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Diffstat (limited to '')
| -rw-r--r-- | src/db/update/InotifyUpdate.cxx | 344 |
1 files changed, 344 insertions, 0 deletions
diff --git a/src/db/update/InotifyUpdate.cxx b/src/db/update/InotifyUpdate.cxx new file mode 100644 index 000000000..26bdddf8d --- /dev/null +++ b/src/db/update/InotifyUpdate.cxx @@ -0,0 +1,344 @@ +/* + * 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 "storage/StorageInterface.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; + + gcc_pure + unsigned GetDepth() const; + + gcc_pure + AllocatedPath GetUriFS() const; +}; + +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; + }); +} + +AllocatedPath +WatchDirectory::GetUriFS() const +{ + if (parent == nullptr) + return AllocatedPath::Null(); + + const auto uri = parent->GetUriFS(); + if (uri.IsNull()) + return name; + + return AllocatedPath::Build(uri, 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 +unsigned +WatchDirectory::GetDepth() const +{ + const WatchDirectory *d = this; + 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 = directory->GetUriFS(); + + 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 = inotify_root->name; + + const auto path_fs = uri_fs.IsNull() + ? root + : AllocatedPath::Build(root, uri_fs.c_str()); + + recursive_watch_subdirectories(directory, path_fs, + directory->GetDepth()); + } + + if ((mask & (IN_CLOSE_WRITE|IN_MOVE|IN_DELETE)) != 0 || + /* at the maximum depth, we watch out for newly created + directories */ + (directory->GetDepth() == 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(EventLoop &loop, Storage &storage, UpdateService &update, + unsigned max_depth) +{ + LogDebug(inotify_domain, "initializing inotify"); + + const auto path = storage.MapFS(""); + if (path.IsNull()) { + LogDebug(inotify_domain, "no music directory configured"); + return; + } + + Error error; + inotify_source = InotifySource::Create(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(loop, update); + + 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(); +} |