Make the Linux System Monitor implementation track all devices

chrome/browser/media_gallery/media_device_notifications_linux.cc

Index: chrome/browser/media_gallery/media_device_notifications_linux.cc
diff --git a/chrome/browser/media_gallery/media_device_notifications_linux.cc b/chrome/browser/media_gallery/media_device_notifications_linux.cc
deleted file mode 100644
index 243b99d358ab9325d8ee6443af58338c542ce85f..0000000000000000000000000000000000000000
--- a/chrome/browser/media_gallery/media_device_notifications_linux.cc
+++ /dev/null
@@ -1,384 +0,0 @@
-// Copyright (c) 2012 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.
-
-// MediaDeviceNotificationsLinux implementation.
-
-#include "chrome/browser/media_gallery/media_device_notifications_linux.h"
-
-#include <libudev.h>
-#include <mntent.h>
-#include <stdio.h>
-
-#include <vector>
-
-#include "base/bind.h"
-#include "base/file_path.h"
-#include "base/memory/scoped_generic_obj.h"
-#include "base/metrics/histogram.h"
-#include "base/stl_util.h"
-#include "base/string_number_conversions.h"
-#include "base/string_util.h"
-#include "base/system_monitor/system_monitor.h"
-#include "base/utf_string_conversions.h"
-#include "chrome/browser/media_gallery/media_device_notifications_utils.h"
-#include "chrome/browser/media_gallery/media_storage_util.h"
-
-namespace {
-
-// List of file systems we care about.
-const char* const kKnownFileSystems[] = {
-  "ext2",
-  "ext3",
-  "ext4",
-  "fat",
-  "hfsplus",
-  "iso9660",
-  "msdos",
-  "ntfs",
-  "udf",
-  "vfat",
-};
-
-// udev device property constants.
-const char kDevName[] = "DEVNAME";
-const char kFsUUID[] = "ID_FS_UUID";
-const char kLabel[] = "ID_FS_LABEL";
-const char kModel[] = "ID_MODEL";
-const char kModelID[] = "ID_MODEL_ID";
-const char kSerial[] = "ID_SERIAL";
-const char kSerialShort[] = "ID_SERIAL_SHORT";
-const char kVendor[] = "ID_VENDOR";
-const char kVendorID[] = "ID_VENDOR_ID";
-
-// Delimiter constants.
-const char kNonSpaceDelim[] = ":";
-const char kSpaceDelim[] = " ";
-
-// Unique id prefix constants.
-const char kFSUniqueIdPrefix[] = "UUID:";
-const char kVendorModelSerialPrefix[] = "VendorModelSerial:";
-
-// Device mount point details.
-struct MountPointEntryInfo {
-  std::string mount_point;
-  int entry_pos;
-};
-
-// ScopedGenericObj functor for UdevObjectRelease().
-class ScopedReleaseUdevObject {
- public:
-  void operator()(struct udev* udev) const {
-    udev_unref(udev);
-  }
-};
-
-// ScopedGenericObj functor for UdevDeviceObjectRelease().
-class ScopedReleaseUdevDeviceObject {
- public:
-  void operator()(struct udev_device* device) const {
-    udev_device_unref(device);
-  }
-};
-
-// Get the device information using udev library.
-// On success, returns true and fill in |id| and |name|.
-bool GetDeviceInfo(const std::string& device_path, std::string* id,
-                   string16* name) {
-  DCHECK(!device_path.empty());
-
-  ScopedGenericObj<struct udev*, ScopedReleaseUdevObject> udev_obj(udev_new());
-  if (!udev_obj.get())
-    return false;
-
-  struct stat device_stat;
-  if (stat(device_path.c_str(), &device_stat) < 0)
-    return false;
-
-  char device_type;
-  if (S_ISCHR(device_stat.st_mode))
-    device_type = 'c';
-  else if (S_ISBLK(device_stat.st_mode))
-    device_type = 'b';
-  else
-    return false;  // Not a supported type.
-
-  ScopedGenericObj<struct udev_device*, ScopedReleaseUdevDeviceObject>
-      device(udev_device_new_from_devnum(udev_obj, device_type,
-                                         device_stat.st_rdev));
-  if (!device.get())
-    return false;
-
-  // Construct a device name using label or manufacturer(vendor and model)
-  // details.
-  if (name) {
-    std::string device_label;
-    const char* device_name = NULL;
-    if ((device_name = udev_device_get_property_value(device, kLabel)) ||
-        (device_name = udev_device_get_property_value(device, kSerial))) {
-      device_label = device_name;
-    } else {
-      // Format: VendorInfo ModelInfo
-      // E.g.: KnCompany Model2010
-      const char* vendor_name = NULL;
-      if ((vendor_name = udev_device_get_property_value(device, kVendor)))
-        device_label = vendor_name;
-
-      const char* model_name = NULL;
-      if ((model_name = udev_device_get_property_value(device, kModel))) {
-        if (!device_label.empty())
-          device_label += kSpaceDelim;
-        device_label += model_name;
-      }
-    }
-
-    if (IsStringUTF8(device_label))
-      *name = UTF8ToUTF16(device_label);
-  }
-
-  if (id) {
-    std::string unique_id;
-    const char* uuid  = NULL;
-    if ((uuid = udev_device_get_property_value(device, kFsUUID))) {
-      unique_id = std::string(kFSUniqueIdPrefix) + uuid;
-    } else {
-      // If one of the vendor, model, serial information is missing, its value
-      // in the string is empty.
