Add CrosDisksClient

chrome/browser/chromeos/disks/disk_mount_manager.cc

Index: chrome/browser/chromeos/disks/disk_mount_manager.cc
diff --git a/chrome/browser/chromeos/disks/disk_mount_manager.cc b/chrome/browser/chromeos/disks/disk_mount_manager.cc
new file mode 100644
index 0000000000000000000000000000000000000000..61fe34d8672b8546a3d9fa06773ce7d7ab00fb37
--- /dev/null
+++ b/chrome/browser/chromeos/disks/disk_mount_manager.cc
@@ -0,0 +1,651 @@
+// Copyright (c) 2011 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/chromeos/disks/disk_mount_manager.h"
+
+#include <map>
+#include <set>
+
+#include <sys/statvfs.h>
+
+#include "base/bind.h"
+#include "base/string_util.h"
+#include "chrome/browser/chromeos/dbus/dbus_thread_manager.h"
+#include "content/public/browser/browser_thread.h"
+
+using content::BrowserThread;
+
+namespace chromeos {
+
+namespace {
+
+const char* kDeviceNotFound = "Device could not be found";

[satorux1, 2011/11/11 19:01:48]

For an obscure reason I cannot explain, the following is slightly more
efficient:

const char kDeviceNotFound[] = "Device could not be found";

See http://udrepper.livejournal.com/13851.html

[hashimoto, 2011/11/14 13:52:45]

Done.

Thank you for the pointer.
Besides the efficiency, const correctness is another good point about using
const char[] instead of const char* because const char[] is not modifieable
while const char* is.

+
+DiskMountManager* g_disk_mount_manager = NULL;
+
+// The DiskMountManager implementation.
+class DiskMountManagerImpl : public DiskMountManager {
+ public:
+  DiskMountManagerImpl() : weak_ptr_factory_(this) {
+    DBusThreadManager* dbus_thread_manager = DBusThreadManager::Get();
+    DCHECK(dbus_thread_manager);
+    cros_disks_client_ = dbus_thread_manager->GetCrosDisksClient();
+    DCHECK(cros_disks_client_);
+
+    cros_disks_client_->SetUpConnections(
+        base::Bind(&DiskMountManagerImpl::OnMountEvent,
+                   weak_ptr_factory_.GetWeakPtr()),
+        base::Bind(&DiskMountManagerImpl::OnMountCompleted,
+                   weak_ptr_factory_.GetWeakPtr()));
+  }
+
+  virtual ~DiskMountManagerImpl() {
+  }
+
+  // DiskMountManager override.
+  virtual void AddObserver(Observer* observer) OVERRIDE {
+    observers_.AddObserver(observer);
+  }
+
+  // DiskMountManager override.
+  virtual void RemoveObserver(Observer* observer) OVERRIDE {
+    observers_.RemoveObserver(observer);
+  }
+
+  // DiskMountManager override.
+  virtual void MountPath(const std::string& source_path,
+                         MountType type) OVERRIDE {
+    // Hidden and non-existent devices should not be mounted.
+    if (type == MOUNT_TYPE_DEVICE) {
+      DiskMap::const_iterator it = disks_.find(source_path);
+      if (it == disks_.end() || it->second->is_hidden()) {
+        OnMountCompleted(MOUNT_ERROR_INTERNAL, source_path, type, "");
+        return;
+      }
+    }
+    DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+    cros_disks_client_->Mount(
+        source_path,
+        type,
+        // When succeeds, OnMountCompleted will be called by
+        // "MountCompleted" signal instead.
+        base::Bind(&DoNothing),

[satorux1, 2011/11/11 19:01:48]

Since this class will likely be the only client of CrosDisksClient, I guess you
can remove the callback parameter, rather than passing a callback that does
nothing. That may be simpler.

[hashimoto, 2011/11/14 13:52:45]

See the comment in UnmountPath.

+        base::Bind(&DiskMountManagerImpl::OnMountCompleted,

[satorux1, 2011/11/11 19:01:48]

The function name may be misleading. OnMountFailed, may be clearer, as it's only
used when it failed.

[hashimoto, 2011/11/14 13:52:45]

OnMountCompleted is also called by MountCompleted signal.

