1 /***************************************************************************/ |
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2 /* */ |
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3 /* ftccache.c */ |
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4 /* */ |
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5 /* The FreeType internal cache interface (body). */ |
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6 /* */ |
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7 /* Copyright 2000-2001, 2002, 2003, 2004, 2005, 2006, 2007, 2009, 2010, */ |
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8 /* 2011 by */ |
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9 /* David Turner, Robert Wilhelm, and Werner Lemberg. */ |
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10 /* */ |
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11 /* This file is part of the FreeType project, and may only be used, */ |
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12 /* modified, and distributed under the terms of the FreeType project */ |
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13 /* license, LICENSE.TXT. By continuing to use, modify, or distribute */ |
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14 /* this file you indicate that you have read the license and */ |
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15 /* understand and accept it fully. */ |
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16 /* */ |
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17 /***************************************************************************/ |
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18 |
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19 |
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20 #include <ft2build.h> |
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21 #include "ftcmanag.h" |
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22 #include FT_INTERNAL_OBJECTS_H |
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23 #include FT_INTERNAL_DEBUG_H |
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24 |
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25 #include "ftccback.h" |
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26 #include "ftcerror.h" |
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27 |
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28 #undef FT_COMPONENT |
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29 #define FT_COMPONENT trace_cache |
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30 |
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31 |
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32 #define FTC_HASH_MAX_LOAD 2 |
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33 #define FTC_HASH_MIN_LOAD 1 |
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34 #define FTC_HASH_SUB_LOAD ( FTC_HASH_MAX_LOAD - FTC_HASH_MIN_LOAD ) |
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35 |
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36 /* this one _must_ be a power of 2! */ |
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37 #define FTC_HASH_INITIAL_SIZE 8 |
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38 |
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39 |
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40 /*************************************************************************/ |
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41 /*************************************************************************/ |
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42 /***** *****/ |
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43 /***** CACHE NODE DEFINITIONS *****/ |
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44 /***** *****/ |
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45 /*************************************************************************/ |
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46 /*************************************************************************/ |
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47 |
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48 /* add a new node to the head of the manager's circular MRU list */ |
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49 static void |
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50 ftc_node_mru_link( FTC_Node node, |
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51 FTC_Manager manager ) |
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52 { |
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53 void *nl = &manager->nodes_list; |
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54 |
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55 |
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56 FTC_MruNode_Prepend( (FTC_MruNode*)nl, |
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57 (FTC_MruNode)node ); |
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58 manager->num_nodes++; |
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59 } |
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60 |
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61 |
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62 /* remove a node from the manager's MRU list */ |
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63 static void |
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64 ftc_node_mru_unlink( FTC_Node node, |
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65 FTC_Manager manager ) |
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66 { |
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67 void *nl = &manager->nodes_list; |
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68 |
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69 |
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70 FTC_MruNode_Remove( (FTC_MruNode*)nl, |
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71 (FTC_MruNode)node ); |
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72 manager->num_nodes--; |
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73 } |
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74 |
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75 |
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76 #ifndef FTC_INLINE |
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77 |
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78 /* move a node to the head of the manager's MRU list */ |
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79 static void |
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80 ftc_node_mru_up( FTC_Node node, |
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81 FTC_Manager manager ) |
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82 { |
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83 FTC_MruNode_Up( (FTC_MruNode*)&manager->nodes_list, |
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84 (FTC_MruNode)node ); |
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85 } |
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86 |
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87 |
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88 /* get a top bucket for specified hash from cache, |
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89 * body for FTC_NODE__TOP_FOR_HASH( cache, hash ) |
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90 */ |
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91 FT_LOCAL_DEF( FTC_Node* ) |
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92 ftc_get_top_node_for_hash( FTC_Cache cache, |
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93 FT_PtrDist hash ) |
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94 { |
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95 FTC_Node* pnode; |
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96 FT_UInt idx; |
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97 |
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98 |
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99 idx = (FT_UInt)( hash & cache->mask ); |
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100 if ( idx < cache->p ) |
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101 idx = (FT_UInt)( hash & ( 2 * cache->mask + 1 ) ); |
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102 pnode = cache->buckets + idx; |
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103 return pnode; |
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104 } |
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105 |
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106 #endif /* !FTC_INLINE */ |
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107 |
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108 |
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109 /* Note that this function cannot fail. If we cannot re-size the |
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110 * buckets array appropriately, we simply degrade the hash table's |
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111 * performance! |
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112 */ |
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113 static void |
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114 ftc_cache_resize( FTC_Cache cache ) |
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115 { |
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116 for (;;) |
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117 { |
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118 FTC_Node node, *pnode; |
