1 // Copyright 2014 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 
6 #include "src/snapshot-source-sink.h"
7 
8 #include "src/base/logging.h"
9 #include "src/handles-inl.h"
10 #include "src/serialize.h"  // for SerializerDeserializer::nop() in AtEOF()
11 
12 
13 namespace v8 {
14 namespace internal {
15 
16 
SnapshotByteSource(const byte * array,int length)17 SnapshotByteSource::SnapshotByteSource(const byte* array, int length)
18     : data_(array), length_(length), position_(0) {
19 }
20 
21 
~SnapshotByteSource()22 SnapshotByteSource::~SnapshotByteSource() { }
23 
24 
GetUnalignedInt()25 int32_t SnapshotByteSource::GetUnalignedInt() {
26   DCHECK(position_ < length_);  // Require at least one byte left.
27   int32_t answer = data_[position_];
28   answer |= data_[position_ + 1] << 8;
29   answer |= data_[position_ + 2] << 16;
30   answer |= data_[position_ + 3] << 24;
31   return answer;
32 }
33 
34 
CopyRaw(byte * to,int number_of_bytes)35 void SnapshotByteSource::CopyRaw(byte* to, int number_of_bytes) {
36   MemCopy(to, data_ + position_, number_of_bytes);
37   position_ += number_of_bytes;
38 }
39 
40 
PutInt(uintptr_t integer,const char * description)41 void SnapshotByteSink::PutInt(uintptr_t integer, const char* description) {
42   DCHECK(integer < 1 << 22);
43   integer <<= 2;
44   int bytes = 1;
45   if (integer > 0xff) bytes = 2;
46   if (integer > 0xffff) bytes = 3;
47   integer |= bytes;
48   Put(static_cast<int>(integer & 0xff), "IntPart1");
49   if (bytes > 1) Put(static_cast<int>((integer >> 8) & 0xff), "IntPart2");
50   if (bytes > 2) Put(static_cast<int>((integer >> 16) & 0xff), "IntPart3");
51 }
52 
PutRaw(byte * data,int number_of_bytes,const char * description)53 void SnapshotByteSink::PutRaw(byte* data, int number_of_bytes,
54                               const char* description) {
55   for (int i = 0; i < number_of_bytes; ++i) {
56     Put(data[i], description);
57   }
58 }
59 
PutBlob(byte * data,int number_of_bytes,const char * description)60 void SnapshotByteSink::PutBlob(byte* data, int number_of_bytes,
61                                const char* description) {
62   PutInt(number_of_bytes, description);
63   PutRaw(data, number_of_bytes, description);
64 }
65 
66 
AtEOF()67 bool SnapshotByteSource::AtEOF() {
68   if (0u + length_ - position_ > 2 * sizeof(uint32_t)) return false;
69   for (int x = position_; x < length_; x++) {
70     if (data_[x] != SerializerDeserializer::nop()) return false;
71   }
72   return true;
73 }
74 
75 
GetBlob(const byte ** data,int * number_of_bytes)76 bool SnapshotByteSource::GetBlob(const byte** data, int* number_of_bytes) {
77   int size = GetInt();
78   *number_of_bytes = size;
79 
80   if (position_ + size < length_) {
81     *data = &data_[position_];
82     Advance(size);
83     return true;
84   } else {
85     Advance(length_ - position_);  // proceed until end.
86     return false;
87   }
88 }
89 
90 
Put(byte b,const char * description)91 void DebugSnapshotSink::Put(byte b, const char* description) {
92   PrintF("%24s: %x\n", description, b);
93   sink_->Put(b, description);
94 }
95 
96 }  // namespace v8::internal
97 }  // namespace v8
98