misc/libfreetype/src/cache/ftccache.h
changeset 5172 88f2e05288ba
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/misc/libfreetype/src/cache/ftccache.h	Mon Apr 25 01:46:54 2011 +0200
@@ -0,0 +1,359 @@
+/***************************************************************************/
+/*                                                                         */
+/*  ftccache.h                                                             */
+/*                                                                         */
+/*    FreeType internal cache interface (specification).                   */
+/*                                                                         */
+/*  Copyright 2000-2001, 2002, 2003, 2004, 2005, 2006, 2007, 2009, 2010,   */
+/*            2011 by                                                      */
+/*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
+/*                                                                         */
+/*  This file is part of the FreeType project, and may only be used,       */
+/*  modified, and distributed under the terms of the FreeType project      */
+/*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
+/*  this file you indicate that you have read the license and              */
+/*  understand and accept it fully.                                        */
+/*                                                                         */
+/***************************************************************************/
+
+
+#ifndef __FTCCACHE_H__
+#define __FTCCACHE_H__
+
+
+#include "ftcmru.h"
+
+FT_BEGIN_HEADER
+
+#define _FTC_FACE_ID_HASH( i )                                                \
+          ((FT_PtrDist)(( (FT_PtrDist)(i) >> 3 ) ^ ( (FT_PtrDist)(i) << 7 )))
+
+  /* handle to cache object */
+  typedef struct FTC_CacheRec_*  FTC_Cache;
+
+  /* handle to cache class */
+  typedef const struct FTC_CacheClassRec_*  FTC_CacheClass;
+
+
+  /*************************************************************************/
+  /*************************************************************************/
+  /*****                                                               *****/
+  /*****                   CACHE NODE DEFINITIONS                      *****/
+  /*****                                                               *****/
+  /*************************************************************************/
+  /*************************************************************************/
+
+  /*************************************************************************/
+  /*                                                                       */
+  /* Each cache controls one or more cache nodes.  Each node is part of    */
+  /* the global_lru list of the manager.  Its `data' field however is used */
+  /* as a reference count for now.                                         */
+  /*                                                                       */
+  /* A node can be anything, depending on the type of information held by  */
+  /* the cache.  It can be an individual glyph image, a set of bitmaps     */
+  /* glyphs for a given size, some metrics, etc.                           */
+  /*                                                                       */
+  /*************************************************************************/
+
+  /* structure size should be 20 bytes on 32-bits machines */
+  typedef struct  FTC_NodeRec_
+  {
+    FTC_MruNodeRec  mru;          /* circular mru list pointer           */
+    FTC_Node        link;         /* used for hashing                    */
+    FT_PtrDist      hash;         /* used for hashing too                */
+    FT_UShort       cache_index;  /* index of cache the node belongs to  */
+    FT_Short        ref_count;    /* reference count for this node       */
+
+  } FTC_NodeRec;
+
+
+#define FTC_NODE( x )    ( (FTC_Node)(x) )
+#define FTC_NODE_P( x )  ( (FTC_Node*)(x) )
+
+#define FTC_NODE__NEXT( x )  FTC_NODE( (x)->mru.next )
+#define FTC_NODE__PREV( x )  FTC_NODE( (x)->mru.prev )
+
+#ifdef FTC_INLINE
+#define FTC_NODE__TOP_FOR_HASH( cache, hash )                     \
+        ( ( cache )->buckets +                                    \
+            ( ( ( ( hash ) &   ( cache )->mask ) < ( cache )->p ) \
