+++ /dev/null
-/***************************************************************************/
-/* */
-/* 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 */
- /* & 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 FT_CACHE_INTERNAL_LRU_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
-
-
- /*************************************************************************/
- /* */
- /* <Struct> */
- /* FTC_ManagerRec */
- /* */
- /* <Description> */
- /* The cache manager structure. */
- /* */
- /* <Fields> */
- /* library :: A handle to a FreeType library instance. */
- /* */
- /* faces_lru :: The lru list of FT_Face objects in the cache. */
- /* */
- /* sizes_lru :: The lru list of FT_Size objects in the cache. */
- /* */
- /* max_bytes :: The maximum number of bytes to be allocated in the */
- /* cache. This is only related to the byte size of */
- /* the nodes cached by the manager. */
- /* */
- /* num_bytes :: The current number of bytes allocated in the */
- /* cache. Only related to the byte size of cached */
- /* nodes. */
- /* */
- /* num_nodes :: The current number of nodes in the manager. */
- /* */
- /* global_lru :: 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_FaceIDs and real FT_Face */
- /* objects. */
- /* */
- typedef struct FTC_ManagerRec_
- {
- FT_Library library;
- FT_Lru faces_lru;
- FT_Lru sizes_lru;
-
- FT_ULong max_bytes;
- FT_ULong num_bytes;
- FT_UInt num_nodes;
- FT_ListRec global_lru;
- FTC_Cache caches[FTC_MAX_CACHES];
-
- 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_EXPORT( void )
- FTC_Manager_Compress( FTC_Manager manager );
-
-
- /*************************************************************************/
- /*************************************************************************/
- /***** *****/
- /***** 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. */
- /* */
-
- typedef FT_ListNodeRec FTC_CacheNodeRec;
- typedef FTC_CacheNodeRec* FTC_CacheNode;
-
-
- /* the field `cachenode.data' is typecast to this type */
- typedef struct FTC_CacheNode_Data_
- {
- FT_UShort cache_index;
- FT_Short ref_count;
-
- } FTC_CacheNode_Data;
-
-
- /* return a pointer to FTC_CacheNode_Data contained in a */
- /* CacheNode's `data' field */
-#define FTC_CACHENODE_TO_DATA_P( n ) \
- ( (FTC_CacheNode_Data*)&(n)->data )
-
-#define FTC_LIST_TO_CACHENODE( n ) ( (FTC_CacheNode)(n) )
-
-
- /*************************************************************************/
- /* */
- /* <FuncType> */
- /* FTC_CacheNode_SizeFunc */
- /* */
- /* <Description> */
- /* A function used to compute the total size in bytes of a given */
- /* cache node. It is used by the cache manager to compute the number */
- /* of old nodes to flush when the cache is full. */
- /* */
- /* <Input> */
- /* node :: A handle to the target cache node. */
- /* */
- /* cache_data :: A generic pointer passed to the destructor. */
- /* */
- /* <Return> */
- /* The size of a given cache node in bytes. */
- /* */
- typedef FT_ULong
- (*FTC_CacheNode_SizeFunc)( FTC_CacheNode node,
- FT_Pointer cache_data );
-
-
- /*************************************************************************/
- /* */
- /* <FuncType> */
- /* FTC_CacheNode_DestroyFunc */
- /* */
- /* <Description> */
- /* A function used to destroy a given cache node. It is called by */
- /* the manager when the cache is full and old nodes need to be */
- /* flushed out. */
- /* */
- /* <Input> */
- /* node :: A handle to the target cache node. */
- /* */
- /* cache_data :: A generic pointer passed to the destructor. */
- /* */
- typedef void
- (*FTC_CacheNode_DestroyFunc)( FTC_CacheNode node,
- FT_Pointer cache_data );
-
-
- /*************************************************************************/
- /* */
- /* <Struct> */
- /* FTC_CacheNode_Class */
- /* */
- /* <Description> */
- /* A very simple structure used to describe a cache node's class to */
- /* the cache manager. */
- /* */
- /* <Fields> */
- /* size_node :: A function used to size the node. */
- /* */
- /* destroy_node :: A function used to destroy the node. */
- /* */
- /* <Note> */
- /* The cache node class doesn't include a `new_node' function because */
- /* the cache manager never allocates cache node directly; it */
- /* delegates this task to its cache objects. */
- /* */
- typedef struct FTC_CacheNode_Class_
- {
- FTC_CacheNode_SizeFunc size_node;
- FTC_CacheNode_DestroyFunc destroy_node;
-
- } FTC_CacheNode_Class;
-
-
- /*************************************************************************/
- /*************************************************************************/
- /***** *****/
- /***** CACHE DEFINITIONS *****/
- /***** *****/
- /*************************************************************************/
- /*************************************************************************/
-
-
- /*************************************************************************/
- /* */
- /* <FuncType> */
- /* FTC_Cache_InitFunc */
- /* */
- /* <Description> */
- /* A function used to initialize a given cache object. */
- /* */
- /* <Input> */
- /* cache :: A handle to the new cache. */
- /* */
- typedef FT_Error
- (*FTC_Cache_InitFunc)( FTC_Cache cache );
-
-
- /*************************************************************************/
- /* */
- /* <FuncType> */
- /* FTC_Cache_DoneFunc */
- /* */
- /* <Description> */
- /* A function to finalize a given cache object. */
- /* */
- /* <Input> */
- /* cache :: A handle to the target cache. */
- /* */
- typedef void
- (*FTC_Cache_DoneFunc)( FTC_Cache cache );
-
-
- /*************************************************************************/
- /* */
- /* <Struct> */
- /* FTC_Cache_Class */
- /* */
- /* <Description> */
- /* A structure used to describe a given cache object class to the */
- /* cache manager. */
- /* */
- /* <Fields> */
- /* cache_byte_size :: The size of the cache object in bytes. */
- /* */
- /* init_cache :: The cache object initializer. */
- /* */
- /* done_cache :: The cache object finalizer. */
- /* */
- struct FTC_Cache_Class_
- {
- FT_UInt cache_byte_size;
- FTC_Cache_InitFunc init_cache;
- FTC_Cache_DoneFunc done_cache;
- };
-
-
- /*************************************************************************/
- /* */
- /* <Struct> */
- /* FTC_CacheRec */
- /* */
- /* <Description> */
- /* A structure used to describe an abstract cache object. */
- /* */
- /* <Fields> */
- /* manager :: A handle to the parent cache manager. */
- /* */
- /* memory :: A handle to the memory manager. */
- /* */
- /* clazz :: A pointer to the cache class. */
- /* */
- /* node_clazz :: A pointer to the cache's node class. */
- /* */
- /* cache_index :: An index of the cache in the manager's table. */
- /* */
- /* cache_data :: Data passed to the cache node */
- /* constructor/finalizer. */
- /* */
- typedef struct FTC_CacheRec_
- {
- FTC_Manager manager;
- FT_Memory memory;
- FTC_Cache_Class* clazz;
- FTC_CacheNode_Class* node_clazz;
-
- FT_UInt cache_index; /* in manager's table */
- FT_Pointer cache_data; /* passed to cache node methods */
-
- } FTC_CacheRec;
-
-
- /* */
-
-
-FT_END_HEADER
-
-#endif /* __FTCMANAG_H__ */
-
-
-/* END */
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