' && path[1] == '.' && path[2] == 0) ||
+ strchr(path, '\n') != nullptr;
+}
+
+static void
+recursive_watch_subdirectories(WatchDirectory *directory,
+ const AllocatedPath &path_fs, unsigned depth)
+{
+ Error error;
+ DIR *dir;
+ struct dirent *ent;
+
+ assert(directory != nullptr);
+ assert(depth <= inotify_max_depth);
+ assert(!path_fs.IsNull());
+
+ ++depth;
+
+ if (depth > inotify_max_depth)
+ return;
+
+ dir = opendir(path_fs.c_str());
+ if (dir == nullptr) {
+ FormatErrno(inotify_domain,
+ "Failed to open directory %s", path_fs.c_str());
+ return;
+ }
+
+ while ((ent = readdir(dir))) {
+ struct stat st;
+ int ret;
+
+ if (skip_path(ent->d_name))
+ continue;
+
+ const auto child_path_fs =
+ AllocatedPath::Build(path_fs, ent->d_name);
+ ret = StatFile(child_path_fs, st);
+ if (ret < 0) {
+ FormatErrno(inotify_domain,
+ "Failed to stat %s",
+ child_path_fs.c_str());
+ continue;
+ }
+
+ if (!S_ISDIR(st.st_mode))
+ continue;
+
+ ret = inotify_source->Add(child_path_fs.c_str(), IN_MASK,
+ error);
+ if (ret < 0) {
+ FormatError(error,
+ "Failed to register %s",
+ child_path_fs.c_str());
+ error.Clear();
+ continue;
+ }
+
+ WatchDirectory *child = tree_find_watch_directory(ret);
+ if (child != nullptr)
+ /* already being watched */
+ continue;
+
+ directory->children.emplace_front(directory,
+ AllocatedPath::FromFS(ent->d_name),
+ ret);
+ child = &directory->children.front();
+
+ tree_add_watch_directory(child);
+
+ recursive_watch_subdirectories(child, child_path_fs, depth);
+ }
+
+ closedir(dir);
+}
+
+gcc_pure
+static unsigned
+watch_directory_depth(const WatchDirectory *d)
+{
+ assert(d != nullptr);
+
+ unsigned depth = 0;
+ while ((d = d->parent) != nullptr)
+ ++depth;
+
+ return depth;
+}
+
+static void
+mpd_inotify_callback(int wd, unsigned mask,
+ gcc_unused const char *name, gcc_unused void *ctx)
+{
+ WatchDirectory *directory;
+
+ /*FormatDebug(inotify_domain, "wd=%d mask=0x%x name='%s'", wd, mask, name);*/
+
+ directory = tree_find_watch_directory(wd);
+ if (directory == nullptr)
+ return;
+
+ const auto uri_fs = watch_directory_get_uri_fs(directory);
+
+ if ((mask & (IN_DELETE_SELF|IN_MOVE_SELF)) != 0) {
+ remove_watch_directory(directory);
+ return;
+ }
+
+ if ((mask & (IN_ATTRIB|IN_CREATE|IN_MOVE)) != 0 &&
+ (mask & IN_ISDIR) != 0) {
+ /* a sub directory was changed: register those in
+ inotify */
+ const auto &root = mapper_get_music_directory_fs();
+
+ const auto path_fs = uri_fs.IsNull()
+ ? root
+ : AllocatedPath::Build(root, uri_fs.c_str());
+
+ recursive_watch_subdirectories(directory, path_fs,
+ watch_directory_depth(directory));
+ }
+
+ if ((mask & (IN_CLOSE_WRITE|IN_MOVE|IN_DELETE)) != 0 ||
+ /* at the maximum depth, we watch out for newly created
+ directories */
+ (watch_directory_depth(directory) == inotify_max_depth &&
+ (mask & (IN_CREATE|IN_ISDIR)) == (IN_CREATE|IN_ISDIR))) {
+ /* a file was changed, or a directory was
+ moved/deleted: queue a database update */
+
+ if (!uri_fs.IsNull()) {
+ const std::string uri_utf8 = uri_fs.ToUTF8();
+ if (!uri_utf8.empty())
+ inotify_queue->Enqueue(uri_utf8.c_str());
+ }
+ else
+ inotify_queue->Enqueue("");
+ }
+}
+
+void
+mpd_inotify_init(unsigned max_depth)
+{
+ LogDebug(inotify_domain, "initializing inotify");
+
+ const auto &path = mapper_get_music_directory_fs();
+ if (path.IsNull()) {
+ LogDebug(inotify_domain, "no music directory configured");
+ return;
+ }
+
+ Error error;
+ inotify_source = InotifySource::Create(*main_loop,
+ mpd_inotify_callback, nullptr,
+ error);
+ if (inotify_source == nullptr) {
+ LogError(error);
+ return;
+ }
+
+ inotify_max_depth = max_depth;
+
+ int descriptor = inotify_source->Add(path.c_str(), IN_MASK, error);
+ if (descriptor < 0) {
+ LogError(error);
+ delete inotify_source;
+ inotify_source = nullptr;
+ return;
+ }
+
+ inotify_root = new WatchDirectory(nullptr, path, descriptor);
+
+ tree_add_watch_directory(inotify_root);
+
+ recursive_watch_subdirectories(inotify_root, path, 0);
+
+ inotify_queue = new InotifyQueue(*main_loop);
+
+ LogDebug(inotify_domain, "watching music directory");
+}
+
+void
+mpd_inotify_finish(void)
+{
+ if (inotify_source == nullptr)
+ return;
+
+ delete inotify_queue;
+ delete inotify_source;
+ delete inotify_root;
+ inotify_directories.clear();
+}