1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/graphite2/src/inc/SegCacheEntry.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,121 @@
1.4 +/* GRAPHITE2 LICENSING
1.5 +
1.6 + Copyright 2010, SIL International
1.7 + All rights reserved.
1.8 +
1.9 + This library is free software; you can redistribute it and/or modify
1.10 + it under the terms of the GNU Lesser General Public License as published
1.11 + by the Free Software Foundation; either version 2.1 of License, or
1.12 + (at your option) any later version.
1.13 +
1.14 + This program is distributed in the hope that it will be useful,
1.15 + but WITHOUT ANY WARRANTY; without even the implied warranty of
1.16 + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
1.17 + Lesser General Public License for more details.
1.18 +
1.19 + You should also have received a copy of the GNU Lesser General Public
1.20 + License along with this library in the file named "LICENSE".
1.21 + If not, write to the Free Software Foundation, 51 Franklin Street,
1.22 + Suite 500, Boston, MA 02110-1335, USA or visit their web page on the
1.23 + internet at http://www.fsf.org/licenses/lgpl.html.
1.24 +
1.25 +Alternatively, the contents of this file may be used under the terms of the
1.26 +Mozilla Public License (http://mozilla.org/MPL) or the GNU General Public
1.27 +License, as published by the Free Software Foundation, either version 2
1.28 +of the License or (at your option) any later version.
1.29 +*/
1.30 +#pragma once
1.31 +
1.32 +#ifndef GRAPHITE2_NSEGCACHE
1.33 +
1.34 +#include "inc/Main.h"
1.35 +#include "inc/Slot.h"
1.36 +
1.37 +namespace graphite2 {
1.38 +
1.39 +class Segment;
1.40 +class Slot;
1.41 +class SegCacheEntry;
1.42 +class SegCachePrefixEntry;
1.43 +
1.44 +enum SegCacheParameters {
1.45 + /** number of characters used in initial prefix tree */
1.46 + ePrefixLength = 2,
1.47 + /** Segments more recent than maxSegmentCount() / eAgeFactor are kept */
1.48 + eAgeFactor = 4,
1.49 + /** Segments are purged according to the formular:
1.50 + * accessCount < (totalAccesses)/(ePurgeFactor * maxSegments) */
1.51 + ePurgeFactor = 5,
1.52 + /** Maximum number of Segments to store which have the same
1.53 + * prefix. Needed to prevent unique identifiers flooding the cache */
1.54 + eMaxSuffixCount = 15
1.55 +
1.56 +};
1.57 +
1.58 +class SegCacheCharInfo
1.59 +{
1.60 +public:
1.61 + uint16 m_unicode;
1.62 + uint16 m_before;
1.63 + uint16 m_after;
1.64 +};
1.65 +
1.66 +/**
1.67 + * SegCacheEntry stores the result of running the engine for specific unicode
1.68 + * code points in the typical mid-line situation.
1.69 + */
1.70 +class SegCacheEntry
1.71 +{
1.72 + // Prevent any implict copying;
1.73 + SegCacheEntry(const SegCacheEntry &);
1.74 + SegCacheEntry & operator = (const SegCacheEntry &);
1.75 +
1.76 + friend class SegCachePrefixEntry;
1.77 +public:
1.78 + SegCacheEntry() :
1.79 + m_glyphLength(0), m_unicode(NULL), m_glyph(NULL), m_attr(NULL), m_justs(0),
1.80 + m_accessCount(0), m_lastAccess(0)
1.81 + {}
1.82 + SegCacheEntry(const uint16 * cmapGlyphs, size_t length, Segment * seg, size_t charOffset, long long cacheTime);
1.83 + ~SegCacheEntry() { clear(); };
1.84 + void clear();
1.85 + size_t glyphLength() const { return m_glyphLength; }
1.86 + const Slot * first() const { return m_glyph; }
1.87 + const Slot * last() const { return m_glyph + (m_glyphLength - 1); }
1.88 +
1.89 + /** Total number of times this entry has been accessed since creation */
1.90 + unsigned long long accessCount() const { return m_accessCount; }
1.91 + /** "time" of last access where "time" is measured in accesses to the cache owning this entry */
1.92 + void accessed(unsigned long long cacheTime) const
1.93 + {
1.94 + m_lastAccess = cacheTime; ++m_accessCount;
1.95 + };
1.96 +
1.97 + int compareRank(const SegCacheEntry & entry) const
1.98 + {
1.99 + if (m_accessCount > entry.m_accessCount) return 1;
1.100 + else if (m_accessCount < entry.m_accessCount) return 1;
1.101 + else if (m_lastAccess > entry.m_lastAccess) return 1;
1.102 + else if (m_lastAccess < entry.m_lastAccess) return -1;
1.103 + return 0;
1.104 + }
1.105 + unsigned long long lastAccess() const { return m_lastAccess; };
1.106 +
1.107 + CLASS_NEW_DELETE;
1.108 +private:
1.109 +
1.110 + size_t m_glyphLength;
1.111 + /** glyph ids resulting from cmap mapping from unicode to glyph before substitution
1.112 + * the length of this array is determined by the position in the SegCachePrefixEntry */
1.113 + uint16 * m_unicode;
1.114 + /** slots after shapping and positioning */
1.115 + Slot * m_glyph;
1.116 + int16 * m_attr;
1.117 + byte * m_justs;
1.118 + mutable unsigned long long m_accessCount;
1.119 + mutable unsigned long long m_lastAccess;
1.120 +};
1.121 +
1.122 +} // namespace graphite2
1.123 +
1.124 +#endif
