Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame^] | 1 | // Copyright 2006-2008 the V8 project authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style license that can be |
| 3 | // found in the LICENSE file. |
| 4 | |
| 5 | #ifndef V8_SNAPSHOT_SNAPSHOT_H_ |
| 6 | #define V8_SNAPSHOT_SNAPSHOT_H_ |
| 7 | |
| 8 | #include "src/snapshot/serialize.h" |
| 9 | |
| 10 | namespace v8 { |
| 11 | namespace internal { |
| 12 | |
| 13 | // Forward declarations. |
| 14 | class Isolate; |
| 15 | class PartialSerializer; |
| 16 | class StartupSerializer; |
| 17 | |
| 18 | class Snapshot : public AllStatic { |
| 19 | public: |
| 20 | class Metadata { |
| 21 | public: |
| 22 | explicit Metadata(uint32_t data = 0) : data_(data) {} |
| 23 | bool embeds_script() { return EmbedsScriptBits::decode(data_); } |
| 24 | void set_embeds_script(bool v) { |
| 25 | data_ = EmbedsScriptBits::update(data_, v); |
| 26 | } |
| 27 | |
| 28 | uint32_t& RawValue() { return data_; } |
| 29 | |
| 30 | private: |
| 31 | class EmbedsScriptBits : public BitField<bool, 0, 1> {}; |
| 32 | uint32_t data_; |
| 33 | }; |
| 34 | |
| 35 | // Initialize the Isolate from the internal snapshot. Returns false if no |
| 36 | // snapshot could be found. |
| 37 | static bool Initialize(Isolate* isolate); |
| 38 | // Create a new context using the internal partial snapshot. |
| 39 | static MaybeHandle<Context> NewContextFromSnapshot( |
| 40 | Isolate* isolate, Handle<JSGlobalProxy> global_proxy); |
| 41 | |
| 42 | static bool HaveASnapshotToStartFrom(Isolate* isolate); |
| 43 | |
| 44 | static bool EmbedsScript(Isolate* isolate); |
| 45 | |
| 46 | static uint32_t SizeOfFirstPage(Isolate* isolate, AllocationSpace space); |
| 47 | |
| 48 | |
| 49 | // To be implemented by the snapshot source. |
| 50 | static const v8::StartupData* DefaultSnapshotBlob(); |
| 51 | |
| 52 | static v8::StartupData CreateSnapshotBlob( |
| 53 | const StartupSerializer& startup_ser, |
| 54 | const PartialSerializer& context_ser, Snapshot::Metadata metadata); |
| 55 | |
| 56 | #ifdef DEBUG |
| 57 | static bool SnapshotIsValid(v8::StartupData* snapshot_blob); |
| 58 | #endif // DEBUG |
| 59 | |
| 60 | private: |
| 61 | static Vector<const byte> ExtractStartupData(const v8::StartupData* data); |
| 62 | static Vector<const byte> ExtractContextData(const v8::StartupData* data); |
| 63 | static Metadata ExtractMetadata(const v8::StartupData* data); |
| 64 | |
| 65 | // Snapshot blob layout: |
| 66 | // [0] metadata |
| 67 | // [1 - 6] pre-calculated first page sizes for paged spaces |
| 68 | // [7] serialized start up data length |
| 69 | // ... serialized start up data |
| 70 | // ... serialized context data |
| 71 | |
| 72 | static const int kNumPagedSpaces = LAST_PAGED_SPACE - FIRST_PAGED_SPACE + 1; |
| 73 | |
| 74 | static const int kMetadataOffset = 0; |
| 75 | static const int kFirstPageSizesOffset = kMetadataOffset + kInt32Size; |
| 76 | static const int kStartupLengthOffset = |
| 77 | kFirstPageSizesOffset + kNumPagedSpaces * kInt32Size; |
| 78 | static const int kStartupDataOffset = kStartupLengthOffset + kInt32Size; |
| 79 | |
| 80 | static int ContextOffset(int startup_length) { |
| 81 | return kStartupDataOffset + startup_length; |
| 82 | } |
| 83 | |
| 84 | DISALLOW_IMPLICIT_CONSTRUCTORS(Snapshot); |
| 85 | }; |
| 86 | |
| 87 | #ifdef V8_USE_EXTERNAL_STARTUP_DATA |
| 88 | void SetSnapshotFromFile(StartupData* snapshot_blob); |
| 89 | #endif |
| 90 | |
| 91 | } // namespace internal |
| 92 | } // namespace v8 |
| 93 | |
| 94 | #endif // V8_SNAPSHOT_SNAPSHOT_H_ |