Index: third_party/WebKit/Source/modules/indexeddb/IDBValueWrapping.cpp |
diff --git a/third_party/WebKit/Source/modules/indexeddb/IDBValueWrapping.cpp b/third_party/WebKit/Source/modules/indexeddb/IDBValueWrapping.cpp |
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index 0000000000000000000000000000000000000000..a834b6a25b11c156cc75e7f2bb49687da56499bf |
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+++ b/third_party/WebKit/Source/modules/indexeddb/IDBValueWrapping.cpp |
@@ -0,0 +1,256 @@ |
+// 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. |
+ |
+#include "modules/indexeddb/IDBValueWrapping.h" |
+ |
+#include <utility> |
+ |
+#include "bindings/core/v8/ScriptValue.h" |
+#include "bindings/core/v8/serialization/SerializationTag.h" |
+#include "bindings/modules/v8/V8BindingForModules.h" |
+#include "core/fileapi/Blob.h" |
+#include "modules/indexeddb/IDBRequest.h" |
+#include "modules/indexeddb/IDBValue.h" |
+#include "platform/blob/BlobData.h" |
+#include "platform/wtf/text/WTFString.h" |
+ |
+namespace blink { |
+ |
+namespace { |
+ |
+// V8 values are stored on disk by IndexedDB using the format implemented in |
+// SerializedScriptValue (SSV). The wrapping detection logic in |
+// IDBValueUnwrapper::IsWrapped() must be able to distinguish between SSV byte |
+// sequences produced and byte sequences expressing the fact that an IDBValue |
+// has been wrapped and requires post-processing. |
+// |
+// The detection logic takes advantage of the highly regular structure around |
+// SerializedScriptValue. A version 17 byte sequence always starts with the |
+// following four bytes: |
+// |
+// 1) 0xFF - kVersionTag |
+// 2) 0x11 - Blink wrapper version, 17 |
+// 3) 0xFF - kVersionTag |
+// 4) 0x0D - V8 serialization version, currently 13, doesn't matter |
+// |
+// It follows that SSV will never produce byte sequences starting with 0xFF, |
+// 0x11, and any value except for 0xFF. If the SSV format changes, the version |
+// will have to be bumped. |
+ |
+// The SSV format version whose encoding hole is (ab)used for wrapping. |
+const static uint8_t kRequiresProcessingSSVPseudoVersion = 17; |
+ |
+// Identifies IndexedDB values that were wrapped in Blobs. The wrapper has the |
+// following format: |
+// |
+// 1) 0xFF - kVersionTag |
+// 2) 0x11 - kRequiresProcessingSSVPseudoVersion |
+// 3) 0x01 - kBlobWrappedValue |
+// 4) varint - Blob size |
+// 5) varint - the offset of the SSV-wrapping Blob in the IDBValue list of Blobs |
+// (should always be the last Blob) |
+const static uint8_t kBlobWrappedValue = 1; |
+ |
+} // namespace |
+ |
+IDBValueWrapper::IDBValueWrapper( |
+ v8::Isolate* isolate, |
+ v8::Local<v8::Value> value, |
+ SerializedScriptValue::SerializeOptions::WasmSerializationPolicy |
+ wasm_policy, |
+ ExceptionState& exception_state) { |
+ SerializedScriptValue::SerializeOptions options; |
+ options.blob_info = &blob_info_; |
+ options.for_storage = SerializedScriptValue::kForStorage; |
+ options.wasm_policy = wasm_policy; |
+ |
+ serialized_value_ = SerializedScriptValue::Serialize(isolate, value, options, |
