blob: 9730ff23d6787ca7e555d1aa2a5f8c0878aa6552 [file] [log] [blame]
/*
* Copyright 2004 The WebRTC Project Authors. All rights reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include "webrtc/base/bytebuffer.h"
#include <assert.h>
#include <string.h>
#include <algorithm>
#include "webrtc/base/basictypes.h"
#include "webrtc/base/byteorder.h"
namespace rtc {
static const int DEFAULT_SIZE = 4096;
ByteBufferWriter::ByteBufferWriter()
: ByteBuffer(ORDER_NETWORK) {
Construct(NULL, DEFAULT_SIZE);
}
ByteBufferWriter::ByteBufferWriter(ByteOrder byte_order)
: ByteBuffer(byte_order) {
Construct(NULL, DEFAULT_SIZE);
}
ByteBufferWriter::ByteBufferWriter(const char* bytes, size_t len)
: ByteBuffer(ORDER_NETWORK) {
Construct(bytes, len);
}
ByteBufferWriter::ByteBufferWriter(const char* bytes, size_t len,
ByteOrder byte_order)
: ByteBuffer(byte_order) {
Construct(bytes, len);
}
void ByteBufferWriter::Construct(const char* bytes, size_t len) {
start_ = 0;
size_ = len;
bytes_ = new char[size_];
if (bytes) {
end_ = len;
memcpy(bytes_, bytes, end_);
} else {
end_ = 0;
}
}
ByteBufferWriter::~ByteBufferWriter() {
delete[] bytes_;
}
void ByteBufferWriter::WriteUInt8(uint8_t val) {
WriteBytes(reinterpret_cast<const char*>(&val), 1);
}
void ByteBufferWriter::WriteUInt16(uint16_t val) {
uint16_t v = (Order() == ORDER_NETWORK) ? HostToNetwork16(val) : val;
WriteBytes(reinterpret_cast<const char*>(&v), 2);
}
void ByteBufferWriter::WriteUInt24(uint32_t val) {
uint32_t v = (Order() == ORDER_NETWORK) ? HostToNetwork32(val) : val;
char* start = reinterpret_cast<char*>(&v);
if (Order() == ORDER_NETWORK || IsHostBigEndian()) {
++start;
}
WriteBytes(start, 3);
}
void ByteBufferWriter::WriteUInt32(uint32_t val) {
uint32_t v = (Order() == ORDER_NETWORK) ? HostToNetwork32(val) : val;
WriteBytes(reinterpret_cast<const char*>(&v), 4);
}
void ByteBufferWriter::WriteUInt64(uint64_t val) {
uint64_t v = (Order() == ORDER_NETWORK) ? HostToNetwork64(val) : val;
WriteBytes(reinterpret_cast<const char*>(&v), 8);
}
// Serializes an unsigned varint in the format described by
// https://developers.google.com/protocol-buffers/docs/encoding#varints
// with the caveat that integers are 64-bit, not 128-bit.
void ByteBufferWriter::WriteUVarint(uint64_t val) {
while (val >= 0x80) {
// Write 7 bits at a time, then set the msb to a continuation byte (msb=1).
char byte = static_cast<char>(val) | 0x80;
WriteBytes(&byte, 1);
val >>= 7;
}
char last_byte = static_cast<char>(val);
WriteBytes(&last_byte, 1);
}
void ByteBufferWriter::WriteString(const std::string& val) {
WriteBytes(val.c_str(), val.size());
}
void ByteBufferWriter::WriteBytes(const char* val, size_t len) {
memcpy(ReserveWriteBuffer(len), val, len);
}
char* ByteBufferWriter::ReserveWriteBuffer(size_t len) {
if (Length() + len > Capacity())
Resize(Length() + len);
char* start = bytes_ + end_;
end_ += len;
return start;
}
void ByteBufferWriter::Resize(size_t size) {
size_t len = std::min(end_ - start_, size);
if (size <= size_) {
// Don't reallocate, just move data backwards
memmove(bytes_, bytes_ + start_, len);
} else {
// Reallocate a larger buffer.
