Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 1 | // Copyright 2016 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 | #include "src/snapshot/serializer.h" |
| 6 | |
| 7 | #include "src/macro-assembler.h" |
| 8 | #include "src/snapshot/natives.h" |
| 9 | |
| 10 | namespace v8 { |
| 11 | namespace internal { |
| 12 | |
Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 13 | Serializer::Serializer(Isolate* isolate) |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 14 | : isolate_(isolate), |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 15 | external_reference_encoder_(isolate), |
| 16 | root_index_map_(isolate), |
| 17 | recursion_depth_(0), |
| 18 | code_address_map_(NULL), |
| 19 | large_objects_total_size_(0), |
| 20 | seen_large_objects_index_(0) { |
| 21 | // The serializer is meant to be used only to generate initial heap images |
| 22 | // from a context in which there is only one isolate. |
| 23 | for (int i = 0; i < kNumberOfPreallocatedSpaces; i++) { |
| 24 | pending_chunk_[i] = 0; |
| 25 | max_chunk_size_[i] = static_cast<uint32_t>( |
| 26 | MemoryAllocator::PageAreaSize(static_cast<AllocationSpace>(i))); |
| 27 | } |
| 28 | |
| 29 | #ifdef OBJECT_PRINT |
| 30 | if (FLAG_serialization_statistics) { |
| 31 | instance_type_count_ = NewArray<int>(kInstanceTypes); |
| 32 | instance_type_size_ = NewArray<size_t>(kInstanceTypes); |
| 33 | for (int i = 0; i < kInstanceTypes; i++) { |
| 34 | instance_type_count_[i] = 0; |
| 35 | instance_type_size_[i] = 0; |
| 36 | } |
| 37 | } else { |
| 38 | instance_type_count_ = NULL; |
| 39 | instance_type_size_ = NULL; |
| 40 | } |
| 41 | #endif // OBJECT_PRINT |
| 42 | } |
| 43 | |
| 44 | Serializer::~Serializer() { |
| 45 | if (code_address_map_ != NULL) delete code_address_map_; |
| 46 | #ifdef OBJECT_PRINT |
| 47 | if (instance_type_count_ != NULL) { |
| 48 | DeleteArray(instance_type_count_); |
| 49 | DeleteArray(instance_type_size_); |
| 50 | } |
| 51 | #endif // OBJECT_PRINT |
| 52 | } |
| 53 | |
| 54 | #ifdef OBJECT_PRINT |
| 55 | void Serializer::CountInstanceType(Map* map, int size) { |
| 56 | int instance_type = map->instance_type(); |
| 57 | instance_type_count_[instance_type]++; |
| 58 | instance_type_size_[instance_type] += size; |
| 59 | } |
| 60 | #endif // OBJECT_PRINT |
| 61 | |
| 62 | void Serializer::OutputStatistics(const char* name) { |
| 63 | if (!FLAG_serialization_statistics) return; |
| 64 | PrintF("%s:\n", name); |
| 65 | PrintF(" Spaces (bytes):\n"); |
| 66 | for (int space = 0; space < kNumberOfSpaces; space++) { |
| 67 | PrintF("%16s", AllocationSpaceName(static_cast<AllocationSpace>(space))); |
| 68 | } |
| 69 | PrintF("\n"); |
| 70 | for (int space = 0; space < kNumberOfPreallocatedSpaces; space++) { |
| 71 | size_t s = pending_chunk_[space]; |
| 72 | for (uint32_t chunk_size : completed_chunks_[space]) s += chunk_size; |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 73 | PrintF("%16" PRIuS, s); |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 74 | } |
| 75 | PrintF("%16d\n", large_objects_total_size_); |
| 76 | #ifdef OBJECT_PRINT |
| 77 | PrintF(" Instance types (count and bytes):\n"); |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 78 | #define PRINT_INSTANCE_TYPE(Name) \ |
| 79 | if (instance_type_count_[Name]) { \ |
| 80 | PrintF("%10d %10" PRIuS " %s\n", instance_type_count_[Name], \ |
| 81 | instance_type_size_[Name], #Name); \ |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 82 | } |
| 83 | INSTANCE_TYPE_LIST(PRINT_INSTANCE_TYPE) |
| 84 | #undef PRINT_INSTANCE_TYPE |
| 85 | PrintF("\n"); |
| 86 | #endif // OBJECT_PRINT |
| 87 | } |
| 88 | |
| 89 | void Serializer::SerializeDeferredObjects() { |
| 90 | while (deferred_objects_.length() > 0) { |
| 91 | HeapObject* obj = deferred_objects_.RemoveLast(); |
Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 92 | ObjectSerializer obj_serializer(this, obj, &sink_, kPlain, kStartOfObject); |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 93 | obj_serializer.SerializeDeferred(); |
| 94 | } |
Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 95 | sink_.Put(kSynchronize, "Finished with deferred objects"); |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 96 | } |
| 97 | |
| 98 | void Serializer::VisitPointers(Object** start, Object** end) { |
| 99 | for (Object** current = start; current < end; current++) { |
| 100 | if ((*current)->IsSmi()) { |
| 101 | PutSmi(Smi::cast(*current)); |
| 102 | } else { |
| 103 | SerializeObject(HeapObject::cast(*current), kPlain, kStartOfObject, 0); |
| 104 | } |
| 105 | } |
| 106 | } |
| 107 | |
| 108 | void Serializer::EncodeReservations( |
| 109 | List<SerializedData::Reservation>* out) const { |
| 110 | for (int i = 0; i < kNumberOfPreallocatedSpaces; i++) { |
| 111 | for (int j = 0; j < completed_chunks_[i].length(); j++) { |
| 112 | out->Add(SerializedData::Reservation(completed_chunks_[i][j])); |
