gfx/graphite2/src/inc/SegCacheEntry.h@b8a032363ba2 (annotated)
gfx/graphite2/src/inc/SegCacheEntry.h
Thu, 22 Jan 2015 13:21:57 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Thu, 22 Jan 2015 13:21:57 +0100
- branch
- TOR_BUG_9701
- changeset 15
- b8a032363ba2
- permissions
- -rw-r--r--
Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6
| michael@0 | 1 | /* GRAPHITE2 LICENSING |
| michael@0 | 2 | |
| michael@0 | 3 | Copyright 2010, SIL International |
| michael@0 | 4 | All rights reserved. |
| michael@0 | 5 | |
| michael@0 | 6 | This library is free software; you can redistribute it and/or modify |
| michael@0 | 7 | it under the terms of the GNU Lesser General Public License as published |
| michael@0 | 8 | by the Free Software Foundation; either version 2.1 of License, or |
| michael@0 | 9 | (at your option) any later version. |
| michael@0 | 10 | |
| michael@0 | 11 | This program is distributed in the hope that it will be useful, |
| michael@0 | 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| michael@0 | 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| michael@0 | 14 | Lesser General Public License for more details. |
| michael@0 | 15 | |
| michael@0 | 16 | You should also have received a copy of the GNU Lesser General Public |
| michael@0 | 17 | License along with this library in the file named "LICENSE". |
| michael@0 | 18 | If not, write to the Free Software Foundation, 51 Franklin Street, |
| michael@0 | 19 | Suite 500, Boston, MA 02110-1335, USA or visit their web page on the |
| michael@0 | 20 | internet at http://www.fsf.org/licenses/lgpl.html. |
| michael@0 | 21 | |
| michael@0 | 22 | Alternatively, the contents of this file may be used under the terms of the |
| michael@0 | 23 | Mozilla Public License (http://mozilla.org/MPL) or the GNU General Public |
| michael@0 | 24 | License, as published by the Free Software Foundation, either version 2 |
| michael@0 | 25 | of the License or (at your option) any later version. |
| michael@0 | 26 | */ |
| michael@0 | 27 | #pragma once |
| michael@0 | 28 | |
| michael@0 | 29 | #ifndef GRAPHITE2_NSEGCACHE |
| michael@0 | 30 | |
| michael@0 | 31 | #include "inc/Main.h" |
| michael@0 | 32 | #include "inc/Slot.h" |
| michael@0 | 33 | |
| michael@0 | 34 | namespace graphite2 { |
| michael@0 | 35 | |
| michael@0 | 36 | class Segment; |
| michael@0 | 37 | class Slot; |
| michael@0 | 38 | class SegCacheEntry; |
| michael@0 | 39 | class SegCachePrefixEntry; |
| michael@0 | 40 | |
| michael@0 | 41 | enum SegCacheParameters { |
| michael@0 | 42 | /** number of characters used in initial prefix tree */ |
| michael@0 | 43 | ePrefixLength = 2, |
| michael@0 | 44 | /** Segments more recent than maxSegmentCount() / eAgeFactor are kept */ |
| michael@0 | 45 | eAgeFactor = 4, |
| michael@0 | 46 | /** Segments are purged according to the formular: |
| michael@0 | 47 | * accessCount < (totalAccesses)/(ePurgeFactor * maxSegments) */ |
| michael@0 | 48 | ePurgeFactor = 5, |
| michael@0 | 49 | /** Maximum number of Segments to store which have the same |
| michael@0 | 50 | * prefix. Needed to prevent unique identifiers flooding the cache */ |
| michael@0 | 51 | eMaxSuffixCount = 15 |
| michael@0 | 52 | |
| michael@0 | 53 | }; |
| michael@0 | 54 | |
| michael@0 | 55 | class SegCacheCharInfo |
| michael@0 | 56 | { |
| michael@0 | 57 | public: |
