icuSources/test/perf/usetperf/bitset.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) 2002-2005, International Business Machines
   8 * Corporation and others.  All Rights Reserved.
   9 ***********************************************************************
  10 * 2002-09-20 aliu Created.
  11 */
  12
  13 #include "unicode/utypes.h"
  14 #include "cmemory.h"
  15 #include "bitset.h"
  16
  17 // TODO: have a separate capacity, so the len can just be set to
  18 // zero in the clearAll() method, and growth can be smarter.
  19
  20 const int32_t SLOP = 8;
  21
  22 const int32_t BYTES_PER_WORD = sizeof(int32_t);
  23
  24 BitSet::BitSet() {
  25     len = SLOP;
  26     data = (int32_t*) uprv_malloc(len * BYTES_PER_WORD);
  27     clearAll();
  28 }
  29
  30 BitSet::~BitSet() {
  31     uprv_free(data);
  32 }
  33
  34 UBool BitSet::get(int32_t bitIndex) const {
  35     uint32_t longIndex = bitIndex >> 5;
  36     int32_t bitInLong = bitIndex & 0x1F;
  37     return (longIndex < len) ? (((data[longIndex] >> bitInLong) & 1) != 0)
  38         : FALSE;
  39 }
  40
  41 void BitSet::set(int32_t bitIndex) {
  42     uint32_t longIndex = bitIndex >> 5;
  43     int32_t bitInLong = bitIndex & 0x1F;
  44     if (longIndex >= len) {
  45         ensureCapacity(longIndex+1);
  46     }
  47     data[longIndex] |= (1 << bitInLong);
  48 }
  49
  50 void BitSet::clearAll() {
  51     for (uint32_t i=0; i<len; ++i) data[i] = 0;
  52 }
  53
  54 void BitSet::ensureCapacity(uint32_t minLen) {
  55     uint32_t newLen = len;
  56     while (newLen < minLen) newLen <<= 1; // grow exponentially
  57     int32_t* newData = (int32_t*) uprv_malloc(newLen * BYTES_PER_WORD);
  58     uprv_memcpy(newData, data, len * BYTES_PER_WORD);
  59     uprv_free(data);
  60     data = newData;
  61     int32_t* p = data + len;
  62     int32_t* limit = data + newLen;
  63     while (p < limit) *p++ = 0;
  64     len = newLen;
  65 }
  66
  67 //eof