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/v8.h"
6
7#include "src/regexp-stack.h"
8
9namespace v8 {
10namespace internal {
11
12RegExpStackScope::RegExpStackScope(Isolate* isolate)
13    : regexp_stack_(isolate->regexp_stack()) {
14  // Initialize, if not already initialized.
15  regexp_stack_->EnsureCapacity(0);
16}
17
18
19RegExpStackScope::~RegExpStackScope() {
20  // Reset the buffer if it has grown.
21  regexp_stack_->Reset();
22}
23
24
25RegExpStack::RegExpStack()
26    : isolate_(NULL) {
27}
28
29
30RegExpStack::~RegExpStack() {
31  thread_local_.Free();
32}
33
34
35char* RegExpStack::ArchiveStack(char* to) {
36  size_t size = sizeof(thread_local_);
37  MemCopy(reinterpret_cast<void*>(to), &thread_local_, size);
38  thread_local_ = ThreadLocal();
39  return to + size;
40}
41
42
43char* RegExpStack::RestoreStack(char* from) {
44  size_t size = sizeof(thread_local_);
45  MemCopy(&thread_local_, reinterpret_cast<void*>(from), size);
46  return from + size;
47}
48
49
50void RegExpStack::Reset() {
51  if (thread_local_.memory_size_ > kMinimumStackSize) {
52    DeleteArray(thread_local_.memory_);
53    thread_local_ = ThreadLocal();
54  }
55}
56
57
58void RegExpStack::ThreadLocal::Free() {
59  if (memory_size_ > 0) {
60    DeleteArray(memory_);
61    Clear();
62  }
63}
64
65
66Address RegExpStack::EnsureCapacity(size_t size) {
67  if (size > kMaximumStackSize) return NULL;
68  if (size < kMinimumStackSize) size = kMinimumStackSize;
69  if (thread_local_.memory_size_ < size) {
70    Address new_memory = NewArray<byte>(static_cast<int>(size));
71    if (thread_local_.memory_size_ > 0) {
72      // Copy original memory into top of new memory.
73      MemCopy(reinterpret_cast<void*>(new_memory + size -
74                                      thread_local_.memory_size_),
75              reinterpret_cast<void*>(thread_local_.memory_),
76              thread_local_.memory_size_);
77      DeleteArray(thread_local_.memory_);
78    }
79    thread_local_.memory_ = new_memory;
80    thread_local_.memory_size_ = size;
81    thread_local_.limit_ = new_memory + kStackLimitSlack * kPointerSize;
82  }
83  return thread_local_.memory_ + thread_local_.memory_size_;
84}
85
86
87}}  // namespace v8::internal
88