| 113 | } |
| 114 | |
| 115 | if (pending_chunk_[i] > 0 || completed_chunks_[i].length() == 0) { |
| 116 | out->Add(SerializedData::Reservation(pending_chunk_[i])); |
| 117 | } |
| 118 | out->last().mark_as_last(); |
| 119 | } |
| 120 | |
| 121 | out->Add(SerializedData::Reservation(large_objects_total_size_)); |
| 122 | out->last().mark_as_last(); |
| 123 | } |
| 124 | |
| 125 | #ifdef DEBUG |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 126 | bool Serializer::BackReferenceIsAlreadyAllocated( |
| 127 | SerializerReference reference) { |
| 128 | DCHECK(reference.is_back_reference()); |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 129 | AllocationSpace space = reference.space(); |
| 130 | int chunk_index = reference.chunk_index(); |
| 131 | if (space == LO_SPACE) { |
| 132 | return chunk_index == 0 && |
| 133 | reference.large_object_index() < seen_large_objects_index_; |
| 134 | } else if (chunk_index == completed_chunks_[space].length()) { |
| 135 | return reference.chunk_offset() < pending_chunk_[space]; |
| 136 | } else { |
| 137 | return chunk_index < completed_chunks_[space].length() && |
| 138 | reference.chunk_offset() < completed_chunks_[space][chunk_index]; |
| 139 | } |
| 140 | } |
| 141 | #endif // DEBUG |
| 142 | |
Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 143 | bool Serializer::SerializeHotObject(HeapObject* obj, HowToCode how_to_code, |
| 144 | WhereToPoint where_to_point, int skip) { |
| 145 | if (how_to_code != kPlain || where_to_point != kStartOfObject) return false; |
| 146 | // Encode a reference to a hot object by its index in the working set. |
| 147 | int index = hot_objects_.Find(obj); |
| 148 | if (index == HotObjectsList::kNotFound) return false; |
| 149 | DCHECK(index >= 0 && index < kNumberOfHotObjects); |
| 150 | if (FLAG_trace_serializer) { |
| 151 | PrintF(" Encoding hot object %d:", index); |
| 152 | obj->ShortPrint(); |
| 153 | PrintF("\n"); |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 154 | } |
Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 155 | if (skip != 0) { |
| 156 | sink_.Put(kHotObjectWithSkip + index, "HotObjectWithSkip"); |
| 157 | sink_.PutInt(skip, "HotObjectSkipDistance"); |
| 158 | } else { |
| 159 | sink_.Put(kHotObject + index, "HotObject"); |
| 160 | } |
| 161 | return true; |
| 162 | } |
| 163 | bool Serializer::SerializeBackReference(HeapObject* obj, HowToCode how_to_code, |
| 164 | WhereToPoint where_to_point, int skip) { |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 165 | SerializerReference reference = reference_map_.Lookup(obj); |
Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 166 | if (!reference.is_valid()) return false; |
| 167 | // Encode the location of an already deserialized object in order to write |
| 168 | // its location into a later object. We can encode the location as an |
| 169 | // offset fromthe start of the deserialized objects or as an offset |
| 170 | // backwards from thecurrent allocation pointer. |
| 171 | if (reference.is_attached_reference()) { |
| 172 | FlushSkip(skip); |
| 173 | if (FLAG_trace_serializer) { |
| 174 | PrintF(" Encoding attached reference %d\n", |
| 175 | reference.attached_reference_index()); |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 176 | } |
Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 177 | PutAttachedReference(reference, how_to_code, where_to_point); |
| 178 | } else { |
| 179 | DCHECK(reference.is_back_reference()); |
| 180 | if (FLAG_trace_serializer) { |
| 181 | PrintF(" Encoding back reference to: "); |
| 182 | obj->ShortPrint(); |
| 183 | PrintF("\n"); |
| 184 | } |
| 185 | |
| 186 | PutAlignmentPrefix(obj); |
| 187 | AllocationSpace space = reference.space(); |
| 188 | if (skip == 0) { |
| 189 | sink_.Put(kBackref + how_to_code + where_to_point + space, "BackRef"); |
| 190 | } else { |
| 191 | sink_.Put(kBackrefWithSkip + how_to_code + where_to_point + space, |
| 192 | "BackRefWithSkip"); |
| 193 | sink_.PutInt(skip, "BackRefSkipDistance"); |
| 194 | } |
| 195 | PutBackReference(obj, reference); |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 196 | } |
Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 197 | return true; |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 198 | } |
| 199 | |
| 200 | void Serializer::PutRoot(int root_index, HeapObject* object, |
| 201 | SerializerDeserializer::HowToCode how_to_code, |
| 202 | SerializerDeserializer::WhereToPoint where_to_point, |
| 203 | int skip) { |
| 204 | if (FLAG_trace_serializer) { |
| 205 | PrintF(" Encoding root %d:", root_index); |
| 206 | object->ShortPrint(); |
| 207 | PrintF("\n"); |
| 208 | } |
| 209 | |
| 210 | if (how_to_code == kPlain && where_to_point == kStartOfObject && |
| 211 | root_index < kNumberOfRootArrayConstants && |
| 212 | !isolate()->heap()->InNewSpace(object)) { |
