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// Copyright 2017 The Chromium OS 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 "puffin/src/puff_writer.h"
#include <algorithm>
#include <memory>
#include <string>
#include <vector>
#include "puffin/src/set_errors.h"
namespace puffin {
namespace {
// Writes a value to the buffer in big-endian mode. Experience showed that
// big-endian creates smaller payloads.
inline void WriteUint16ToByteArray(uint16_t value, uint8_t* buffer) {
*buffer = value >> 8;
*(buffer + 1) = value & 0x00FF;
}
constexpr size_t kLiteralsMaxLength = (1 << 16) + 127; // 65663
} // namespace
bool BufferPuffWriter::Insert(const PuffData& pd, Error* error) {
switch (pd.type) {
case PuffData::Type::kLiterals:
if (pd.length == 0) {
return true;
}
// We don't break here. It will be processed in kLiteral;
case PuffData::Type::kLiteral: {
DVLOG(2) << "Write literals length: " << pd.length;
size_t length = pd.type == PuffData::Type::kLiteral ? 1 : pd.length;
if (state_ == State::kWritingNonLiteral) {
len_index_ = index_;
index_++;
state_ = State::kWritingSmallLiteral;
}
if (state_ == State::kWritingSmallLiteral) {
if ((cur_literals_length_ + length) > 127) {
if (puff_buf_out_ != nullptr) {
// Boundary check
TEST_AND_RETURN_FALSE_SET_ERROR(index_ + 2 <= puff_size_,
Error::kInsufficientOutput);
// Shift two bytes forward to open space for length value.
memmove(&puff_buf_out_[len_index_ + 3],
&puff_buf_out_[len_index_ + 1], cur_literals_length_);
}
index_ += 2;
state_ = State::kWritingLargeLiteral;
}
}
if (puff_buf_out_ != nullptr) {
// Boundary check
TEST_AND_RETURN_FALSE_SET_ERROR(index_ + length <= puff_size_,
Error::kInsufficientOutput);
if (pd.type == PuffData::Type::kLiteral) {
puff_buf_out_[index_] = pd.byte;
} else {
TEST_AND_RETURN_FALSE_SET_ERROR(
pd.read_fn(&puff_buf_out_[index_], length),
Error::kInsufficientInput);
}
} else if (pd.type == PuffData::Type::kLiterals) {
TEST_AND_RETURN_FALSE_SET_ERROR(pd.read_fn(nullptr, length),
Error::kInsufficientInput);
}
index_ += length;
cur_literals_length_ += length;
// Technically with the current structure of the puff stream, we cannot
// have total length of more than 65663 bytes for a series of literals. So
// we have to cap it at 65663 and continue afterwards.
if (cur_literals_length_ == kLiteralsMaxLength) {
TEST_AND_RETURN_FALSE(FlushLiterals(error));
}
break;
}
case PuffData::Type::kLenDist:
DVLOG(2) << "Write length: " << pd.length << " distance: " << pd.distance;
TEST_AND_RETURN_FALSE(FlushLiterals(error));
TEST_AND_RETURN_FALSE_SET_ERROR(pd.length <= 258 && pd.length >= 3,
Error::kInvalidInput);
TEST_AND_RETURN_FALSE_SET_ERROR(pd.distance <= 32768 && pd.distance >= 1,
Error::kInvalidInput);
if (pd.length < 130) {
if (puff_buf_out_ != nullptr) {
// Boundary check
TEST_AND_RETURN_FALSE_SET_ERROR(index_ + 3 <= puff_size_,
Error::kInsufficientOutput);
puff_buf_out_[index_++] =
kLenDistHeader | static_cast<uint8_t>(pd.length - 3);
} else {
index_++;
}
} else {
if (puff_buf_out_ != nullptr) {
// Boundary check
TEST_AND_RETURN_FALSE_SET_ERROR(index_ + 4 <= puff_size_,
Error::kInsufficientOutput);
puff_buf_out_[index_++] = kLenDistHeader | 127;
puff_buf_out_[index_++] = static_cast<uint8_t>(pd.length - 3 - 127);
} else {
index_ += 2;
}
}
if (puff_buf_out_ != nullptr) {
// Write the distance in the range [1..32768] zero-based.