+ exception_state); |
+ |
+#if DCHECK_IS_ON() |
+ if (exception_state.HadException()) |
+ had_exception_ = true; |
+#endif // DCHECK_IS_ON() |
+} |
+ |
+void IDBValueWrapper::Clone(ScriptState* script_state, ScriptValue* clone) { |
+#if DCHECK_IS_ON() |
+ DCHECK(!had_exception_) << __FUNCTION__ |
+ << " called on wrapper with serialization exception"; |
+ DCHECK(!wrap_called_) << "Clone() called after WrapIfBiggerThan()"; |
+#endif // DCHECK_IS_ON() |
+ *clone = DeserializeScriptValue(script_state, serialized_value_.Get(), |
+ &blob_info_); |
+} |
+ |
+void IDBValueWrapper::WriteVarint(unsigned value, Vector<char>& output) { |
+ // Writes an unsigned integer as a base-128 varint. |
+ // The number is written, 7 bits at a time, from the least significant to |
+ // the most significant 7 bits. Each byte, except the last, has the MSB set. |
+ // See also https://developers.google.com/protocol-buffers/docs/encoding |
+ do { |
+ output.push_back((value & 0x7F) | 0x80); |
+ value >>= 7; |
+ } while (value); |
+ output.back() &= 0x7F; |
+} |
+ |
+bool IDBValueWrapper::WrapIfBiggerThan(unsigned max_bytes) { |
+#if DCHECK_IS_ON() |
+ DCHECK(!had_exception_) << __FUNCTION__ |
+ << " called on wrapper with serialization exception"; |
+ DCHECK(!wrap_called_) << __FUNCTION__ << " called twice on the same wrapper"; |
+ wrap_called_ = true; |
+#endif // DCHECK_IS_ON() |
+ |
+ serialized_value_->ToWireBytes(wire_bytes_); |
+ if (wire_bytes_.size() <= max_bytes) |
+ return false; |
+ |
+ // TODO(pwnall): The MIME type should probably be an atomic string. |
+ String mime_type(kWrapMimeType); |
+ // TODO(crbug.com/721516): Use WebBlobRegistry::CreateBuilder instead of |
+ // Blob::Create to avoid a buffer copy. |
+ Blob* wrapper = |
+ Blob::Create(reinterpret_cast<unsigned char*>(wire_bytes_.data()), |
+ wire_bytes_.size(), mime_type); |
+ |
+ wrapper_handle_ = wrapper->GetBlobDataHandle(); |
+ blob_info_.emplace_back(wrapper_handle_->Uuid(), wrapper_handle_->GetType(), |
+ wrapper->size()); |
+ |
+ wire_bytes_.clear(); |
+ |
+ wire_bytes_.push_back(kVersionTag); |
+ wire_bytes_.push_back(kRequiresProcessingSSVPseudoVersion); |
+ wire_bytes_.push_back(kBlobWrappedValue); |
+ IDBValueWrapper::WriteVarint(wrapper->size(), wire_bytes_); |
+ IDBValueWrapper::WriteVarint(serialized_value_->BlobDataHandles().size(), |
+ wire_bytes_); |
+ return true; |
+} |
+ |
+void IDBValueWrapper::ExtractBlobDataHandles( |
+ Vector<RefPtr<BlobDataHandle>>* blob_data_handles) { |
+ for (const auto& kvp : serialized_value_->BlobDataHandles()) |
+ blob_data_handles->push_back(kvp.value); |
+ if (wrapper_handle_) |
+ blob_data_handles->push_back(std::move(wrapper_handle_)); |
+} |
+ |
+RefPtr<SharedBuffer> IDBValueWrapper::ExtractWireBytes() { |
+#if DCHECK_IS_ON() |
+ DCHECK(!had_exception_) << __FUNCTION__ |
+ << " called on wrapper with serialization exception"; |
+#endif // DCHECK_IS_ON() |
+ |
+ return SharedBuffer::AdoptVector(wire_bytes_); |
+} |
+ |
+IDBValueUnwrapper::IDBValueUnwrapper() { |
+ Reset(); |
+} |
+ |
