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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.
#ifndef LIB_JXL_JPEG_DEC_JPEG_OUTPUT_CHUNK_H_
#define LIB_JXL_JPEG_DEC_JPEG_OUTPUT_CHUNK_H_
#include <stddef.h>
#include <stdint.h>
#include <initializer_list>
#include <memory>
#include <vector>
#include "lib/jxl/base/common.h"
namespace jxl {
namespace jpeg {
/**
* A chunk of output data.
*
* Data producer creates OutputChunks and adds them to the end output queue.
* Once control flow leaves the producer code, it is considered that chunk of
* data is final and can not be changed; to underline this fact |next| is a
* const-pointer.
*
* Data consumer removes OutputChunks from the beginning of the output queue.
* It is possible to consume OutputChunks partially, by updating |next| and
* |len|.
*
* There are 2 types of output chunks:
* - owning: actual data is stored in |buffer| field; producer fills data after
* the instance it created; it is legal to reduce |len| to show that not all
* the capacity of |buffer| is used
* - non-owning: represents the data stored (owned) somewhere else
*/
struct OutputChunk {
// Non-owning
template <typename Bytes>
explicit OutputChunk(Bytes& bytes) : len(bytes.size()) {
// Deal both with const qualifier and data type.
const void* src = bytes.data();
next = reinterpret_cast<const uint8_t*>(src);
}
// Non-owning
OutputChunk(const uint8_t* data, size_t size) : next(data), len(size) {}
// Owning
explicit OutputChunk(size_t size = 0) {
buffer = jxl::make_unique<std::vector<uint8_t>>(size);
next = buffer->data();
len = size;
}
// Owning
OutputChunk(std::initializer_list<uint8_t> bytes) {
buffer = jxl::make_unique<std::vector<uint8_t>>(bytes);
next = buffer->data();
len = bytes.size();
}
const uint8_t* next;
size_t len;
// TODO(veluca): consider removing the unique_ptr.
std::unique_ptr<std::vector<uint8_t>> buffer;
};
} // namespace jpeg
} // namespace jxl
#endif // LIB_JXL_JPEG_DEC_JPEG_OUTPUT_CHUNK_H_