| /**************************************************************************** |
| * |
| * ftccache.h |
| * |
| * FreeType internal cache interface (specification). |
| * |
| * Copyright (C) 2000-2021 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 <freetype/internal/compiler-macros.h> |
| #include "ftcmru.h" |
| |
| FT_BEGIN_HEADER |
| |
| #define FTC_FACE_ID_HASH( i ) \ |
| ( ( (FT_Offset)(i) >> 3 ) ^ ( (FT_Offset)(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_Offset 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_Offset hash ); |
| #define FTC_NODE_TOP_FOR_HASH( cache, hash ) \ |
| ftc_get_top_node_for_hash( ( cache ), ( hash ) ) |
| #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_Offset hash, |
| FT_Pointer query, |
| FTC_Node *anode ); |
| #endif |
| |
| FT_LOCAL( FT_Error ) |
| FTC_Cache_NewNode( FTC_Cache cache, |
| FT_Offset 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_Offset _hash = (FT_Offset)(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 ) \ |
| 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 ) \ |
| { \ |
| 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 || FT_ERR_NEQ( error, Out_Of_Memory ) ) \ |
| break; \ |
| \ |
| _try_done = FTC_Manager_FlushN( _try_manager, _try_count ); \ |
| if ( _try_done > 0 && list_changed != NULL ) \ |
| *(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 */ |
