[IndexedDB] Refactoring to remove ref ptrs and host transaction ids.

content/browser/indexed_db/indexed_db_cursor.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_cursor.h"
 
 #include <stddef.h>
 #include <utility>
 #include <vector>
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "content/browser/indexed_db/indexed_db_callbacks.h"
 #include "content/browser/indexed_db/indexed_db_database_error.h"
 #include "content/browser/indexed_db/indexed_db_tracing.h"
 #include "content/browser/indexed_db/indexed_db_transaction.h"
 #include "content/browser/indexed_db/indexed_db_value.h"
+#include "third_party/WebKit/public/platform/modules/indexeddb/WebIDBDatabaseException.h"
 
 namespace content {
 
 IndexedDBCursor::IndexedDBCursor(
     std::unique_ptr<IndexedDBBackingStore::Cursor> cursor,
     indexed_db::CursorType cursor_type,
     blink::WebIDBTaskType task_type,
     IndexedDBTransaction* transaction)
     : task_type_(task_type),
       cursor_type_(cursor_type),
       transaction_(transaction),
       cursor_(std::move(cursor)),
-      closed_(false) {
-  transaction_->RegisterOpenCursor(this);
-}
+      closed_(false),
+      ptr_factory_(this) {}
 
-IndexedDBCursor::~IndexedDBCursor() {
-  transaction_->UnregisterOpenCursor(this);
-}
+IndexedDBCursor::~IndexedDBCursor() {}
 
 void IndexedDBCursor::Continue(std::unique_ptr<IndexedDBKey> key,
                                std::unique_ptr<IndexedDBKey> primary_key,
                                scoped_refptr<IndexedDBCallbacks> callbacks) {
   IDB_TRACE("IndexedDBCursor::Continue");
 
+  if (!transaction_) {
+    callbacks->OnError(IndexedDBDatabaseError(

[cmumford, 2016/11/04 23:33:12]

nit: IndexedDBDatabaseError is created three times with same data. A helper
function would simplify this code slightly.

[dmurph, 2016/11/07 20:05:23]

Done.

+        blink::WebIDBDatabaseExceptionAbortError, "Transaction was aborted."));
+    return;
+  }
+
   transaction_->ScheduleTask(
-      task_type_,
-      base::Bind(&IndexedDBCursor::CursorIterationOperation,
-                 this,
-                 base::Passed(&key),
-                 base::Passed(&primary_key),
-                 callbacks));
+      task_type_, base::Bind(&IndexedDBCursor::CursorIterationOperation,
+                             ptr_factory_.GetWeakPtr(), base::Passed(&key),
+                             base::Passed(&primary_key), callbacks));
 }
 
 void IndexedDBCursor::Advance(uint32_t count,
                               scoped_refptr<IndexedDBCallbacks> callbacks) {
   IDB_TRACE("IndexedDBCursor::Advance");
 
+  if (!transaction_) {
+    callbacks->OnError(IndexedDBDatabaseError(
+        blink::WebIDBDatabaseExceptionAbortError, "Transaction was aborted."));
+    return;
+  }
+
   transaction_->ScheduleTask(
-      task_type_,
-      base::Bind(
-          &IndexedDBCursor::CursorAdvanceOperation, this, count, callbacks));
+      task_type_, base::Bind(&IndexedDBCursor::CursorAdvanceOperation,
+                             ptr_factory_.GetWeakPtr(), count, callbacks));
+}
+
+void IndexedDBCursor::Close() {
+  IDB_TRACE("IndexedDBCursor::Close");
+  closed_ = true;
+  cursor_.reset();
+  saved_cursor_.reset();
+  transaction_ = nullptr;
+}
+
+void IndexedDBCursor::RemoveCursorFromTransaction() {
+  if (transaction_)
+    transaction_->UnregisterOpenCursor(this);
 }
 
 void IndexedDBCursor::CursorAdvanceOperation(
     uint32_t count,
     scoped_refptr<IndexedDBCallbacks> callbacks,
     IndexedDBTransaction* /*transaction*/) {
   IDB_TRACE("IndexedDBCursor::CursorAdvanceOperation");
   leveldb::Status s;
   // TODO(cmumford): Handle this error (crbug.com/363397). Although this will
   //                 properly fail, caller will not know why, and any corruption
@@ skipping 27 matching lines @@
   }
 
   callbacks->OnSuccess(this->key(), this->primary_key(), Value());
 }
 
 void IndexedDBCursor::PrefetchContinue(
     int number_to_fetch,
     scoped_refptr<IndexedDBCallbacks> callbacks) {
   IDB_TRACE("IndexedDBCursor::PrefetchContinue");
 
+  if (!transaction_) {
+    callbacks->OnError(IndexedDBDatabaseError(
+        blink::WebIDBDatabaseExceptionAbortError, "Transaction was aborted."));
+    return;
+  }
+
   transaction_->ScheduleTask(
       task_type_,
       base::Bind(&IndexedDBCursor::CursorPrefetchIterationOperation,
-                 this,
-                 number_to_fetch,
-                 callbacks));
+                 ptr_factory_.GetWeakPtr(), number_to_fetch, callbacks));
 }
 
 void IndexedDBCursor::CursorPrefetchIterationOperation(
     int number_to_fetch,
     scoped_refptr<IndexedDBCallbacks> callbacks,
     IndexedDBTransaction* /*transaction*/) {
   IDB_TRACE("IndexedDBCursor::CursorPrefetchIterationOperation");
 
   std::vector<IndexedDBKey> found_keys;
   std::vector<IndexedDBKey> found_primary_keys;
@@ skipping 67 matching lines @@
     DCHECK_GT(used_prefetches, 0);
     for (int i = 0; i < used_prefetches - 1; ++i) {
       bool ok = cursor_->Continue(&s);
       DCHECK(ok);
     }
   }
 
   return s;
 }
 
-void IndexedDBCursor::Close() {
-  IDB_TRACE("IndexedDBCursor::Close");
-  closed_ = true;
-  cursor_.reset();
-  saved_cursor_.reset();
-}
-
 }  // namespace content