| 213 | if (skip == 0) { |
Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 214 | sink_.Put(kRootArrayConstants + root_index, "RootConstant"); |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 215 | } else { |
Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 216 | sink_.Put(kRootArrayConstantsWithSkip + root_index, "RootConstant"); |
| 217 | sink_.PutInt(skip, "SkipInPutRoot"); |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 218 | } |
| 219 | } else { |
| 220 | FlushSkip(skip); |
Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 221 | sink_.Put(kRootArray + how_to_code + where_to_point, "RootSerialization"); |
| 222 | sink_.PutInt(root_index, "root_index"); |
| 223 | hot_objects_.Add(object); |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 224 | } |
| 225 | } |
| 226 | |
| 227 | void Serializer::PutSmi(Smi* smi) { |
Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 228 | sink_.Put(kOnePointerRawData, "Smi"); |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 229 | byte* bytes = reinterpret_cast<byte*>(&smi); |
Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 230 | for (int i = 0; i < kPointerSize; i++) sink_.Put(bytes[i], "Byte"); |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 231 | } |
| 232 | |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 233 | void Serializer::PutBackReference(HeapObject* object, |
| 234 | SerializerReference reference) { |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 235 | DCHECK(BackReferenceIsAlreadyAllocated(reference)); |
Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 236 | sink_.PutInt(reference.back_reference(), "BackRefValue"); |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 237 | hot_objects_.Add(object); |
| 238 | } |
| 239 | |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 240 | void Serializer::PutAttachedReference(SerializerReference reference, |
| 241 | HowToCode how_to_code, |
| 242 | WhereToPoint where_to_point) { |
| 243 | DCHECK(reference.is_attached_reference()); |
| 244 | DCHECK((how_to_code == kPlain && where_to_point == kStartOfObject) || |
| 245 | (how_to_code == kPlain && where_to_point == kInnerPointer) || |
| 246 | (how_to_code == kFromCode && where_to_point == kInnerPointer)); |
Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 247 | sink_.Put(kAttachedReference + how_to_code + where_to_point, "AttachedRef"); |
| 248 | sink_.PutInt(reference.attached_reference_index(), "AttachedRefIndex"); |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 249 | } |
| 250 | |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 251 | int Serializer::PutAlignmentPrefix(HeapObject* object) { |
| 252 | AllocationAlignment alignment = object->RequiredAlignment(); |
| 253 | if (alignment != kWordAligned) { |
| 254 | DCHECK(1 <= alignment && alignment <= 3); |
| 255 | byte prefix = (kAlignmentPrefix - 1) + alignment; |
Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 256 | sink_.Put(prefix, "Alignment"); |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 257 | return Heap::GetMaximumFillToAlign(alignment); |
| 258 | } |
| 259 | return 0; |
| 260 | } |
| 261 | |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 262 | SerializerReference Serializer::AllocateLargeObject(int size) { |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 263 | // Large objects are allocated one-by-one when deserializing. We do not |
| 264 | // have to keep track of multiple chunks. |
| 265 | large_objects_total_size_ += size; |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 266 | return SerializerReference::LargeObjectReference(seen_large_objects_index_++); |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 267 | } |
| 268 | |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 269 | SerializerReference Serializer::Allocate(AllocationSpace space, int size) { |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 270 | DCHECK(space >= 0 && space < kNumberOfPreallocatedSpaces); |
| 271 | DCHECK(size > 0 && size <= static_cast<int>(max_chunk_size(space))); |
| 272 | uint32_t new_chunk_size = pending_chunk_[space] + size; |
| 273 | if (new_chunk_size > max_chunk_size(space)) { |
| 274 | // The new chunk size would not fit onto a single page. Complete the |
| 275 | // current chunk and start a new one. |
Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 276 | sink_.Put(kNextChunk, "NextChunk"); |
| 277 | sink_.Put(space, "NextChunkSpace"); |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 278 | completed_chunks_[space].Add(pending_chunk_[space]); |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 279 | pending_chunk_[space] = 0; |
| 280 | new_chunk_size = size; |
| 281 | } |
| 282 | uint32_t offset = pending_chunk_[space]; |
| 283 | pending_chunk_[space] = new_chunk_size; |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 284 | return SerializerReference::BackReference( |
