/* * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, * 2018, 2019 * Jonathan Schleifer <js@heap.zone> * * 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