+                   weak_ptr_factory_.GetWeakPtr(),
+                   MOUNT_ERROR_INTERNAL,
+                   source_path,
+                   type,
+                   ""));
+  }
+
+  // DiskMountManager override.
+  virtual void UnmountPath(const std::string& mount_path) OVERRIDE {
+    DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+    cros_disks_client_->Unmount(mount_path,
+                                base::Bind(&DiskMountManagerImpl::OnUnmountPath,
+                                           weak_ptr_factory_.GetWeakPtr()),
+                                base::Bind(&DoNothing));

[satorux1, 2011/11/11 19:01:48]

likewise, you might want to remove the parameter.

[hashimoto, 2011/11/14 13:52:45]

Call for Unmount here does not require error handling, however, call for Unmount
in DiskMountManagerImpl::UnmountDeviceRecursive requires error handling.

Besides Unmount, some of CrosDisksClient's methods do not require error handling
at all (EnumerateAutoMountableDevices and GetDeviceProperties) and Mount does
not require handling of success case as you say.
But, it is highly context dependent if a method call requires success/error
handling or not, like the case of Unmount.
I prefer simple success-and-error-handler-pair pattern rather than having
mixture of success-handler-only, error-handler-only and
success-and-error-handlers method signatures.

I think we should do some refactoring at first to eliminate ugly error handling
like appending "!" to indicate failure.
After the refactoring is done, we can make the error handling paths simpler and
remove the unused CrosDisksClient's callback arguments so that we no longer need
to have DoNothing.

[satorux1, 2011/11/14 17:56:23]

Thank you for the explanation. Your comment here looks valuable. Would be nice
to put this comment in the code.

[hashimoto, 2011/11/15 02:23:55]

Done.

+  }
+
+  // DiskMountManager override.
+  virtual void GetSizeStatsOnFileThread(const std::string& mount_path,
+                                        size_t* total_size_kb,
+                                        size_t* remaining_size_kb) OVERRIDE {
+    DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+
+    uint64_t total_size_uint64 = 0;

[satorux1, 2011/11/11 19:01:48]

total_size_uint64 -> total_size_in_bytes

[hashimoto, 2011/11/14 13:52:45]

Done.

+    uint64_t remaining_size_uint64 = 0;
+
+    struct statvfs stat = {};  // Zero-clear
+    if (statvfs(mount_path.c_str(), &stat) == 0) {
+      total_size_uint64 =
+          static_cast<uint64_t>(stat.f_blocks) * stat.f_frsize;
+      remaining_size_uint64 =
+          static_cast<uint64_t>(stat.f_bfree) * stat.f_frsize;
+    }
+    *total_size_kb = static_cast<size_t>(total_size_uint64 / 1024);
+    *remaining_size_kb = static_cast<size_t>(remaining_size_uint64 / 1024);
+  }
+
+  // DiskMountManager override.
+  virtual void FormatUnmountedDevice(const std::string& file_path) OVERRIDE {
+    DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+    for (DiskMountManager::DiskMap::iterator it = disks_.begin();
+         it != disks_.end(); ++it) {
+      if (it->second->file_path() == file_path &&
+          !it->second->mount_path().empty()) {
+        LOG(ERROR) << "Device is still mounted: " << file_path;
+        OnFormatDevice(file_path, false);
+        return;
+      }
+    }
+    const char kFormatVFAT[] = "vfat";
+    cros_disks_client_->FormatDevice(
+        file_path,
+        kFormatVFAT,
+        base::Bind(&DiskMountManagerImpl::OnFormatDevice,
+                   weak_ptr_factory_.GetWeakPtr()),
+        base::Bind(&DiskMountManagerImpl::OnFormatDevice,
+                   weak_ptr_factory_.GetWeakPtr(),
+                   file_path,
+                   false));
+  }
+
+  // DiskMountManager override.
+  virtual void FormatMountedDevice(const std::string& mount_path) OVERRIDE {
+    Disk* disk = NULL;
+    for (DiskMountManager::DiskMap::iterator it = disks_.begin();
+         it != disks_.end(); ++it) {
+      if (it->second->mount_path() == mount_path) {
+        disk = it->second;
+        break;
+      }
+    }
+    if (!disk) {
+      LOG(ERROR) << "Device with this mount path not found: " << mount_path;
+      OnFormatDevice(mount_path, false);
+      return;
+    }
+    if (formatting_pending_.find(disk->device_path()) !=
+        formatting_pending_.end()) {
+      LOG(ERROR) << "Formatting is already pending: " << mount_path;
+      OnFormatDevice(mount_path, false);
+      return;
+    }
+    // Formatting process continues, after unmounting.
+    formatting_pending_[disk->device_path()] = disk->file_path();
+    UnmountPath(disk->mount_path());
+  }
+
+  // DiskMountManager override.
+  virtual void UnmountDeviceRecursive(
+      const std::string& device_path,
+      UnmountDeviceRecursiveCallbackType callback,
+      void* user_data) OVERRIDE {
+    bool success = true;
+    std::string error_message;
+    std::vector<std::string> devices_to_unmount;
+
+    // Get list of all devices to unmount.
+    int device_path_len = device_path.length();
+    for (DiskMap::iterator it = disks_.begin(); it != disks_.end(); ++it) {
+      if (!it->second->mount_path().empty() &&
+          strncmp(device_path.c_str(), it->second->device_path().c_str(),
+                  device_path_len) == 0) {
+        devices_to_unmount.push_back(it->second->mount_path());
+      }
+    }
+    // We should detect at least original device.
+    if (devices_to_unmount.empty()) {
+      if (disks_.find(device_path) == disks_.end()) {
+        success = false;
+        error_message = kDeviceNotFound;
+      } else {
+        // Nothing to unmount.
+        callback(user_data, true);
+        return;
+      }
+    }
+    if (success) {
+      // We will send the same callback data object to all Unmount calls and use
+      // it to syncronize callbacks.
+      UnmountDeviceRecursiveCallbackData* cb_data =
+          new UnmountDeviceRecursiveCallbackData(user_data, callback,
+                                                 devices_to_unmount.size());
+      for (std::vector<std::string>::iterator it = devices_to_unmount.begin();
+           it != devices_to_unmount.end();
+           ++it) {

