blob: cf4a865d35c337421b0acea57a05211fa076b06f [file] [log] [blame]
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "base/pickle.h"
#include <stdlib.h>
#include <algorithm> // for max()
namespace base {
// static
const int Pickle::kPayloadUnit = 64;
static const size_t kCapacityReadOnly = static_cast<size_t>(-1);
PickleIterator::PickleIterator(const Pickle& pickle)
: payload_(pickle.payload()),
read_index_(0),
end_index_(pickle.payload_size()) {
}
template <typename Type>
inline bool PickleIterator::ReadBuiltinType(Type* result) {
const char* read_from = GetReadPointerAndAdvance<Type>();
if (!read_from)
return false;
if (sizeof(Type) > sizeof(uint32))
memcpy(result, read_from, sizeof(*result));
else
*result = *reinterpret_cast<const Type*>(read_from);
return true;
}
inline void PickleIterator::Advance(size_t size) {
size_t aligned_size = AlignInt(size, sizeof(uint32_t));
if (end_index_ - read_index_ < aligned_size) {
read_index_ = end_index_;
} else {
read_index_ += aligned_size;
}
}
template<typename Type>
inline const char* PickleIterator::GetReadPointerAndAdvance() {
if (sizeof(Type) > end_index_ - read_index_) {
read_index_ = end_index_;
return NULL;
}
const char* current_read_ptr = payload_ + read_index_;
Advance(sizeof(Type));
return current_read_ptr;
}
const char* PickleIterator::GetReadPointerAndAdvance(int num_bytes) {
if (num_bytes < 0 ||
end_index_ - read_index_ < static_cast<size_t>(num_bytes)) {
read_index_ = end_index_;
return NULL;
}
const char* current_read_ptr = payload_ + read_index_;
Advance(num_bytes);
return current_read_ptr;
}
inline const char* PickleIterator::GetReadPointerAndAdvance(
int num_elements,
size_t size_element) {
// Check for int32 overflow.
int64 num_bytes = static_cast<int64>(num_elements) * size_element;
int num_bytes32 = static_cast<int>(num_bytes);
if (num_bytes != static_cast<int64>(num_bytes32))
return NULL;
return GetReadPointerAndAdvance(num_bytes32);
}
bool PickleIterator::ReadBool(bool* result) {
return ReadBuiltinType(result);
}
bool PickleIterator::ReadInt(int* result) {
return ReadBuiltinType(result);
}
bool PickleIterator::ReadLong(long* result) {
return ReadBuiltinType(result);
}
bool PickleIterator::ReadUInt16(uint16* result) {
return ReadBuiltinType(result);
}
bool PickleIterator::ReadUInt32(uint32* result) {
return ReadBuiltinType(result);
}
bool PickleIterator::ReadInt64(int64* result) {
return ReadBuiltinType(result);
}
bool PickleIterator::ReadUInt64(uint64* result) {
return ReadBuiltinType(result);
}
bool PickleIterator::ReadSizeT(size_t* result) {
// Always read size_t as a 64-bit value to ensure compatibility between 32-bit
// and 64-bit processes.
uint64 result_uint64 = 0;
bool success = ReadBuiltinType(&result_uint64);
*result = static_cast<size_t>(result_uint64);
// Fail if the cast above truncates the value.
return success && (*result == result_uint64);
}
bool PickleIterator::ReadFloat(float* result) {
// crbug.com/315213
// The source data may not be properly aligned, and unaligned float reads
// cause SIGBUS on some ARM platforms, so force using memcpy to copy the data
// into the result.
const char* read_from = GetReadPointerAndAdvance<float>();
if (!read_from)
return false;
memcpy(result, read_from, sizeof(*result));
return true;
}
bool PickleIterator::ReadDouble(double* result) {
// crbug.com/315213
// The source data may not be properly aligned, and unaligned double reads
// cause SIGBUS on some ARM platforms, so force using memcpy to copy the data
// into the result.
const char* read_from = GetReadPointerAndAdvance<double>();
if (!read_from)
return false;
memcpy(result, read_from, sizeof(*result));
return true;
}
bool PickleIterator::ReadString(std::string* result) {
int len;
if (!ReadInt(&len))
return false;
const char* read_from = GetReadPointerAndAdvance(len);
if (!read_from)
return false;
result->assign(read_from, len);
return true;
}
bool PickleIterator::ReadStringPiece(StringPiece* result) {
int len;
if (!ReadInt(&len))
return false;
const char* read_from = GetReadPointerAndAdvance(len);
if (!read_from)
return false;
*result = StringPiece(read_from, len);
return true;
}
bool PickleIterator::ReadString16(string16* result) {
int len;
if (!ReadInt(&len))
return false;
const char* read_from = GetReadPointerAndAdvance(len, sizeof(char16));
if (!read_from)
return false;
result->assign(reinterpret_cast<const char16*>(read_from), len);
return true;
}
bool PickleIterator::ReadStringPiece16(StringPiece16* result) {
int len;
if (!ReadInt(&len))
return false;
const char* read_from = GetReadPointerAndAdvance(len, sizeof(char16));
if (!read_from)
return false;
*result = StringPiece16(reinterpret_cast<const char16*>(read_from), len);
return true;
}
bool PickleIterator::ReadData(const char** data, int* length) {
*length = 0;
*data = 0;
if (!ReadInt(length))
return false;
return ReadBytes(data, *length);
}
bool PickleIterator::ReadBytes(const char** data, int length) {
const char* read_from = GetReadPointerAndAdvance(length);
if (!read_from)
return false;
*data = read_from;
return true;
}
// Payload is uint32 aligned.