+bool IDBValueUnwrapper::IsWrapped(IDBValue* value) { |
+ DCHECK(value); |
+ |
+ uint8_t header[3]; |
+ if (!value->data_ || value->data_->size() < sizeof(header)) |
+ return false; |
+ |
+ value->data_->GetPartAsBytes(header, static_cast<size_t>(0), sizeof(header)); |
+ return header[0] == kVersionTag && |
+ header[1] == kRequiresProcessingSSVPseudoVersion && |
+ header[2] == kBlobWrappedValue; |
+} |
+ |
+bool IDBValueUnwrapper::IsWrapped(const Vector<RefPtr<IDBValue>>& values) { |
+ for (const auto& value : values) { |
+ if (IsWrapped(value.Get())) |
+ return true; |
+ } |
+ return false; |
+} |
+ |
+RefPtr<IDBValue> IDBValueUnwrapper::Unwrap( |
+ IDBValue* wrapped_value, |
+ RefPtr<SharedBuffer>&& wrapper_blob_content) { |
+ DCHECK(wrapped_value); |
+ DCHECK(wrapped_value->data_); |
+ DCHECK_GT(wrapped_value->blob_info_->size(), 0U); |
+ DCHECK_EQ(wrapped_value->blob_info_->size(), |
+ wrapped_value->blob_data_->size()); |
+ |
+ // Create an IDBValue with the same blob information, minus the last blob. |
+ unsigned blob_count = wrapped_value->BlobInfo()->size() - 1; |
+ std::unique_ptr<Vector<RefPtr<BlobDataHandle>>> blob_data = |
+ WTF::MakeUnique<Vector<RefPtr<BlobDataHandle>>>(); |
+ blob_data->ReserveCapacity(blob_count); |
+ std::unique_ptr<Vector<WebBlobInfo>> blob_info = |
+ WTF::MakeUnique<Vector<WebBlobInfo>>(); |
+ blob_info->ReserveCapacity(blob_count); |
+ |
+ for (unsigned i = 0; i < blob_count; ++i) { |
+ blob_data->push_back((*wrapped_value->blob_data_)[i]); |
+ blob_info->push_back((*wrapped_value->blob_info_)[i]); |
+ } |
+ |
+ return IDBValue::Create(std::move(wrapper_blob_content), std::move(blob_data), |
+ std::move(blob_info)); |
+} |
+ |
+bool IDBValueUnwrapper::Parse(IDBValue* value) { |
+ // Fast path that avoids unnecessary dynamic allocations. |
+ if (!IDBValueUnwrapper::IsWrapped(value)) |
+ return false; |
+ |
+ const uint8_t* data = reinterpret_cast<const uint8_t*>(value->data_->Data()); |
+ end_ = data + value->data_->size(); |
+ current_ = data + 3; |
+ |
+ if (!ReadVarint(blob_size_)) |
+ return Reset(); |
+ |
+ unsigned blob_offset; |
+ if (!ReadVarint(blob_offset)) |
+ return Reset(); |
+ |
+ size_t value_blob_count = value->blob_data_->size(); |
+ if (!value_blob_count || blob_offset != value_blob_count - 1) |
+ return Reset(); |
+ |
+ blob_handle_ = value->blob_data_->back(); |
+ if (blob_handle_->size() != blob_size_) |
+ return Reset(); |
+ |
+ return true; |
+} |
+ |
+RefPtr<BlobDataHandle> IDBValueUnwrapper::WrapperBlobHandle() { |
+ DCHECK(blob_handle_); |
+ |
+ return std::move(blob_handle_); |
+} |
+ |
+bool IDBValueUnwrapper::ReadVarint(unsigned& value) { |
+ value = 0; |
+ unsigned shift = 0; |
+ bool has_another_byte; |
+ do { |
+ if (current_ >= end_) |
+ return false; |
+ |
+ if (shift >= sizeof(unsigned) * 8) |
+ return false; |
+ uint8_t byte = *current_; |
+ ++current_; |
+ value |= static_cast<unsigned>(byte & 0x7F) << shift; |
+ shift += 7; |
+ |
+ has_another_byte = byte & 0x80; |
+ } while (has_another_byte); |
+ return true; |
+} |
+ |
+} // namespace blink |