[satorux1, 2011/11/11 19:01:48]

For vectors, the following is more common and concise:

for (size_t i = 0; i < devices_to_unmount.size(); ++i)

[hashimoto, 2011/11/14 13:52:45]

Done.

+        cros_disks_client_->Unmount(
+            *it,
+            base::Bind(&DiskMountManagerImpl::OnUnmountDeviceRecursive,
+                       weak_ptr_factory_.GetWeakPtr(), cb_data, true),

[satorux1, 2011/11/11 19:01:48]

Does this compile? I think the last parameter (mount_path) is missing here.

[hashimoto, 2011/11/14 13:52:45]

It compiles because cros-disks returns the path as the response for a method
call.

[satorux1, 2011/11/14 17:56:23]

Oh you are right. I got confused as base::Bind() on the next line had one more
parameter.

+            base::Bind(&DiskMountManagerImpl::OnUnmountDeviceRecursive,
+                       weak_ptr_factory_.GetWeakPtr(), cb_data, false, *it));
+      }
+    } else {
+      LOG(WARNING) << "Unmount recursive request failed for device "
+                   << device_path << ", with error: " << error_message;
+      callback(user_data, false);
+    }
+  }
+
+  // DiskMountManager override.
+  virtual void RequestMountInfoRefresh() OVERRIDE {
+    DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+    cros_disks_client_->EnumerateAutoMountableDevices(
+        base::Bind(&DiskMountManagerImpl::OnRequestMountInfo,
+                   weak_ptr_factory_.GetWeakPtr()),
+        base::Bind(&DoNothing));
+  }
+
+  // DiskMountManager override.
+  const DiskMap& disks() const OVERRIDE { return disks_; }
+
+
+  // DiskMountManager override.
+  const MountPointMap& mount_points() const OVERRIDE { return mount_points_; }
+
+ private:
+  struct UnmountDeviceRecursiveCallbackData {
+    void* user_data;
+    UnmountDeviceRecursiveCallbackType callback;
+    size_t pending_callbacks_count;
+
+    UnmountDeviceRecursiveCallbackData(void* ud,
+                                       UnmountDeviceRecursiveCallbackType cb,
+                                       int count)
+        : user_data(ud),
+          callback(cb),
+          pending_callbacks_count(count) {
+    }
+  };
+
+  // Callback for UnmountDeviceRecursive.
+  void OnUnmountDeviceRecursive(UnmountDeviceRecursiveCallbackData* cb_data,
+                                bool success,
+                                const std::string& mount_path) {
+    if (success) {
+      // Do standard processing for Unmount event.
+      OnUnmountPath(mount_path);
+      LOG(INFO) << mount_path <<  " unmounted.";
+    }
+    // This is safe as long as all callbacks are called on the same thread as
+    // UnmountDeviceRecursive.
+    cb_data->pending_callbacks_count--;
+
+    if (cb_data->pending_callbacks_count == 0) {
+      cb_data->callback(cb_data->user_data, success);
+      delete cb_data;
+    }
+  }
+
+  // Callback to handle MountCompleted signal and Mount method call failure.
+  void OnMountCompleted(MountError error_code,
+                        const std::string& source_path,
+                        MountType type,

