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// Copyright (c) the JPEG XL 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.
#include "lib/jxl/box_content_decoder.h"
#include <algorithm>
#include <cstddef>
#include <cstdint>
#include <cstring>
#include "lib/jxl/base/sanitizers.h"
namespace jxl {
JxlBoxContentDecoder::JxlBoxContentDecoder() = default;
JxlBoxContentDecoder::~JxlBoxContentDecoder() {
if (brotli_dec) {
BrotliDecoderDestroyInstance(brotli_dec);
}
}
void JxlBoxContentDecoder::StartBox(bool brob_decode, bool box_until_eof,
size_t contents_size) {
if (brotli_dec) {
BrotliDecoderDestroyInstance(brotli_dec);
brotli_dec = nullptr;
}
header_done_ = false;
brob_decode_ = brob_decode;
box_until_eof_ = box_until_eof;
remaining_ = box_until_eof ? 0 : contents_size;
pos_ = 0;
}
JxlDecoderStatus JxlBoxContentDecoder::Process(const uint8_t* next_in,
size_t avail_in, size_t box_pos,
uint8_t** next_out,
size_t* avail_out) {
next_in += pos_ - box_pos;
avail_in -= pos_ - box_pos;
if (brob_decode_) {
if (!header_done_) {
if (avail_in < 4) return JXL_DEC_NEED_MORE_INPUT;
if (!box_until_eof_) {
if (remaining_ < 4) return JXL_DEC_ERROR;
remaining_ -= 4;
}
next_in += 4;
avail_in -= 4;
pos_ += 4;
header_done_ = true;
}
if (!brotli_dec) {
brotli_dec = BrotliDecoderCreateInstance(nullptr, nullptr, nullptr);
}
const uint8_t* next_in_before = next_in;
uint8_t* next_out_before = *next_out;
msan::MemoryIsInitialized(next_in, avail_in);
BrotliDecoderResult res = BrotliDecoderDecompressStream(
brotli_dec, &avail_in, &next_in, avail_out, next_out, nullptr);
size_t consumed = next_in - next_in_before;
size_t produced = *next_out - next_out_before;
if (res == BROTLI_DECODER_RESULT_ERROR) {
return JXL_DEC_ERROR;
}
msan::UnpoisonMemory(next_out_before, produced);
pos_ += consumed;
if (!box_until_eof_) remaining_ -= consumed;
if (res == BROTLI_DECODER_RESULT_NEEDS_MORE_INPUT) {
return JXL_DEC_NEED_MORE_INPUT;
}
if (res == BROTLI_DECODER_RESULT_NEEDS_MORE_OUTPUT) {
return JXL_DEC_BOX_NEED_MORE_OUTPUT;
}
if (res == BROTLI_DECODER_RESULT_SUCCESS) {
return JXL_DEC_BOX_COMPLETE;
}
// unknown Brotli result
return JXL_DEC_ERROR;
} else {
// remaining box bytes as seen from dec->file_pos
size_t can_read = avail_in;
if (!box_until_eof_) can_read = std::min<size_t>(can_read, remaining_);
size_t to_write = std::min<size_t>(can_read, *avail_out);
memcpy(*next_out, next_in, to_write);
*next_out += to_write;
*avail_out -= to_write;
if (!box_until_eof_) remaining_ -= to_write;
pos_ += to_write;
if (to_write < can_read) return JXL_DEC_BOX_NEED_MORE_OUTPUT;
if (!box_until_eof_ && remaining_ > 0) return JXL_DEC_NEED_MORE_INPUT;
return JXL_DEC_BOX_COMPLETE;
}
}
} // namespace jxl