forked from bartvdbraak/blender
This is an alternative method for fitting a curve which incrementally simplifies the curve, then re-fits. Generally gives better results, also improves corner detection.
221 lines
6.3 KiB
C
221 lines
6.3 KiB
C
/*
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* Copyright (c) 2016, Blender Foundation.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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* * Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* * Neither the name of the <organization> nor the
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* names of its contributors may be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
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* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
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* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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/**
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* \file generic_alloc_impl.c
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* \ingroup curve_fit
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*
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* Simple Memory Chunking Allocator
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* ================================
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*
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* Defines need to be set:
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* - #TPOOL_IMPL_PREFIX: Prefix to use for the API.
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* - #TPOOL_ALLOC_TYPE: Struct type this pool handles.
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* - #TPOOL_STRUCT: Name for pool struct name.
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* - #TPOOL_CHUNK_SIZE: Chunk size (optional), use 64kb when not defined.
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*
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* \note #TPOOL_ALLOC_TYPE must be at least ``sizeof(void *)``.
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*
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* Defines the API, uses #TPOOL_IMPL_PREFIX to prefix each function.
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*
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* - *_pool_create()
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* - *_pool_destroy()
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* - *_pool_clear()
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*
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* - *_pool_elem_alloc()
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* - *_pool_elem_calloc()
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* - *_pool_elem_free()
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*/
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/* check we're not building directly */
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#if !defined(TPOOL_IMPL_PREFIX) || \
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!defined(TPOOL_ALLOC_TYPE) || \
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!defined(TPOOL_STRUCT)
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# error "This file can't be compiled directly, include in another source file"
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#endif
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#define _CONCAT_AUX(MACRO_ARG1, MACRO_ARG2) MACRO_ARG1 ## MACRO_ARG2
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#define _CONCAT(MACRO_ARG1, MACRO_ARG2) _CONCAT_AUX(MACRO_ARG1, MACRO_ARG2)
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#define _TPOOL_PREFIX(id) _CONCAT(TPOOL_IMPL_PREFIX, _##id)
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/* local identifiers */
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#define pool_create _TPOOL_PREFIX(pool_create)
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#define pool_destroy _TPOOL_PREFIX(pool_destroy)
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#define pool_clear _TPOOL_PREFIX(pool_clear)
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#define pool_elem_alloc _TPOOL_PREFIX(pool_elem_alloc)
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#define pool_elem_calloc _TPOOL_PREFIX(pool_elem_calloc)
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#define pool_elem_free _TPOOL_PREFIX(pool_elem_free)
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/* private identifiers (only for this file, undefine after) */
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#define pool_alloc_chunk _TPOOL_PREFIX(pool_alloc_chunk)
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#define TPoolChunk _TPOOL_PREFIX(TPoolChunk)
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#define TPoolChunkElemFree _TPOOL_PREFIX(TPoolChunkElemFree)
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#ifndef TPOOL_CHUNK_SIZE
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#define TPOOL_CHUNK_SIZE (1 << 16) /* 64kb */
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#define _TPOOL_CHUNK_SIZE_UNDEF
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#endif
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#ifndef UNLIKELY
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# ifdef __GNUC__
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# define UNLIKELY(x) __builtin_expect(!!(x), 0)
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# else
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# define UNLIKELY(x) (x)
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# endif
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#endif
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#ifdef __GNUC__
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# define MAYBE_UNUSED __attribute__((unused))
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#else
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# define MAYBE_UNUSED
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#endif
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struct TPoolChunk {
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struct TPoolChunk *prev;
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unsigned int size;
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unsigned int bufsize;
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TPOOL_ALLOC_TYPE buf[0];
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};
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struct TPoolChunkElemFree {
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struct TPoolChunkElemFree *next;
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};
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struct TPOOL_STRUCT {
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/* Always keep at least one chunk (never NULL) */
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struct TPoolChunk *chunk;
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/* when NULL, allocate a new chunk */
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struct TPoolChunkElemFree *free;
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};
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/**
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* Number of elems to include per #TPoolChunk when no reserved size is passed,
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* or we allocate past the reserved number.
