Line data    Source code

       1             : /*
       2             :  * Copyright (c) 2013, Andrea Mazzoleni. All rights reserved.
       3             :  *
       4             :  * Redistribution and use in source and binary forms, with or without
       5             :  * modification, are permitted provided that the following conditions
       6             :  * are met:
       7             :  *
       8             :  * 1. Redistributions of source code must retain the above copyright
       9             :  *    notice, this list of conditions and the following disclaimer.
      10             :  *
      11             :  * 2. Redistributions in binary form must reproduce the above copyright
      12             :  *    notice, this list of conditions and the following disclaimer in the
      13             :  *    documentation and/or other materials provided with the distribution.
      14             :  *
      15             :  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
      16             :  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
      17             :  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
      18             :  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
      19             :  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
      20             :  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
      21             :  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
      22             :  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
      23             :  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
      24             :  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
      25             :  * POSSIBILITY OF SUCH DAMAGE.
      26             :  */
      27             : 
      28             : /** \file
      29             :  * Dynamic array based on blocks of fixed size.
      30             :  *
      31             :  * This array is able to grow dynamically upon request, without any reallocation.
      32             :  *
      33             :  * The grow operation involves an allocation of a new array block, without reallocating
      34             :  * the already used memory, and thus **not increasing** the heap fragmentation,
      35             :  * and **minimizing** the space occupation.
      36             :  * This also implies that the address of the stored elements never change.
      37             :  *
      38             :  * Allocated blocks are always of the same fixed size of 4 Ki pointers.
      39             :  */
      40             : 
      41             : #ifndef __TOMMYARRAYBLK_H
      42             : #define __TOMMYARRAYBLK_H
      43             : 
      44             : #include "tommytypes.h"
      45             : #include "tommyarray.h"
      46             : 
      47             : #include <assert.h> /* for assert */
      48             : 
      49             : /******************************************************************************/
      50             : /* array */
      51             : 
      52             : /**
      53             :  * Elements for each block.
      54             :  */
      55             : #define TOMMY_ARRAYBLK_SIZE (4 * 1024)
      56             : 
      57             : /**
      58             :  * Array container type.
      59             :  * \note Don't use internal fields directly, but access the container only using functions.
      60             :  */
      61             : typedef struct tommy_arrayblk_struct {
      62             :         tommy_array block; /**< Array of blocks. */
      63             :         tommy_size_t count; /**< Number of initialized elements in the array. */
      64             : } tommy_arrayblk;
      65             : 
      66             : /**
      67             :  * Initializes the array.
      68             :  */
      69             : TOMMY_API void tommy_arrayblk_init(tommy_arrayblk* array);
      70             : 
      71             : /**
      72             :  * Deinitializes the array.
      73             :  */
      74             : TOMMY_API void tommy_arrayblk_done(tommy_arrayblk* array);
      75             : 
      76             : /**
      77             :  * Grows the size up to the specified value.
      78             :  * All the new elements in the array are initialized with the 0 value.
      79             :  */
      80             : TOMMY_API void tommy_arrayblk_grow(tommy_arrayblk* array, tommy_size_t size);
      81             : 
      82             : /**
      83             :  * Gets a reference of the element at the specified position.
      84             :  * You must be sure that space for this position is already
      85             :  * allocated calling tommy_arrayblk_grow().
      86             :  */
      87   150000000 : tommy_inline void** tommy_arrayblk_ref(tommy_arrayblk* array, tommy_size_t pos)
      88             : {
      89             :         void** ptr;
      90             : 
      91   150000000 :         assert(pos < array->count);
      92             : 
      93   150000000 :         ptr = tommy_cast(void**, tommy_array_get(&array->block, pos / TOMMY_ARRAYBLK_SIZE));
      94             : 
      95   150000000 :         return &ptr[pos % TOMMY_ARRAYBLK_SIZE];
      96             : }
      97             : 
      98             : /**
      99             :  * Sets the element at the specified position.
     100             :  * You must be sure that space for this position is already
     101             :  * allocated calling tommy_arrayblk_grow().
     102             :  */
     103    50000000 : tommy_inline void tommy_arrayblk_set(tommy_arrayblk* array, tommy_size_t pos, void* element)
     104             : {
     105    50000000 :         *tommy_arrayblk_ref(array, pos) = element;
     106    50000000 : }
     107             : 
     108             : /**
     109             :  * Gets the element at the specified position.
     110             :  * You must be sure that space for this position is already
     111             :  * allocated calling tommy_arrayblk_grow().
     112             :  */
     113   100000000 : tommy_inline void* tommy_arrayblk_get(tommy_arrayblk* array, tommy_size_t pos)
     114             : {
     115   100000000 :         return *tommy_arrayblk_ref(array, pos);
     116             : }
     117             : 
     118             : /**
     119             :  * Grows and inserts a new element at the end of the array.
     120             :  */
     121             : tommy_inline void tommy_arrayblk_insert(tommy_arrayblk* array, void* element)
     122             : {
     123             :         tommy_size_t pos = array->count;
     124             : 
     125             :         tommy_arrayblk_grow(array, pos + 1);
     126             : 
     127             :         tommy_arrayblk_set(array, pos, element);
     128             : }
     129             : 
     130             : /**
     131             :  * Gets the initialized size of the array.
     132             :  */
     133             : tommy_inline tommy_size_t tommy_arrayblk_size(tommy_arrayblk* array)
     134             : {
     135             :         return array->count;
     136             : }
     137             : 
     138             : /**
     139             :  * Gets the size of allocated memory.
     140             :  */
     141             : TOMMY_API tommy_size_t tommy_arrayblk_memory_usage(tommy_arrayblk* array);
     142             : 
     143             : #endif