Blob support for IDB [Chromium]

content/browser/indexed_db/indexed_db_transaction.cc

 // Copyright (c) 2013 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 "content/browser/indexed_db/indexed_db_transaction.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 41 matching lines @@
     int64 id,
     scoped_refptr<IndexedDBDatabaseCallbacks> callbacks,
     const std::set<int64>& object_store_ids,
     indexed_db::TransactionMode mode,
     IndexedDBDatabase* database)
     : id_(id),
       object_store_ids_(object_store_ids),
       mode_(mode),
       state_(UNUSED),
       commit_pending_(false),
+      blob_write_success_(false),
       callbacks_(callbacks),
       database_(database),
       transaction_(database->BackingStore().get()),
       should_process_queue_(false),
       pending_preemptive_events_(0) {
+  fprintf(stderr, "ERICU: IndexedDBTransaction::IndexedDBTransaction(%p).\n",
+      this);
   database_->transaction_coordinator().DidCreateTransaction(this);
 }
 
 IndexedDBTransaction::~IndexedDBTransaction() {
   // It shouldn't be possible for this object to get deleted until it's either
   // complete or aborted.
+  fprintf(stderr, "ERICU: IndexedDBTransaction::~IndexedDBTransaction.\n");
   DCHECK_EQ(state_, FINISHED);
   DCHECK(preemptive_task_queue_.empty());
   DCHECK(task_queue_.empty());
   DCHECK(abort_task_stack_.empty());
 }
 
 void IndexedDBTransaction::ScheduleTask(Operation task, Operation abort_task) {
   if (state_ == FINISHED)
     return;
   task_queue_.push(task);
   abort_task_stack_.push(abort_task);
   EnsureTasksRunning();
 }
 
 void IndexedDBTransaction::ScheduleTask(IndexedDBDatabase::TaskType type,
                                         Operation task) {
-  if (state_ == FINISHED)
+  if (IsStatePastRunning())
     return;
 
   if (type == IndexedDBDatabase::NORMAL_TASK)
     task_queue_.push(task);
   else
     preemptive_task_queue_.push(task);
   EnsureTasksRunning();
 }
 
 void IndexedDBTransaction::EnsureTasksRunning() {
@@ skipping 88 matching lines @@
 }
 
 void IndexedDBTransaction::Start() {
   DCHECK_EQ(state_, UNUSED);
 
   state_ = START_PENDING;
   database_->transaction_coordinator().DidStartTransaction(this);
   database_->TransactionStarted(this);
 }
 
+class BlobWriteCallbackImpl : public IndexedDBBackingStore::BlobWriteCallback {
+ public:
+  BlobWriteCallbackImpl(scoped_refptr<IndexedDBTransaction> transaction)
+    : transaction_(transaction) { }
+  virtual ~BlobWriteCallbackImpl() { }
+  virtual void didSucceed() {
+    transaction_->BlobWriteComplete(true);
+  }
+  virtual void didFail() {
+    transaction_->BlobWriteComplete(false);
+  }
+ private:
+  scoped_refptr<IndexedDBTransaction> transaction_;
+};
+
 void IndexedDBTransaction::Commit() {
   IDB_TRACE("IndexedDBTransaction::Commit");
+  fprintf(stderr, "ERICU: IndexedDBTransaction::Commit.\n");
 
   // In multiprocess ports, front-end may have requested a commit but
   // an abort has already been initiated asynchronously by the
   // back-end.
-  if (state_ == FINISHED)
+  if (IsStatePastRunning())
     return;
 
   DCHECK(state_ == UNUSED || state_ == RUNNING);
   commit_pending_ = true;
 
   // Front-end has requested a commit, but there may be tasks like
   // create_index which are considered synchronous by the front-end
   // but are processed asynchronously.
   if (HasPendingTasks())
     return;
 
-  // The last reference to this object may be released while performing the
-  // commit steps below. We therefore take a self reference to keep ourselves
-  // alive while executing this method.
-  scoped_refptr<IndexedDBTransaction> protect(this);
+  bool unused = state_ == UNUSED;
+  state_ = COMMITTING;
 
-  // TODO(jsbell): Run abort tasks if commit fails? http://crbug.com/241843
-  abort_task_stack_.clear();
-
-  bool unused = state_ == UNUSED;
-  state_ = FINISHED;
-
-  bool committed = unused || transaction_.Commit();
-
-  // Backing store resources (held via cursors) must be released
-  // before script callbacks are fired, as the script callbacks may
-  // release references and allow the backing store itself to be
-  // released, and order is critical.
-  CloseOpenCursors();
-  transaction_.Reset();
-
-  // Transactions must also be marked as completed before the
-  // front-end is notified, as the transaction completion unblocks
-  // operations like closing connections.
-  database_->transaction_coordinator().DidFinishTransaction(this);
-  database_->TransactionFinished(this);
-
-  if (committed) {
-    callbacks_->OnComplete(id_);
-    database_->TransactionFinishedAndCompleteFired(this);
-  } else {
-    callbacks_->OnAbort(
-        id_,
-        IndexedDBDatabaseError(WebKit::WebIDBDatabaseExceptionUnknownError,
-                               "Internal error committing transaction."));
-    database_->TransactionFinishedAndAbortFired(this);
+  if (unused)
+    CommitPhaseTwo(WAS_NOT_USED, DO_COMMIT);
+  else {
+    scoped_refptr<IndexedDBBackingStore::BlobWriteCallback> callback(
+        new BlobWriteCallbackImpl(this));
+    // CommitPhaseOne will call the callback synchronously if there are no blobs
+    // to write.
+    if (!transaction_.CommitPhaseOne(callback))
+      CommitPhaseTwo(WAS_USED, SKIP_COMMIT);
   }
-
-  database_ = NULL;
 }
 