-      // Format: VendorModelSerial:VendorInfo:ModelInfo:SerialShortInfo
-      // E.g.: VendorModelSerial:Kn:DataTravel_12.10:8000000000006CB02CDB
-      const char* vendor = udev_device_get_property_value(device, kVendorID);
-      const char* model = udev_device_get_property_value(device, kModelID);
-      const char* serial_short = udev_device_get_property_value(device,
-                                                                kSerialShort);
-      if (!vendor && !model && !serial_short)
-        return false;
-
-      unique_id = std::string(kVendorModelSerialPrefix) +
-                  (vendor ? vendor : "") + kNonSpaceDelim +
-                  (model ? model : "") + kNonSpaceDelim +
-                  (serial_short ? serial_short : "");
-    }
-    *id = chrome::MediaStorageUtil::MakeDeviceId(
-        chrome::MediaStorageUtil::USB_MASS_STORAGE_WITH_DCIM, unique_id);
-  }
-
-  return true;
-}
-
-}  // namespace
-
-namespace chrome {
-
-using base::SystemMonitor;
-using content::BrowserThread;
-
-MediaDeviceNotificationsLinux::MediaDeviceNotificationsLinux(
-    const FilePath& path)
-    : initialized_(false),
-      mtab_path_(path),
-      get_device_info_func_(&GetDeviceInfo) {
-}
-
-MediaDeviceNotificationsLinux::MediaDeviceNotificationsLinux(
-    const FilePath& path,
-    GetDeviceInfoFunc get_device_info_func)
-    : initialized_(false),
-      mtab_path_(path),
-      get_device_info_func_(get_device_info_func) {
-}
-
-MediaDeviceNotificationsLinux::~MediaDeviceNotificationsLinux() {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
-}
-
-void MediaDeviceNotificationsLinux::Init() {
-  DCHECK(!mtab_path_.empty());
-
-  // Put |kKnownFileSystems| in std::set to get O(log N) access time.
-  for (size_t i = 0; i < arraysize(kKnownFileSystems); ++i)
-    known_file_systems_.insert(kKnownFileSystems[i]);
-
-  BrowserThread::PostTask(
-      BrowserThread::FILE, FROM_HERE,
-      base::Bind(&MediaDeviceNotificationsLinux::InitOnFileThread, this));
-}
-
-void MediaDeviceNotificationsLinux::OnFilePathChanged(const FilePath& path,
-                                                      bool error) {
-  if (path != mtab_path_) {
-    // This cannot happen unless FilePathWatcher is buggy. Just ignore this
-    // notification and do nothing.
-    NOTREACHED();
-    return;
-  }
-  if (error) {
-    LOG(ERROR) << "Error watching " << mtab_path_.value();
-    return;
-  }
-
-  UpdateMtab();
-}
-
-void MediaDeviceNotificationsLinux::InitOnFileThread() {
-  DCHECK(!initialized_);
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
-  initialized_ = true;
-
-  // The callback passed to Watch() has to be unretained. Otherwise
-  // MediaDeviceNotificationsLinux will live longer than expected, and
-  // FilePathWatcher will get in trouble at shutdown time.
-  bool ret = file_watcher_.Watch(
-      mtab_path_,
-      base::Bind(&MediaDeviceNotificationsLinux::OnFilePathChanged,
-                 base::Unretained(this)));
-  if (!ret) {
-    LOG(ERROR) << "Adding watch for " << mtab_path_.value() << " failed";
-    return;
-  }
-
-  UpdateMtab();
-}
-
-void MediaDeviceNotificationsLinux::UpdateMtab() {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
-
-  MountPointDeviceMap new_mtab;
-  ReadMtab(&new_mtab);
-
-  // Check existing mtab entries for unaccounted mount points.
-  // These mount points must have been removed in the new mtab.
-  std::vector<std::string> mount_points_to_erase;
-  for (MountMap::const_iterator old_iter = mount_info_map_.begin();
-       old_iter != mount_info_map_.end(); ++old_iter) {
-    const std::string& mount_point = old_iter->first;
-    const std::string& mount_device = old_iter->second.mount_device;
-    MountPointDeviceMap::iterator new_iter = new_mtab.find(mount_point);
-    // |mount_point| not in |new_mtab| or |mount_device| is no longer mounted at
-    // |mount_point|.
-    if (new_iter == new_mtab.end() || (new_iter->second != mount_device)) {
-      RemoveOldDevice(old_iter->second.device_id);
-      mount_points_to_erase.push_back(mount_point);
-    }
-  }
-  // Erase the |mount_info_map_| entries afterwards. Erasing in the loop above
-  // using the iterator is slightly more efficient, but more tricky, since
-  // calling std::map::erase() on an iterator invalidates it.
