Move:...

chrome/browser/file_path_watcher_inotify.cc

Index: chrome/browser/file_path_watcher_inotify.cc
===================================================================
--- chrome/browser/file_path_watcher_inotify.cc	(revision 68044)
+++ chrome/browser/file_path_watcher_inotify.cc	(working copy)
@@ -1,410 +0,0 @@
-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "chrome/browser/file_path_watcher.h"
-
-#include <errno.h>
-#include <string.h>
-#include <sys/inotify.h>
-#include <sys/ioctl.h>
-#include <sys/select.h>
-#include <unistd.h>
-
-#include <algorithm>
-#include <set>
-#include <utility>
-#include <vector>
-
-#include "base/eintr_wrapper.h"
-#include "base/file_path.h"
-#include "base/file_util.h"
-#include "base/hash_tables.h"
-#include "base/lock.h"
-#include "base/logging.h"
-#include "base/message_loop.h"
-#include "base/scoped_ptr.h"
-#include "base/singleton.h"
-#include "base/task.h"
-#include "base/thread.h"
-
-namespace {
-
-class FilePathWatcherImpl;
-
-// Singleton to manage all inotify watches.
-// TODO(tony): It would be nice if this wasn't a singleton.
-// http://crbug.com/38174
-class InotifyReader {
- public:
-  typedef int Watch;  // Watch descriptor used by AddWatch and RemoveWatch.
-  static const Watch kInvalidWatch = -1;
-
-  // Watch directory |path| for changes. |watcher| will be notified on each
-  // change. Returns kInvalidWatch on failure.
-  Watch AddWatch(const FilePath& path, FilePathWatcherImpl* watcher);
-
-  // Remove |watch|. Returns true on success.
-  bool RemoveWatch(Watch watch, FilePathWatcherImpl* watcher);
-
-  // Callback for InotifyReaderTask.
-  void OnInotifyEvent(const inotify_event* event);
-
- private:
-  friend struct DefaultSingletonTraits<InotifyReader>;
-
-  typedef std::set<FilePathWatcherImpl*> WatcherSet;
-
-  InotifyReader();
-  ~InotifyReader();
-
-  // We keep track of which delegates want to be notified on which watches.
-  base::hash_map<Watch, WatcherSet> watchers_;
-
-  // Lock to protect watchers_.
-  Lock lock_;
-
-  // Separate thread on which we run blocking read for inotify events.
-  base::Thread thread_;
-
-  // File descriptor returned by inotify_init.
-  const int inotify_fd_;
-
-  // Use self-pipe trick to unblock select during shutdown.
-  int shutdown_pipe_[2];
-
-  // Flag set to true when startup was successful.
-  bool valid_;
-
-  DISALLOW_COPY_AND_ASSIGN(InotifyReader);
-};
-
-class FilePathWatcherImpl : public FilePathWatcher::PlatformDelegate {
- public:
-  FilePathWatcherImpl();
-  virtual ~FilePathWatcherImpl() {}
-
-  // Called for each event coming from the watch. |fired_watch| identifies the
-  // watch that fired, |child| indicates what has changed, and is relative to
-  // the currently watched path for |fired_watch|. The flag |created| is true if
-  // the object appears, and |is_directory| is set when the event refers to a
-  // directory.
-  void OnFilePathChanged(InotifyReader::Watch fired_watch,
-                         const FilePath::StringType& child,
-                         bool created,
-                         bool is_directory);
-
-  // Start watching |path| for changes and notify |delegate| on each change.
-  // Returns true if watch for |path| has been added successfully.
-  virtual bool Watch(const FilePath& path, FilePathWatcher::Delegate* delegate);
-
-  // Cancel the watch. This unregisters the instance with InotifyReader.
-  virtual void Cancel();
-
- private:
-  // Inotify watches are installed for all directory components of |target_|. A
-  // WatchEntry instance holds the watch descriptor for a component and the
-  // subdirectory for that identifies the next component.
-  struct WatchEntry {
-    WatchEntry(InotifyReader::Watch watch, const FilePath::StringType& subdir)
-        : watch_(watch),
-          subdir_(subdir) {}
-
-    InotifyReader::Watch watch_;
-    FilePath::StringType subdir_;
-  };
-  typedef std::vector<WatchEntry> WatchVector;
-
-  // Reconfigure to watch for the most specific parent directory of |target_|
-  // that exists. Updates |watched_path_|. Returns true on success.
-  bool UpdateWatches() WARN_UNUSED_RESULT;
-
-  // Delegate to notify upon changes.
-  scoped_refptr<FilePathWatcher::Delegate> delegate_;
-
-  // The file or directory we're supposed to watch.
-  FilePath target_;
-
-  // The vector of watches and next component names for all path components,
-  // starting at the root directory. The last entry corresponds to the watch for
-  // |target_| and always stores an empty next component name in |subdir_|.
