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-rw-r--r-- | third-party/tommyds/tommyarray.h | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/third-party/tommyds/tommyarray.h b/third-party/tommyds/tommyarray.h new file mode 100644 index 0000000..c04193f --- /dev/null +++ b/third-party/tommyds/tommyarray.h @@ -0,0 +1,151 @@ +/* + * Copyright (c) 2011, Andrea Mazzoleni. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +/** \file + * Dynamic array based on segments of exponential growing size. + * + * This array is able to grow dynamically upon request, without any reallocation. + * + * The grow operation involves an allocation of a new array segment, without reallocating + * the already used memory, and then not increasing the heap fragmentation. + * This also implies that the address of the stored elements never change. + * + * Allocated segments grow in size exponentially. + */ + +#ifndef __TOMMYARRAY_H +#define __TOMMYARRAY_H + +#include "tommytypes.h" + +#include <assert.h> /* for assert */ + +/******************************************************************************/ +/* array */ + +/** + * Initial and minimal size of the array expressed as a power of 2. + * The initial size is 2^TOMMY_ARRAY_BIT. + */ +#define TOMMY_ARRAY_BIT 6 + +/** \internal + * Max number of elements as a power of 2. + */ +#define TOMMY_ARRAY_BIT_MAX 32 + +/** + * Array container type. + * \note Don't use internal fields directly, but access the container only using functions. + */ +typedef struct tommy_array_struct { + void** bucket[TOMMY_ARRAY_BIT_MAX]; /**< Dynamic array of buckets. */ + tommy_uint_t bucket_bit; /**< Bits used in the bit mask. */ + tommy_count_t bucket_max; /**< Number of buckets. */ + tommy_count_t count; /**< Number of initialized elements in the array. */ +} tommy_array; + +/** + * Initializes the array. + */ +void tommy_array_init(tommy_array* array); + +/** + * Deinitializes the array. + */ +void tommy_array_done(tommy_array* array); + +/** + * Grows the size up to the specified value. + * All the new elements in the array are initialized with the 0 value. + */ +void tommy_array_grow(tommy_array* array, tommy_count_t size); + +/** + * Gets a reference of the element at the specified position. + * You must be sure that space for this position is already + * allocated calling tommy_array_grow(). + */ +tommy_inline void** tommy_array_ref(tommy_array* array, tommy_count_t pos) +{ + tommy_uint_t bsr; + + assert(pos < array->count); + + /* get the highest bit set, in case of all 0, return 0 */ + bsr = tommy_ilog2_u32(pos | 1); + + return &array->bucket[bsr][pos]; +} + +/** + * Sets the element at the specified position. + * You must be sure that space for this position is already + * allocated calling tommy_array_grow(). + */ +tommy_inline void tommy_array_set(tommy_array* array, tommy_count_t pos, void* element) +{ + *tommy_array_ref(array, pos) = element; +} + +/** + * Gets the element at the specified position. + * You must be sure that space for this position is already + * allocated calling tommy_array_grow(). + */ +tommy_inline void* tommy_array_get(tommy_array* array, tommy_count_t pos) +{ + return *tommy_array_ref(array, pos); +} + +/** + * Grows and inserts a new element at the end of the array. + */ +tommy_inline void tommy_array_insert(tommy_array* array, void* element) +{ + tommy_count_t pos = array->count; + + tommy_array_grow(array, pos + 1); + + tommy_array_set(array, pos, element); +} + +/** + * Gets the initialized size of the array. + */ +tommy_inline tommy_count_t tommy_array_size(tommy_array* array) +{ + return array->count; +} + +/** + * Gets the size of allocated memory. + */ +tommy_size_t tommy_array_memory_usage(tommy_array* array); + +#endif + |