size_ = std::max(size, 3 * size_ / 2);
char* new_bytes = new char[size_];
memcpy(new_bytes, bytes_ + start_, len);
delete [] bytes_;
bytes_ = new_bytes;
}
start_ = 0;
end_ = len;
}
void ByteBufferWriter::Clear() {
memset(bytes_, 0, size_);
start_ = end_ = 0;
}
ByteBufferReader::ByteBufferReader(const char* bytes, size_t len)
: ByteBuffer(ORDER_NETWORK) {
Construct(bytes, len);
}
ByteBufferReader::ByteBufferReader(const char* bytes, size_t len,
ByteOrder byte_order)
: ByteBuffer(byte_order) {
Construct(bytes, len);
}
ByteBufferReader::ByteBufferReader(const char* bytes)
: ByteBuffer(ORDER_NETWORK) {
Construct(bytes, strlen(bytes));
}
ByteBufferReader::ByteBufferReader(const Buffer& buf)
: ByteBuffer(ORDER_NETWORK) {
Construct(buf.data<char>(), buf.size());
}
ByteBufferReader::ByteBufferReader(const ByteBufferWriter& buf)
: ByteBuffer(buf.Order()) {
Construct(buf.Data(), buf.Length());
}
void ByteBufferReader::Construct(const char* bytes, size_t len) {
bytes_ = bytes;
size_ = len;
start_ = 0;
end_ = len;
}
bool ByteBufferReader::ReadUInt8(uint8_t* val) {
if (!val) return false;
return ReadBytes(reinterpret_cast<char*>(val), 1);
}
bool ByteBufferReader::ReadUInt16(uint16_t* val) {
if (!val) return false;
uint16_t v;
if (!ReadBytes(reinterpret_cast<char*>(&v), 2)) {
return false;
} else {
*val = (Order() == ORDER_NETWORK) ? NetworkToHost16(v) : v;
return true;
}
}
bool ByteBufferReader::ReadUInt24(uint32_t* val) {
if (!val) return false;
uint32_t v = 0;
char* read_into = reinterpret_cast<char*>(&v);
if (Order() == ORDER_NETWORK || IsHostBigEndian()) {
++read_into;
}
if (!ReadBytes(read_into, 3)) {
return false;
} else {
*val = (Order() == ORDER_NETWORK) ? NetworkToHost32(v) : v;
return true;
}
}
bool ByteBufferReader::ReadUInt32(uint32_t* val) {
if (!val) return false;
uint32_t v;
if (!ReadBytes(reinterpret_cast<char*>(&v), 4)) {
return false;
} else {
*val = (Order() == ORDER_NETWORK) ? NetworkToHost32(v) : v;
return true;
}
}
bool ByteBufferReader::ReadUInt64(uint64_t* val) {
if (!val) return false;
uint64_t v;
if (!ReadBytes(reinterpret_cast<char*>(&v), 8)) {
return false;
} else {
*val = (Order() == ORDER_NETWORK) ? NetworkToHost64(v) : v;
return true;
}
}
bool ByteBufferReader::ReadUVarint(uint64_t* val) {
if (!val) {
return false;
}
// Integers are deserialized 7 bits at a time, with each byte having a
// continuation byte (msb=1) if there are more bytes to be read.
uint64_t v = 0;
for (int i = 0; i < 64; i += 7) {
char byte;
if (!ReadBytes(&byte, 1)) {
return false;
}
// Read the first 7 bits of the byte, then offset by bits read so far.
v |= (static_cast<uint64_t>(byte) & 0x7F) << i;
// True if the msb is not a continuation byte.
if (static_cast<uint64_t>(byte) < 0x80) {
*val = v;
return true;
}
}
return false;
}
bool ByteBufferReader::ReadString(std::string* val, size_t len) {
if (!val) return false;
if (len > Length()) {
return false;
} else {
val->append(bytes_ + start_, len);
start_ += len;
return true;
}
}
bool ByteBufferReader::ReadBytes(char* val, size_t len) {
if (len > Length()) {
return false;
} else {
memcpy(val, bytes_ + start_, len);
start_ += len;
return true;
}
}
bool ByteBufferReader::Consume(size_t size) {
if (size > Length())
return false;
start_ += size;
return true;
}
} // namespace rtc