| /* |
| ********************************************************************** |
| * Copyright (c) 2002-2005, International Business Machines |
| * Corporation and others. All Rights Reserved. |
| ********************************************************************** |
| * 2002-09-20 aliu Created. |
| */ |
| |
| #include "unicode/utypes.h" |
| #include "cmemory.h" |
| #include "bitset.h" |
| |
| // TODO: have a separate capacity, so the len can just be set to |
| // zero in the clearAll() method, and growth can be smarter. |
| |
| const int32_t SLOP = 8; |
| |
| const int32_t BYTES_PER_WORD = sizeof(int32_t); |
| |
| BitSet::BitSet() { |
| len = SLOP; |
| data = (int32_t*) uprv_malloc(len * BYTES_PER_WORD); |
| clearAll(); |
| } |
| |
| BitSet::~BitSet() { |
| uprv_free(data); |
| } |
| |
| UBool BitSet::get(int32_t bitIndex) const { |
| uint32_t longIndex = bitIndex >> 5; |
| int32_t bitInLong = bitIndex & 0x1F; |
| return (longIndex < len) ? (((data[longIndex] >> bitInLong) & 1) != 0) |
| : FALSE; |
| } |
| |
| void BitSet::set(int32_t bitIndex) { |
| uint32_t longIndex = bitIndex >> 5; |
| int32_t bitInLong = bitIndex & 0x1F; |
| if (longIndex >= len) { |
| ensureCapacity(longIndex+1); |
| } |
| data[longIndex] |= (1 << bitInLong); |
| } |
| |
| void BitSet::clearAll() { |
| for (uint32_t i=0; i<len; ++i) data[i] = 0; |
| } |
| |
| void BitSet::ensureCapacity(uint32_t minLen) { |
| uint32_t newLen = len; |
| while (newLen < minLen) newLen <<= 1; // grow exponentially |
| int32_t* newData = (int32_t*) uprv_malloc(newLen * BYTES_PER_WORD); |
| uprv_memcpy(newData, data, len * BYTES_PER_WORD); |
| uprv_free(data); |
| data = newData; |
| int32_t* p = data + len; |
| int32_t* limit = data + newLen; |
| while (p < limit) *p++ = 0; |
| len = newLen; |
| } |
| |
| //eof |