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119 FT_UFast p = cache->p; |
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120 FT_UFast mask = cache->mask; |
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121 FT_UFast count = mask + p + 1; /* number of buckets */ |
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122 |
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123 |
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124 /* do we need to shrink the buckets array? */ |
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125 if ( cache->slack < 0 ) |
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126 { |
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127 FTC_Node new_list = NULL; |
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128 |
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129 |
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130 /* try to expand the buckets array _before_ splitting |
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131 * the bucket lists |
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132 */ |
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133 if ( p >= mask ) |
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134 { |
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135 FT_Memory memory = cache->memory; |
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136 FT_Error error; |
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137 |
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138 |
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139 /* if we can't expand the array, leave immediately */ |
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140 if ( FT_RENEW_ARRAY( cache->buckets, |
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141 ( mask + 1 ) * 2, ( mask + 1 ) * 4 ) ) |
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142 break; |
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143 } |
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144 |
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145 /* split a single bucket */ |
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146 pnode = cache->buckets + p; |
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147 |
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148 for (;;) |
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149 { |
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150 node = *pnode; |
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151 if ( node == NULL ) |
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152 break; |
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153 |
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154 if ( node->hash & ( mask + 1 ) ) |
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155 { |
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156 *pnode = node->link; |
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157 node->link = new_list; |
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158 new_list = node; |
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159 } |
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160 else |
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161 pnode = &node->link; |
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162 } |
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163 |
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164 cache->buckets[p + mask + 1] = new_list; |
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165 |
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166 cache->slack += FTC_HASH_MAX_LOAD; |
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167 |
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168 if ( p >= mask ) |
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169 { |
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170 cache->mask = 2 * mask + 1; |
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171 cache->p = 0; |
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172 } |
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173 else |
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174 cache->p = p + 1; |
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175 } |
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176 |
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177 /* do we need to expand the buckets array? */ |
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178 else if ( cache->slack > (FT_Long)count * FTC_HASH_SUB_LOAD ) |
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179 { |
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180 FT_UFast old_index = p + mask; |
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181 FTC_Node* pold; |
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182 |
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183 |
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184 if ( old_index + 1 <= FTC_HASH_INITIAL_SIZE ) |
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185 break; |
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186 |
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187 if ( p == 0 ) |
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188 { |
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189 FT_Memory memory = cache->memory; |
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190 FT_Error error; |
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191 |
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192 |
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193 /* if we can't shrink the array, leave immediately */ |
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194 if ( FT_RENEW_ARRAY( cache->buckets, |
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195 ( mask + 1 ) * 2, mask + 1 ) ) |
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196 break; |
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197 |
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198 cache->mask >>= 1; |
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199 p = cache->mask; |
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200 } |
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201 else |
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202 p--; |
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203 |
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204 pnode = cache->buckets + p; |
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205 while ( *pnode ) |
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206 pnode = &(*pnode)->link; |
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207 |
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208 pold = cache->buckets + old_index; |
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209 *pnode = *pold; |
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210 *pold = NULL; |
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211 |
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212 cache->slack -= FTC_HASH_MAX_LOAD; |
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213 cache->p = p; |
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214 } |
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215 |
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216 /* otherwise, the hash table is balanced */ |
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217 else |
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218 break; |
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219 } |
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220 } |
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221 |
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222 |
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223 /* remove a node from its cache's hash table */ |
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224 static void |
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225 ftc_node_hash_unlink( FTC_Node node0, |
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226 FTC_Cache cache ) |
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227 { |
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228 FTC_Node *pnode = FTC_NODE__TOP_FOR_HASH( cache, node0->hash ); |
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229 |
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230 |
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231 for (;;) |
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232 { |
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233 FTC_Node node = *pnode; |
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234 |
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235 |
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236 if ( node == NULL ) |
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237 { |
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238 FT_TRACE0(( "ftc_node_hash_unlink: unknown node\n" )); |
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239 return; |
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240 } |
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241 |
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242 if ( node == node0 ) |
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243 break; |
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244 |
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245 pnode = &(*pnode)->link; |
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246 } |
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247 |
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248 *pnode = node0->link; |