Pickle::Pickle()
: header_(NULL),
header_size_(sizeof(Header)),
capacity_after_header_(0),
write_offset_(0) {
Resize(kPayloadUnit);
header_->payload_size = 0;
}
Pickle::Pickle(int header_size)
: header_(NULL),
header_size_(AlignInt(header_size, sizeof(uint32))),
capacity_after_header_(0),
write_offset_(0) {
DCHECK_GE(static_cast<size_t>(header_size), sizeof(Header));
DCHECK_LE(header_size, kPayloadUnit);
Resize(kPayloadUnit);
header_->payload_size = 0;
}
Pickle::Pickle(const char* data, int data_len)
: header_(reinterpret_cast<Header*>(const_cast<char*>(data))),
header_size_(0),
capacity_after_header_(kCapacityReadOnly),
write_offset_(0) {
if (data_len >= static_cast<int>(sizeof(Header)))
header_size_ = data_len - header_->payload_size;
if (header_size_ > static_cast<unsigned int>(data_len))
header_size_ = 0;
if (header_size_ != AlignInt(header_size_, sizeof(uint32)))
header_size_ = 0;
// If there is anything wrong with the data, we're not going to use it.
if (!header_size_)
header_ = NULL;
}
Pickle::Pickle(const Pickle& other)
: header_(NULL),
header_size_(other.header_size_),
capacity_after_header_(0),
write_offset_(other.write_offset_) {
size_t payload_size = header_size_ + other.header_->payload_size;
Resize(payload_size);
memcpy(header_, other.header_, payload_size);
}
Pickle::~Pickle() {
if (capacity_after_header_ != kCapacityReadOnly)
free(header_);
}
Pickle& Pickle::operator=(const Pickle& other) {
if (this == &other) {
NOTREACHED();
return *this;
}
if (capacity_after_header_ == kCapacityReadOnly) {
header_ = NULL;
capacity_after_header_ = 0;
}
if (header_size_ != other.header_size_) {
free(header_);
header_ = NULL;
header_size_ = other.header_size_;
}
Resize(other.header_->payload_size);
memcpy(header_, other.header_,
other.header_size_ + other.header_->payload_size);
write_offset_ = other.write_offset_;
return *this;
}
bool Pickle::WriteString(const StringPiece& value) {
if (!WriteInt(static_cast<int>(value.size())))
return false;
return WriteBytes(value.data(), static_cast<int>(value.size()));
}
bool Pickle::WriteString16(const StringPiece16& value) {
if (!WriteInt(static_cast<int>(value.size())))
return false;
return WriteBytes(value.data(),
static_cast<int>(value.size()) * sizeof(char16));
}
bool Pickle::WriteData(const char* data, int length) {
return length >= 0 && WriteInt(length) && WriteBytes(data, length);
}
bool Pickle::WriteBytes(const void* data, int length) {
WriteBytesCommon(data, length);
return true;
}
void Pickle::Reserve(size_t length) {
size_t data_len = AlignInt(length, sizeof(uint32));
DCHECK_GE(data_len, length);
#ifdef ARCH_CPU_64_BITS
DCHECK_LE(data_len, kuint32max);
#endif
DCHECK_LE(write_offset_, kuint32max - data_len);
size_t new_size = write_offset_ + data_len;
if (new_size > capacity_after_header_)
Resize(capacity_after_header_ * 2 + new_size);
}
void Pickle::Resize(size_t new_capacity) {
CHECK_NE(capacity_after_header_, kCapacityReadOnly);
capacity_after_header_ = AlignInt(new_capacity, kPayloadUnit);
void* p = realloc(header_, GetTotalAllocatedSize());
CHECK(p);
header_ = reinterpret_cast<Header*>(p);
}
size_t Pickle::GetTotalAllocatedSize() const {
if (capacity_after_header_ == kCapacityReadOnly)
return 0;
return header_size_ + capacity_after_header_;
}
// static
const char* Pickle::FindNext(size_t header_size,
const char* start,
const char* end) {
DCHECK_EQ(header_size, AlignInt(header_size, sizeof(uint32)));
DCHECK_LE(header_size, static_cast<size_t>(kPayloadUnit));
size_t length = static_cast<size_t>(end - start);
if (length < sizeof(Header))
return NULL;
const Header* hdr = reinterpret_cast<const Header*>(start);
if (length < header_size || length - header_size < hdr->payload_size)
return NULL;
return start + header_size + hdr->payload_size;
}
template <size_t length> void Pickle::WriteBytesStatic(const void* data) {
WriteBytesCommon(data, length);
}
template void Pickle::WriteBytesStatic<2>(const void* data);
template void Pickle::WriteBytesStatic<4>(const void* data);
template void Pickle::WriteBytesStatic<8>(const void* data);
inline void Pickle::WriteBytesCommon(const void* data, size_t length) {
DCHECK_NE(kCapacityReadOnly, capacity_after_header_)
<< "oops: pickle is readonly";
MSAN_CHECK_MEM_IS_INITIALIZED(data, length);
size_t data_len = AlignInt(length, sizeof(uint32));
DCHECK_GE(data_len, length);
#ifdef ARCH_CPU_64_BITS
DCHECK_LE(data_len, kuint32max);
#endif
DCHECK_LE(write_offset_, kuint32max - data_len);
size_t new_size = write_offset_ + data_len;
if (new_size > capacity_after_header_) {
Resize(std::max(capacity_after_header_ * 2, new_size));
}
char* write = mutable_payload() + write_offset_;
memcpy(write, data, length);
memset(write + length, 0, data_len - length);
header_->payload_size = static_cast<uint32>(new_size);
write_offset_ = new_size;
}
} // namespace base