/***************************************************************************/ | |
/* */ | |
/* ftcmanag.h */ | |
/* */ | |
/* FreeType Cache Manager (specification). */ | |
/* */ | |
/* Copyright 2000-2015 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 */ |