| 285 | space, completed_chunks_[space].length(), offset); |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 286 | } |
| 287 | |
| 288 | void Serializer::Pad() { |
| 289 | // The non-branching GetInt will read up to 3 bytes too far, so we need |
| 290 | // to pad the snapshot to make sure we don't read over the end. |
| 291 | for (unsigned i = 0; i < sizeof(int32_t) - 1; i++) { |
Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 292 | sink_.Put(kNop, "Padding"); |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 293 | } |
| 294 | // Pad up to pointer size for checksum. |
Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 295 | while (!IsAligned(sink_.Position(), kPointerAlignment)) { |
| 296 | sink_.Put(kNop, "Padding"); |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 297 | } |
| 298 | } |
| 299 | |
| 300 | void Serializer::InitializeCodeAddressMap() { |
| 301 | isolate_->InitializeLoggingAndCounters(); |
| 302 | code_address_map_ = new CodeAddressMap(isolate_); |
| 303 | } |
| 304 | |
| 305 | Code* Serializer::CopyCode(Code* code) { |
| 306 | code_buffer_.Rewind(0); // Clear buffer without deleting backing store. |
| 307 | int size = code->CodeSize(); |
| 308 | code_buffer_.AddAll(Vector<byte>(code->address(), size)); |
| 309 | return Code::cast(HeapObject::FromAddress(&code_buffer_.first())); |
| 310 | } |
| 311 | |
| 312 | bool Serializer::HasNotExceededFirstPageOfEachSpace() { |
| 313 | for (int i = 0; i < kNumberOfPreallocatedSpaces; i++) { |
| 314 | if (!completed_chunks_[i].is_empty()) return false; |
| 315 | } |
| 316 | return true; |
| 317 | } |
| 318 | |
| 319 | void Serializer::ObjectSerializer::SerializePrologue(AllocationSpace space, |
| 320 | int size, Map* map) { |
| 321 | if (serializer_->code_address_map_) { |
| 322 | const char* code_name = |
| 323 | serializer_->code_address_map_->Lookup(object_->address()); |
| 324 | LOG(serializer_->isolate_, |
| 325 | CodeNameEvent(object_->address(), sink_->Position(), code_name)); |
| 326 | } |
| 327 | |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 328 | SerializerReference back_reference; |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 329 | if (space == LO_SPACE) { |
| 330 | sink_->Put(kNewObject + reference_representation_ + space, |
| 331 | "NewLargeObject"); |
| 332 | sink_->PutInt(size >> kObjectAlignmentBits, "ObjectSizeInWords"); |
| 333 | if (object_->IsCode()) { |
| 334 | sink_->Put(EXECUTABLE, "executable large object"); |
| 335 | } else { |
| 336 | sink_->Put(NOT_EXECUTABLE, "not executable large object"); |
| 337 | } |
| 338 | back_reference = serializer_->AllocateLargeObject(size); |
| 339 | } else { |
| 340 | int fill = serializer_->PutAlignmentPrefix(object_); |
| 341 | back_reference = serializer_->Allocate(space, size + fill); |
| 342 | sink_->Put(kNewObject + reference_representation_ + space, "NewObject"); |
| 343 | sink_->PutInt(size >> kObjectAlignmentBits, "ObjectSizeInWords"); |
| 344 | } |
| 345 | |
| 346 | #ifdef OBJECT_PRINT |
| 347 | if (FLAG_serialization_statistics) { |
| 348 | serializer_->CountInstanceType(map, size); |
| 349 | } |
| 350 | #endif // OBJECT_PRINT |
| 351 | |
| 352 | // Mark this object as already serialized. |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 353 | serializer_->reference_map()->Add(object_, back_reference); |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 354 | |
| 355 | // Serialize the map (first word of the object). |
| 356 | serializer_->SerializeObject(map, kPlain, kStartOfObject, 0); |
| 357 | } |
| 358 | |
| 359 | void Serializer::ObjectSerializer::SerializeExternalString() { |
| 360 | // Instead of serializing this as an external string, we serialize |
| 361 | // an imaginary sequential string with the same content. |
| 362 | Isolate* isolate = serializer_->isolate(); |
| 363 | DCHECK(object_->IsExternalString()); |
| 364 | DCHECK(object_->map() != isolate->heap()->native_source_string_map()); |
| 365 | ExternalString* string = ExternalString::cast(object_); |
| 366 | int length = string->length(); |
| 367 | Map* map; |
| 368 | int content_size; |
| 369 | int allocation_size; |
| 370 | const byte* resource; |
| 371 | // Find the map and size for the imaginary sequential string. |
| 372 | bool internalized = object_->IsInternalizedString(); |
| 373 | if (object_->IsExternalOneByteString()) { |
| 374 | map = internalized ? isolate->heap()->one_byte_internalized_string_map() |
| 375 | : isolate->heap()->one_byte_string_map(); |
| 376 | allocation_size = SeqOneByteString::SizeFor(length); |
| 377 | content_size = length * kCharSize; |
| 378 | resource = reinterpret_cast<const byte*>( |
| 379 | ExternalOneByteString::cast(string)->resource()->data()); |
| 380 | } else { |
| 381 | map = internalized ? isolate->heap()->internalized_string_map() |
| 382 | : isolate->heap()->string_map(); |
