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
20const int32_t SLOP = 8;
21
22const int32_t BYTES_PER_WORD = sizeof(int32_t);
23
24BitSet::BitSet() {
25    len = SLOP;
26    data = (int32_t*) uprv_malloc(len * BYTES_PER_WORD);
27    clearAll();
28}
29
30BitSet::~BitSet() {
31    uprv_free(data);
32}
33
34UBool 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
41void 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
50void BitSet::clearAll() {
51    for (uint32_t i=0; i<len; ++i) data[i] = 0;
52}
53
54void 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
68