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 70 matching lines @@
   // complete or aborted.
   DCHECK_EQ(state_, FINISHED);
   DCHECK(preemptive_task_queue_.empty());
   DCHECK_EQ(pending_preemptive_events_, 0);
   DCHECK(task_queue_.empty());
   DCHECK(abort_task_stack_.empty());
 }
 
 void IndexedDBTransaction::ScheduleTask(IndexedDBDatabase::TaskType type,
                                         Operation task) {
-  if (state_ == FINISHED)
+  if (IsStatePastStarted())
     return;
 
   timeout_timer_.Stop();
   used_ = true;
   if (type == IndexedDBDatabase::NORMAL_TASK) {
     task_queue_.push(task);
     ++diagnostics_.tasks_scheduled;
   } else {
     preemptive_task_queue_.push(task);
   }
@@ skipping 97 matching lines @@
   DCHECK_EQ(CREATED, state_);
   state_ = STARTED;
   diagnostics_.start_time = base::Time::Now();
 
   if (!used_)
     return;
 
   RunTasksIfStarted();
 }
 
+class BlobWriteCallbackImpl : public IndexedDBBackingStore::BlobWriteCallback {
+ public:
+  BlobWriteCallbackImpl(scoped_refptr<IndexedDBTransaction> transaction)
+      : transaction_(transaction) {}
+  virtual void Run(bool succeeded) OVERRIDE {
+    transaction_->BlobWriteComplete(succeeded);
+  }
+
+ protected:
+  virtual ~BlobWriteCallbackImpl() {}
+
+ private:
+  scoped_refptr<IndexedDBTransaction> transaction_;
+};
+
+void IndexedDBTransaction::BlobWriteComplete(bool success) {
+  IDB_TRACE("IndexedDBTransaction::BlobWriteComplete");
+  if (state_ == FINISHED)  // aborted
+    return;
+  DCHECK_EQ(state_, COMMITTING);
+  if (success)
+    CommitPhaseTwo();
+  else
+    Abort(IndexedDBDatabaseError(blink::WebIDBDatabaseExceptionDataError,
+                                 "Failed to write blobs."));
+}
+
 void IndexedDBTransaction::Commit() {
   IDB_TRACE("IndexedDBTransaction::Commit");
 
   // 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 (IsStatePastStarted()) {
+    DCHECK(state_ == FINISHED);
     return;
+  }
 
   DCHECK(!used_ || state_ == STARTED);
   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;
 
+  state_ = COMMITTING;
+
+  if (!used_)
+    CommitPhaseTwo();
+  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).ok())

[cmumford, 2014/05/28 22:35:02]

Are we still preserving the ability to distinguish failures due to corruption,
vs. other causes (full disk, etc.)? If this failure is a result of corruption
then we need (somewhere) to delete the database and inform the page. Just making
sure that's still done.

[ericu, 2014/05/28 22:50:43]

This change doesn't worsen corruption reporting.  A failure on commit doesn't
currently distinguish between corruption, disk-full, etc.  We can add that, but
there's no reporting back to the IndexedDBDatabase of the reason for any
failure.  We'll need to update IndexedDBTransaction::Commit,
IndexedDBDatabase::TransactionCommitFailed, and several places in
IndexedDBDatabase, at a minimum.

+      Abort(IndexedDBDatabaseError(blink::WebIDBDatabaseExceptionDataError,
+                                   "Error processing blob journal."));
+  }
+}
+
+void IndexedDBTransaction::CommitPhaseTwo() {
+  // Abort may have been called just as the blob write completed.
+  if (state_ == FINISHED)
+    return;
+
+  DCHECK_EQ(state_, COMMITTING);
+
   // 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);
 
   timeout_timer_.Stop();
 
   state_ = FINISHED;
 
-  bool committed = !used_ || transaction_->Commit().ok();
+  bool committed = !used_ || transaction_->CommitPhaseTwo().ok();
 
   // 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
@@ skipping 34 matching lines @@
     backing_store_transaction_begun_ = true;
   }
 
   // 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) {
-    DCHECK_EQ(STARTED, state_);
+  while (!task_queue->empty() && !IsStatePastStarted()) {
+    DCHECK_EQ(state_, STARTED);
     Operation task(task_queue->pop());
     task.Run(this);
     if (!pending_preemptive_events_) {
       DCHECK(diagnostics_.tasks_completed < diagnostics_.tasks_scheduled);
       ++diagnostics_.tasks_completed;
     }
 
     // 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() && !IsStatePastStarted() && commit_pending_) {
     Commit();
     return;
   }
 
   // The transaction may have been aborted while processing tasks.
   if (state_ == FINISHED)
     return;
 
   // Otherwise, start a timer in case the front-end gets wedged and
   // never requests further activity. Read-only transactions don't
@@ skipping 14 matching lines @@
 
 void IndexedDBTransaction::CloseOpenCursors() {
   for (std::set<IndexedDBCursor*>::iterator i = open_cursors_.begin();
        i != open_cursors_.end();
        ++i)
     (*i)->Close();
   open_cursors_.clear();
 }
 
 }  // namespace content