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249 node0->link = NULL; |
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250 |
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251 cache->slack++; |
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252 ftc_cache_resize( cache ); |
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253 } |
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254 |
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255 |
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256 /* add a node to the `top' of its cache's hash table */ |
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257 static void |
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258 ftc_node_hash_link( FTC_Node node, |
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259 FTC_Cache cache ) |
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260 { |
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261 FTC_Node *pnode = FTC_NODE__TOP_FOR_HASH( cache, node->hash ); |
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262 |
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263 |
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264 node->link = *pnode; |
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265 *pnode = node; |
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266 |
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267 cache->slack--; |
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268 ftc_cache_resize( cache ); |
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269 } |
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270 |
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271 |
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272 /* remove a node from the cache manager */ |
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273 #ifdef FT_CONFIG_OPTION_OLD_INTERNALS |
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274 FT_BASE_DEF( void ) |
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275 #else |
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276 FT_LOCAL_DEF( void ) |
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277 #endif |
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278 ftc_node_destroy( FTC_Node node, |
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279 FTC_Manager manager ) |
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280 { |
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281 FTC_Cache cache; |
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282 |
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283 |
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284 #ifdef FT_DEBUG_ERROR |
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285 /* find node's cache */ |
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286 if ( node->cache_index >= manager->num_caches ) |
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287 { |
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288 FT_TRACE0(( "ftc_node_destroy: invalid node handle\n" )); |
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289 return; |
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290 } |
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291 #endif |
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292 |
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293 cache = manager->caches[node->cache_index]; |
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294 |
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295 #ifdef FT_DEBUG_ERROR |
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296 if ( cache == NULL ) |
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297 { |
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298 FT_TRACE0(( "ftc_node_destroy: invalid node handle\n" )); |
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299 return; |
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300 } |
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301 #endif |
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302 |
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303 manager->cur_weight -= cache->clazz.node_weight( node, cache ); |
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304 |
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305 /* remove node from mru list */ |
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306 ftc_node_mru_unlink( node, manager ); |
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307 |
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308 /* remove node from cache's hash table */ |
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309 ftc_node_hash_unlink( node, cache ); |
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310 |
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311 /* now finalize it */ |
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312 cache->clazz.node_free( node, cache ); |
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313 |
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314 #if 0 |
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315 /* check, just in case of general corruption :-) */ |
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316 if ( manager->num_nodes == 0 ) |
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317 FT_TRACE0(( "ftc_node_destroy: invalid cache node count (%d)\n", |
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318 manager->num_nodes )); |
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319 #endif |
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320 } |
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321 |
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322 |
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323 /*************************************************************************/ |
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324 /*************************************************************************/ |
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325 /***** *****/ |
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326 /***** ABSTRACT CACHE CLASS *****/ |
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327 /***** *****/ |
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328 /*************************************************************************/ |
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329 /*************************************************************************/ |
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330 |
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331 |
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332 FT_LOCAL_DEF( FT_Error ) |
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333 FTC_Cache_Init( FTC_Cache cache ) |
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334 { |
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335 return ftc_cache_init( cache ); |
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336 } |
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337 |
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338 |
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339 FT_LOCAL_DEF( FT_Error ) |
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340 ftc_cache_init( FTC_Cache cache ) |
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341 { |
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342 FT_Memory memory = cache->memory; |
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343 FT_Error error; |
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344 |
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345 |
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346 cache->p = 0; |
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347 cache->mask = FTC_HASH_INITIAL_SIZE - 1; |
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348 cache->slack = FTC_HASH_INITIAL_SIZE * FTC_HASH_MAX_LOAD; |
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349 |
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350 (void)FT_NEW_ARRAY( cache->buckets, FTC_HASH_INITIAL_SIZE * 2 ); |
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351 return error; |
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352 } |
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353 |
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354 |
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355 static void |
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356 FTC_Cache_Clear( FTC_Cache cache ) |
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357 { |
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358 if ( cache && cache->buckets ) |
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359 { |
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360 FTC_Manager manager = cache->manager; |
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361 FT_UFast i; |
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362 FT_UFast count; |
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363 |
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364 |
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365 count = cache->p + cache->mask + 1; |
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366 |
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367 for ( i = 0; i < count; i++ ) |
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368 { |
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369 FTC_Node *pnode = cache->buckets + i, next, node = *pnode; |
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370 |
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371 |
