| // Copyright 2006-2008 the V8 project 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 V8_SNAPSHOT_SNAPSHOT_H_ |
| #define V8_SNAPSHOT_SNAPSHOT_H_ |
| |
| #include "src/snapshot/partial-serializer.h" |
| #include "src/snapshot/startup-serializer.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| // Forward declarations. |
| class Isolate; |
| class PartialSerializer; |
| class StartupSerializer; |
| |
| // Wrapper around reservation sizes and the serialization payload. |
| class SnapshotData : public SerializedData { |
| public: |
| // Used when producing. |
| explicit SnapshotData(const Serializer* serializer); |
| |
| // Used when consuming. |
| explicit SnapshotData(const Vector<const byte> snapshot) |
| : SerializedData(const_cast<byte*>(snapshot.begin()), snapshot.length()) { |
| CHECK(IsSane()); |
| } |
| |
| Vector<const Reservation> Reservations() const; |
| Vector<const byte> Payload() const; |
| |
| Vector<const byte> RawData() const { |
| return Vector<const byte>(data_, size_); |
| } |
| |
| private: |
| bool IsSane(); |
| |
| // The data header consists of uint32_t-sized entries: |
| // [0] magic number and external reference count |
| // [1] version hash |
| // [2] number of reservation size entries |
| // [3] payload length |
| // ... reservations |
| // ... serialized payload |
| static const int kCheckSumOffset = kMagicNumberOffset + kInt32Size; |
| static const int kNumReservationsOffset = kCheckSumOffset + kInt32Size; |
| static const int kPayloadLengthOffset = kNumReservationsOffset + kInt32Size; |
| static const int kHeaderSize = kPayloadLengthOffset + kInt32Size; |
| }; |
| |
| class Snapshot : public AllStatic { |
| public: |
| // Initialize the Isolate from the internal snapshot. Returns false if no |
| // snapshot could be found. |
| static bool Initialize(Isolate* isolate); |
| // Create a new context using the internal partial snapshot. |
| static MaybeHandle<Context> NewContextFromSnapshot( |
| Isolate* isolate, Handle<JSGlobalProxy> global_proxy, |
| size_t context_index); |
| |
| static bool HaveASnapshotToStartFrom(Isolate* isolate); |
| |
| static bool EmbedsScript(Isolate* isolate); |
| |
| static uint32_t SizeOfFirstPage(Isolate* isolate, AllocationSpace space); |
| |
| |
| // To be implemented by the snapshot source. |
| static const v8::StartupData* DefaultSnapshotBlob(); |
| |
| static v8::StartupData CreateSnapshotBlob( |
| const SnapshotData* startup_snapshot, |
| const List<SnapshotData*>* context_snapshots); |
| |
| #ifdef DEBUG |
| static bool SnapshotIsValid(v8::StartupData* snapshot_blob); |
| #endif // DEBUG |
| |
| private: |
| static int ExtractNumContexts(const v8::StartupData* data); |
| static Vector<const byte> ExtractStartupData(const v8::StartupData* data); |
| static Vector<const byte> ExtractContextData(const v8::StartupData* data, |
| int index); |
| |
| // Snapshot blob layout: |
| // [0 - 5] pre-calculated first page sizes for paged spaces |
| // [6] number of contexts N |
| // [7] offset to context 0 |
| // [8] offset to context 1 |
| // ... |
| // ... offset to context N - 1 |
| // ... startup snapshot data |
| // ... context 0 snapshot data |
| // ... context 1 snapshot data |
| |
| static const int kNumPagedSpaces = LAST_PAGED_SPACE - FIRST_PAGED_SPACE + 1; |
| |
| static const int kFirstPageSizesOffset = 0; |
| static const int kNumberOfContextsOffset = |
| kFirstPageSizesOffset + kNumPagedSpaces * kInt32Size; |
| static const int kFirstContextOffsetOffset = |
| kNumberOfContextsOffset + kInt32Size; |
| |
| static int StartupSnapshotOffset(int num_contexts) { |
| return kFirstContextOffsetOffset + num_contexts * kInt32Size; |
| } |
| |
| static int ContextSnapshotOffsetOffset(int index) { |
| return kFirstContextOffsetOffset + index * kInt32Size; |
| } |
| |
| DISALLOW_IMPLICIT_CONSTRUCTORS(Snapshot); |
| }; |
| |
| #ifdef V8_USE_EXTERNAL_STARTUP_DATA |
| void SetSnapshotFromFile(StartupData* snapshot_blob); |
| #endif |
| |
| } // namespace internal |
| } // namespace v8 |
| |
| #endif // V8_SNAPSHOT_SNAPSHOT_H_ |