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*
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* \note Optimize number for 64kb allocs.
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*/
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#define _TPOOL_CHUNK_DEFAULT_NUM \
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(((1 << 16) - sizeof(struct TPoolChunk)) / sizeof(TPOOL_ALLOC_TYPE))
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/** \name Internal Memory Management
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* \{ */
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static struct TPoolChunk *pool_alloc_chunk(
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unsigned int tot_elems, struct TPoolChunk *chunk_prev)
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{
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struct TPoolChunk *chunk = malloc(
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sizeof(struct TPoolChunk) + (sizeof(TPOOL_ALLOC_TYPE) * tot_elems));
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chunk->prev = chunk_prev;
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chunk->bufsize = tot_elems;
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chunk->size = 0;
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return chunk;
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}
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static TPOOL_ALLOC_TYPE *pool_elem_alloc(struct TPOOL_STRUCT *pool)
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{
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TPOOL_ALLOC_TYPE *elem;
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if (pool->free) {
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elem = (TPOOL_ALLOC_TYPE *)pool->free;
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pool->free = pool->free->next;
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}
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else {
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struct TPoolChunk *chunk = pool->chunk;
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if (UNLIKELY(chunk->size == chunk->bufsize)) {
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chunk = pool->chunk = pool_alloc_chunk(_TPOOL_CHUNK_DEFAULT_NUM, chunk);
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}
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elem = &chunk->buf[chunk->size++];
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}
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return elem;
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}
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MAYBE_UNUSED
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static TPOOL_ALLOC_TYPE *pool_elem_calloc(struct TPOOL_STRUCT *pool)
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{
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TPOOL_ALLOC_TYPE *elem = pool_elem_alloc(pool);
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memset(elem, 0, sizeof(*elem));
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return elem;
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}
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static void pool_elem_free(struct TPOOL_STRUCT *pool, TPOOL_ALLOC_TYPE *elem)
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{
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struct TPoolChunkElemFree *elem_free = (struct TPoolChunkElemFree *)elem;
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elem_free->next = pool->free;
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pool->free = elem_free;
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}
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static void pool_create(struct TPOOL_STRUCT *pool, unsigned int tot_reserve)
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{
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pool->chunk = pool_alloc_chunk((tot_reserve > 1) ? tot_reserve : _TPOOL_CHUNK_DEFAULT_NUM, NULL);
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pool->free = NULL;
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}
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MAYBE_UNUSED
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static void pool_clear(struct TPOOL_STRUCT *pool)
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{
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/* Remove all except the last chunk */
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while (pool->chunk->prev) {
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struct TPoolChunk *chunk_prev = pool->chunk->prev;
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free(pool->chunk);
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pool->chunk = chunk_prev;
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}
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pool->chunk->size = 0;
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pool->free = NULL;
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}
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static void pool_destroy(struct TPOOL_STRUCT *pool)
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{
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struct TPoolChunk *chunk = pool->chunk;
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do {
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struct TPoolChunk *chunk_prev;
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chunk_prev = chunk->prev;
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free(chunk);
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chunk = chunk_prev;
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} while (chunk);
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pool->chunk = NULL;
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pool->free = NULL;
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}
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/** \} */
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#undef _TPOOL_CHUNK_DEFAULT_NUM
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#undef _CONCAT_AUX
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#undef _CONCAT
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#undef _TPOOL_PREFIX
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#undef TPoolChunk
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#undef TPoolChunkElemFree
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#ifdef _TPOOL_CHUNK_SIZE_UNDEF
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# undef TPOOL_CHUNK_SIZE
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# undef _TPOOL_CHUNK_SIZE_UNDEF
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#endif
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