pickle.cc revision 1e9bf3e0803691d0a228da41fc608347b6db4340 
1// Copyright (c) 2012 The Chromium 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 "base/pickle.h"
6
7#include <stdlib.h>
8
9#include <algorithm>  // for max()
10
11//------------------------------------------------------------------------------
12
13// static
14const int Pickle::kPayloadUnit = 64;
15
16static const size_t kCapacityReadOnly = static_cast<size_t>(-1);
17
18PickleIterator::PickleIterator(const Pickle& pickle)
19    : read_ptr_(pickle.payload()),
20      read_end_ptr_(pickle.end_of_payload()) {
21}
22
23template <typename Type>
24inline bool PickleIterator::ReadBuiltinType(Type* result) {
25  const char* read_from = GetReadPointerAndAdvance<Type>();
26  if (!read_from)
27    return false;
28  if (sizeof(Type) > sizeof(uint32))
29    memcpy(result, read_from, sizeof(*result));
30  else
31    *result = *reinterpret_cast<const Type*>(read_from);
32  return true;
33}
34
35template<typename Type>
36inline const char* PickleIterator::GetReadPointerAndAdvance() {
37  const char* current_read_ptr = read_ptr_;
38  if (read_ptr_ + sizeof(Type) > read_end_ptr_)
39    return NULL;
40  if (sizeof(Type) < sizeof(uint32))
41    read_ptr_ += AlignInt(sizeof(Type), sizeof(uint32));
42  else
43    read_ptr_ += sizeof(Type);
44  return current_read_ptr;
45}
46
47const char* PickleIterator::GetReadPointerAndAdvance(int num_bytes) {
48  if (num_bytes < 0 || read_end_ptr_ - read_ptr_ < num_bytes)
49    return NULL;
50  const char* current_read_ptr = read_ptr_;
51  read_ptr_ += AlignInt(num_bytes, sizeof(uint32));
52  return current_read_ptr;
53}
54
55inline const char* PickleIterator::GetReadPointerAndAdvance(int num_elements,
56                                                          size_t size_element) {
57  // Check for int32 overflow.
58  int64 num_bytes = static_cast<int64>(num_elements) * size_element;
59  int num_bytes32 = static_cast<int>(num_bytes);
60  if (num_bytes != static_cast<int64>(num_bytes32))
61    return NULL;
62  return GetReadPointerAndAdvance(num_bytes32);
63}
64
65bool PickleIterator::ReadBool(bool* result) {
66  return ReadBuiltinType(result);
67}
68
69bool PickleIterator::ReadInt(int* result) {
70  return ReadBuiltinType(result);
71}
72
73bool PickleIterator::ReadLong(long* result) {
74  return ReadBuiltinType(result);
75}
76
77bool PickleIterator::ReadUInt16(uint16* result) {
78  return ReadBuiltinType(result);
79}
80
81bool PickleIterator::ReadUInt32(uint32* result) {
82  return ReadBuiltinType(result);
83}
84
85bool PickleIterator::ReadInt64(int64* result) {
86  return ReadBuiltinType(result);
87}
88
89bool PickleIterator::ReadUInt64(uint64* result) {
90  return ReadBuiltinType(result);
91}
92
93bool PickleIterator::ReadFloat(float* result) {
94  return ReadBuiltinType(result);
95}
96
97bool PickleIterator::ReadString(std::string* result) {
98  int len;
99  if (!ReadInt(&len))
100    return false;
101  const char* read_from = GetReadPointerAndAdvance(len);
102  if (!read_from)
103    return false;
104
105  result->assign(read_from, len);
106  return true;
107}
108
109bool PickleIterator::ReadWString(std::wstring* result) {
110  int len;
111  if (!ReadInt(&len))
112    return false;
113  const char* read_from = GetReadPointerAndAdvance(len, sizeof(wchar_t));
114  if (!read_from)
115    return false;
116
117  result->assign(reinterpret_cast<const wchar_t*>(read_from), len);
118  return true;
119}
120
121bool PickleIterator::ReadString16(string16* result) {
122  int len;
123  if (!ReadInt(&len))
124    return false;
125  const char* read_from = GetReadPointerAndAdvance(len, sizeof(char16));
126  if (!read_from)
127    return false;
128
129  result->assign(reinterpret_cast<const char16*>(read_from), len);
130  return true;
131}
132
133bool PickleIterator::ReadData(const char** data, int* length) {
134  *length = 0;
135  *data = 0;
136
137  if (!ReadInt(length))
138    return false;
139
140  return ReadBytes(data, *length);
141}
142
143bool PickleIterator::ReadBytes(const char** data, int length) {
144  const char* read_from = GetReadPointerAndAdvance(length);
145  if (!read_from)
146    return false;
147  *data = read_from;
148  return true;
149}
150
151// Payload is uint32 aligned.
152
153Pickle::Pickle()
154    : header_(NULL),
155      header_size_(sizeof(Header)),
156      capacity_after_header_(0),
157      write_offset_(0) {
158  Resize(kPayloadUnit);
159  header_->payload_size = 0;
160}
161
162Pickle::Pickle(int header_size)
163    : header_(NULL),
164      header_size_(AlignInt(header_size, sizeof(uint32))),
165      capacity_after_header_(0),
166      write_offset_(0) {
167  DCHECK_GE(static_cast<size_t>(header_size), sizeof(Header));
168  DCHECK_LE(header_size, kPayloadUnit);
169  Resize(kPayloadUnit);
170  header_->payload_size = 0;
171}
172
173Pickle::Pickle(const char* data, size_t data_len)
174    : header_(reinterpret_cast<Header*>(const_cast<char*>(data))),
175      header_size_(0),
176      capacity_after_header_(kCapacityReadOnly),
177      write_offset_(0) {
178  if (data_len >= sizeof(Header))
179    header_size_ = data_len - header_->payload_size;
180
181  if (header_size_ > data_len)
182    header_size_ = 0;
183
184  if (header_size_ != AlignInt(header_size_, sizeof(uint32)))
185    header_size_ = 0;
186
187  // If there is anything wrong with the data, we're not going to use it.