+              ? ( ( hash ) & ( ( cache )->mask * 2 + 1 ) )        \
+              : ( ( hash ) &   ( cache )->mask ) ) )
+#else
+  FT_LOCAL( FTC_Node* )
+  ftc_get_top_node_for_hash( FTC_Cache   cache,
+                             FT_PtrDist  hash );
+#define FTC_NODE__TOP_FOR_HASH( cache, hash )            \
+        ftc_get_top_node_for_hash( ( cache ), ( hash ) )
+#endif
+
+#ifdef FT_CONFIG_OPTION_OLD_INTERNALS
+  FT_BASE( void )
+  ftc_node_destroy( FTC_Node     node,
+                    FTC_Manager  manager );
+#endif
+
+
+  /*************************************************************************/
+  /*************************************************************************/
+  /*****                                                               *****/
+  /*****                       CACHE DEFINITIONS                       *****/
+  /*****                                                               *****/
+  /*************************************************************************/
+  /*************************************************************************/
+
+  /* initialize a new cache node */
+  typedef FT_Error
+  (*FTC_Node_NewFunc)( FTC_Node    *pnode,
+                       FT_Pointer   query,
+                       FTC_Cache    cache );
+
+  typedef FT_Offset
+  (*FTC_Node_WeightFunc)( FTC_Node   node,
+                          FTC_Cache  cache );
+
+  /* compare a node to a given key pair */
+  typedef FT_Bool
+  (*FTC_Node_CompareFunc)( FTC_Node    node,
+                           FT_Pointer  key,
+                           FTC_Cache   cache,
+                           FT_Bool*    list_changed );
+
+
+  typedef void
+  (*FTC_Node_FreeFunc)( FTC_Node   node,
+                        FTC_Cache  cache );
+
+  typedef FT_Error
+  (*FTC_Cache_InitFunc)( FTC_Cache  cache );
+
+  typedef void
+  (*FTC_Cache_DoneFunc)( FTC_Cache  cache );
+
+
+  typedef struct  FTC_CacheClassRec_
+  {
+    FTC_Node_NewFunc      node_new;
+    FTC_Node_WeightFunc   node_weight;
+    FTC_Node_CompareFunc  node_compare;
+    FTC_Node_CompareFunc  node_remove_faceid;
+    FTC_Node_FreeFunc     node_free;
+
+    FT_Offset             cache_size;
+    FTC_Cache_InitFunc    cache_init;
+    FTC_Cache_DoneFunc    cache_done;
+
+  } FTC_CacheClassRec;
+
+
+  /* each cache really implements a dynamic hash table to manage its nodes */
+  typedef struct  FTC_CacheRec_
+  {
+    FT_UFast           p;
+    FT_UFast           mask;
+    FT_Long            slack;
+    FTC_Node*          buckets;
+
+    FTC_CacheClassRec  clazz;       /* local copy, for speed  */
+
+    FTC_Manager        manager;
+    FT_Memory          memory;
+    FT_UInt            index;       /* in manager's table     */
+
+    FTC_CacheClass     org_class;   /* original class pointer */
+
+  } FTC_CacheRec;
+
+
+#define FTC_CACHE( x )    ( (FTC_Cache)(x) )
+#define FTC_CACHE_P( x )  ( (FTC_Cache*)(x) )
+
+
+  /* default cache initialize */
+  FT_LOCAL( FT_Error )
+  FTC_Cache_Init( FTC_Cache  cache );
+
+  /* default cache finalizer */
+  FT_LOCAL( void )
+  FTC_Cache_Done( FTC_Cache  cache );
+
+  /* Call this function to look up the cache.  If no corresponding
+   * node is found, a new one is automatically created.  This function
+   * is capable of flushing the cache adequately to make room for the
+   * new cache object.
+   */
+
+#ifndef FTC_INLINE
+  FT_LOCAL( FT_Error )
+  FTC_Cache_Lookup( FTC_Cache   cache,
+                    FT_PtrDist  hash,
+                    FT_Pointer  query,
+                    FTC_Node   *anode );
+#endif
+
+  FT_LOCAL( FT_Error )
+  FTC_Cache_NewNode( FTC_Cache   cache,
+                     FT_PtrDist  hash,
+                     FT_Pointer  query,
+                     FTC_Node   *anode );
+
+  /* Remove all nodes that relate to a given face_id.  This is useful
+   * when un-installing fonts.  Note that if a cache node relates to
+   * the face_id but is locked (i.e., has `ref_count > 0'), the node
+   * will _not_ be destroyed, but its internal face_id reference will
+   * be modified.
+   *
+   * The final result will be that the node will never come back
+   * in further lookup requests, and will be flushed on demand from
+   * the cache normally when its reference count reaches 0.