-  WatchVector watches_;
-
-  DISALLOW_COPY_AND_ASSIGN(FilePathWatcherImpl);
-};
-
-class InotifyReaderTask : public Task {
- public:
-  InotifyReaderTask(InotifyReader* reader, int inotify_fd, int shutdown_fd)
-      : reader_(reader),
-        inotify_fd_(inotify_fd),
-        shutdown_fd_(shutdown_fd) {
-  }
-
-  virtual void Run() {
-    while (true) {
-      fd_set rfds;
-      FD_ZERO(&rfds);
-      FD_SET(inotify_fd_, &rfds);
-      FD_SET(shutdown_fd_, &rfds);
-
-      // Wait until some inotify events are available.
-      int select_result =
-        HANDLE_EINTR(select(std::max(inotify_fd_, shutdown_fd_) + 1,
-                            &rfds, NULL, NULL, NULL));
-      if (select_result < 0) {
-        DPLOG(WARNING) << "select failed";
-        return;
-      }
-
-      if (FD_ISSET(shutdown_fd_, &rfds))
-        return;
-
-      // Adjust buffer size to current event queue size.
-      int buffer_size;
-      int ioctl_result = HANDLE_EINTR(ioctl(inotify_fd_, FIONREAD,
-                                            &buffer_size));
-
-      if (ioctl_result != 0) {
-        DPLOG(WARNING) << "ioctl failed";
-        return;
-      }
-
-      std::vector<char> buffer(buffer_size);
-
-      ssize_t bytes_read = HANDLE_EINTR(read(inotify_fd_, &buffer[0],
-                                             buffer_size));
-
-      if (bytes_read < 0) {
-        DPLOG(WARNING) << "read from inotify fd failed";
-        return;
-      }
-
-      ssize_t i = 0;
-      while (i < bytes_read) {
-        inotify_event* event = reinterpret_cast<inotify_event*>(&buffer[i]);
-        size_t event_size = sizeof(inotify_event) + event->len;
-        DCHECK(i + event_size <= static_cast<size_t>(bytes_read));
-        reader_->OnInotifyEvent(event);
-        i += event_size;
-      }
-    }
-  }
-
- private:
-  InotifyReader* reader_;
-  int inotify_fd_;
-  int shutdown_fd_;
-
-  DISALLOW_COPY_AND_ASSIGN(InotifyReaderTask);
-};
-
-InotifyReader::InotifyReader()
-    : thread_("inotify_reader"),
-      inotify_fd_(inotify_init()),
-      valid_(false) {
-  shutdown_pipe_[0] = -1;
-  shutdown_pipe_[1] = -1;
-  if (inotify_fd_ >= 0 && pipe(shutdown_pipe_) == 0 && thread_.Start()) {
-    thread_.message_loop()->PostTask(
-        FROM_HERE, new InotifyReaderTask(this, inotify_fd_, shutdown_pipe_[0]));
-    valid_ = true;
-  }
-}
-
-InotifyReader::~InotifyReader() {
-  if (valid_) {
-    // Write to the self-pipe so that the select call in InotifyReaderTask
-    // returns.
-    ssize_t ret = HANDLE_EINTR(write(shutdown_pipe_[1], "", 1));
-    DPCHECK(ret > 0);
-    DCHECK_EQ(ret, 1);
-    thread_.Stop();
-  }
-  if (inotify_fd_ >= 0)
-    close(inotify_fd_);
-  if (shutdown_pipe_[0] >= 0)
-    close(shutdown_pipe_[0]);
-  if (shutdown_pipe_[1] >= 0)
-    close(shutdown_pipe_[1]);
-}
-
-InotifyReader::Watch InotifyReader::AddWatch(
-    const FilePath& path, FilePathWatcherImpl* watcher) {
-  if (!valid_)
-    return kInvalidWatch;
-
-  AutoLock auto_lock(lock_);
-
-  Watch watch = inotify_add_watch(inotify_fd_, path.value().c_str(),
-                                  IN_CREATE | IN_DELETE |
-                                  IN_CLOSE_WRITE | IN_MOVE |
-                                  IN_ONLYDIR);
-
-  if (watch == kInvalidWatch)
-    return kInvalidWatch;
-
-  watchers_[watch].insert(watcher);
-
-  return watch;
-}
-
-bool InotifyReader::RemoveWatch(Watch watch,
-                                FilePathWatcherImpl* watcher) {
-  if (!valid_)
-    return false;
-
-  AutoLock auto_lock(lock_);
-
-  watchers_[watch].erase(watcher);
-
-  if (watchers_[watch].empty()) {
-    watchers_.erase(watch);
-    return (inotify_rm_watch(inotify_fd_, watch) == 0);
-  }
-
-  return true;
-}
-
-void InotifyReader::OnInotifyEvent(const inotify_event* event) {
-  if (event->mask & IN_IGNORED)
-    return;
-
-  FilePath::StringType child(event->len ? event->name : FILE_PATH_LITERAL(""));
-  AutoLock auto_lock(lock_);
-
-  for (WatcherSet::iterator watcher = watchers_[event->wd].begin();
-       watcher != watchers_[event->wd].end();
-       ++watcher) {
-    BrowserThread::PostTask(BrowserThread::FILE, FROM_HERE,
-        NewRunnableMethod(*watcher,
-                          &FilePathWatcherImpl::OnFilePathChanged,
-                          event->wd,
-                          child,
-                          event->mask & (IN_CREATE | IN_MOVED_TO),
-                          event->mask & IN_ISDIR));
-  }
-}
-
-FilePathWatcherImpl::FilePathWatcherImpl()
-    : delegate_(NULL) {
-}
-
-void FilePathWatcherImpl::OnFilePathChanged(InotifyReader::Watch fired_watch,
-                                            const FilePath::StringType& child,
-                                            bool created,
-                                            bool is_directory) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
-
-  // Find the entry in |watches_| that corresponds to |fired_watch|.