188  if (!header_size_)
189    header_ = NULL;
190}
191
192Pickle::Pickle(const Pickle& other)
193    : header_(NULL),
194      header_size_(other.header_size_),
195      capacity_after_header_(0),
196      write_offset_(other.write_offset_) {
197  size_t payload_size = header_size_ + other.header_->payload_size;
198  Resize(payload_size);
199  memcpy(header_, other.header_, payload_size);
200}
201
202Pickle::~Pickle() {
203  if (capacity_after_header_ != kCapacityReadOnly)
204    free(header_);
205}
206
207Pickle& Pickle::operator=(const Pickle& other) {
208  if (this == &other) {
209    NOTREACHED();
210    return *this;
211  }
212  if (capacity_after_header_ == kCapacityReadOnly) {
213    header_ = NULL;
214    capacity_after_header_ = 0;
215  }
216  if (header_size_ != other.header_size_) {
217    free(header_);
218    header_ = NULL;
219    header_size_ = other.header_size_;
220  }
221  Resize(other.header_->payload_size);
222  memcpy(header_, other.header_,
223         other.header_size_ + other.header_->payload_size);
224  write_offset_ = other.write_offset_;
225  return *this;
226}
227
228bool Pickle::WriteString(const std::string& value) {
229  if (!WriteInt(static_cast<int>(value.size())))
230    return false;
231
232  return WriteBytes(value.data(), static_cast<int>(value.size()));
233}
234
235bool Pickle::WriteWString(const std::wstring& value) {
236  if (!WriteInt(static_cast<int>(value.size())))
237    return false;
238
239  return WriteBytes(value.data(),
240                    static_cast<int>(value.size() * sizeof(wchar_t)));
241}
242
243bool Pickle::WriteString16(const string16& value) {
244  if (!WriteInt(static_cast<int>(value.size())))
245    return false;
246
247  return WriteBytes(value.data(),
248                    static_cast<int>(value.size()) * sizeof(char16));
249}
250
251bool Pickle::WriteData(const char* data, int length) {
252  return length >= 0 && WriteInt(length) && WriteBytes(data, length);
253}
254
255bool Pickle::WriteBytes(const void* data, int length) {
256  WriteBytesCommon(data, length);
257  return true;
258}
259
260void Pickle::Reserve(size_t length) {
261  size_t data_len = AlignInt(length, sizeof(uint32));
262  DCHECK_GE(data_len, length);
263#ifdef ARCH_CPU_64_BITS
264  DCHECK_LE(data_len, kuint32max);
265#endif
266  DCHECK_LE(write_offset_, kuint32max - data_len);
267  size_t new_size = write_offset_ + data_len;
268  if (new_size > capacity_after_header_)
269    Resize(capacity_after_header_ * 2 + new_size);
270}
271
272void Pickle::Resize(size_t new_capacity) {
273  new_capacity = AlignInt(new_capacity, kPayloadUnit);
274
275  CHECK_NE(capacity_after_header_, kCapacityReadOnly);
276  void* p = realloc(header_, header_size_ + new_capacity);
277  CHECK(p);
278  header_ = reinterpret_cast<Header*>(p);
279  capacity_after_header_ = new_capacity;
280}
281
282// static
283const char* Pickle::FindNext(size_t header_size,
284                             const char* start,
285                             const char* end) {
286  DCHECK_EQ(header_size, AlignInt(header_size, sizeof(uint32)));
287  DCHECK_LE(header_size, static_cast<size_t>(kPayloadUnit));
288
289  if (static_cast<size_t>(end - start) < sizeof(Header))
290    return NULL;
291
292  const Header* hdr = reinterpret_cast<const Header*>(start);
293  const char* payload_base = start + header_size;
294  const char* payload_end = payload_base + hdr->payload_size;
295  if (payload_end < payload_base)
296    return NULL;
297
298  return (payload_end > end) ? NULL : payload_end;
299}
300
301template <size_t length> void Pickle::WriteBytesStatic(const void* data) {
302  WriteBytesCommon(data, length);
303}
304
305template void Pickle::WriteBytesStatic<2>(const void* data);
306template void Pickle::WriteBytesStatic<4>(const void* data);
307template void Pickle::WriteBytesStatic<8>(const void* data);
308
309inline void Pickle::WriteBytesCommon(const void* data, size_t length) {
310  DCHECK_NE(kCapacityReadOnly, capacity_after_header_)
311      << "oops: pickle is readonly";
312  size_t data_len = AlignInt(length, sizeof(uint32));
313  DCHECK_GE(data_len, length);
314#ifdef ARCH_CPU_64_BITS
315  DCHECK_LE(data_len, kuint32max);
316#endif
317  DCHECK_LE(write_offset_, kuint32max - data_len);
318  size_t new_size = write_offset_ + data_len;
319  if (new_size > capacity_after_header_) {
320    Resize(std::max(capacity_after_header_ * 2, new_size));
321  }
322
323  char* write = mutable_payload() + write_offset_;
324  memcpy(write, data, length);
325  memset(write + length, 0, data_len - length);
326  header_->payload_size = static_cast<uint32>(write_offset_ + length);
327  write_offset_ = new_size;
328}
329