ref: cc712a248c2075b126429d677357bb3a732759a1
dir: /src/cache/ftccache.h/
/***************************************************************************/
/* */
/* ftccache.h */
/* */
/* FreeType internal cache interface (specification). */
/* */
/* Copyright 2000-2001, 2002, 2003, 2004, 2005, 2006 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; \
\
\
if ( _node != _manager->nodes_list ) \
FTC_MruNode_Up( (FTC_MruNode*)&_manager->nodes_list, \
(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 */