| 383 | allocation_size = SeqTwoByteString::SizeFor(length); |
| 384 | content_size = length * kShortSize; |
| 385 | resource = reinterpret_cast<const byte*>( |
| 386 | ExternalTwoByteString::cast(string)->resource()->data()); |
| 387 | } |
| 388 | |
| 389 | AllocationSpace space = (allocation_size > Page::kMaxRegularHeapObjectSize) |
| 390 | ? LO_SPACE |
| 391 | : OLD_SPACE; |
| 392 | SerializePrologue(space, allocation_size, map); |
| 393 | |
| 394 | // Output the rest of the imaginary string. |
| 395 | int bytes_to_output = allocation_size - HeapObject::kHeaderSize; |
| 396 | |
| 397 | // Output raw data header. Do not bother with common raw length cases here. |
| 398 | sink_->Put(kVariableRawData, "RawDataForString"); |
| 399 | sink_->PutInt(bytes_to_output, "length"); |
| 400 | |
| 401 | // Serialize string header (except for map). |
| 402 | Address string_start = string->address(); |
| 403 | for (int i = HeapObject::kHeaderSize; i < SeqString::kHeaderSize; i++) { |
| 404 | sink_->PutSection(string_start[i], "StringHeader"); |
| 405 | } |
| 406 | |
| 407 | // Serialize string content. |
| 408 | sink_->PutRaw(resource, content_size, "StringContent"); |
| 409 | |
| 410 | // Since the allocation size is rounded up to object alignment, there |
| 411 | // maybe left-over bytes that need to be padded. |
| 412 | int padding_size = allocation_size - SeqString::kHeaderSize - content_size; |
| 413 | DCHECK(0 <= padding_size && padding_size < kObjectAlignment); |
| 414 | for (int i = 0; i < padding_size; i++) sink_->PutSection(0, "StringPadding"); |
| 415 | |
| 416 | sink_->Put(kSkip, "SkipAfterString"); |
| 417 | sink_->PutInt(bytes_to_output, "SkipDistance"); |
| 418 | } |
| 419 | |
| 420 | // Clear and later restore the next link in the weak cell or allocation site. |
| 421 | // TODO(all): replace this with proper iteration of weak slots in serializer. |
| 422 | class UnlinkWeakNextScope { |
| 423 | public: |
| 424 | explicit UnlinkWeakNextScope(HeapObject* object) : object_(nullptr) { |
| 425 | if (object->IsWeakCell()) { |
| 426 | object_ = object; |
| 427 | next_ = WeakCell::cast(object)->next(); |
| 428 | WeakCell::cast(object)->clear_next(object->GetHeap()->the_hole_value()); |
| 429 | } else if (object->IsAllocationSite()) { |
| 430 | object_ = object; |
| 431 | next_ = AllocationSite::cast(object)->weak_next(); |
| 432 | AllocationSite::cast(object)->set_weak_next( |
| 433 | object->GetHeap()->undefined_value()); |
| 434 | } |
| 435 | } |
| 436 | |
| 437 | ~UnlinkWeakNextScope() { |
| 438 | if (object_ != nullptr) { |
| 439 | if (object_->IsWeakCell()) { |
| 440 | WeakCell::cast(object_)->set_next(next_, UPDATE_WEAK_WRITE_BARRIER); |
| 441 | } else { |
| 442 | AllocationSite::cast(object_)->set_weak_next(next_, |
| 443 | UPDATE_WEAK_WRITE_BARRIER); |
| 444 | } |
| 445 | } |
| 446 | } |
| 447 | |
| 448 | private: |
| 449 | HeapObject* object_; |
| 450 | Object* next_; |
| 451 | DisallowHeapAllocation no_gc_; |
| 452 | }; |
| 453 | |
| 454 | void Serializer::ObjectSerializer::Serialize() { |
| 455 | if (FLAG_trace_serializer) { |
| 456 | PrintF(" Encoding heap object: "); |
| 457 | object_->ShortPrint(); |
| 458 | PrintF("\n"); |
| 459 | } |
| 460 | |
| 461 | // We cannot serialize typed array objects correctly. |
| 462 | DCHECK(!object_->IsJSTypedArray()); |
| 463 | |
| 464 | // We don't expect fillers. |
| 465 | DCHECK(!object_->IsFiller()); |
| 466 | |
| 467 | if (object_->IsScript()) { |
| 468 | // Clear cached line ends. |
| 469 | Object* undefined = serializer_->isolate()->heap()->undefined_value(); |
| 470 | Script::cast(object_)->set_line_ends(undefined); |
| 471 | } |
| 472 | |
| 473 | if (object_->IsExternalString()) { |
| 474 | Heap* heap = serializer_->isolate()->heap(); |
| 475 | if (object_->map() != heap->native_source_string_map()) { |
| 476 | // Usually we cannot recreate resources for external strings. To work |
| 477 | // around this, external strings are serialized to look like ordinary |
| 478 | // sequential strings. |
| 479 | // The exception are native source code strings, since we can recreate |
| 480 | // their resources. In that case we fall through and leave it to |
| 481 | // VisitExternalOneByteString further down. |
| 482 | SerializeExternalString(); |
| 483 | return; |
| 484 | } |
| 485 | } |
| 486 | |
| 487 | int size = object_->Size(); |
| 488 | Map* map = object_->map(); |
| 489 | AllocationSpace space = |
| 490 | MemoryChunk::FromAddress(object_->address())->owner()->identity(); |
| 491 | SerializePrologue(space, size, map); |
| 492 | |
| 493 | // Serialize the rest of the object. |
| 494 | CHECK_EQ(0, bytes_processed_so_far_); |
| 495 | bytes_processed_so_far_ = kPointerSize; |
| 496 | |
| 497 | RecursionScope recursion(serializer_); |
| 498 | // Objects that are immediately post processed during deserialization |
| 499 | // cannot be deferred, since post processing requires the object content. |