 void IndexedDBTransaction::ProcessTaskQueue() {
   IDB_TRACE("IndexedDBTransaction::ProcessTaskQueue");
 
   // May have been aborted.
   if (!should_process_queue_)
     return;
 
   DCHECK(!IsTaskQueueEmpty());
   should_process_queue_ = false;
 
   if (state_ == START_PENDING) {
     transaction_.Begin();
     state_ = RUNNING;
   }
 
   // The last reference to this object may be released while performing the
   // tasks. Take take a self reference to keep this object alive so that
   // the loop termination conditions can be checked.
   scoped_refptr<IndexedDBTransaction> protect(this);
 
   TaskQueue* task_queue =
       pending_preemptive_events_ ? &preemptive_task_queue_ : &task_queue_;
-  while (!task_queue->empty() && state_ != FINISHED) {
+  while (!task_queue->empty() && !IsStatePastRunning()) {
     DCHECK_EQ(state_, RUNNING);
     Operation task(task_queue->pop());
     task.Run(this);
 
     // Event itself may change which queue should be processed next.
     task_queue =
         pending_preemptive_events_ ? &preemptive_task_queue_ : &task_queue_;
   }
 
   // If there are no pending tasks, we haven't already committed/aborted,
   // and the front-end requested a commit, it is now safe to do so.
-  if (!HasPendingTasks() && state_ != FINISHED && commit_pending_)
+  if (!HasPendingTasks() && !IsStatePastRunning() && commit_pending_)
     Commit();
 }
 
+void IndexedDBTransaction::BlobWriteComplete(bool success)
+{
+  IDB_TRACE("IndexedDBTransaction::BlobWriteComplete");
+  if (state_ == FINISHED) // aborted
+    return;
+  DCHECK_EQ(state_, COMMITTING);
+  if (success)
+    CommitPhaseTwo(WAS_USED, DO_COMMIT);
+  else
+    Abort(IndexedDBDatabaseError(WebKit::WebIDBDatabaseExceptionDataError,
+                                 "Failed to write blobs"));
+}
+
 void IndexedDBTransaction::CloseOpenCursors() {
   for (std::set<IndexedDBCursor*>::iterator i = open_cursors_.begin();
        i != open_cursors_.end();
        ++i)
     (*i)->Close();
   open_cursors_.clear();
 }
 
+void IndexedDBTransaction::CommitPhaseTwo(TransactionUseState use_state,
+    ShouldSkipCommit skip_commit) {
+  DCHECK_EQ(state_, COMMITTING);
+  state_ = FINISHED;
+
+  // The last reference to this object may be released while performing the
+  // commit steps below. We therefore take a self reference to keep ourselves
+  // alive while executing this method.
+  scoped_refptr<IndexedDBTransaction> protect(this);
+
+  // TODO(jsbell): Run abort tasks if commit fails? http://crbug.com/241843
+  abort_task_stack_.clear();
+
+  state_ = FINISHED;
+
+  bool committed = (use_state == WAS_NOT_USED) ||

[jsbell, 2013/09/13 00:12:21]

Seems like use_state and skip_commit effectively have the same meaning?

[ericu, 2013/11/20 23:05:39]

No--we skip_commit if we've failed or aborted, but sometimes we want to pretend
to commit on an unused transaction so that the end-of-transaction events get
fired.  See also my response in the header file.

+      ((skip_commit == DO_COMMIT) && transaction_.CommitPhaseTwo());
+
+  // Backing store resources (held via cursors) must be released
+  // before script callbacks are fired, as the script callbacks may
+  // release references and allow the backing store itself to be
+  // released, and order is critical.
+  CloseOpenCursors();
+  transaction_.Reset();
+
+  // Transactions must also be marked as completed before the
+  // front-end is notified, as the transaction completion unblocks
+  // operations like closing connections.
+  database_->transaction_coordinator().DidFinishTransaction(this);
+  database_->TransactionFinished(this);
+
+  if (committed) {
+    callbacks_->OnComplete(id_);
+    database_->TransactionFinishedAndCompleteFired(this);
+  } else {
+    callbacks_->OnAbort(
+        id_,
+        IndexedDBDatabaseError(WebKit::WebIDBDatabaseExceptionUnknownError,
+                               "Internal error committing transaction."));
+    database_->TransactionFinishedAndAbortFired(this);
+  }
+
+  database_ = NULL;
+}
+
 }  // namespace content