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/*
* 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 "rtc_base/byte_buffer.h"
#include <string.h>
#include <cstdint>
#include <string>
#include "absl/strings/string_view.h"
#include "api/array_view.h"
#include "rtc_base/byte_order.h"
namespace webrtc {
ByteBufferWriter::ByteBufferWriter() : ByteBufferWriterT() {}
ByteBufferWriter::ByteBufferWriter(const uint8_t* bytes, size_t len)
: ByteBufferWriterT(bytes, len) {}
ByteBufferReader::ByteBufferReader(ArrayView<const uint8_t> bytes) {
Construct(bytes.data(), bytes.size());
}
ByteBufferReader::ByteBufferReader(const ByteBufferWriter& buf) {
Construct(reinterpret_cast<const uint8_t*>(buf.Data()), buf.Length());
}
void ByteBufferReader::Construct(const uint8_t* bytes, size_t len) {
bytes_ = bytes;
size_ = len;
start_ = 0;
end_ = len;
}
bool ByteBufferReader::ReadUInt8(uint8_t* val) {
if (!val)
return false;
return ReadBytes(val, 1);
}
bool ByteBufferReader::ReadUInt16(uint16_t* val) {
if (!val)
return false;
uint16_t v;
if (!ReadBytes(reinterpret_cast<uint8_t*>(&v), 2)) {
return false;
} else {
*val = NetworkToHost16(v);
return true;
}
}
bool ByteBufferReader::ReadUInt24(uint32_t* val) {
if (!val)
return false;
uint32_t v = 0;
uint8_t* read_into = reinterpret_cast<uint8_t*>(&v);
++read_into;
if (!ReadBytes(read_into, 3)) {
return false;
} else {
*val = NetworkToHost32(v);
return true;
}
}
bool ByteBufferReader::ReadUInt32(uint32_t* val) {
if (!val)
return false;
uint32_t v;
if (!ReadBytes(reinterpret_cast<uint8_t*>(&v), 4)) {
return false;
} else {
*val = NetworkToHost32(v);
return true;
}
}
bool ByteBufferReader::ReadUInt64(uint64_t* val) {
if (!val)
return false;
uint64_t v;
if (!ReadBytes(reinterpret_cast<uint8_t*>(&v), 8)) {
return false;
} else {
*val = NetworkToHost64(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) {
uint8_t 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;
// Return if the msb is not a continuation byte.
if (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(reinterpret_cast<const char*>(bytes_ + start_), len);
start_ += len;
return true;
}
}
bool ByteBufferReader::ReadStringView(absl::string_view* val, size_t len) {
if (!val || len > Length())
return false;
*val = absl::string_view(reinterpret_cast<const char*>(bytes_ + start_), len);
start_ += len;
return true;
}
bool ByteBufferReader::ReadBytes(ArrayView<uint8_t> val) {
if (val.size() == 0) {
return true;
}
return ReadBytes(val.data(), val.size());
}
// Private function supporting the other Read* functions.
bool ByteBufferReader::ReadBytes(uint8_t* val, size_t len) {
if (len > Length()) {
return false;
}
if (len == 0) {
return true;
}
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 webrtc
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