Index: third_party/WebKit/Source/modules/indexeddb/IDBValueWrapper.h |
diff --git a/third_party/WebKit/Source/modules/indexeddb/IDBValueWrapper.h b/third_party/WebKit/Source/modules/indexeddb/IDBValueWrapper.h |
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+// Copyright 2017 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. |
+ |
+#ifndef IDBValueWrapper_h |
+#define IDBValueWrapper_h |
+ |
+#include "bindings/core/v8/ExceptionState.h" |
+#include "platform/SharedBuffer.h" |
+#include "platform/wtf/PassRefPtr.h" |
+#include "platform/wtf/RefPtr.h" |
+#include "platform/wtf/Vector.h" |
+#include "public/platform/WebBlobInfo.h" |
+#include "v8/include/v8.h" |
+ |
+namespace blink { |
+ |
+class Blob; |
+class BlobDataHandle; |
+class ExceptionState; |
+class ScriptState; |
+class ScriptValue; |
+class SerializedScriptValue; |
+class SharedBuffer; |
+ |
+// Logic for wrapping large IndexedDB values in Blobs. |
+class IDBValueWrapper { |
+ public: |
+ // Wrapper for an IndexedDB value. |
+ // |
+ // The serialization process can throw an exception. The caller is responsible |
+ // for checking exception_state. |
+ IDBValueWrapper(v8::Isolate*, |
+ v8::Local<v8::Value>, |
+ bool write_wasm_to_stream, |
+ ExceptionState&); |
+ |
+ // Creates a clone of the serialized value. |
+ // |
+ // This method is necessary because the IndexedDB specification demands that a |
+ // value's key and index keys are extracted from a structured clone of the |
+ // value. |
+ // |
+ // This method cannot be called after WrapIfBiggerThan(). |
+ void Clone(ScriptState*, ScriptValue* clone); |
+ |
+ // Wraps the serialized value into a Blob if it exceeds the given size. |
+ // |
+ // In production, the threshold is currently always kWrapThreshold. |
+ // |
+ // This method must be called before ExtractWireBytes() and cannot be called |
+ // after ExtractWireBytes(). |
+ bool WrapIfBiggerThan(unsigned max_bytes); |
+ |
+ void ExtractBlobDataHandles( |
+ Vector<RefPtr<BlobDataHandle>>* blob_data_handles); |
+ |
+ PassRefPtr<SharedBuffer> ExtractWireBytes(); |
+ |
+ inline Vector<WebBlobInfo>& WrappedBlobInfo() { |
+#if DCHECK_IS_ON() |
+ DCHECK(!had_exception_) |
+ << "WrapBlobInfo() called on wrapper with serialization exception"; |
+#endif // DCHECK_IS_ON() |
+ return blob_info_; |
+ } |
+ |
+ // Default threshold for WrapIfBiggerThan(). |
+ // |
+ // This should be tuned to achieve a compromise between short-term IndexedDB |
+ // throughput and long-term I/O load and memory usage. LevelDB, the underlying |
+ // storage for IndexedDB, was not designed with large values in mind. At the |
+ // very least, large values will slow down compaction, causing occasional I/O |
+ // spikes. |
+ static constexpr unsigned kWrapThreshold = 64 * 1024; |
+ |
+ // MIME type used for Blobs that wrap IDBValues. |
+ static constexpr const char* kWrapMimeType = |
+ "application/x-blink-idb-value-wrapper"; |
+ |
+ private: |
+ // Used to serialize the wrapped value. |
+ static void WriteVarint(unsigned value, Vector<char>& output); |
+ static void WriteAsciiString(const String& value, Vector<char>& output); |
+ |
+ RefPtr<SerializedScriptValue> serialized_value_; |
+ RefPtr<BlobDataHandle> wrapper_handle_; |
+ Vector<WebBlobInfo> blob_info_; |
+ Vector<BlobDataHandle> blob_handles_; |
+ Vector<char> wire_bytes_; |
+#if DCHECK_IS_ON() |
+ bool had_exception_ = false; |
+ bool wrap_called_ = false; |
+#endif // DCHECK_IS_ON() |
+}; |
+ |
+} // namespace blink |
+ |
+#endif // IDBValueWrapper_h |