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 64
