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| 1 /***************************************************************************/ |
| 2 /* */ |
| 3 /* ftcmanag.h */ |
| 4 /* */ |
| 5 /* FreeType Cache Manager (specification). */ |
| 6 /* */ |
| 7 /* Copyright 2000-2001, 2003, 2004, 2006, 2010, 2013 by */ |
| 8 /* David Turner, Robert Wilhelm, and Werner Lemberg. */ |
| 9 /* */ |
| 10 /* This file is part of the FreeType project, and may only be used, */ |
| 11 /* modified, and distributed under the terms of the FreeType project */ |
| 12 /* license, LICENSE.TXT. By continuing to use, modify, or distribute */ |
| 13 /* this file you indicate that you have read the license and */ |
| 14 /* understand and accept it fully. */ |
| 15 /* */ |
| 16 /***************************************************************************/ |
| 17 |
| 18 |
| 19 /*************************************************************************/ |
| 20 /* */ |
| 21 /* A cache manager is in charge of the following: */ |
| 22 /* */ |
| 23 /* - Maintain a mapping between generic FTC_FaceIDs and live FT_Face */ |
| 24 /* objects. The mapping itself is performed through a user-provided */ |
| 25 /* callback. However, the manager maintains a small cache of FT_Face */ |
| 26 /* and FT_Size objects in order to speed up things considerably. */ |
| 27 /* */ |
| 28 /* - Manage one or more cache objects. Each cache is in charge of */ |
| 29 /* holding a varying number of `cache nodes'. Each cache node */ |
| 30 /* represents a minimal amount of individually accessible cached */ |
| 31 /* data. For example, a cache node can be an FT_Glyph image */ |
| 32 /* containing a vector outline, or some glyph metrics, or anything */ |
| 33 /* else. */ |
| 34 /* */ |
| 35 /* Each cache node has a certain size in bytes that is added to the */ |
| 36 /* total amount of `cache memory' within the manager. */ |
| 37 /* */ |
| 38 /* All cache nodes are located in a global LRU list, where the oldest */ |
| 39 /* node is at the tail of the list. */ |
| 40 /* */ |
| 41 /* Each node belongs to a single cache, and includes a reference */ |
| 42 /* count to avoid destroying it (due to caching). */ |
| 43 /* */ |
| 44 /*************************************************************************/ |
| 45 |
| 46 |
| 47 /*************************************************************************/ |
| 48 /*************************************************************************/ |
| 49 /*************************************************************************/ |
| 50 /*************************************************************************/ |
| 51 /*************************************************************************/ |
| 52 /********* *********/ |
| 53 /********* WARNING, THIS IS BETA CODE. *********/ |
| 54 /********* *********/ |
| 55 /*************************************************************************/ |
| 56 /*************************************************************************/ |
| 57 /*************************************************************************/ |
| 58 /*************************************************************************/ |
| 59 /*************************************************************************/ |
| 60 |
| 61 |
| 62 #ifndef __FTCMANAG_H__ |
| 63 #define __FTCMANAG_H__ |
| 64 |
| 65 |
| 66 #include <ft2build.h> |
| 67 #include FT_CACHE_H |
| 68 #include "ftcmru.h" |
| 69 #include "ftccache.h" |
| 70 |
| 71 |
| 72 FT_BEGIN_HEADER |
| 73 |
| 74 |
| 75 /*************************************************************************/ |
| 76 /* */ |
| 77 /* <Section> */ |
| 78 /* cache_subsystem */ |
| 79 /* */ |
| 80 /*************************************************************************/ |
| 81 |
| 82 |
| 83 #define FTC_MAX_FACES_DEFAULT 2 |
| 84 #define FTC_MAX_SIZES_DEFAULT 4 |
| 85 #define FTC_MAX_BYTES_DEFAULT 200000L /* ~200kByte by default */ |
| 86 |
| 87 /* maximum number of caches registered in a single manager */ |
| 88 #define FTC_MAX_CACHES 16 |
| 89 |
| 90 |
| 91 typedef struct FTC_ManagerRec_ |
| 92 { |
| 93 FT_Library library; |
| 94 FT_Memory memory; |
| 95 |
| 96 FTC_Node nodes_list; |
| 97 FT_Offset max_weight; |
| 98 FT_Offset cur_weight; |
| 99 FT_UInt num_nodes; |
| 100 |
| 101 FTC_Cache caches[FTC_MAX_CACHES]; |
| 102 FT_UInt num_caches; |
| 103 |
| 104 FTC_MruListRec faces; |
| 105 FTC_MruListRec sizes; |
| 106 |
| 107 FT_Pointer request_data; |
| 108 FTC_Face_Requester request_face; |
| 109 |
| 110 } FTC_ManagerRec; |
| 111 |
| 112 |
| 113 /*************************************************************************/ |
| 114 /* */ |
| 115 /* <Function> */ |
| 116 /* FTC_Manager_Compress */ |
| 117 /* */ |
| 118 /* <Description> */ |
| 119 /* This function is used to check the state of the cache manager if */ |
| 120 /* its `num_bytes' field is greater than its `max_bytes' field. It */ |
| 121 /* will flush as many old cache nodes as possible (ignoring cache */ |
| 122 /* nodes with a non-zero reference count). */ |
| 123 /* */ |
| 124 /* <InOut> */ |
| 125 /* manager :: A handle to the cache manager. */ |
| 126 /* */ |
| 127 /* <Note> */ |
| 128 /* Client applications should not call this function directly. It is */ |
| 129 /* normally invoked by specific cache implementations. */ |
| 130 /* */ |
| 131 /* The reason this function is exported is to allow client-specific */ |
| 132 /* cache classes. */ |
| 133 /* */ |
| 134 FT_LOCAL( void ) |
| 135 FTC_Manager_Compress( FTC_Manager manager ); |
| 136 |
| 137 |
| 138 /* try to flush `count' old nodes from the cache; return the number |
| 139 * of really flushed nodes |
| 140 */ |
| 141 FT_LOCAL( FT_UInt ) |
| 142 FTC_Manager_FlushN( FTC_Manager manager, |
| 143 FT_UInt count ); |
| 144 |
| 145 |
| 146 /* this must be used internally for the moment */ |
| 147 FT_LOCAL( FT_Error ) |
| 148 FTC_Manager_RegisterCache( FTC_Manager manager, |
| 149 FTC_CacheClass clazz, |
| 150 FTC_Cache *acache ); |
| 151 |
| 152 /* */ |
| 153 |
| 154 #define FTC_SCALER_COMPARE( a, b ) \ |
| 155 ( (a)->face_id == (b)->face_id && \ |
| 156 (a)->width == (b)->width && \ |
| 157 (a)->height == (b)->height && \ |
| 158 ((a)->pixel != 0) == ((b)->pixel != 0) && \ |
| 159 ( (a)->pixel || \ |
| 160 ( (a)->x_res == (b)->x_res && \ |
| 161 (a)->y_res == (b)->y_res ) ) ) |
| 162 |
| 163 #define FTC_SCALER_HASH( q ) \ |
| 164 ( _FTC_FACE_ID_HASH( (q)->face_id ) + \ |
| 165 (q)->width + (q)->height*7 + \ |
| 166 ( (q)->pixel ? 0 : ( (q)->x_res*33 ^ (q)->y_res*61 ) ) ) |
| 167 |
| 168 /* */ |
| 169 |
| 170 FT_END_HEADER |
| 171 |
| 172 #endif /* __FTCMANAG_H__ */ |
| 173 |
| 174 |
| 175 /* END */ |
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