64 lines
1.6 KiB
C++
64 lines
1.6 KiB
C++
/*
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**********************************************************************
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* Copyright (c) 2002, International Business Machines
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* Corporation and others. All Rights Reserved.
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**********************************************************************
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* 2002-09-20 aliu Created.
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*/
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#include "unicode/utypes.h"
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#include "cmemory.h"
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#include "bitset.h"
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// TODO: have a separate capacity, so the len can just be set to
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// zero in the clearAll() method, and growth can be smarter.
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const int32_t SLOP = 8;
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const int32_t BYTES_PER_WORD = sizeof(int32_t);
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BitSet::BitSet() {
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len = SLOP;
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data = (int32_t*) uprv_malloc(len * BYTES_PER_WORD);
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clearAll();
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}
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BitSet::~BitSet() {
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uprv_free(data);
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}
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UBool BitSet::get(int32_t bitIndex) const {
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uint32_t longIndex = bitIndex >> 5;
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int32_t bitInLong = bitIndex & 0x1F;
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return (longIndex < len) ? (((data[longIndex] >> bitInLong) & 1) != 0)
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: FALSE;
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}
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void BitSet::set(int32_t bitIndex) {
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uint32_t longIndex = bitIndex >> 5;
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int32_t bitInLong = bitIndex & 0x1F;
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if (longIndex >= len) {
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ensureCapacity(longIndex+1);
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}
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data[longIndex] |= (1 << bitInLong);
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}
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void BitSet::clearAll() {
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for (uint32_t i=0; i<len; ++i) data[i] = 0;
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}
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void BitSet::ensureCapacity(uint32_t minLen) {
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uint32_t newLen = len;
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while (newLen < minLen) newLen <<= 1; // grow exponentially
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int32_t* newData = (int32_t*) uprv_malloc(newLen * BYTES_PER_WORD);
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uprv_memcpy(newData, data, len * BYTES_PER_WORD);
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uprv_free(data);
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data = newData;
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int32_t* p = data + len;
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int32_t* limit = data + newLen;
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while (p < limit) *p++ = 0;
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len = newLen;
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}
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//eof
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