-  WatchVector::const_iterator watch_entry(watches_.begin());
-  for ( ; watch_entry != watches_.end(); ++watch_entry) {
-    if (fired_watch == watch_entry->watch_)
-      break;
-  }
-
-  // If this notification is from a previous generation of watches or the watch
-  // has been cancelled (|watches_| is empty then), bail out.
-  if (watch_entry == watches_.end())
-    return;
-
-  // Check whether a path component of |target_| changed.
-  bool change_on_target_path = child.empty() || child == watch_entry->subdir_;
-
-  // Check whether the change references |target_| or a direct child.
-  DCHECK(watch_entry->subdir_.empty() || (watch_entry + 1) != watches_.end());
-  bool target_changed = watch_entry->subdir_.empty() ||
-      (watch_entry->subdir_ == child && (++watch_entry)->subdir_.empty());
-
-  // Update watches if a directory component of the |target_| path (dis)appears.
-  if (is_directory && change_on_target_path && !UpdateWatches()) {
-    delegate_->OnError();
-    return;
-  }
-
-  // Report the following events:
-  //  - The target or a direct child of the target got changed (in case the
-  //    watched path refers to a directory).
-  //  - One of the parent directories got moved or deleted, since the target
-  //    disappears in this case.
-  //  - One of the parent directories appears. The event corresponding to the
-  //    target appearing might have been missed in this case, so recheck.
-  if (target_changed ||
-      (change_on_target_path && !created) ||
-      (change_on_target_path && file_util::PathExists(target_))) {
-    delegate_->OnFilePathChanged(target_);
-  }
-}
-
-bool FilePathWatcherImpl::Watch(const FilePath& path,
-                                FilePathWatcher::Delegate* delegate) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
-  DCHECK(target_.empty());
-
-  delegate_ = delegate;
-  target_ = path;
-  std::vector<FilePath::StringType> comps;
-  target_.GetComponents(&comps);
-  DCHECK(!comps.empty());
-  for (std::vector<FilePath::StringType>::const_iterator comp(++comps.begin());
-       comp != comps.end(); ++comp) {
-    watches_.push_back(WatchEntry(InotifyReader::kInvalidWatch, *comp));
-  }
-  watches_.push_back(WatchEntry(InotifyReader::kInvalidWatch,
-                                FilePath::StringType()));
-  return UpdateWatches();
-}
-
-void FilePathWatcherImpl::Cancel() {
-  // Switch to the file thread if necessary so we can access |watches_|.
-  if (!BrowserThread::CurrentlyOn(BrowserThread::FILE)) {
-    BrowserThread::PostTask(BrowserThread::FILE, FROM_HERE,
-        NewRunnableMethod(this, &FilePathWatcherImpl::Cancel));
-    return;
-  }
-
-  for (WatchVector::iterator watch_entry(watches_.begin());
-       watch_entry != watches_.end(); ++watch_entry) {
-    if (watch_entry->watch_ != InotifyReader::kInvalidWatch)
-      Singleton<InotifyReader>::get()->RemoveWatch(watch_entry->watch_, this);
-  }
-  watches_.clear();
-  delegate_ = NULL;
-  target_.clear();
-}
-
-bool FilePathWatcherImpl::UpdateWatches() {
-  // Ensure this runs on the file thread exclusively in order to avoid
-  // concurrency issues.
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
-
-  // Walk the list of watches and update them as we go.
-  FilePath path(FILE_PATH_LITERAL("/"));
-  bool path_valid = true;
-  for (WatchVector::iterator watch_entry(watches_.begin());
-       watch_entry != watches_.end(); ++watch_entry) {
-    InotifyReader::Watch old_watch = watch_entry->watch_;
-    if (path_valid) {
-      watch_entry->watch_ =
-          Singleton<InotifyReader>::get()->AddWatch(path, this);
-      if (watch_entry->watch_ == InotifyReader::kInvalidWatch) {
-        path_valid = false;
-      }
-    } else {
-      watch_entry->watch_ = InotifyReader::kInvalidWatch;
-    }
-    if (old_watch != InotifyReader::kInvalidWatch &&
-        old_watch != watch_entry->watch_) {
-      Singleton<InotifyReader>::get()->RemoveWatch(old_watch, this);
-    }
-    path = path.Append(watch_entry->subdir_);
-  }
-
-  return true;
-}
-
-}  // namespace
-
-FilePathWatcher::FilePathWatcher() {
-  impl_ = new FilePathWatcherImpl();
-}