git.sesse.net Git - casparcg/blob - SFML-1.6/extlibs/headers/freetype/cache/ftccache.h

   1 /***************************************************************************/
   2 /*                                                                         */
   3 /*  ftccache.h                                                             */
   4 /*                                                                         */
   5 /*    FreeType internal cache interface (specification).                   */
   6 /*                                                                         */
   7 /*  Copyright 2000-2001, 2002, 2003, 2004, 2005 by                         */
   8 /*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
   9 /*                                                                         */
  10 /*  This file is part of the FreeType project, and may only be used,       */
  11 /*  modified, and distributed under the terms of the FreeType project      */
  12 /*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
  13 /*  this file you indicate that you have read the license and              */
  14 /*  understand and accept it fully.                                        */
  15 /*                                                                         */
  16 /***************************************************************************/
  17
  18
  19 #ifndef __FTCCACHE_H__
  20 #define __FTCCACHE_H__
  21
  22
  23 #include FT_CACHE_INTERNAL_MRU_H
  24
  25 FT_BEGIN_HEADER
  26
  27   /* handle to cache object */
  28   typedef struct FTC_CacheRec_*  FTC_Cache;
  29
  30   /* handle to cache class */
  31   typedef const struct FTC_CacheClassRec_*  FTC_CacheClass;
  32
  33
  34   /*************************************************************************/
  35   /*************************************************************************/
  36   /*****                                                               *****/
  37   /*****                   CACHE NODE DEFINITIONS                      *****/
  38   /*****                                                               *****/
  39   /*************************************************************************/
  40   /*************************************************************************/
  41
  42   /*************************************************************************/
  43   /*                                                                       */
  44   /* Each cache controls one or more cache nodes.  Each node is part of    */
  45   /* the global_lru list of the manager.  Its `data' field however is used */
  46   /* as a reference count for now.                                         */
  47   /*                                                                       */
  48   /* A node can be anything, depending on the type of information held by  */
  49   /* the cache.  It can be an individual glyph image, a set of bitmaps     */
  50   /* glyphs for a given size, some metrics, etc.                           */
  51   /*                                                                       */
  52   /*************************************************************************/
  53
  54   /* structure size should be 20 bytes on 32-bits machines */
  55   typedef struct  FTC_NodeRec_
  56   {
  57     FTC_MruNodeRec  mru;          /* circular mru list pointer           */
  58     FTC_Node        link;         /* used for hashing                    */
  59     FT_UInt32       hash;         /* used for hashing too                */
  60     FT_UShort       cache_index;  /* index of cache the node belongs to  */
  61     FT_Short        ref_count;    /* reference count for this node       */
  62
  63   } FTC_NodeRec;
  64
  65
  66 #define FTC_NODE( x )    ( (FTC_Node)(x) )
  67 #define FTC_NODE_P( x )  ( (FTC_Node*)(x) )
  68
  69 #define FTC_NODE__NEXT(x)  FTC_NODE( (x)->mru.next )
  70 #define FTC_NODE__PREV(x)  FTC_NODE( (x)->mru.prev )
  71
  72
  73   /*************************************************************************/
  74   /*                                                                       */
  75   /* These functions are exported so that they can be called from          */
  76   /* user-provided cache classes; otherwise, they are really part of the   */
