sql::MetaTable.next_download_id, DownloadManager::GetNextId()

chrome/browser/download/download_manager.cc

 // 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/download/download_manager.h"
 
+#include "base/bind.h"
 #include "base/callback.h"
 #include "base/file_util.h"
 #include "base/i18n/case_conversion.h"
 #include "base/logging.h"
 #include "base/path_service.h"
 #include "base/rand_util.h"
 #include "base/stl_util.h"
 #include "base/stringprintf.h"
+#include "base/synchronization/lock.h"
 #include "base/sys_string_conversions.h"
 #include "base/task.h"
 #include "base/utf_string_conversions.h"
 #include "build/build_config.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/download/download_create_info.h"
 #include "chrome/browser/download/download_extensions.h"
 #include "chrome/browser/download/download_file_manager.h"
 #include "chrome/browser/download/download_history.h"
 #include "chrome/browser/download/download_item.h"
@@ skipping 20 matching lines @@
 #include "googleurl/src/gurl.h"
 #include "grit/generated_resources.h"
 #include "grit/theme_resources.h"
 #include "net/base/mime_util.h"
 #include "net/base/net_util.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/resource/resource_bundle.h"
 
 DownloadManager::DownloadManager(DownloadStatusUpdater* status_updater)
     : shutdown_needed_(false),
+      next_id_(0),
       profile_(NULL),
       file_manager_(NULL),
       status_updater_(status_updater->AsWeakPtr()) {
   if (status_updater_)
     status_updater_->AddDelegate(this);
 }
 
 DownloadManager::~DownloadManager() {
   DCHECK(!shutdown_needed_);
   if (status_updater_)
@@ skipping 150 matching lines @@
     if (download_item->MatchesQuery(query_lower))
       result->push_back(download_item);
   }
 
   // If we have a parent profile, let it add its downloads to the results.
   Profile* original_profile = profile_->GetOriginalProfile();
   if (original_profile != profile_)
     original_profile->GetDownloadManager()->SearchDownloads(query, result);
 }
 
+void DownloadManager::OnHistoryGetNextId(int next_id) {
+  DVLOG(1) << __FUNCTION__ << " " << next_id;
+  base::AutoLock _(next_id_lock_);

[Randy Smith (Not in Mondays), 2011/07/28 21:03:16]

I puzzled over this for a while before I got it.  It's a fine idiom, but it's
not one I've seen before in Chrome, and if you're not used to it I think it'll
confused people.  I'd use "autolock" instead of "_".

[benjhayden, 2011/08/03 17:44:46]

Done.

+  // TODO(benjhayden) Delay Profile initialization until here, and set next_id_
+  // = next_id.

[Randy Smith (Not in Mondays), 2011/07/28 21:03:16]

A bit more of a comment as to why this actually makes sense would make sense, I
think (i.e. explain that we just need to make sure assigned ids are unique per
session for right now, and this does it in the face of the download/getting
first id race).

[benjhayden, 2011/08/03 17:44:46]

Done.

+  next_id_ += next_id;
+}
+
+DownloadId DownloadManager::GetNextId() {
+  // May be called on any thread via the GetNextIdThunk.
+  // TODO(benjhayden) If otr, forward to parent DM.
+  base::AutoLock _(next_id_lock_);
+  return DownloadId(this, next_id_++);
+}
+
+DownloadManager::GetNextIdThunkType DownloadManager::GetNextIdThunk() {
+  // TODO(benjhayden) If otr, forward to parent DM.
+  return base::Bind(&DownloadManager::GetNextId, this);
+}
+
 // Query the history service for information about all persisted downloads.
 bool DownloadManager::Init(Profile* profile) {
   DCHECK(profile);
   DCHECK(!shutdown_needed_)  << "DownloadManager already initialized.";
   shutdown_needed_ = true;
 
   profile_ = profile;
   download_history_.reset(new DownloadHistory(profile));
+  download_history_->GetNextId(NewCallback(
+      this, &DownloadManager::OnHistoryGetNextId));
   download_history_->Load(
       NewCallback(this, &DownloadManager::OnQueryDownloadEntriesComplete));
 
   download_prefs_.reset(new DownloadPrefs(profile_->GetPrefs()));
 