| 500 | if (recursion.ExceedsMaximum() && CanBeDeferred(object_)) { |
| 501 | serializer_->QueueDeferredObject(object_); |
| 502 | sink_->Put(kDeferred, "Deferring object content"); |
| 503 | return; |
| 504 | } |
| 505 | |
| 506 | UnlinkWeakNextScope unlink_weak_next(object_); |
| 507 | |
| 508 | object_->IterateBody(map->instance_type(), size, this); |
| 509 | OutputRawData(object_->address() + size); |
| 510 | } |
| 511 | |
| 512 | void Serializer::ObjectSerializer::SerializeDeferred() { |
| 513 | if (FLAG_trace_serializer) { |
| 514 | PrintF(" Encoding deferred heap object: "); |
| 515 | object_->ShortPrint(); |
| 516 | PrintF("\n"); |
| 517 | } |
| 518 | |
| 519 | int size = object_->Size(); |
| 520 | Map* map = object_->map(); |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 521 | SerializerReference back_reference = |
| 522 | serializer_->reference_map()->Lookup(object_); |
| 523 | DCHECK(back_reference.is_back_reference()); |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 524 | |
| 525 | // Serialize the rest of the object. |
| 526 | CHECK_EQ(0, bytes_processed_so_far_); |
| 527 | bytes_processed_so_far_ = kPointerSize; |
| 528 | |
| 529 | serializer_->PutAlignmentPrefix(object_); |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 530 | sink_->Put(kNewObject + back_reference.space(), "deferred object"); |
| 531 | serializer_->PutBackReference(object_, back_reference); |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 532 | sink_->PutInt(size >> kPointerSizeLog2, "deferred object size"); |
| 533 | |
| 534 | UnlinkWeakNextScope unlink_weak_next(object_); |
| 535 | |
| 536 | object_->IterateBody(map->instance_type(), size, this); |
| 537 | OutputRawData(object_->address() + size); |
| 538 | } |
| 539 | |
| 540 | void Serializer::ObjectSerializer::VisitPointers(Object** start, Object** end) { |
| 541 | Object** current = start; |
| 542 | while (current < end) { |
| 543 | while (current < end && (*current)->IsSmi()) current++; |
| 544 | if (current < end) OutputRawData(reinterpret_cast<Address>(current)); |
| 545 | |
| 546 | while (current < end && !(*current)->IsSmi()) { |
| 547 | HeapObject* current_contents = HeapObject::cast(*current); |
| 548 | int root_index = serializer_->root_index_map()->Lookup(current_contents); |
| 549 | // Repeats are not subject to the write barrier so we can only use |
| 550 | // immortal immovable root members. They are never in new space. |
| 551 | if (current != start && root_index != RootIndexMap::kInvalidRootIndex && |
| 552 | Heap::RootIsImmortalImmovable(root_index) && |
| 553 | current_contents == current[-1]) { |
| 554 | DCHECK(!serializer_->isolate()->heap()->InNewSpace(current_contents)); |
| 555 | int repeat_count = 1; |
| 556 | while (¤t[repeat_count] < end - 1 && |
| 557 | current[repeat_count] == current_contents) { |
| 558 | repeat_count++; |
| 559 | } |
| 560 | current += repeat_count; |
| 561 | bytes_processed_so_far_ += repeat_count * kPointerSize; |
| 562 | if (repeat_count > kNumberOfFixedRepeat) { |
| 563 | sink_->Put(kVariableRepeat, "VariableRepeat"); |
| 564 | sink_->PutInt(repeat_count, "repeat count"); |
| 565 | } else { |
| 566 | sink_->Put(kFixedRepeatStart + repeat_count, "FixedRepeat"); |
| 567 | } |
| 568 | } else { |
| 569 | serializer_->SerializeObject(current_contents, kPlain, kStartOfObject, |
| 570 | 0); |
| 571 | bytes_processed_so_far_ += kPointerSize; |
| 572 | current++; |
| 573 | } |
| 574 | } |
| 575 | } |
| 576 | } |
| 577 | |
| 578 | void Serializer::ObjectSerializer::VisitEmbeddedPointer(RelocInfo* rinfo) { |
| 579 | int skip = OutputRawData(rinfo->target_address_address(), |
| 580 | kCanReturnSkipInsteadOfSkipping); |
| 581 | HowToCode how_to_code = rinfo->IsCodedSpecially() ? kFromCode : kPlain; |
| 582 | Object* object = rinfo->target_object(); |
| 583 | serializer_->SerializeObject(HeapObject::cast(object), how_to_code, |
| 584 | kStartOfObject, skip); |
| 585 | bytes_processed_so_far_ += rinfo->target_address_size(); |
| 586 | } |
| 587 | |
| 588 | void Serializer::ObjectSerializer::VisitExternalReference(Address* p) { |
| 589 | int skip = OutputRawData(reinterpret_cast<Address>(p), |
| 590 | kCanReturnSkipInsteadOfSkipping); |
| 591 | sink_->Put(kExternalReference + kPlain + kStartOfObject, "ExternalRef"); |
| 592 | sink_->PutInt(skip, "SkipB4ExternalRef"); |
| 593 | Address target = *p; |
| 594 | sink_->PutInt(serializer_->EncodeExternalReference(target), "reference id"); |
| 595 | bytes_processed_so_far_ += kPointerSize; |
| 596 | } |
| 597 | |
| 598 | void Serializer::ObjectSerializer::VisitExternalReference(RelocInfo* rinfo) { |
| 599 | int skip = OutputRawData(rinfo->target_address_address(), |
| 600 | kCanReturnSkipInsteadOfSkipping); |
| 601 | HowToCode how_to_code = rinfo->IsCodedSpecially() ? kFromCode : kPlain; |
| 602 | sink_->Put(kExternalReference + how_to_code + kStartOfObject, "ExternalRef"); |