| michael@0 | 58 | uint16 m_unicode; |
| michael@0 | 59 | uint16 m_before; |
| michael@0 | 60 | uint16 m_after; |
| michael@0 | 61 | }; |
| michael@0 | 62 | |
| michael@0 | 63 | /** |
| michael@0 | 64 | * SegCacheEntry stores the result of running the engine for specific unicode |
| michael@0 | 65 | * code points in the typical mid-line situation. |
| michael@0 | 66 | */ |
| michael@0 | 67 | class SegCacheEntry |
| michael@0 | 68 | { |
| michael@0 | 69 | // Prevent any implict copying; |
| michael@0 | 70 | SegCacheEntry(const SegCacheEntry &); |
| michael@0 | 71 | SegCacheEntry & operator = (const SegCacheEntry &); |
| michael@0 | 72 | |
| michael@0 | 73 | friend class SegCachePrefixEntry; |
| michael@0 | 74 | public: |
| michael@0 | 75 | SegCacheEntry() : |
| michael@0 | 76 | m_glyphLength(0), m_unicode(NULL), m_glyph(NULL), m_attr(NULL), m_justs(0), |
| michael@0 | 77 | m_accessCount(0), m_lastAccess(0) |
| michael@0 | 78 | {} |
| michael@0 | 79 | SegCacheEntry(const uint16 * cmapGlyphs, size_t length, Segment * seg, size_t charOffset, long long cacheTime); |
| michael@0 | 80 | ~SegCacheEntry() { clear(); }; |
| michael@0 | 81 | void clear(); |
| michael@0 | 82 | size_t glyphLength() const { return m_glyphLength; } |
| michael@0 | 83 | const Slot * first() const { return m_glyph; } |
| michael@0 | 84 | const Slot * last() const { return m_glyph + (m_glyphLength - 1); } |
| michael@0 | 85 | |
| michael@0 | 86 | /** Total number of times this entry has been accessed since creation */ |
| michael@0 | 87 | unsigned long long accessCount() const { return m_accessCount; } |
| michael@0 | 88 | /** "time" of last access where "time" is measured in accesses to the cache owning this entry */ |
| michael@0 | 89 | void accessed(unsigned long long cacheTime) const |
| michael@0 | 90 | { |
| michael@0 | 91 | m_lastAccess = cacheTime; ++m_accessCount; |
| michael@0 | 92 | }; |
| michael@0 | 93 | |
| michael@0 | 94 | int compareRank(const SegCacheEntry & entry) const |
| michael@0 | 95 | { |
| michael@0 | 96 | if (m_accessCount > entry.m_accessCount) return 1; |
| michael@0 | 97 | else if (m_accessCount < entry.m_accessCount) return 1; |
| michael@0 | 98 | else if (m_lastAccess > entry.m_lastAccess) return 1; |
| michael@0 | 99 | else if (m_lastAccess < entry.m_lastAccess) return -1; |
| michael@0 | 100 | return 0; |
| michael@0 | 101 | } |
| michael@0 | 102 | unsigned long long lastAccess() const { return m_lastAccess; }; |
| michael@0 | 103 | |
| michael@0 | 104 | CLASS_NEW_DELETE; |
| michael@0 | 105 | private: |
| michael@0 | 106 | |
| michael@0 | 107 | size_t m_glyphLength; |
| michael@0 | 108 | /** glyph ids resulting from cmap mapping from unicode to glyph before substitution |
| michael@0 | 109 | * the length of this array is determined by the position in the SegCachePrefixEntry */ |
| michael@0 | 110 | uint16 * m_unicode; |
| michael@0 | 111 | /** slots after shapping and positioning */ |
| michael@0 | 112 | Slot * m_glyph; |
| michael@0 | 113 | int16 * m_attr; |
| michael@0 | 114 | byte * m_justs; |
| michael@0 | 115 | mutable unsigned long long m_accessCount; |
| michael@0 | 116 | mutable unsigned long long m_lastAccess; |
| michael@0 | 117 | }; |
| michael@0 | 118 | |
| michael@0 | 119 | } // namespace graphite2 |
| michael@0 | 120 | |
| michael@0 | 121 | #endif |