  77   /* cache sub-system internals.                                           */
  78   /*                                                                       */
  79
  80   /* reserved for manager's use */
  81   FT_EXPORT( void )
  82   ftc_node_destroy( FTC_Node     node,
  83                     FTC_Manager  manager );
  84
  85
  86   /*************************************************************************/
  87   /*************************************************************************/
  88   /*****                                                               *****/
  89   /*****                       CACHE DEFINITIONS                       *****/
  90   /*****                                                               *****/
  91   /*************************************************************************/
  92   /*************************************************************************/
  93
  94   /* initialize a new cache node */
  95   typedef FT_Error
  96   (*FTC_Node_NewFunc)( FTC_Node    *pnode,
  97                        FT_Pointer   query,
  98                        FTC_Cache    cache );
  99
 100   typedef FT_ULong
 101   (*FTC_Node_WeightFunc)( FTC_Node   node,
 102                           FTC_Cache  cache );
 103
 104   /* compare a node to a given key pair */
 105   typedef FT_Bool
 106   (*FTC_Node_CompareFunc)( FTC_Node    node,
 107                            FT_Pointer  key,
 108                            FTC_Cache   cache );
 109
 110
 111   typedef void
 112   (*FTC_Node_FreeFunc)( FTC_Node   node,
 113                         FTC_Cache  cache );
 114
 115   typedef FT_Error
 116   (*FTC_Cache_InitFunc)( FTC_Cache  cache );
 117
 118   typedef void
 119   (*FTC_Cache_DoneFunc)( FTC_Cache  cache );
 120
 121
 122   typedef struct  FTC_CacheClassRec_
 123   {
 124     FTC_Node_NewFunc      node_new;
 125     FTC_Node_WeightFunc   node_weight;
 126     FTC_Node_CompareFunc  node_compare;
 127     FTC_Node_CompareFunc  node_remove_faceid;
 128     FTC_Node_FreeFunc     node_free;
 129
 130     FT_UInt               cache_size;
 131     FTC_Cache_InitFunc    cache_init;
 132     FTC_Cache_DoneFunc    cache_done;
 133
 134   } FTC_CacheClassRec;
 135
 136
 137   /* each cache really implements a dynamic hash table to manage its nodes */
 138   typedef struct  FTC_CacheRec_
 139   {
 140     FT_UFast           p;
 141     FT_UFast           mask;
 142     FT_Long            slack;
 143     FTC_Node*          buckets;
 144
 145     FTC_CacheClassRec  clazz;       /* local copy, for speed  */
 146
 147     FTC_Manager        manager;
 148     FT_Memory          memory;
 149     FT_UInt            index;       /* in manager's table     */
 150
 151     FTC_CacheClass     org_class;   /* original class pointer */
 152
 153   } FTC_CacheRec;
 154
 155
 156 #define FTC_CACHE( x )    ( (FTC_Cache)(x) )
 157 #define FTC_CACHE_P( x )  ( (FTC_Cache*)(x) )
 158
 159
 160   /* default cache initialize */
 161   FT_EXPORT( FT_Error )
 162   FTC_Cache_Init( FTC_Cache  cache );
 163
 164   /* default cache finalizer */
 165   FT_EXPORT( void )
 166   FTC_Cache_Done( FTC_Cache  cache );
 167
 168   /* Call this function to lookup the cache.  If no corresponding
 169    * node is found, a new one is automatically created.  This function
 170    * is capable of flushing the cache adequately to make room for the
 171    * new cache object.
 172    */
 173   FT_EXPORT( FT_Error )
 174   FTC_Cache_Lookup( FTC_Cache   cache,
 175                     FT_UInt32   hash,
 176                     FT_Pointer  query,
 177                     FTC_Node   *anode );
 178
 179   FT_EXPORT( FT_Error )
 180   FTC_Cache_NewNode( FTC_Cache   cache,
 181                      FT_UInt32   hash,
 182                      FT_Pointer  query,
 183                      FTC_Node   *anode );
 184
 185   /* Remove all nodes that relate to a given face_id.  This is useful
 186    * when un-installing fonts.  Note that if a cache node relates to
 187    * the face_id, but is locked (i.e., has 'ref_count > 0'), the node
 188    * will _not_ be destroyed, but its internal face_id reference will
 189    * be modified.
 190    *
 191    * The final result will be that the node will never come back
 192    * in further lookup requests, and will be flushed on demand from
 193    * the cache normally when its reference count reaches 0.
