icuSources/test/perf/usetperf/bitset.cpp

   1 /*
   2 **********************************************************************
   3 * Copyright (c) 2002-2005, International Business Machines
   4 * Corporation and others.  All Rights Reserved.
   5 **********************************************************************
   6 * 2002-09-20 aliu Created.
   7 */
   8
   9 #include "unicode/utypes.h"
  10 #include "cmemory.h"
  11 #include "bitset.h"
  12
  13 // TODO: have a separate capacity, so the len can just be set to
  14 // zero in the clearAll() method, and growth can be smarter.
  15
  16 const int32_t SLOP = 8;
  17
  18 const int32_t BYTES_PER_WORD = sizeof(int32_t);
  19
  20 BitSet::BitSet() {
  21     len = SLOP;
  22     data = (int32_t*) uprv_malloc(len * BYTES_PER_WORD);
  23     clearAll();
  24 }
  25
  26 BitSet::~BitSet() {
  27     uprv_free(data);
  28 }
  29
  30 UBool BitSet::get(int32_t bitIndex) const {
  31     uint32_t longIndex = bitIndex >> 5;
  32     int32_t bitInLong = bitIndex & 0x1F;
  33     return (longIndex < len) ? (((data[longIndex] >> bitInLong) & 1) != 0)
  34         : FALSE;
  35 }
  36
  37 void BitSet::set(int32_t bitIndex) {
  38     uint32_t longIndex = bitIndex >> 5;
  39     int32_t bitInLong = bitIndex & 0x1F;
  40     if (longIndex >= len) {
  41         ensureCapacity(longIndex+1);
  42     }
  43     data[longIndex] |= (1 << bitInLong);
  44 }
  45
  46 void BitSet::clearAll() {
  47     for (uint32_t i=0; i<len; ++i) data[i] = 0;
  48 }
  49
  50 void BitSet::ensureCapacity(uint32_t minLen) {
  51     uint32_t newLen = len;
  52     while (newLen < minLen) newLen <<= 1; // grow exponentially
  53     int32_t* newData = (int32_t*) uprv_malloc(newLen * BYTES_PER_WORD);
  54     uprv_memcpy(newData, data, len * BYTES_PER_WORD);
  55     uprv_free(data);
  56     data = newData;
  57     int32_t* p = data + len;
  58     int32_t* limit = data + newLen;
  59     while (p < limit) *p++ = 0;
  60     len = newLen;
  61 }
  62
  63 //eof