[satorux1, 2011/11/11 19:01:48]

type -> mount_type?

[hashimoto, 2011/11/14 13:52:45]

Done.

+                        const std::string& mount_path) {
+    MountCondition mount_condition = MOUNT_CONDITION_NONE;
+    if (type == MOUNT_TYPE_DEVICE) {
+      if (error_code == MOUNT_ERROR_UNKNOWN_FILESYSTEM)
+        mount_condition = MOUNT_CONDITION_UNKNOWN_FILESYSTEM;
+      if (error_code == MOUNT_ERROR_UNSUPORTED_FILESYSTEM)
+        mount_condition = MOUNT_CONDITION_UNSUPPORTED_FILESYSTEM;
+    }
+    const MountPointInfo mount_info(source_path, mount_path, type,
+                                    mount_condition);
+
+    NotifyMountCompleted(MOUNTING, error_code, mount_info);
+
+    // If the device is corrupted but it's still possible to format it, it will
+    // be fake mounted.
+    if ((error_code == MOUNT_ERROR_NONE || mount_info.mount_condition) &&
+        mount_points_.find(mount_info.mount_path) == mount_points_.end()) {
+      mount_points_.insert(MountPointMap::value_type(mount_info.mount_path,
+                                                     mount_info));
+    }
+    if ((error_code == MOUNT_ERROR_NONE || mount_info.mount_condition) &&
+        mount_info.mount_type == MOUNT_TYPE_DEVICE &&
+        !mount_info.source_path.empty() &&
+        !mount_info.mount_path.empty()) {
+      DiskMap::iterator iter = disks_.find(mount_info.source_path);
+      if (iter == disks_.end()) {
+        // disk might have been removed by now?
+        return;
+      }
+      Disk* disk = iter->second;
+      DCHECK(disk);
+      disk->set_mount_path(mount_info.mount_path);
+      NotifyDiskStatusUpdate(MOUNT_DISK_MOUNTED, disk);
+    }
+  }
+
+  // Callback for UnmountPath.
+  void OnUnmountPath(const std::string& mount_path) {
+    MountPointMap::iterator mount_points_it = mount_points_.find(mount_path);
+    if (mount_points_it == mount_points_.end())
+      return;
+    // TODO(tbarzic): Add separate, PathUnmounted event to Observer.
+    NotifyMountCompleted(UNMOUNTING,
+                         MOUNT_ERROR_NONE,
+                         MountPointInfo(mount_points_it->second.source_path,
+                                        mount_points_it->second.mount_path,
+                                        mount_points_it->second.mount_type,
+                                        mount_points_it->second.mount_condition)
+                         );
+    std::string path(mount_points_it->second.source_path);
+    mount_points_.erase(mount_points_it);
+    DiskMap::iterator iter = disks_.find(path);
+    if (iter == disks_.end()) {
+      // disk might have been removed by now.
+      return;
+    }
+    Disk* disk = iter->second;
+    DCHECK(disk);
+    disk->clear_mount_path();
+    // Check if there is a formatting scheduled
+    PathMap::iterator it = formatting_pending_.find(disk->device_path());
+    if (it != formatting_pending_.end()) {
+      const std::string file_path = it->second;

[satorux1, 2011/11/11 19:01:48]

You can make it a reference. 

const std::string&

[hashimoto, 2011/11/14 13:52:45]

Done.

