Skip to content
Fetching contributors…
Cannot retrieve contributors at this time
434 lines (335 sloc) 11 KB
// Copyright (c) 2011 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()
#include <limits>
//------------------------------------------------------------------------------
// static
const int Pickle::kPayloadUnit = 64;
// We mark a read only pickle with a special capacity_.
static const size_t kCapacityReadOnly = std::numeric_limits<size_t>::max();
// Payload is uint32 aligned.
Pickle::Pickle()
: header_(NULL),
header_size_(sizeof(Header)),
capacity_(0),
variable_buffer_offset_(0) {
Resize(kPayloadUnit);
header_->payload_size = 0;
}
Pickle::Pickle(int header_size)
: header_(NULL),
header_size_(AlignInt(header_size, sizeof(uint32))),
capacity_(0),
variable_buffer_offset_(0) {
DCHECK_GE(static_cast<size_t>(header_size), sizeof(Header));
DCHECK(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_(kCapacityReadOnly),
variable_buffer_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_(0),
variable_buffer_offset_(other.variable_buffer_offset_) {
size_t payload_size = header_size_ + other.header_->payload_size;
bool resized = Resize(payload_size);
CHECK(resized); // Realloc failed.
memcpy(header_, other.header_, payload_size);
}
Pickle::~Pickle() {
if (capacity_ != kCapacityReadOnly)
free(header_);
}
Pickle& Pickle::operator=(const Pickle& other) {
if (this == &other) {
NOTREACHED();
return *this;
}
if (capacity_ == kCapacityReadOnly) {
header_ = NULL;
capacity_ = 0;
}
if (header_size_ != other.header_size_) {
free(header_);
header_ = NULL;
header_size_ = other.header_size_;
}
bool resized = Resize(other.header_size_ + other.header_->payload_size);
CHECK(resized); // Realloc failed.
memcpy(header_, other.header_,
other.header_size_ + other.header_->payload_size);
variable_buffer_offset_ = other.variable_buffer_offset_;
return *this;
}
bool Pickle::ReadBool(void** iter, bool* result) const {
DCHECK(iter);
int tmp;
if (!ReadInt(iter, &tmp))
return false;
DCHECK(0 == tmp || 1 == tmp);
*result = tmp ? true : false;
return true;
}
bool Pickle::ReadInt(void** iter, int* result) const {
DCHECK(iter);
if (!*iter)
*iter = const_cast<char*>(payload());
if (!IteratorHasRoomFor(*iter, sizeof(*result)))
return false;
// TODO(jar): http://crbug.com/13108 Pickle should be cleaned up, and not
// dependent on alignment.
// Next line is otherwise the same as: memcpy(result, *iter, sizeof(*result));
*result = *reinterpret_cast<int*>(*iter);
UpdateIter(iter, sizeof(*result));
return true;
}
bool Pickle::ReadLong(void** iter, long* result) const {
DCHECK(iter);
if (!*iter)
*iter = const_cast<char*>(payload());
if (!IteratorHasRoomFor(*iter, sizeof(*result)))
return false;
// TODO(jar): http://crbug.com/13108 Pickle should be cleaned up, and not
// dependent on alignment.
memcpy(result, *iter, sizeof(*result));
UpdateIter(iter, sizeof(*result));
return true;
}
bool Pickle::ReadSize(void** iter, size_t* result) const {
DCHECK(iter);
if (!*iter)
*iter = const_cast<char*>(payload());
if (!IteratorHasRoomFor(*iter, sizeof(*result)))
return false;
// TODO(jar): http://crbug.com/13108 Pickle should be cleaned up, and not
// dependent on alignment.
// Next line is otherwise the same as: memcpy(result, *iter, sizeof(*result));
*result = *reinterpret_cast<size_t*>(*iter);
UpdateIter(iter, sizeof(*result));
return true;
}
bool Pickle::ReadUInt16(void** iter, uint16* result) const {
DCHECK(iter);
if (!*iter)
*iter = const_cast<char*>(payload());
if (!IteratorHasRoomFor(*iter, sizeof(*result)))
return false;
memcpy(result, *iter, sizeof(*result));
UpdateIter(iter, sizeof(*result));
return true;
}
bool Pickle::ReadUInt32(void** iter, uint32* result) const {
DCHECK(iter);
if (!*iter)
*iter = const_cast<char*>(payload());
if (!IteratorHasRoomFor(*iter, sizeof(*result)))
return false;
memcpy(result, *iter, sizeof(*result));
UpdateIter(iter, sizeof(*result));
return true;
}
bool Pickle::ReadInt64(void** iter, int64* result) const {
DCHECK(iter);
if (!*iter)
*iter = const_cast<char*>(payload());
if (!IteratorHasRoomFor(*iter, sizeof(*result)))
return false;
memcpy(result, *iter, sizeof(*result));
UpdateIter(iter, sizeof(*result));
return true;
}
bool Pickle::ReadUInt64(void** iter, uint64* result) const {
DCHECK(iter);
if (!*iter)
*iter = const_cast<char*>(payload());
if (!IteratorHasRoomFor(*iter, sizeof(*result)))
return false;
memcpy(result, *iter, sizeof(*result));
UpdateIter(iter, sizeof(*result));
return true;
}
bool Pickle::ReadString(void** iter, std::string* result) const {
DCHECK(iter);
int len;
if (!ReadLength(iter, &len))
return false;
if (!IteratorHasRoomFor(*iter, len))
return false;
char* chars = reinterpret_cast<char*>(*iter);
result->assign(chars, len);
UpdateIter(iter, len);
return true;
}
bool Pickle::ReadWString(void** iter, std::wstring* result) const {
DCHECK(iter);
int len;
if (!ReadLength(iter, &len))
return false;
// Avoid integer overflow.