   // In test mode, there may be no ResourceDispatcherHost.  In this case it's
   // safe to avoid setting |file_manager_| because we only call a small set of
   // functions, none of which need it.
   ResourceDispatcherHost* rdh = g_browser_process->resource_dispatcher_host();
   if (rdh) {
@@ skipping 356 matching lines @@
     // name after user confirmation will be set from
     // DownloadItem::OnDownloadCompleting.
     download_path =
         download_util::GetCrDownloadPath(download->full_path());
   }
 
   BrowserThread::PostTask(
       BrowserThread::FILE, FROM_HERE,
       NewRunnableMethod(
           file_manager_, &DownloadFileManager::RenameInProgressDownloadFile,
-          download->id(), download_path));
+          download->gid(), download_path));
 
   download->Rename(download_path);
 
   download_history_->AddEntry(download,
       NewCallback(this, &DownloadManager::OnCreateDownloadEntryComplete));
 }
 
 void DownloadManager::UpdateDownload(int32 download_id, int64 size) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   DownloadMap::iterator it = active_downloads_.find(download_id);
@@ skipping 186 matching lines @@
   if (!item)
     return;
 
   if (item->safety_state() == DownloadItem::SAFE) {
     DCHECK_EQ(0, uniquifier) << "We should not uniquify SAFE downloads twice";
   }
 
   BrowserThread::PostTask(
       BrowserThread::FILE, FROM_HERE,
       NewRunnableMethod(
-          file_manager_, &DownloadFileManager::CompleteDownload, download_id));
+          file_manager_, &DownloadFileManager::CompleteDownload, item->gid()));
 
   if (uniquifier)
     item->set_path_uniquifier(uniquifier);
 
   item->OnDownloadRenamedToFinalName(full_path);
   download_history_->UpdateDownloadPath(item, full_path);
 }
 
 void DownloadManager::DownloadCancelled(int32 download_id) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
@@ skipping 15 matching lines @@
   }
 
   DownloadCancelledInternal(download_id, download->request_handle());
 }
 
 void DownloadManager::DownloadCancelledInternal(
     int download_id, const DownloadRequestHandle& request_handle) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   request_handle.CancelRequest();
 
-  BrowserThread::PostTask(
-      BrowserThread::FILE, FROM_HERE,
-      NewRunnableMethod(
-          file_manager_, &DownloadFileManager::CancelDownload, download_id));
+  BrowserThread::PostTask(BrowserThread::FILE, FROM_HERE, NewRunnableMethod(
+      file_manager_, &DownloadFileManager::CancelDownload,
+      DownloadId(this, download_id)));
 }
 
 void DownloadManager::OnDownloadError(int32 download_id,
                                       int64 size,
                                       int os_error) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   DownloadMap::iterator it = active_downloads_.find(download_id);
   // A cancel at the right time could remove the download from the
   // |active_downloads_| map before we get here.
   if (it == active_downloads_.end())
@@ skipping 12 matching lines @@
   //
   // Clean up will happen when the history system create callback runs if we
   // don't have a valid db_handle yet.
   if (download->db_handle() != DownloadHistory::kUninitializedHandle) {
     in_progress_.erase(download_id);
     active_downloads_.erase(download_id);
     UpdateAppIcon();  // Reflect removal from in_progress_.
     download_history_->UpdateEntry(download);
   }
 
-  BrowserThread::PostTask(
-      BrowserThread::FILE, FROM_HERE,
-      NewRunnableMethod(
-          file_manager_, &DownloadFileManager::CancelDownload, download_id));
+  BrowserThread::PostTask(BrowserThread::FILE, FROM_HERE, NewRunnableMethod(
+      file_manager_, &DownloadFileManager::CancelDownload, download->gid()));
 }
 
 void DownloadManager::UpdateAppIcon() {
   if (status_updater_)
     status_updater_->Update();
 }
 
 void DownloadManager::RemoveDownload(int64 download_handle) {
   DownloadMap::iterator it = history_downloads_.find(download_handle);
   if (it == history_downloads_.end())
@@ skipping 441 matching lines @@
     observed_download_manager_->RemoveObserver(this);
 }
 
 void DownloadManager::OtherDownloadManagerObserver::ModelChanged() {
   observing_download_manager_->NotifyModelChanged();
 }
 
 void DownloadManager::OtherDownloadManagerObserver::ManagerGoingDown() {
   observed_download_manager_ = NULL;
 }