+   */
+  FT_LOCAL( void )
+  FTC_Cache_RemoveFaceID( FTC_Cache   cache,
+                          FTC_FaceID  face_id );
+
+
+#ifdef FTC_INLINE
+
+#define FTC_CACHE_LOOKUP_CMP( cache, nodecmp, hash, query, node, error ) \
+  FT_BEGIN_STMNT                                                         \
+    FTC_Node             *_bucket, *_pnode, _node;                       \
+    FTC_Cache             _cache   = FTC_CACHE(cache);                   \
+    FT_PtrDist            _hash    = (FT_PtrDist)(hash);                 \
+    FTC_Node_CompareFunc  _nodcomp = (FTC_Node_CompareFunc)(nodecmp);    \
+    FT_Bool               _list_changed = FALSE;                         \
+                                                                         \
+                                                                         \
+    error = FTC_Err_Ok;                                                  \
+    node  = NULL;                                                        \
+                                                                         \
+    /* Go to the `top' node of the list sharing same masked hash */      \
+    _bucket = _pnode = FTC_NODE__TOP_FOR_HASH( _cache, _hash );          \
+                                                                         \
+    /* Look up a node with identical hash and queried properties.    */  \
+    /* NOTE: _nodcomp() may change the linked list to reduce memory. */  \
+    for (;;)                                                             \
+    {                                                                    \
+      _node = *_pnode;                                                   \
+      if ( _node == NULL )                                               \
+        goto _NewNode;                                                   \
+                                                                         \
+      if ( _node->hash == _hash                             &&           \
+           _nodcomp( _node, query, _cache, &_list_changed ) )            \
+        break;                                                           \
+                                                                         \
+      _pnode = &_node->link;                                             \
+    }                                                                    \
+                                                                         \
+    if ( _list_changed )                                                 \
+    {                                                                    \
+      /* Update _bucket by possibly modified linked list */              \
+      _bucket = _pnode = FTC_NODE__TOP_FOR_HASH( _cache, _hash );        \
+                                                                         \
+      /* Update _pnode by possibly modified linked list */               \
+      while ( *_pnode != _node )                                         \
+      {                                                                  \
+        if ( *_pnode == NULL )                                           \
+        {                                                                \
+          FT_ERROR(( "FTC_CACHE_LOOKUP_CMP: oops!!! node missing\n" ));  \
+          goto _NewNode;                                                 \
+        }                                                                \
+        else                                                             \
+          _pnode = &((*_pnode)->link);                                   \
+      }                                                                  \
+    }                                                                    \
+                                                                         \
+    /* Reorder the list to move the found node to the `top' */           \
+    if ( _node != *_bucket )                                             \
+    {                                                                    \
+      *_pnode     = _node->link;                                         \
+      _node->link = *_bucket;                                            \
+      *_bucket    = _node;                                               \
+    }                                                                    \
+                                                                         \
+    /* Update MRU list */                                                \
+    {                                                                    \
+      FTC_Manager  _manager = _cache->manager;                           \
+      void*        _nl      = &_manager->nodes_list;                     \
+                                                                         \
+                                                                         \
+      if ( _node != _manager->nodes_list )                               \
+        FTC_MruNode_Up( (FTC_MruNode*)_nl,                               \
+                        (FTC_MruNode)_node );                            \
+    }                                                                    \
+    goto _Ok;                                                            \
+                                                                         \
+  _NewNode:                                                              \
+    error = FTC_Cache_NewNode( _cache, _hash, query, &_node );           \
+                                                                         \
+  _Ok:                                                                   \
+    node = _node;                                                        \
+  FT_END_STMNT
+
+#else /* !FTC_INLINE */
+
+#define FTC_CACHE_LOOKUP_CMP( cache, nodecmp, hash, query, node, error ) \
+  FT_BEGIN_STMNT                                                         \
+    error = FTC_Cache_Lookup( FTC_CACHE( cache ), hash, query,           \
+                              (FTC_Node*)&(node) );                      \
+  FT_END_STMNT
+
+#endif /* !FTC_INLINE */
+
+
+  /*
+   * This macro, together with FTC_CACHE_TRYLOOP_END, defines a retry
+   * loop to flush the cache repeatedly in case of memory overflows.
+   *
+   * It is used when creating a new cache node, or within a lookup
+   * that needs to allocate data (e.g. the sbit cache lookup).
+   *
+   * Example:
+   *
+   *   {
+   *     FTC_CACHE_TRYLOOP( cache )
+   *       error = load_data( ... );
+   *     FTC_CACHE_TRYLOOP_END()
+   *   }
+   *
+   */
+#define FTC_CACHE_TRYLOOP( cache )                           \
+  {                                                          \
+    FTC_Manager  _try_manager = FTC_CACHE( cache )->manager; \
+    FT_UInt      _try_count   = 4;                           \
+                                                             \
+                                                             \
+    for (;;)                                                 \
+    {                                                        \
+      FT_UInt  _try_done;
+
+
+#define FTC_CACHE_TRYLOOP_END( list_changed )                     \
+      if ( !error || error != FTC_Err_Out_Of_Memory )             \
+        break;                                                    \
+                                                                  \
+      _try_done = FTC_Manager_FlushN( _try_manager, _try_count ); \
+      if ( _try_done > 0 && ( list_changed ) )                    \
+        *(FT_Bool*)( list_changed ) = TRUE;                       \
+                                                                  \
+      if ( _try_done == 0 )                                       \
+        break;                                                    \
+                                                                  \
+      if ( _try_done == _try_count )                              \
+      {                                                           \
+        _try_count *= 2;                                          \
+        if ( _try_count < _try_done              ||               \
+            _try_count > _try_manager->num_nodes )                \
+          _try_count = _try_manager->num_nodes;                   \
+      }                                                           \
+    }                                                             \
+  }
+
+ /* */
+
+FT_END_HEADER
+
+
+#endif /* __FTCCACHE_H__ */
+
+
+/* END */