| 603 | sink_->PutInt(skip, "SkipB4ExternalRef"); |
| 604 | Address target = rinfo->target_external_reference(); |
| 605 | sink_->PutInt(serializer_->EncodeExternalReference(target), "reference id"); |
| 606 | bytes_processed_so_far_ += rinfo->target_address_size(); |
| 607 | } |
| 608 | |
| 609 | void Serializer::ObjectSerializer::VisitInternalReference(RelocInfo* rinfo) { |
| 610 | // We can only reference to internal references of code that has been output. |
| 611 | DCHECK(object_->IsCode() && code_has_been_output_); |
| 612 | // We do not use skip from last patched pc to find the pc to patch, since |
| 613 | // target_address_address may not return addresses in ascending order when |
| 614 | // used for internal references. External references may be stored at the |
| 615 | // end of the code in the constant pool, whereas internal references are |
| 616 | // inline. That would cause the skip to be negative. Instead, we store the |
| 617 | // offset from code entry. |
| 618 | Address entry = Code::cast(object_)->entry(); |
| 619 | intptr_t pc_offset = rinfo->target_internal_reference_address() - entry; |
| 620 | intptr_t target_offset = rinfo->target_internal_reference() - entry; |
| 621 | DCHECK(0 <= pc_offset && |
| 622 | pc_offset <= Code::cast(object_)->instruction_size()); |
| 623 | DCHECK(0 <= target_offset && |
| 624 | target_offset <= Code::cast(object_)->instruction_size()); |
| 625 | sink_->Put(rinfo->rmode() == RelocInfo::INTERNAL_REFERENCE |
| 626 | ? kInternalReference |
| 627 | : kInternalReferenceEncoded, |
| 628 | "InternalRef"); |
| 629 | sink_->PutInt(static_cast<uintptr_t>(pc_offset), "internal ref address"); |
| 630 | sink_->PutInt(static_cast<uintptr_t>(target_offset), "internal ref value"); |
| 631 | } |
| 632 | |
| 633 | void Serializer::ObjectSerializer::VisitRuntimeEntry(RelocInfo* rinfo) { |
| 634 | int skip = OutputRawData(rinfo->target_address_address(), |
| 635 | kCanReturnSkipInsteadOfSkipping); |
| 636 | HowToCode how_to_code = rinfo->IsCodedSpecially() ? kFromCode : kPlain; |
| 637 | sink_->Put(kExternalReference + how_to_code + kStartOfObject, "ExternalRef"); |
| 638 | sink_->PutInt(skip, "SkipB4ExternalRef"); |
| 639 | Address target = rinfo->target_address(); |
| 640 | sink_->PutInt(serializer_->EncodeExternalReference(target), "reference id"); |
| 641 | bytes_processed_so_far_ += rinfo->target_address_size(); |
| 642 | } |
| 643 | |
| 644 | void Serializer::ObjectSerializer::VisitCodeTarget(RelocInfo* rinfo) { |
| 645 | int skip = OutputRawData(rinfo->target_address_address(), |
| 646 | kCanReturnSkipInsteadOfSkipping); |
| 647 | Code* object = Code::GetCodeFromTargetAddress(rinfo->target_address()); |
| 648 | serializer_->SerializeObject(object, kFromCode, kInnerPointer, skip); |
| 649 | bytes_processed_so_far_ += rinfo->target_address_size(); |
| 650 | } |
| 651 | |
| 652 | void Serializer::ObjectSerializer::VisitCodeEntry(Address entry_address) { |
| 653 | int skip = OutputRawData(entry_address, kCanReturnSkipInsteadOfSkipping); |
| 654 | Code* object = Code::cast(Code::GetObjectFromEntryAddress(entry_address)); |
| 655 | serializer_->SerializeObject(object, kPlain, kInnerPointer, skip); |
| 656 | bytes_processed_so_far_ += kPointerSize; |
| 657 | } |
| 658 | |
| 659 | void Serializer::ObjectSerializer::VisitCell(RelocInfo* rinfo) { |
| 660 | int skip = OutputRawData(rinfo->pc(), kCanReturnSkipInsteadOfSkipping); |
| 661 | Cell* object = Cell::cast(rinfo->target_cell()); |
| 662 | serializer_->SerializeObject(object, kPlain, kInnerPointer, skip); |
| 663 | bytes_processed_so_far_ += kPointerSize; |
| 664 | } |
| 665 | |
| 666 | bool Serializer::ObjectSerializer::SerializeExternalNativeSourceString( |
| 667 | int builtin_count, |
| 668 | v8::String::ExternalOneByteStringResource** resource_pointer, |
| 669 | FixedArray* source_cache, int resource_index) { |
Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 670 | Isolate* isolate = serializer_->isolate(); |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 671 | for (int i = 0; i < builtin_count; i++) { |
| 672 | Object* source = source_cache->get(i); |
Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 673 | if (!source->IsUndefined(isolate)) { |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 674 | ExternalOneByteString* string = ExternalOneByteString::cast(source); |
| 675 | typedef v8::String::ExternalOneByteStringResource Resource; |
| 676 | const Resource* resource = string->resource(); |
| 677 | if (resource == *resource_pointer) { |
| 678 | sink_->Put(resource_index, "NativesStringResource"); |
| 679 | sink_->PutSection(i, "NativesStringResourceEnd"); |
| 680 | bytes_processed_so_far_ += sizeof(resource); |
| 681 | return true; |
| 682 | } |
| 683 | } |
| 684 | } |
| 685 | return false; |
| 686 | } |
| 687 | |