+      formatting_pending_.erase(it);
+      FormatUnmountedDevice(file_path);
+    }
+  }
+
+  // Callback for FormatDevice.
+  void OnFormatDevice(const std::string& device_path, bool success) {
+    if (success) {
+      NotifyDeviceStatusUpdate(MOUNT_FORMATTING_STARTED, device_path);
+    } else {
+      NotifyDeviceStatusUpdate(MOUNT_FORMATTING_STARTED,
+                             std::string("!") + device_path);
+      LOG(WARNING) << "Format request failed for device " << device_path;
+    }
+  }
+
+  // Callbcak for GetDeviceProperties.
+  void OnGetDeviceProperties(const DiskInfo& disk_info) {
+    // TODO(zelidrag): Find a better way to filter these out before we
+    // fetch the properties:
+    // Ignore disks coming from the device we booted the system from.
+    if (disk_info.on_boot_device())
+      return;
+
+    LOG(WARNING) << "Found disk " << disk_info.device_path();
+    // Delete previous disk info for this path:
+    bool is_new = true;
+    DiskMap::iterator iter = disks_.find(disk_info.device_path());
+    if (iter != disks_.end()) {
+      delete iter->second;
+      disks_.erase(iter);
+      is_new = false;
+    }
+    Disk* disk = new Disk(disk_info.device_path(),
+                          disk_info.mount_path(),
+                          disk_info.system_path(),
+                          disk_info.file_path(),
+                          disk_info.label(),
+                          disk_info.drive_label(),
+                          disk_info.partition_slave(),
+                          FindSystemPathPrefix(disk_info.system_path()),
+                          disk_info.device_type(),
+                          disk_info.total_size_in_bytes(),
+                          disk_info.is_drive(),
+                          disk_info.is_read_only(),
+                          disk_info.has_media(),
+                          disk_info.on_boot_device(),
+                          disk_info.is_hidden());
+    disks_.insert(std::pair<std::string, Disk*>(disk_info.device_path(),

[satorux1, 2011/11/11 19:01:48]

disks_.insert(std::make_pair(disk_info.device_path(), disk));

[hashimoto, 2011/11/14 13:52:45]

Done.

+                                                disk));
+    NotifyDiskStatusUpdate(is_new ? MOUNT_DISK_ADDED : MOUNT_DISK_CHANGED,
+                           disk);
+  }
+
+  // Callbcak for RequestMountInfo.
+  void OnRequestMountInfo(const std::vector<std::string>& devices) {
+    std::set<std::string> current_device_set;
+    if (!devices.empty()) {
+      // Initiate properties fetch for all removable disks,
+      for (size_t i = 0; i < devices.size(); i++) {
+        current_device_set.insert(devices[i]);
+        // Initiate disk property retrieval for each relevant device path.
+        cros_disks_client_->GetDeviceProperties(
+            devices[i],
+            base::Bind(&DiskMountManagerImpl::OnGetDeviceProperties,
+                       weak_ptr_factory_.GetWeakPtr()),
+            base::Bind(&DoNothing));
+      }
+    }
+    // Search and remove disks that are no longer present.
+    for (DiskMap::iterator iter = disks_.begin(); iter != disks_.end(); ) {
+      if (current_device_set.find(iter->first) == current_device_set.end()) {
+        Disk* disk = iter->second;
+        NotifyDiskStatusUpdate(MOUNT_DISK_REMOVED, disk);
+        delete iter->second;
+        disks_.erase(iter++);
+      } else {
+        ++iter;
+      }
+    }
+  }
+
+  // Callback to handle mount event signals.
+  void OnMountEvent(MountEventType event, std::string device_path) {
+    DiskMountManagerEventType type = MOUNT_DEVICE_ADDED;
+    switch (event) {
+      case DISK_ADDED: {
+        cros_disks_client_->GetDeviceProperties(
+            device_path,
+            base::Bind(&DiskMountManagerImpl::OnGetDeviceProperties,
+                       weak_ptr_factory_.GetWeakPtr()),
+            base::Bind(&DoNothing));
+        return;
+      }
+      case DISK_REMOVED: {
+        // Search and remove disks that are no longer present.
+        DiskMountManager::DiskMap::iterator iter = disks_.find(device_path);
+        if (iter != disks_.end()) {
+          Disk* disk = iter->second;
+          NotifyDiskStatusUpdate(MOUNT_DISK_REMOVED, disk);
+          delete iter->second;
+          disks_.erase(iter);
+        }
+        return;
+      }
+      case DEVICE_ADDED: {
+        type = MOUNT_DEVICE_ADDED;
+        system_path_prefixes_.insert(device_path);
+        break;
+      }
+      case DEVICE_REMOVED: {
+        type = MOUNT_DEVICE_REMOVED;
+        system_path_prefixes_.erase(device_path);
+        break;
+      }
+      case DEVICE_SCANNED: {
+        type = MOUNT_DEVICE_SCANNED;
+        break;
+      }
+      case FORMATTING_FINISHED: {
+        // FORMATTING_FINISHED actually returns file path instead of device
+        // path.
+        device_path = FilePathToDevicePath(device_path);
+        if (device_path.empty()) {
+          LOG(ERROR) << "Error while handling disks metadata. Cannot find "
+                     << "device that is being formatted.";
+          return;
+        }
+        type = MOUNT_FORMATTING_FINISHED;
+        break;
+      }
+      default: {
+        return;