 194    */
 195   FT_EXPORT( void )
 196   FTC_Cache_RemoveFaceID( FTC_Cache   cache,
 197                           FTC_FaceID  face_id );
 198
 199
 200 #ifdef FTC_INLINE
 201
 202 #define FTC_CACHE_LOOKUP_CMP( cache, nodecmp, hash, query, node, error ) \
 203   FT_BEGIN_STMNT                                                         \
 204     FTC_Node             *_bucket, *_pnode, _node;                       \
 205     FTC_Cache             _cache   = FTC_CACHE(cache);                   \
 206     FT_UInt32             _hash    = (FT_UInt32)(hash);                  \
 207     FTC_Node_CompareFunc  _nodcomp = (FTC_Node_CompareFunc)(nodecmp);    \
 208     FT_UInt               _idx;                                          \
 209                                                                          \
 210                                                                          \
 211     error = 0;                                                           \
 212     node  = NULL;                                                        \
 213     _idx  = _hash & _cache->mask;                                        \
 214     if ( _idx < _cache->p )                                              \
 215       _idx = _hash & ( _cache->mask*2 + 1 );                             \
 216                                                                          \
 217     _bucket = _pnode = _cache->buckets + _idx;                           \
 218     for (;;)                                                             \
 219     {                                                                    \
 220       _node = *_pnode;                                                   \
 221       if ( _node == NULL )                                               \
 222         goto _NewNode;                                                   \
 223                                                                          \
 224       if ( _node->hash == _hash && _nodcomp( _node, query, _cache ) )    \
 225         break;                                                           \
 226                                                                          \
 227       _pnode = &_node->link;                                             \
 228     }                                                                    \
 229                                                                          \
 230     if ( _node != *_bucket )                                             \
 231     {                                                                    \
 232       *_pnode     = _node->link;                                         \
 233       _node->link = *_bucket;                                            \
 234       *_bucket    = _node;                                               \
 235     }                                                                    \
 236                                                                          \
 237     {                                                                    \
 238       FTC_Manager  _manager = _cache->manager;                           \
 239                                                                          \
 240                                                                          \
 241       if ( _node != _manager->nodes_list )                               \
 242         FTC_MruNode_Up( (FTC_MruNode*)&_manager->nodes_list,             \
 243                         (FTC_MruNode)_node );                            \
 244     }                                                                    \
 245     goto _Ok;                                                            \
 246                                                                          \
 247   _NewNode:                                                              \
 248     error = FTC_Cache_NewNode( _cache, _hash, query, &_node );           \
 249                                                                          \
 250   _Ok:                                                                   \
 251     _pnode = (FTC_Node*)(void*)&(node);                                  \
 252     *_pnode = _node;                                                     \
 253   FT_END_STMNT
 254
 255 #else /* !FTC_INLINE */
 256
 257 #define FTC_CACHE_LOOKUP_CMP( cache, nodecmp, hash, query, node, error ) \
 258   FT_BEGIN_STMNT                                                         \
 259     error = FTC_Cache_Lookup( FTC_CACHE( cache ), hash, query,           \
 260                               (FTC_Node*)&(node) );                      \
 261   FT_END_STMNT
 262
 263 #endif /* !FTC_INLINE */
 264
 265
 266   /*
 267    * This macro, together with FTC_CACHE_TRYLOOP_END, defines a retry
 268    * loop to flush the cache repeatedly in case of memory overflows.
 269    *
 270    * It is used when creating a new cache node, or within a lookup
 271    * that needs to allocate data (e.g., the sbit cache lookup).
 272    *
 273    * Example:
 274    *
 275    *   {
 276    *     FTC_CACHE_TRYLOOP( cache )
 277    *       error = load_data( ... );
 278    *     FTC_CACHE_TRYLOOP_END()
 279    *   }
 280    *
 281    */
 282 #define FTC_CACHE_TRYLOOP( cache )                           \
 283   {                                                          \
 284     FTC_Manager  _try_manager = FTC_CACHE( cache )->manager; \
 285     FT_UInt      _try_count   = 4;                           \
 286                                                              \
 287                                                              \
 288     for (;;)                                                 \
 289     {                                                        \
 290       FT_UInt  _try_done;
 291
 292
 293 #define FTC_CACHE_TRYLOOP_END()                                   \
 294       if ( !error || error != FT_Err_Out_Of_Memory )              \
 295         break;                                                    \
 296                                                                   \
 297       _try_done = FTC_Manager_FlushN( _try_manager, _try_count ); \
 298       if ( _try_done == 0 )                                       \
 299         break;                                                    \
 300                                                                   \
 301       if ( _try_done == _try_count )                              \
 302       {                                                           \
 303         _try_count *= 2;                                          \
 304         if ( _try_count < _try_done              ||               \
 305             _try_count > _try_manager->num_nodes )                \
 306           _try_count = _try_manager->num_nodes;                   \
 307       }                                                           \
 308     }                                                             \
 309   }
 310
 311  /* */
 312
 313 FT_END_HEADER
 314
 315
 316 #endif /* __FTCCACHE_H__ */
 317
 318
 319 /* END */