if (len > INT_MAX / static_cast<int>(sizeof(wchar_t)))
return false;
if (!IteratorHasRoomFor(*iter, len * sizeof(wchar_t)))
return false;
wchar_t* chars = reinterpret_cast<wchar_t*>(*iter);
result->assign(chars, len);
UpdateIter(iter, len * sizeof(wchar_t));
return true;
}
bool Pickle::ReadString16(void** iter, string16* result) const {
DCHECK(iter);
int len;
if (!ReadLength(iter, &len))
return false;
if (!IteratorHasRoomFor(*iter, len * sizeof(char16)))
return false;
char16* chars = reinterpret_cast<char16*>(*iter);
result->assign(chars, len);
UpdateIter(iter, len * sizeof(char16));
return true;
}
bool Pickle::ReadData(void** iter, const char** data, int* length) const {
DCHECK(iter);
DCHECK(data);
DCHECK(length);
*length = 0;
*data = 0;
if (!ReadLength(iter, length))
return false;
return ReadBytes(iter, data, *length);
}
bool Pickle::ReadBytes(void** iter, const char** data, int length) const {
DCHECK(iter);
DCHECK(data);
*data = 0;
if (!*iter)
*iter = const_cast<char*>(payload());
if (!IteratorHasRoomFor(*iter, length))
return false;
*data = reinterpret_cast<const char*>(*iter);
UpdateIter(iter, length);
return true;
}
bool Pickle::ReadLength(void** iter, int* result) const {
if (!ReadInt(iter, result))
return false;
return ((*result) >= 0);
}
bool Pickle::WriteString(const std::string& value) {
if (!WriteInt(static_cast<int>(value.size())))
return false;
return WriteBytes(value.data(), static_cast<int>(value.size()));
}
bool Pickle::WriteWString(const std::wstring& value) {
if (!WriteInt(static_cast<int>(value.size())))
return false;
return WriteBytes(value.data(),
static_cast<int>(value.size() * sizeof(wchar_t)));
}
bool Pickle::WriteString16(const string16& 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 data_len) {
DCHECK(capacity_ != kCapacityReadOnly) << "oops: pickle is readonly";
char* dest = BeginWrite(data_len);
if (!dest)
return false;
memcpy(dest, data, data_len);
EndWrite(dest, data_len);
return true;
}
char* Pickle::BeginWriteData(int length) {
DCHECK_EQ(variable_buffer_offset_, 0U) <<
"There can only be one variable buffer in a Pickle";
if (length < 0 || !WriteInt(length))
return NULL;
char *data_ptr = BeginWrite(length);
if (!data_ptr)
return NULL;
variable_buffer_offset_ =
data_ptr - reinterpret_cast<char*>(header_) - sizeof(int);
// EndWrite doesn't necessarily have to be called after the write operation,
// so we call it here to pad out what the caller will eventually write.
EndWrite(data_ptr, length);
return data_ptr;
}
void Pickle::TrimWriteData(int new_length) {
DCHECK_NE(variable_buffer_offset_, 0U);
// Fetch the the variable buffer size
int* cur_length = reinterpret_cast<int*>(
reinterpret_cast<char*>(header_) + variable_buffer_offset_);
if (new_length < 0 || new_length > *cur_length) {
NOTREACHED() << "Invalid length in TrimWriteData.";
return;
}
// Update the payload size and variable buffer size
header_->payload_size -= (*cur_length - new_length);
*cur_length = new_length;
}
char* Pickle::BeginWrite(size_t length) {
// write at a uint32-aligned offset from the beginning of the header
size_t offset = AlignInt(header_->payload_size, sizeof(uint32));
size_t new_size = offset + length;
size_t needed_size = header_size_ + new_size;
if (needed_size > capacity_ && !Resize(std::max(capacity_ * 2, needed_size)))
return NULL;
#ifdef ARCH_CPU_64_BITS
DCHECK_LE(length, std::numeric_limits<uint32>::max());
#endif
header_->payload_size = static_cast<uint32>(new_size);
return payload() + offset;
}
void Pickle::EndWrite(char* dest, int length) {
// Zero-pad to keep tools like purify from complaining about uninitialized
// memory.
if (length % sizeof(uint32))
memset(dest + length, 0, sizeof(uint32) - (length % sizeof(uint32)));
}
bool Pickle::Resize(size_t new_capacity) {
new_capacity = AlignInt(new_capacity, kPayloadUnit);
CHECK_NE(capacity_, kCapacityReadOnly);
void* p = realloc(header_, new_capacity);
if (!p)
return false;
header_ = reinterpret_cast<Header*>(p);
capacity_ = new_capacity;
return true;
}
// static
const char* Pickle::FindNext(size_t header_size,
const char* start,
const char* end) {
DCHECK(header_size == AlignInt(header_size, sizeof(uint32)));
DCHECK(header_size <= static_cast<size_t>(kPayloadUnit));
if (static_cast<size_t>(end - start) < sizeof(Header))
return NULL;
const Header* hdr = reinterpret_cast<const Header*>(start);
const char* payload_base = start + header_size;
const char* payload_end = payload_base + hdr->payload_size;
if (payload_end < payload_base)
return NULL;
return (payload_end > end) ? NULL : payload_end;
}
Something went wrong with that request. Please try again.