[satorux1, 2011/11/11 19:01:48]

LOG(ERROR) << "Unknown event" << event;

may be useful to have before 'return'

[hashimoto, 2011/11/14 13:52:45]

Done.

+      }
+    }
+    NotifyDeviceStatusUpdate(type, device_path);
+  }
+
+  // Notifies all observers about disk status update.
+  void NotifyDiskStatusUpdate(DiskMountManagerEventType event,
+                              const Disk* disk) {
+    // Make sure we run on UI thread.

[satorux1, 2011/11/11 19:01:48]

You can remove the comment. DCHECK(...) is clear about the intention.

[hashimoto, 2011/11/14 13:52:45]

Done.

+    DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+    FOR_EACH_OBSERVER(Observer, observers_, DiskChanged(event, disk));
+  }
+
+  // Notifies all observers about device status update.
+  void NotifyDeviceStatusUpdate(DiskMountManagerEventType event,
+                                const std::string& device_path) {
+    // Make sure we run on UI thread.
+    DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+    FOR_EACH_OBSERVER(Observer, observers_, DeviceChanged(event, device_path));
+  }
+
+  // Notifies all observers about mount completion.
+  void NotifyMountCompleted(MountEvent event_type,
+                            MountError error_code,
+                            const MountPointInfo& mount_info) {
+    // Make sure we run on UI thread.
+    DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+    FOR_EACH_OBSERVER(Observer, observers_,
+                      MountCompleted(event_type, error_code, mount_info));
+  }
+
+  // Converts file path to device path.
+  std::string FilePathToDevicePath(const std::string& file_path) {
+    int failed = (file_path[0] == '!') ? 1 : 0;

[satorux1, 2011/11/11 19:01:48]

This is unsafe if file_path is empty. What about:

const int failed = StartsWithASCII(file_path, "!", false);

[hashimoto, 2011/11/14 13:52:45]

Done.

+    for (DiskMountManager::DiskMap::iterator it = disks_.begin();
+         it != disks_.end(); ++it) {
+      if (it->second->file_path().compare(file_path.c_str() + failed) == 0) {

[satorux1, 2011/11/11 19:01:48]

The following would be easier to read?

// Skip the leading '!' on the failure case.
if (it->second->file_path() == file_path.substr(failed)) {

[hashimoto, 2011/11/14 13:52:45]

Done.

+        if (failed)
+          return std::string("!") + it->second->device_path();
+        else
+          return it->second->device_path();
+      }
+    }
+    return "";
+  }
+
+  // Finds system path prefix from |system_path|
+  const std::string& FindSystemPathPrefix(const std::string& system_path) {
+    if (system_path.empty())
+      return EmptyString();
+    for (SystemPathPrefixSet::const_iterator it = system_path_prefixes_.begin();
+         it != system_path_prefixes_.end();
+         ++it) {
+      if (system_path.find(*it, 0) == 0)

[satorux1, 2011/11/11 19:01:48]

The following would be clearer?

const std::string& prefix = *it;
if (StartsWithASCII(system_path, prefix, false))
  return prefix;

[hashimoto, 2011/11/14 13:52:45]

Why is the last argument of StartsWithASCII is false?
Shouldn't we treat file paths in case sensitive way?

[satorux1, 2011/11/14 17:56:23]

I misunderstood the meaning of the last parameter of StartsWithASCII(). This is
why boolean parameter like this is bad. I wouldn't be confused if it's an enum
like CASE_SENSITIVE or CASE_INSENSITIVE...