WriteUint16ToByteArray(pd.distance - 1, &puff_buf_out_[index_]);
}
index_ += 2;
len_index_ = index_;
state_ = State::kWritingNonLiteral;
break;
case PuffData::Type::kBlockMetadata:
DVLOG(2) << "Write block metadata length: " << pd.length;
TEST_AND_RETURN_FALSE(FlushLiterals(error));
TEST_AND_RETURN_FALSE_SET_ERROR(
pd.length <= sizeof(pd.block_metadata) && pd.length > 0,
Error::kInvalidInput);
if (puff_buf_out_ != nullptr) {
// Boundary check
TEST_AND_RETURN_FALSE_SET_ERROR(index_ + pd.length + 2 <= puff_size_,
Error::kInsufficientOutput);
WriteUint16ToByteArray(pd.length - 1, &puff_buf_out_[index_]);
}
index_ += 2;
if (puff_buf_out_ != nullptr) {
memcpy(&puff_buf_out_[index_], pd.block_metadata, pd.length);
}
index_ += pd.length;
len_index_ = index_;
state_ = State::kWritingNonLiteral;
break;
case PuffData::Type::kEndOfBlock:
DVLOG(2) << "Write end of block";
TEST_AND_RETURN_FALSE(FlushLiterals(error));
if (puff_buf_out_ != nullptr) {
// Boundary check
TEST_AND_RETURN_FALSE_SET_ERROR(index_ + 2 <= puff_size_,
Error::kInsufficientOutput);
puff_buf_out_[index_++] = kLenDistHeader | 127;
puff_buf_out_[index_++] = static_cast<uint8_t>(259 - 3 - 127);
} else {
index_ += 2;
}
len_index_ = index_;
state_ = State::kWritingNonLiteral;
break;
default:
LOG(ERROR) << "Invalid PuffData::Type";
*error = Error::kInvalidInput;
return false;
}
*error = Error::kSuccess;
return true;
}
bool BufferPuffWriter::FlushLiterals(Error* error) {
if (cur_literals_length_ == 0) {
return true;
}
switch (state_) {
case State::kWritingSmallLiteral:
TEST_AND_RETURN_FALSE_SET_ERROR(
cur_literals_length_ == (index_ - len_index_ - 1),
Error::kInvalidInput);
if (puff_buf_out_ != nullptr) {
puff_buf_out_[len_index_] =
kLiteralsHeader | static_cast<uint8_t>(cur_literals_length_ - 1);
}
len_index_ = index_;
state_ = State::kWritingNonLiteral;
DVLOG(2) << "Write small literals length: " << cur_literals_length_;
break;
case State::kWritingLargeLiteral:
TEST_AND_RETURN_FALSE_SET_ERROR(
cur_literals_length_ == (index_ - len_index_ - 3),
Error::kInvalidInput);
if (puff_buf_out_ != nullptr) {
puff_buf_out_[len_index_++] = kLiteralsHeader | 127;
WriteUint16ToByteArray(
static_cast<uint16_t>(cur_literals_length_ - 127 - 1),
&puff_buf_out_[len_index_]);
}
len_index_ = index_;
state_ = State::kWritingNonLiteral;
DVLOG(2) << "Write large literals length: " << cur_literals_length_;
break;
case State::kWritingNonLiteral:
// Do nothing.
break;
default:
LOG(ERROR) << "Invalid State";
*error = Error::kInvalidInput;
return false;
}
cur_literals_length_ = 0;
return true;
}
bool BufferPuffWriter::Flush(Error* error) {
TEST_AND_RETURN_FALSE(FlushLiterals(error));
return true;
}
size_t BufferPuffWriter::Size() {
return index_;
}
} // namespace puffin
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