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372 while ( node ) |
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373 { |
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374 next = node->link; |
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375 node->link = NULL; |
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376 |
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377 /* remove node from mru list */ |
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378 ftc_node_mru_unlink( node, manager ); |
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379 |
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380 /* now finalize it */ |
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381 manager->cur_weight -= cache->clazz.node_weight( node, cache ); |
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382 |
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383 cache->clazz.node_free( node, cache ); |
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384 node = next; |
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385 } |
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386 cache->buckets[i] = NULL; |
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387 } |
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388 ftc_cache_resize( cache ); |
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389 } |
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390 } |
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391 |
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392 |
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393 FT_LOCAL_DEF( void ) |
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394 ftc_cache_done( FTC_Cache cache ) |
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395 { |
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396 if ( cache->memory ) |
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397 { |
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398 FT_Memory memory = cache->memory; |
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399 |
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400 |
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401 FTC_Cache_Clear( cache ); |
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402 |
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403 FT_FREE( cache->buckets ); |
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404 cache->mask = 0; |
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405 cache->p = 0; |
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406 cache->slack = 0; |
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407 |
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408 cache->memory = NULL; |
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409 } |
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410 } |
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411 |
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412 |
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413 FT_LOCAL_DEF( void ) |
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414 FTC_Cache_Done( FTC_Cache cache ) |
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415 { |
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416 ftc_cache_done( cache ); |
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417 } |
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418 |
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419 |
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420 static void |
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421 ftc_cache_add( FTC_Cache cache, |
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422 FT_PtrDist hash, |
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423 FTC_Node node ) |
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424 { |
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425 node->hash = hash; |
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426 node->cache_index = (FT_UInt16)cache->index; |
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427 node->ref_count = 0; |
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428 |
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429 ftc_node_hash_link( node, cache ); |
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430 ftc_node_mru_link( node, cache->manager ); |
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431 |
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432 { |
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433 FTC_Manager manager = cache->manager; |
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434 |
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435 |
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436 manager->cur_weight += cache->clazz.node_weight( node, cache ); |
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437 |
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438 if ( manager->cur_weight >= manager->max_weight ) |
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439 { |
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440 node->ref_count++; |
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441 FTC_Manager_Compress( manager ); |
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442 node->ref_count--; |
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443 } |
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444 } |
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445 } |
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446 |
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447 |
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448 FT_LOCAL_DEF( FT_Error ) |
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449 FTC_Cache_NewNode( FTC_Cache cache, |
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450 FT_PtrDist hash, |
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451 FT_Pointer query, |
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452 FTC_Node *anode ) |
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453 { |
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454 FT_Error error; |
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455 FTC_Node node; |
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456 |
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457 |
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458 /* |
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459 * We use the FTC_CACHE_TRYLOOP macros to support out-of-memory |
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460 * errors (OOM) correctly, i.e., by flushing the cache progressively |
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461 * in order to make more room. |
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462 */ |
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463 |
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464 FTC_CACHE_TRYLOOP( cache ) |
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465 { |
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466 error = cache->clazz.node_new( &node, query, cache ); |
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467 } |
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468 FTC_CACHE_TRYLOOP_END( NULL ); |
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469 |
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470 if ( error ) |
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471 node = NULL; |
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472 else |
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473 { |
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474 /* don't assume that the cache has the same number of buckets, since |
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475 * our allocation request might have triggered global cache flushing |
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476 */ |
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477 ftc_cache_add( cache, hash, node ); |
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478 } |
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479 |
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480 *anode = node; |
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481 return error; |
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482 } |
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483 |
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484 |
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485 #ifndef FTC_INLINE |
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486 |
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487 FT_LOCAL_DEF( FT_Error ) |
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488 FTC_Cache_Lookup( FTC_Cache cache, |
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489 FT_PtrDist hash, |
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490 FT_Pointer query, |
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491 FTC_Node *anode ) |
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492 { |
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493 FTC_Node* bucket; |
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494 FTC_Node* pnode; |
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495 FTC_Node node; |
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496 FT_Error error = FTC_Err_Ok; |
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497 FT_Bool list_changed = FALSE; |
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498 |
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499 FTC_Node_CompareFunc compare = cache->clazz.node_compare; |
