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/***************************************************************************/ |
/* */ |
/* ftccache.h */ |
/* */ |
/* FreeType internal cache interface (specification). */ |
/* */ |
/* Copyright 2000-2007, 2009-2011, 2013 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. */ |
/* */ |
/***************************************************************************/ |
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#ifndef __FTCCACHE_H__ |
#define __FTCCACHE_H__ |
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#include "ftcmru.h" |
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FT_BEGIN_HEADER |
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#define _FTC_FACE_ID_HASH( i ) \ |
((FT_PtrDist)(( (FT_PtrDist)(i) >> 3 ) ^ ( (FT_PtrDist)(i) << 7 ))) |
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/* handle to cache object */ |
typedef struct FTC_CacheRec_* FTC_Cache; |
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/* handle to cache class */ |
typedef const struct FTC_CacheClassRec_* FTC_CacheClass; |
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/*************************************************************************/ |
/*************************************************************************/ |
/***** *****/ |
/***** CACHE NODE DEFINITIONS *****/ |
/***** *****/ |
/*************************************************************************/ |
/*************************************************************************/ |
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/*************************************************************************/ |
/* */ |
/* 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. */ |
/* */ |
/*************************************************************************/ |
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/* 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 */ |
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} FTC_NodeRec; |
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#define FTC_NODE( x ) ( (FTC_Node)(x) ) |
#define FTC_NODE_P( x ) ( (FTC_Node*)(x) ) |
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#define FTC_NODE__NEXT( x ) FTC_NODE( (x)->mru.next ) |
#define FTC_NODE__PREV( x ) FTC_NODE( (x)->mru.prev ) |
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#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 |
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/*************************************************************************/ |
/*************************************************************************/ |
/***** *****/ |
/***** CACHE DEFINITIONS *****/ |
/***** *****/ |
/*************************************************************************/ |
/*************************************************************************/ |
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/* initialize a new cache node */ |
typedef FT_Error |
(*FTC_Node_NewFunc)( FTC_Node *pnode, |
FT_Pointer query, |
FTC_Cache cache ); |
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typedef FT_Offset |
(*FTC_Node_WeightFunc)( FTC_Node node, |
FTC_Cache cache ); |
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/* 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 ); |
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typedef void |
(*FTC_Node_FreeFunc)( FTC_Node node, |
FTC_Cache cache ); |
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typedef FT_Error |
(*FTC_Cache_InitFunc)( FTC_Cache cache ); |
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typedef void |
(*FTC_Cache_DoneFunc)( FTC_Cache cache ); |
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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; |
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FT_Offset cache_size; |
FTC_Cache_InitFunc cache_init; |
FTC_Cache_DoneFunc cache_done; |
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} FTC_CacheClassRec; |
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/* 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; |
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FTC_CacheClassRec clazz; /* local copy, for speed */ |
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FTC_Manager manager; |
FT_Memory memory; |
FT_UInt index; /* in manager's table */ |
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FTC_CacheClass org_class; /* original class pointer */ |
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} FTC_CacheRec; |
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#define FTC_CACHE( x ) ( (FTC_Cache)(x) ) |
#define FTC_CACHE_P( x ) ( (FTC_Cache*)(x) ) |
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/* default cache initialize */ |
FT_LOCAL( FT_Error ) |
FTC_Cache_Init( FTC_Cache cache ); |
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/* default cache finalizer */ |
FT_LOCAL( void ) |
FTC_Cache_Done( FTC_Cache cache ); |
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/* 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. |
*/ |
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#ifndef FTC_INLINE |
FT_LOCAL( FT_Error ) |
FTC_Cache_Lookup( FTC_Cache cache, |
FT_PtrDist hash, |
FT_Pointer query, |
FTC_Node *anode ); |
#endif |
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FT_LOCAL( FT_Error ) |
FTC_Cache_NewNode( FTC_Cache cache, |
FT_PtrDist hash, |
FT_Pointer query, |
FTC_Node *anode ); |
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/* 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 ); |
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#ifdef FTC_INLINE |
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#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 = FT_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 |
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#else /* !FTC_INLINE */ |
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#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 |
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#endif /* !FTC_INLINE */ |
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/* |
* 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; |
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#define FTC_CACHE_TRYLOOP_END( list_changed ) \ |
if ( !error || FT_ERR_NEQ( error, 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; \ |
} \ |
} \ |
} |
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/* */ |
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FT_END_HEADER |
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#endif /* __FTCCACHE_H__ */ |
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/* END */ |