V8 API Reference, 7.2.502.16 (for Deno 0.2.4)
regexp-stack.cc
1 // Copyright 2009 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/regexp/regexp-stack.h"
6 
7 #include "src/isolate.h"
8 
9 namespace v8 {
10 namespace internal {
11 
12 RegExpStackScope::RegExpStackScope(Isolate* isolate)
13  : regexp_stack_(isolate->regexp_stack()) {
14  // Initialize, if not already initialized.
15  regexp_stack_->EnsureCapacity(0);
16 }
17 
18 
19 RegExpStackScope::~RegExpStackScope() {
20  // Reset the buffer if it has grown.
21  regexp_stack_->Reset();
22 }
23 
24 RegExpStack::RegExpStack() : isolate_(nullptr) {}
25 
26 RegExpStack::~RegExpStack() {
27  thread_local_.Free();
28 }
29 
30 
31 char* RegExpStack::ArchiveStack(char* to) {
32  size_t size = sizeof(thread_local_);
33  MemCopy(reinterpret_cast<void*>(to), &thread_local_, size);
34  thread_local_ = ThreadLocal();
35  return to + size;
36 }
37 
38 
39 char* RegExpStack::RestoreStack(char* from) {
40  size_t size = sizeof(thread_local_);
41  MemCopy(&thread_local_, reinterpret_cast<void*>(from), size);
42  return from + size;
43 }
44 
45 
46 void RegExpStack::Reset() {
47  if (thread_local_.memory_size_ > kMinimumStackSize) {
48  DeleteArray(thread_local_.memory_);
49  thread_local_ = ThreadLocal();
50  }
51 }
52 
53 
54 void RegExpStack::ThreadLocal::Free() {
55  if (memory_size_ > 0) {
56  DeleteArray(memory_);
57  Clear();
58  }
59 }
60 
61 
62 Address RegExpStack::EnsureCapacity(size_t size) {
63  if (size > kMaximumStackSize) return kNullAddress;
64  if (size < kMinimumStackSize) size = kMinimumStackSize;
65  if (thread_local_.memory_size_ < size) {
66  byte* new_memory = NewArray<byte>(size);
67  if (thread_local_.memory_size_ > 0) {
68  // Copy original memory into top of new memory.
69  MemCopy(new_memory + size - thread_local_.memory_size_,
70  thread_local_.memory_, thread_local_.memory_size_);
71  DeleteArray(thread_local_.memory_);
72  }
73  thread_local_.memory_ = new_memory;
74  thread_local_.memory_size_ = size;
75  thread_local_.limit_ =
76  reinterpret_cast<Address>(new_memory) + kStackLimitSlack * kPointerSize;
77  }
78  return reinterpret_cast<Address>(thread_local_.memory_) +
79  thread_local_.memory_size_;
80 }
81 
82 
83 } // namespace internal
84 } // namespace v8
Definition: libplatform.h:13