icuSources/samples/layout/FontTableCache.cpp

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