/*
* Copyright (c) 2008-2021 Jonathan Schleifer <js@nil.im>
*
* All rights reserved.
*
* This file is part of ObjFW. It may be distributed under the terms of the
* Q Public License 1.0, which can be found in the file LICENSE.QPL included in
* the packaging of this file.
*
* Alternatively, it may be distributed under the terms of the GNU General
* Public License, either version 2 or 3, which can be found in the file
* LICENSE.GPLv2 or LICENSE.GPLv3 respectively included in the packaging of this
* file.
*/
#include <stdbool.h>
#include <stdint.h>
#import "macros.h"
#import "OFInvalidFormatException.h"
OF_ASSUME_NONNULL_BEGIN
struct of_huffman_tree {
struct of_huffman_tree *_Nullable leaves[2];
uint16_t value;
};
static OF_INLINE bool
of_huffman_tree_walk(id _Nullable stream,
bool (*bitReader)(id _Nullable, uint16_t *_Nonnull, uint8_t),
struct of_huffman_tree *_Nonnull *_Nonnull tree, uint16_t *_Nonnull value)
{
struct of_huffman_tree *iter = *tree;
uint16_t bits;
while (iter->value == 0xFFFF) {
if OF_UNLIKELY (!bitReader(stream, &bits, 1)) {
*tree = iter;
return false;
}
if OF_UNLIKELY (iter->leaves[bits] == NULL)
@throw [OFInvalidFormatException exception];
iter = iter->leaves[bits];
}
*value = iter->value;
return true;
}
#ifdef __cplusplus
extern "C" {
#endif
extern struct of_huffman_tree *_Nonnull of_huffman_tree_construct(
uint8_t lengths[_Nonnull], uint16_t count);
extern struct of_huffman_tree *_Nonnull of_huffman_tree_construct_single(
uint16_t value);
extern void of_huffman_tree_release(struct of_huffman_tree *_Nonnull tree);
#ifdef __cplusplus
}
#endif
OF_ASSUME_NONNULL_END