www.pudn.com > freetype.rar > ftcmanag.h
/***************************************************************************/ /* */ /* ftcmanag.h */ /* */ /* FreeType Cache Manager (specification). */ /* */ /* Copyright 2000-2001 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. */ /* */ /***************************************************************************/ /*************************************************************************/ /* */ /* A cache manager is in charge of the following: */ /* */ /* - Maintain a mapping between generic FTC_FaceIDs and live FT_Face */ /* objects. The mapping itself is performed through a user-provided */ /* callback. However, the manager maintains a small cache of FT_Face */ /* and FT_Size objects in order to speed up things considerably. */ /* */ /* - Manage one or more cache objects. Each cache is in charge of */ /* holding a varying number of `cache nodes'. Each cache node */ /* represents a minimal amount of individually accessible cached */ /* data. For example, a cache node can be an FT_Glyph image */ /* containing a vector outline, or some glyph metrics, or anything */ /* else. */ /* */ /* Each cache node has a certain size in bytes that is added to the */ /* total amount of `cache memory' within the manager. */ /* */ /* All cache nodes are located in a global LRU list, where the oldest */ /* node is at the tail of the list. */ /* */ /* Each node belongs to a single cache, and includes a reference */ /* count to avoid destroying it (due to caching). */ /* */ /*************************************************************************/ /*************************************************************************/ /*************************************************************************/ /*************************************************************************/ /*************************************************************************/ /*************************************************************************/ /********* *********/ /********* WARNING, THIS IS BETA CODE. *********/ /********* *********/ /*************************************************************************/ /*************************************************************************/ /*************************************************************************/ /*************************************************************************/ /*************************************************************************/ #ifndef __FTCMANAG_H__ #define __FTCMANAG_H__ #include "ft2build.h" #include "freetype/ftcache.h" #include "freetype/cache/ftlru.h" #include "freetype/cache/ftccache.h" FT_BEGIN_HEADER /*************************************************************************/ /* */ /**/ /* cache_subsystem */ /* */ /*************************************************************************/ #define FTC_MAX_FACES_DEFAULT 2 #define FTC_MAX_SIZES_DEFAULT 4 #define FTC_MAX_BYTES_DEFAULT 200000L /* ~200kByte by default */ /* maximum number of caches registered in a single manager */ #define FTC_MAX_CACHES 16 typedef struct FTC_FamilyEntryRec_ { FTC_Family family; FTC_Cache cache; FT_UInt index; FT_UInt link; } FTC_FamilyEntryRec, *FTC_FamilyEntry; #define FTC_FAMILY_ENTRY_NONE ( (FT_UInt)-1 ) typedef struct FTC_FamilyTableRec_ { FT_UInt count; FT_UInt size; FTC_FamilyEntry entries; FT_UInt free; } FTC_FamilyTableRec, *FTC_FamilyTable; FT_EXPORT( FT_Error ) ftc_family_table_alloc( FTC_FamilyTable table, FT_Memory memory, FTC_FamilyEntry *aentry ); FT_EXPORT( void ) ftc_family_table_free( FTC_FamilyTable table, FT_UInt idx ); /*************************************************************************/ /* */ /* */ /* FTC_ManagerRec */ /* */ /* */ /* The cache manager structure. */ /* */ /* */ /* library :: A handle to a FreeType library instance. */ /* */ /* faces_list :: The lru list of @FT_Face objects in the cache. */ /* */ /* sizes_list :: The lru list of @FT_Size objects in the cache. */ /* */ /* max_weight :: The maximum cache pool weight. */ /* */ /* cur_weight :: The current cache pool weight. */ /* */ /* num_nodes :: The current number of nodes in the manager. */ /* */ /* nodes_list :: The global lru list of all cache nodes. */ /* */ /* caches :: A table of installed/registered cache objects. */ /* */ /* request_data :: User-provided data passed to the requester. */ /* */ /* request_face :: User-provided function used to implement a mapping */ /* between abstract @FTC_FaceID values and real */ /* @FT_Face objects. */ /* */ /* families :: Global table of families. */ /* */ typedef struct FTC_ManagerRec_ { FT_Library library; FT_LruList faces_list; FT_LruList sizes_list; FT_ULong max_weight; FT_ULong cur_weight; FT_UInt num_nodes; FTC_Node nodes_list; FTC_Cache caches[FTC_MAX_CACHES]; FT_Pointer request_data; FTC_Face_Requester request_face; FTC_FamilyTableRec families; } FTC_ManagerRec; /*************************************************************************/ /* */ /* */ /* FTC_Manager_Compress */ /* */ /* */ /* This function is used to check the state of the cache manager if */ /* its `num_bytes' field is greater than its `max_bytes' field. It */ /* will flush as many old cache nodes as possible (ignoring cache */ /* nodes with a non-zero reference count). */ /* */ /* */ /* manager :: A handle to the cache manager. */ /* */ /* */ /* Client applications should not call this function directly. It is */ /* normally invoked by specific cache implementations. */ /* */ /* The reason this function is exported is to allow client-specific */ /* cache classes. */ /* */ FT_EXPORT( void ) FTC_Manager_Compress( FTC_Manager manager ); /* this must be used internally for the moment */ FT_EXPORT( FT_Error ) FTC_Manager_Register_Cache( FTC_Manager manager, FTC_Cache_Class clazz, FTC_Cache *acache ); /* can be called to increment a node's reference count */ FT_EXPORT( void ) FTC_Node_Ref( FTC_Node node, FTC_Manager manager ); /*************************************************************************/ /* */ /* */ /* FTC_Node_Unref */ /* */ /* */ /* Decrement a cache node's internal reference count. When the count */ /* reaches 0, it is not destroyed but becomes eligible for subsequent */ /* cache flushes. */ /* */ /* */ /* node :: The cache node handle. */ /* */ /* manager :: The cache manager handle. */ /* */ FT_EXPORT( void ) FTC_Node_Unref( FTC_Node node, FTC_Manager manager ); /* */ FT_END_HEADER #endif /* __FTCMANAG_H__ */ /* END */