-  for (size_t i = 0; i < mount_points_to_erase.size(); ++i)
-    mount_info_map_.erase(mount_points_to_erase[i]);
-
-  // Check new mtab entries against existing ones.
-  for (MountPointDeviceMap::iterator new_iter = new_mtab.begin();
-       new_iter != new_mtab.end(); ++new_iter) {
-    const std::string& mount_point = new_iter->first;
-    const std::string& mount_device = new_iter->second;
-    MountMap::iterator old_iter = mount_info_map_.find(mount_point);
-    if (old_iter == mount_info_map_.end() ||
-        old_iter->second.mount_device != mount_device) {
-      // New mount point found or an existing mount point found with a new
-      // device.
-      CheckAndAddMediaDevice(mount_device, mount_point);
-    }
-  }
-}
-
-void MediaDeviceNotificationsLinux::ReadMtab(MountPointDeviceMap* mtab) {
-  FILE* fp = setmntent(mtab_path_.value().c_str(), "r");
-  if (!fp)
-    return;
-
-  mntent entry;
-  char buf[512];
-
-  // Keep track of mount point entry positions in mtab file.
-  int entry_pos = 0;
-
-  // Helper map to store the device mount point details.
-  // (mount device, MountPointEntryInfo)
-  typedef std::map<std::string, MountPointEntryInfo> DeviceMap;
-  DeviceMap device_map;
-  while (getmntent_r(fp, &entry, buf, sizeof(buf))) {
-    // We only care about real file systems.
-    if (!ContainsKey(known_file_systems_, entry.mnt_type))
-      continue;
-
-    // Add entries, but overwrite entries for the same mount device. Keep track
-    // of the entry positions in |entry_info| and use that below to resolve
-    // multiple devices mounted at the same mount point.
-    MountPointEntryInfo entry_info;
-    entry_info.mount_point = entry.mnt_dir;
-    entry_info.entry_pos = entry_pos++;
-    device_map[entry.mnt_fsname] = entry_info;
-  }
-  endmntent(fp);
-
-  // Helper map to store mount point entries.
-  // (mount point, entry position in mtab file)
-  typedef std::map<std::string, int> MountPointsInfoMap;
-  MountPointsInfoMap mount_points_info_map;
-  MountPointDeviceMap& new_mtab = *mtab;
-  for (DeviceMap::const_iterator device_it = device_map.begin();
-       device_it != device_map.end();
-       ++device_it) {
-    // Add entries, but overwrite entries for the same mount point. Keep track
-    // of the entry positions and use that information to resolve multiple
-    // devices mounted at the same mount point.
-    const std::string& mount_device = device_it->first;
-    const std::string& mount_point = device_it->second.mount_point;
-    const int entry_pos = device_it->second.entry_pos;
-    MountPointDeviceMap::iterator new_it = new_mtab.find(mount_point);
-    MountPointsInfoMap::iterator mount_point_info_map_it =
-        mount_points_info_map.find(mount_point);
-
-    // New mount point entry found or there is already a device mounted at
-    // |mount_point| and the existing mount entry is older than the current one.
-    if (new_it == new_mtab.end() ||
-        (mount_point_info_map_it != mount_points_info_map.end() &&
-         mount_point_info_map_it->second < entry_pos)) {
-      new_mtab[mount_point] = mount_device;
-      mount_points_info_map[mount_point] = entry_pos;
-    }
-  }
-}
-
-void MediaDeviceNotificationsLinux::CheckAndAddMediaDevice(
-    const std::string& mount_device,
-    const std::string& mount_point) {
-  if (!IsMediaDevice(mount_point))
-    return;
-
-  std::string id;
-  string16 name;
-  bool result = (*get_device_info_func_)(mount_device, &id, &name);
-
-  // Keep track of GetDeviceInfo result, to see how often we fail to get device
-  // details.
-  UMA_HISTOGRAM_BOOLEAN("MediaDeviceNotification.device_info_available",
-                        result);
-  if (!result)
-    return;
-
-  // Keep track of device uuid, to see how often we receive empty values.
-  UMA_HISTOGRAM_BOOLEAN("MediaDeviceNotification.device_uuid_available",
-                        !id.empty());
-  UMA_HISTOGRAM_BOOLEAN("MediaDeviceNotification.device_name_available",
-                        !name.empty());
-
-  if (id.empty() || name.empty())
-    return;
-
-  MountDeviceAndId mount_device_and_id;
-  mount_device_and_id.mount_device = mount_device;
-  mount_device_and_id.device_id = id;
-  mount_info_map_[mount_point] = mount_device_and_id;
-
-  base::SystemMonitor* system_monitor = base::SystemMonitor::Get();
-  system_monitor->ProcessMediaDeviceAttached(id, name, mount_point);
-}
-
-void MediaDeviceNotificationsLinux::RemoveOldDevice(
-    const std::string& device_id) {
-  base::SystemMonitor* system_monitor = base::SystemMonitor::Get();
-  system_monitor->ProcessMediaDeviceDetached(device_id);
-}
-
-}  // namespace chrome