+        return *it;
+    }
+    return EmptyString();
+  }
+
+  // A function to be used as an empty callback
+  static void DoNothing() {
+  }
+
+  // Mount event change observers.
+  ObserverList<Observer> observers_;
+
+  CrosDisksClient* cros_disks_client_;
+
+  // The list of disks found.
+  DiskMountManager::DiskMap disks_;
+
+  DiskMountManager::MountPointMap mount_points_;
+
+  typedef std::set<std::string> SystemPathPrefixSet;
+  SystemPathPrefixSet system_path_prefixes_;
+
+  // Set of devices that are supposed to be formated, but are currently waiting
+  // to be unmounted. When device is in this map, the formatting process HAVEN'T
+  // started yet.
+  PathMap formatting_pending_;

[satorux1, 2011/11/11 19:01:48]

This looks like a map of device_path -> file_path. Could you add some comment on
it, with some example?

[hashimoto, 2011/11/14 13:52:45]

Done.

+
+  base::WeakPtrFactory<DiskMountManagerImpl> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(DiskMountManagerImpl);
+};
+
+} // namespace
+
+DiskMountManager::Disk::Disk(const std::string& device_path,
+                             const std::string& mount_path,
+                             const std::string& system_path,
+                             const std::string& file_path,
+                             const std::string& device_label,
+                             const std::string& drive_label,
+                             const std::string& parent_path,
+                             const std::string& system_path_prefix,
+                             DeviceType device_type,
+                             uint64 total_size_in_bytes,
+                             bool is_parent,
+                             bool is_read_only,
+                             bool has_media,
+                             bool on_boot_device,
+                             bool is_hidden)
+    : device_path_(device_path),
+      mount_path_(mount_path),
+      system_path_(system_path),
+      file_path_(file_path),
+      device_label_(device_label),
+      drive_label_(drive_label),
+      parent_path_(parent_path),
+      system_path_prefix_(system_path_prefix),
+      device_type_(device_type),
+      total_size_in_bytes_(total_size_in_bytes),
+      is_parent_(is_parent),
+      is_read_only_(is_read_only),
+      has_media_(has_media),
+      on_boot_device_(on_boot_device),
+      is_hidden_(is_hidden) {
+}
+
+DiskMountManager::Disk::~Disk() {}
+
+// static
+std::string DiskMountManager::MountTypeToString(MountType type) {
+  switch (type) {
+    case MOUNT_TYPE_DEVICE:
+      return "device";
+    case MOUNT_TYPE_ARCHIVE:
+      return "file";
+    case MOUNT_TYPE_NETWORK_STORAGE:
+      return "network";
+    case MOUNT_TYPE_INVALID:
+      return "invalid";
+    default:
+      NOTREACHED();
+  }
+  return "";
+}
+
+// static
+std::string DiskMountManager::MountConditionToString(MountCondition condition) {
+  switch (condition) {
+    case MOUNT_CONDITION_NONE:
+      return "";
+    case MOUNT_CONDITION_UNKNOWN_FILESYSTEM:
+      return "unknown_filesystem";
+    case MOUNT_CONDITION_UNSUPPORTED_FILESYSTEM:
+      return "unsupported_filesystem";
+    default:
+      NOTREACHED();
+  }
+  return "";
+}
+
+// static
+MountType DiskMountManager::MountTypeFromString(const std::string& type_str) {
+  if (type_str == "device")
+    return MOUNT_TYPE_DEVICE;
+  else if (type_str == "network")
+    return MOUNT_TYPE_NETWORK_STORAGE;
+  else if (type_str == "file")
+    return MOUNT_TYPE_ARCHIVE;
+  else
+    return MOUNT_TYPE_INVALID;
+}
+
+// static
+void DiskMountManager::Initialize() {
+  VLOG(1) << "DiskMountManager::Initialize";
+  DCHECK(!g_disk_mount_manager);
+  g_disk_mount_manager = new DiskMountManagerImpl();
+  DCHECK(g_disk_mount_manager);
+}
+
+// static
+void DiskMountManager::Shutdown() {
+  VLOG(1) << "DiskMountManager::Shutdown";
+  if (g_disk_mount_manager) {
+    delete g_disk_mount_manager;
+    g_disk_mount_manager = NULL;
+  }
+}
+
+// static
+DiskMountManager* DiskMountManager::GetInstance() {
+  return g_disk_mount_manager;
+}
+
+}  // namespace chromeos