| 688 | void Serializer::ObjectSerializer::VisitExternalOneByteString( |
| 689 | v8::String::ExternalOneByteStringResource** resource_pointer) { |
Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 690 | DCHECK_EQ(serializer_->isolate()->heap()->native_source_string_map(), |
| 691 | object_->map()); |
| 692 | DCHECK(ExternalOneByteString::cast(object_)->is_short()); |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 693 | Address references_start = reinterpret_cast<Address>(resource_pointer); |
| 694 | OutputRawData(references_start); |
| 695 | if (SerializeExternalNativeSourceString( |
| 696 | Natives::GetBuiltinsCount(), resource_pointer, |
| 697 | Natives::GetSourceCache(serializer_->isolate()->heap()), |
| 698 | kNativesStringResource)) { |
| 699 | return; |
| 700 | } |
| 701 | if (SerializeExternalNativeSourceString( |
| 702 | ExtraNatives::GetBuiltinsCount(), resource_pointer, |
| 703 | ExtraNatives::GetSourceCache(serializer_->isolate()->heap()), |
| 704 | kExtraNativesStringResource)) { |
| 705 | return; |
| 706 | } |
| 707 | // One of the strings in the natives cache should match the resource. We |
| 708 | // don't expect any other kinds of external strings here. |
| 709 | UNREACHABLE(); |
| 710 | } |
| 711 | |
| 712 | Address Serializer::ObjectSerializer::PrepareCode() { |
Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 713 | Code* code = Code::cast(object_); |
| 714 | if (FLAG_predictable) { |
| 715 | // To make snapshots reproducible, we make a copy of the code object |
| 716 | // and wipe all pointers in the copy, which we then serialize. |
| 717 | code = serializer_->CopyCode(code); |
| 718 | int mode_mask = RelocInfo::kCodeTargetMask | |
| 719 | RelocInfo::ModeMask(RelocInfo::EMBEDDED_OBJECT) | |
| 720 | RelocInfo::ModeMask(RelocInfo::EXTERNAL_REFERENCE) | |
| 721 | RelocInfo::ModeMask(RelocInfo::RUNTIME_ENTRY) | |
| 722 | RelocInfo::ModeMask(RelocInfo::INTERNAL_REFERENCE) | |
| 723 | RelocInfo::ModeMask(RelocInfo::INTERNAL_REFERENCE_ENCODED); |
| 724 | for (RelocIterator it(code, mode_mask); !it.done(); it.next()) { |
| 725 | RelocInfo* rinfo = it.rinfo(); |
| 726 | rinfo->WipeOut(); |
| 727 | } |
| 728 | // We need to wipe out the header fields *after* wiping out the |
| 729 | // relocations, because some of these fields are needed for the latter. |
| 730 | code->WipeOutHeader(); |
| 731 | } |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 732 | // Code age headers are not serializable. |
| 733 | code->MakeYoung(serializer_->isolate()); |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 734 | return code->address(); |
| 735 | } |
| 736 | |
| 737 | int Serializer::ObjectSerializer::OutputRawData( |
| 738 | Address up_to, Serializer::ObjectSerializer::ReturnSkip return_skip) { |
| 739 | Address object_start = object_->address(); |
| 740 | int base = bytes_processed_so_far_; |
| 741 | int up_to_offset = static_cast<int>(up_to - object_start); |
| 742 | int to_skip = up_to_offset - bytes_processed_so_far_; |
| 743 | int bytes_to_output = to_skip; |
| 744 | bytes_processed_so_far_ += to_skip; |
| 745 | // This assert will fail if the reloc info gives us the target_address_address |
| 746 | // locations in a non-ascending order. Luckily that doesn't happen. |
| 747 | DCHECK(to_skip >= 0); |
| 748 | bool outputting_code = false; |
| 749 | bool is_code_object = object_->IsCode(); |
| 750 | if (to_skip != 0 && is_code_object && !code_has_been_output_) { |
| 751 | // Output the code all at once and fix later. |
| 752 | bytes_to_output = object_->Size() + to_skip - bytes_processed_so_far_; |
| 753 | outputting_code = true; |
| 754 | code_has_been_output_ = true; |
| 755 | } |
| 756 | if (bytes_to_output != 0 && (!is_code_object || outputting_code)) { |
| 757 | if (!outputting_code && bytes_to_output == to_skip && |
| 758 | IsAligned(bytes_to_output, kPointerAlignment) && |
| 759 | bytes_to_output <= kNumberOfFixedRawData * kPointerSize) { |
| 760 | int size_in_words = bytes_to_output >> kPointerSizeLog2; |
| 761 | sink_->PutSection(kFixedRawDataStart + size_in_words, "FixedRawData"); |
| 762 | to_skip = 0; // This instruction includes skip. |
| 763 | } else { |
| 764 | // We always end up here if we are outputting the code of a code object. |
| 765 | sink_->Put(kVariableRawData, "VariableRawData"); |
| 766 | sink_->PutInt(bytes_to_output, "length"); |
| 767 | } |
| 768 | |
| 769 | if (is_code_object) object_start = PrepareCode(); |
| 770 | |
| 771 | const char* description = is_code_object ? "Code" : "Byte"; |
| 772 | sink_->PutRaw(object_start + base, bytes_to_output, description); |
| 773 | } |
| 774 | if (to_skip != 0 && return_skip == kIgnoringReturn) { |
| 775 | sink_->Put(kSkip, "Skip"); |
| 776 | sink_->PutInt(to_skip, "SkipDistance"); |
| 777 | to_skip = 0; |
| 778 | } |
| 779 | return to_skip; |
| 780 | } |
| 781 | |
| 782 | } // namespace internal |
| 783 | } // namespace v8 |