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kc3-lang/freetype/src/cache/ftcmanag.h
Werner Lemberg
- src/cache/ftcmanag.h
-
/***************************************************************************/ /* */ /* ftcmanag.h */ /* */ /* FreeType Cache Manager (specification). */ /* */ /* Copyright 2000-2017 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 FT_CACHE_H #include "ftcmru.h" #include "ftccache.h" FT_BEGIN_HEADER /*************************************************************************/ /* */ /* <Section> */ /* 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_ManagerRec_ { FT_Library library; FT_Memory memory; FTC_Node nodes_list; FT_Offset max_weight; FT_Offset cur_weight; FT_UInt num_nodes; FTC_Cache caches[FTC_MAX_CACHES]; FT_UInt num_caches; FTC_MruListRec faces; FTC_MruListRec sizes; FT_Pointer request_data; FTC_Face_Requester request_face; } FTC_ManagerRec; /*************************************************************************/ /* */ /* <Function> */ /* FTC_Manager_Compress */ /* */ /* <Description> */ /* 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). */ /* */ /* <InOut> */ /* manager :: A handle to the cache manager. */ /* */ /* <Note> */ /* 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_LOCAL( void ) FTC_Manager_Compress( FTC_Manager manager ); /* try to flush `count' old nodes from the cache; return the number * of really flushed nodes */ FT_LOCAL( FT_UInt ) FTC_Manager_FlushN( FTC_Manager manager, FT_UInt count ); /* this must be used internally for the moment */ FT_LOCAL( FT_Error ) FTC_Manager_RegisterCache( FTC_Manager manager, FTC_CacheClass clazz, FTC_Cache *acache ); /* */ #define FTC_SCALER_COMPARE( a, b ) \ ( (a)->face_id == (b)->face_id && \ (a)->width == (b)->width && \ (a)->height == (b)->height && \ ((a)->pixel != 0) == ((b)->pixel != 0) && \ ( (a)->pixel || \ ( (a)->x_res == (b)->x_res && \ (a)->y_res == (b)->y_res ) ) ) #define FTC_SCALER_HASH( q ) \ ( FTC_FACE_ID_HASH( (q)->face_id ) + \ (q)->width + (q)->height*7 + \ ( (q)->pixel ? 0 : ( (q)->x_res*33 ^ (q)->y_res*61 ) ) ) /* */ FT_END_HEADER #endif /* FTCMANAG_H_ */ /* END */