src/add-ons/translators/gif/SFHash.cpp

   1 ////////////////////////////////////////////////////////////////////////////////
   2 //
   3 //      File: SFHash.cpp
   4 //
   5 //      Date: December 1999
   6 //
   7 //      Author: Daniel Switkin
   8 //
   9 //      Copyright 2003 (c) by Daniel Switkin. This file is made publically available
  10 //      under the BSD license, with the stipulations that this complete header must
  11 //      remain at the top of the file indefinitely, and credit must be given to the
  12 //      original author in any about box using this software.
  13 //
  14 ////////////////////////////////////////////////////////////////////////////////
  15
  16 // Additional authors:  Stephan Aßmus, <superstippi@gmx.de>
  17 //                                              John Scipione, <jscipione@gmail.com>
  18
  19
  20 #include "SFHash.h"
  21
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24
  25
  26 SFHash::SFHash(int size) {
  27         fatalerror = false;
  28         this->size = size;
  29         iterate_pos = iterate_depth = 0;
  30         main_array = (HashItem**)malloc(this->size * sizeof(HashItem*));
  31
  32         if (main_array == NULL) {
  33                 fatalerror = true;
  34                 return;
  35         }
  36
  37         for (int x = 0; x < this->size; x++)
  38                 main_array[x] = NULL;
  39 }
  40
  41
  42 SFHash::~SFHash() {
  43         for (int x = 0; x < size; x++) {
  44                 HashItem* item = main_array[x];
  45                 while (item != NULL) {
  46                         HashItem* t = item->next;
  47                         delete item;
  48                         item = t;
  49                 }
  50         }
  51     free(main_array);
  52 }
  53
  54
  55 void
  56 SFHash::AddItem(HashItem* item) {
  57         item->next = NULL;
  58         int pos = item->key % size;
  59
  60         if (main_array[pos] == NULL)
  61                 main_array[pos] = item;
  62         else {
  63                 HashItem* temp = main_array[pos];
  64                 while (temp->next != NULL) temp = temp->next;
  65                 temp->next = item;
  66         }
  67 }
  68
  69
  70 HashItem*
  71 SFHash::GetItem(unsigned int key)
  72 {
  73         int pos = key % size;
  74         HashItem* item = main_array[pos];
  75
  76         while (item != NULL) {
  77                 if (item->key == key) return item;
  78                 item = item->next;
  79         }
  80
  81         return NULL;
  82 }
  83
  84
  85 unsigned int
  86 SFHash::CountItems()
  87 {
  88         unsigned int count = 0;
  89         for (int x = 0; x < this->size; x++) {
  90                 HashItem* item = main_array[x];
  91                 while (item != NULL) {
  92                         count++;
  93                         item = item->next;
  94                 }
  95         }
  96
  97         return count;
  98 }
  99
 100
 101 HashItem*
 102 SFHash::NextItem()
 103 {
 104         if (iterate_pos >= size) {
 105                 Rewind();
 106                 return NULL;
 107         }
 108         HashItem* item;
 109         while ((item = main_array[iterate_pos]) == NULL)
 110                 iterate_pos++;
 111
 112         for (int d = 0; d < iterate_depth; d++)
 113                 item = item->next;
 114
 115         if (item->next != NULL)
 116                 iterate_depth++;
 117         else {
 118                 iterate_pos++;
 119                 iterate_depth = 0;
 120         }
 121
 122         return item;
 123 }
 124
 125
 126 void
 127 SFHash::Rewind() {
 128         iterate_pos = 0;
 129         iterate_depth = 0;
 130 }