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+/***************************************************************************/
+/* */
+/* ftccache.h */
+/* */
+/* FreeType internal cache interface (specification). */
+/* */
+/* Copyright 2000-2001, 2002, 2003, 2004, 2005, 2006, 2007 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
+
+ /* 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_UInt32 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 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_ULong
+ (*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 );
+
+
+ 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_UInt 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 lookup 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_UInt32 hash,
+ FT_Pointer query,
+ FTC_Node *anode );
+#endif
+
+ FT_LOCAL( FT_Error )
+ FTC_Cache_NewNode( FTC_Cache cache,
+ FT_UInt32 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_UInt32 _hash = (FT_UInt32)(hash); \
+ FTC_Node_CompareFunc _nodcomp = (FTC_Node_CompareFunc)(nodecmp); \
+ FT_UInt _idx; \
+ \
+ \
+ error = 0; \
+ node = NULL; \
+ _idx = _hash & _cache->mask; \
+ if ( _idx < _cache->p ) \
+ _idx = _hash & ( _cache->mask*2 + 1 ); \
+ \
+ _bucket = _pnode = _cache->buckets + _idx; \
+ for (;;) \
+ { \
+ _node = *_pnode; \
+ if ( _node == NULL ) \
+ goto _NewNode; \
+ \
+ if ( _node->hash == _hash && _nodcomp( _node, query, _cache ) ) \
+ break; \
+ \
+ _pnode = &_node->link; \
+ } \
+ \
+ if ( _node != *_bucket ) \
+ { \
+ *_pnode = _node->link; \
+ _node->link = *_bucket; \
+ *_bucket = _node; \
+ } \
+ \
+ { \
+ 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: \
+ _pnode = (FTC_Node*)(void*)&(node); \
+ *_pnode = _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() \
+ if ( !error || error != FT_Err_Out_Of_Memory ) \
+ break; \
+ \
+ _try_done = FTC_Manager_FlushN( _try_manager, _try_count ); \
+ 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 */
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