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// 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 "net/quic/quic_data_writer.h"
#include <algorithm>
#include <limits>
#include <string>
#include "base/basictypes.h"
#include "base/logging.h"
using base::StringPiece;
using std::numeric_limits;
namespace net {
QuicDataWriter::QuicDataWriter(size_t size)
: buffer_(new char[size]),
capacity_(size),
length_(0) {
}
QuicDataWriter::~QuicDataWriter() {
delete[] buffer_;
}
char* QuicDataWriter::take() {
char* rv = buffer_;
buffer_ = NULL;
capacity_ = 0;
length_ = 0;
return rv;
}
bool QuicDataWriter::WriteUInt8(uint8 value) {
return WriteBytes(&value, sizeof(value));
}
bool QuicDataWriter::WriteUInt16(uint16 value) {
return WriteBytes(&value, sizeof(value));
}
bool QuicDataWriter::WriteUInt32(uint32 value) {
return WriteBytes(&value, sizeof(value));
}
bool QuicDataWriter::WriteUInt48(uint64 value) {
uint32 hi = value >> 32;
uint32 lo = value & GG_UINT64_C(0x00000000FFFFFFFF);
return WriteUInt32(lo) && WriteUInt16(hi);
}
bool QuicDataWriter::WriteUInt64(uint64 value) {
return WriteBytes(&value, sizeof(value));
}
bool QuicDataWriter::WriteUInt128(uint128 value) {
return WriteUInt64(Uint128Low64(value)) && WriteUInt64(Uint128High64(value));
}
bool QuicDataWriter::WriteStringPiece16(StringPiece val) {
if (val.length() > numeric_limits<uint16>::max()) {
return false;
}
if (!WriteUInt16(val.size())) {
return false;
}
return WriteBytes(val.data(), val.size());
}
char* QuicDataWriter::BeginWrite(size_t length) {
if (length_ > capacity_) {
return NULL;
}
if (capacity_ - length_ < length) {
return NULL;
}
#ifdef ARCH_CPU_64_BITS
DCHECK_LE(length, numeric_limits<uint32>::max());
#endif
return buffer_ + length_;
}
bool QuicDataWriter::WriteBytes(const void* data, size_t data_len) {
char* dest = BeginWrite(data_len);
if (!dest) {
return false;
}
memcpy(dest, data, data_len);
length_ += data_len;
return true;
}
void QuicDataWriter::WritePadding() {
memset(buffer_ + length_, 0x00, capacity_ - length_);
length_ = capacity_;
}
bool QuicDataWriter::WriteUInt8ToOffset(uint8 value, size_t offset) {
DCHECK_LT(offset, capacity_);
int latched_length = length_;
length_ = offset;
bool success = WriteUInt8(value);
length_ = latched_length;
return success;
}
bool QuicDataWriter::WriteUInt48ToOffset(uint64 value, size_t offset) {
DCHECK_LT(offset, capacity_);
int latched_length = length_;
length_ = offset;
bool success = WriteUInt48(value);
length_ = latched_length;
return success;
}
} // namespace net
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