The Tor Browser: gfx/graphite2/src/inc/SegCacheEntry.h@6474c204b198

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

     1 /*  GRAPHITE2 LICENSING

     3     Copyright 2010, SIL International

     4     All rights reserved.

     6     This library is free software; you can redistribute it and/or modify

     7     it under the terms of the GNU Lesser General Public License as published

     8     by the Free Software Foundation; either version 2.1 of License, or

     9     (at your option) any later version.

    11     This program is distributed in the hope that it will be useful,

    12     but WITHOUT ANY WARRANTY; without even the implied warranty of

    13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

    14     Lesser General Public License for more details.

    16     You should also have received a copy of the GNU Lesser General Public

    17     License along with this library in the file named "LICENSE".

    18     If not, write to the Free Software Foundation, 51 Franklin Street,

    19     Suite 500, Boston, MA 02110-1335, USA or visit their web page on the

    20     internet at http://www.fsf.org/licenses/lgpl.html.

    22 Alternatively, the contents of this file may be used under the terms of the

    23 Mozilla Public License (http://mozilla.org/MPL) or the GNU General Public

    24 License, as published by the Free Software Foundation, either version 2

    25 of the License or (at your option) any later version.

    26 */

    27 #pragma once

    29 #ifndef GRAPHITE2_NSEGCACHE

    31 #include "inc/Main.h"

    32 #include "inc/Slot.h"

    34 namespace graphite2 {

    36 class Segment;

    37 class Slot;

    38 class SegCacheEntry;

    39 class SegCachePrefixEntry;

    41 enum SegCacheParameters {

    42     /** number of characters used in initial prefix tree */

    43     ePrefixLength = 2,

    44     /** Segments more recent than maxSegmentCount() / eAgeFactor are kept */

    45     eAgeFactor = 4,

    46     /** Segments are purged according to the formular:

    47      * accessCount < (totalAccesses)/(ePurgeFactor * maxSegments) */

    48     ePurgeFactor = 5,

    49     /** Maximum number of Segments to store which have the same

    50      * prefix. Needed to prevent unique identifiers flooding the cache */

    51     eMaxSuffixCount = 15

    53 };

    55 class SegCacheCharInfo

    56 {

    57 public:

    58     uint16 m_unicode;

    59     uint16 m_before;

    60     uint16 m_after;

    61 };

    63 /**

    64  * SegCacheEntry stores the result of running the engine for specific unicode

    65  * code points in the typical mid-line situation.

    66  */

    67 class SegCacheEntry

    68 {

    69     // Prevent any implict copying;

    70     SegCacheEntry(const SegCacheEntry &);

    71     SegCacheEntry & operator = (const SegCacheEntry &);

    73     friend class SegCachePrefixEntry;

    74 public:

    75     SegCacheEntry() :

    76         m_glyphLength(0), m_unicode(NULL), m_glyph(NULL), m_attr(NULL), m_justs(0),

    77         m_accessCount(0), m_lastAccess(0)

    78     {}

    79     SegCacheEntry(const uint16 * cmapGlyphs, size_t length, Segment * seg, size_t charOffset, long long cacheTime);

    80     ~SegCacheEntry() { clear(); };

    81     void clear();

    82     size_t glyphLength() const { return m_glyphLength; }

    83     const Slot * first() const { return m_glyph; }

    84     const Slot * last() const { return m_glyph + (m_glyphLength - 1); }

    86     /** Total number of times this entry has been accessed since creation */

    87     unsigned long long accessCount() const { return m_accessCount; }

    88     /** "time" of last access where "time" is measured in accesses to the cache owning this entry */

    89     void accessed(unsigned long long cacheTime) const

    90     {

    91         m_lastAccess = cacheTime; ++m_accessCount;

    92     };

    94     int compareRank(const SegCacheEntry & entry) const

    95     {

    96         if (m_accessCount > entry.m_accessCount) return 1;

    97         else if (m_accessCount < entry.m_accessCount) return 1;

    98         else if (m_lastAccess > entry.m_lastAccess) return 1;

    99         else if (m_lastAccess < entry.m_lastAccess) return -1;

   100         return 0;

   101     }

   102     unsigned long long lastAccess() const { return m_lastAccess; };

   104     CLASS_NEW_DELETE;

   105 private:

   107     size_t   m_glyphLength;

   108     /** glyph ids resulting from cmap mapping from unicode to glyph before substitution

   109      * the length of this array is determined by the position in the SegCachePrefixEntry */

   110     uint16 * m_unicode;

   111     /** slots after shapping and positioning */

   112     Slot   * m_glyph;

   113     int16  * m_attr;

   114     byte   * m_justs;

   115     mutable unsigned long long m_accessCount;

   116     mutable unsigned long long m_lastAccess;

   117 };

   119 } // namespace graphite2

   121 #endif

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