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500 |
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501 |
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502 if ( cache == NULL || anode == NULL ) |
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503 return FTC_Err_Invalid_Argument; |
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504 |
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505 /* Go to the `top' node of the list sharing same masked hash */ |
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506 bucket = pnode = FTC_NODE__TOP_FOR_HASH( cache, hash ); |
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507 |
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508 /* Lookup a node with exactly same hash and queried properties. */ |
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509 /* NOTE: _nodcomp() may change the linked list to reduce memory. */ |
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510 for (;;) |
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511 { |
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512 node = *pnode; |
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513 if ( node == NULL ) |
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514 goto NewNode; |
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515 |
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516 if ( node->hash == hash && |
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517 compare( node, query, cache, &list_changed ) ) |
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518 break; |
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519 |
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520 pnode = &node->link; |
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521 } |
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522 |
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523 if ( list_changed ) |
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524 { |
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525 /* Update bucket by modified linked list */ |
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526 bucket = pnode = FTC_NODE__TOP_FOR_HASH( cache, hash ); |
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527 |
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528 /* Update pnode by modified linked list */ |
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529 while ( *pnode != node ) |
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530 { |
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531 if ( *pnode == NULL ) |
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532 { |
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533 FT_ERROR(( "FTC_Cache_Lookup: oops!!! node missing\n" )); |
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534 goto NewNode; |
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535 } |
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536 else |
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537 pnode = &((*pnode)->link); |
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538 } |
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539 } |
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540 |
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541 /* Reorder the list to move the found node to the `top' */ |
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542 if ( node != *bucket ) |
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543 { |
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544 *pnode = node->link; |
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545 node->link = *bucket; |
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546 *bucket = node; |
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547 } |
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548 |
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549 /* move to head of MRU list */ |
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550 { |
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551 FTC_Manager manager = cache->manager; |
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552 |
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553 |
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554 if ( node != manager->nodes_list ) |
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555 ftc_node_mru_up( node, manager ); |
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556 } |
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557 *anode = node; |
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558 |
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559 return error; |
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560 |
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561 NewNode: |
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562 return FTC_Cache_NewNode( cache, hash, query, anode ); |
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563 } |
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564 |
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565 #endif /* !FTC_INLINE */ |
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566 |
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567 |
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568 FT_LOCAL_DEF( void ) |
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569 FTC_Cache_RemoveFaceID( FTC_Cache cache, |
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570 FTC_FaceID face_id ) |
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571 { |
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572 FT_UFast i, count; |
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573 FTC_Manager manager = cache->manager; |
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574 FTC_Node frees = NULL; |
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575 |
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576 |
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577 count = cache->p + cache->mask + 1; |
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578 for ( i = 0; i < count; i++ ) |
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579 { |
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580 FTC_Node* bucket = cache->buckets + i; |
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581 FTC_Node* pnode = bucket; |
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582 |
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583 |
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584 for ( ;; ) |
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585 { |
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586 FTC_Node node = *pnode; |
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587 FT_Bool list_changed = FALSE; |
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588 |
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589 |
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590 if ( node == NULL ) |
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591 break; |
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592 |
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593 if ( cache->clazz.node_remove_faceid( node, face_id, |
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594 cache, &list_changed ) ) |
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595 { |
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596 *pnode = node->link; |
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597 node->link = frees; |
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598 frees = node; |
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599 } |
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600 else |
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601 pnode = &node->link; |
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602 } |
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603 } |
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604 |
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605 /* remove all nodes in the free list */ |
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606 while ( frees ) |
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607 { |
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608 FTC_Node node; |
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609 |
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610 |
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611 node = frees; |
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612 frees = node->link; |
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613 |
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614 manager->cur_weight -= cache->clazz.node_weight( node, cache ); |
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615 ftc_node_mru_unlink( node, manager ); |
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616 |
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617 cache->clazz.node_free( node, cache ); |
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618 |
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619 cache->slack++; |
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620 } |
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621 |
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622 ftc_cache_resize( cache ); |
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623 } |
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624 |
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625 |
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626 /* END */ |
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