icuSources/samples/layout/FontTableCache.cpp

   1 /*
   2  *************************************************************************
   3  *   © 2016 and later: Unicode, Inc. and others.
   4  *   License & terms of use: http://www.unicode.org/copyright.html#License
   5  *************************************************************************
   6  *************************************************************************
   7  *   Copyright (C) 2003 - 2008, International Business Machines
   8  *   Corporation and others.  All Rights Reserved.
   9  *************************************************************************
  10  */
  11
  12 #include "layout/LETypes.h"
  13
  14 #include "FontTableCache.h"
  15
  16 #define TABLE_CACHE_INIT 5
  17 #define TABLE_CACHE_GROW 5
  18
  19 struct FontTableCacheEntry
  20 {
  21     LETag tag;
  22     const void *table;
  23 };
  24
  25 FontTableCache::FontTableCache()
  26     : fTableCacheCurr(0), fTableCacheSize(TABLE_CACHE_INIT)
  27 {
  28     fTableCache = LE_NEW_ARRAY(FontTableCacheEntry, fTableCacheSize);
  29
  30     if (fTableCache == NULL) {
  31         fTableCacheSize = 0;
  32         return;
  33     }
  34
  35     for (int i = 0; i < fTableCacheSize; i += 1) {
  36         fTableCache[i].tag   = 0;
  37         fTableCache[i].table = NULL;
  38     }
  39 }
  40
  41 FontTableCache::~FontTableCache()
  42 {
  43     for (int i = fTableCacheCurr - 1; i >= 0; i -= 1) {
  44         freeFontTable(fTableCache[i].table);
  45
  46         fTableCache[i].tag   = 0;
  47         fTableCache[i].table = NULL;
  48     }
  49
  50     fTableCacheCurr = 0;
  51
  52     LE_DELETE_ARRAY(fTableCache);
  53     fTableCache = NULL;
  54 }
  55
  56 void FontTableCache::freeFontTable(const void *table) const
  57 {
  58     LE_DELETE_ARRAY(table);
  59 }
  60
  61 const void *FontTableCache::find(LETag tableTag) const
  62 {
  63     for (int i = 0; i < fTableCacheCurr; i += 1) {
  64         if (fTableCache[i].tag == tableTag) {
  65             return fTableCache[i].table;
  66         }
  67     }
  68
  69     const void *table = readFontTable(tableTag);
  70
  71     ((FontTableCache *) this)->add(tableTag, table);
  72
  73     return table;
  74 }
  75
  76 void FontTableCache::add(LETag tableTag, const void *table)
  77 {
  78     if (fTableCacheCurr >= fTableCacheSize) {
  79         le_int32 newSize = fTableCacheSize + TABLE_CACHE_GROW;
  80
  81         fTableCache = (FontTableCacheEntry *) LE_GROW_ARRAY(fTableCache, newSize);
  82
  83         for (le_int32 i = fTableCacheSize; i < newSize; i += 1) {
  84             fTableCache[i].tag   = 0;
  85             fTableCache[i].table = NULL;
  86         }
  87
  88         fTableCacheSize = newSize;
  89     }
  90
  91     fTableCache[fTableCacheCurr].tag   = tableTag;
  92     fTableCache[fTableCacheCurr].table = table;
  93
  94     fTableCacheCurr += 1;
  95 }