Files
pvData/pvDataApp/misc/bitSet.cpp
2013-10-31 06:03:51 -04:00

377 lines
11 KiB
C++

/* bitSet.cpp */
/**
* Copyright - See the COPYRIGHT that is included with this distribution.
* EPICS pvData is distributed subject to a Software License Agreement found
* in file LICENSE that is included with this distribution.
*/
/**
* @author mes
*/
#include "string.h"
#include "stdio.h"
#include <iostream>
#include <pv/bitSet.h>
#include <pv/lock.h>
#include <pv/serializeHelper.h>
namespace epics { namespace pvData {
BitSet::shared_pointer BitSet::create(uint32 nbits)
{
return BitSet::shared_pointer(new BitSet(nbits));
}
BitSet::BitSet() : words(0), wordsLength(0), wordsInUse(0) {
initWords(BITS_PER_WORD);
}
BitSet::BitSet(uint32 nbits) : words(0), wordsLength(0), wordsInUse(0) {
initWords(nbits);
}
BitSet::~BitSet() {
delete[] words;
}
void BitSet::initWords(uint32 nbits) {
uint32 length = (nbits <= 0) ? 1 : wordIndex(nbits-1) + 1;
if (words) delete[] words;
words = new uint64[length];
memset(words, 0, sizeof(uint64)*length);
wordsLength = length;
}
void BitSet::recalculateWordsInUse() {
// wordsInUse is unsigned
if (wordsInUse == 0)
return;
// Traverse the bitset until a used word is found
int32 i;
for (i = (int32)wordsInUse-1; i >= 0; i--)
if (words[i] != 0)
break;
wordsInUse = i+1; // The new logical size
}
void BitSet::ensureCapacity(uint32 wordsRequired) {
if (wordsLength < wordsRequired) {
// create and copy
uint64* newwords = new uint64[wordsRequired];
memset(newwords, 0, sizeof(uint64)*wordsRequired);
memcpy(newwords, words, sizeof(uint64)*wordsLength);
if (words) delete[] words;
words = newwords;
wordsLength = wordsRequired;
}
}
void BitSet::expandTo(uint32 wordIndex) {
uint32 wordsRequired = wordIndex+1;
if (wordsInUse < wordsRequired) {
ensureCapacity(wordsRequired);
wordsInUse = wordsRequired;
}
}
void BitSet::flip(uint32 bitIndex) {
uint32 wordIdx = wordIndex(bitIndex);
expandTo(wordIdx);
words[wordIdx] ^= (((uint64)1) << (bitIndex % BITS_PER_WORD));
recalculateWordsInUse();
}
void BitSet::set(uint32 bitIndex) {
uint32 wordIdx = wordIndex(bitIndex);
expandTo(wordIdx);
words[wordIdx] |= (((uint64)1) << (bitIndex % BITS_PER_WORD));
}
void BitSet::clear(uint32 bitIndex) {
uint32 wordIdx = wordIndex(bitIndex);
if (wordIdx >= wordsInUse)
return;
words[wordIdx] &= ~(((uint64)1) << (bitIndex % BITS_PER_WORD));
recalculateWordsInUse();
}
void BitSet::set(uint32 bitIndex, bool value) {
if (value)
set(bitIndex);
else
clear(bitIndex);
}
bool BitSet::get(uint32 bitIndex) const {
uint32 wordIdx = wordIndex(bitIndex);
return ((wordIdx < wordsInUse)
&& ((words[wordIdx] & (((uint64)1) << (bitIndex % BITS_PER_WORD))) != 0));
}
void BitSet::clear() {
while (wordsInUse > 0)
words[--wordsInUse] = 0;
}
uint32 BitSet::numberOfTrailingZeros(uint64 i) {
// HD, Figure 5-14
uint32 x, y;
if (i == 0) return 64;
uint32 n = 63;
y = (uint32)i; if (y != 0) { n = n -32; x = y; } else x = (uint32)(i>>32);
y = x <<16; if (y != 0) { n = n -16; x = y; }
y = x << 8; if (y != 0) { n = n - 8; x = y; }
y = x << 4; if (y != 0) { n = n - 4; x = y; }
y = x << 2; if (y != 0) { n = n - 2; x = y; }
return n - ((x << 1) >> 31);
}
uint32 BitSet::bitCount(uint64 i) {
// HD, Figure 5-14
i = i - ((i >> 1) & 0x5555555555555555LL);
i = (i & 0x3333333333333333LL) + ((i >> 2) & 0x3333333333333333LL);
i = (i + (i >> 4)) & 0x0f0f0f0f0f0f0f0fLL;
i = i + (i >> 8);
i = i + (i >> 16);
i = i + (i >> 32);
return (uint32)(i & 0x7f);
}
int32 BitSet::nextSetBit(uint32 fromIndex) const {
uint32 u = wordIndex(fromIndex);
if (u >= wordsInUse)
return -1;
uint64 word = words[u] & (WORD_MASK << (fromIndex % BITS_PER_WORD));
while (true) {
if (word != 0)
return (u * BITS_PER_WORD) + numberOfTrailingZeros(word);
if (++u == wordsInUse)
return -1;
word = words[u];
}
}
int32 BitSet::nextClearBit(uint32 fromIndex) const {
// Neither spec nor implementation handle bitsets of maximal length.
uint32 u = wordIndex(fromIndex);
if (u >= wordsInUse)
return fromIndex;
uint64 word = ~words[u] & (WORD_MASK << (fromIndex % BITS_PER_WORD));
while (true) {
if (word != 0)
return (u * BITS_PER_WORD) + numberOfTrailingZeros(word);
if (++u == wordsInUse)
return wordsInUse * BITS_PER_WORD;
word = ~words[u];
}
}
bool BitSet::isEmpty() const {
return (wordsInUse == 0);
}
uint32 BitSet::cardinality() const {
uint32 sum = 0;
for (uint32 i = 0; i < wordsInUse; i++)
sum += bitCount(words[i]);
return sum;
}
uint32 BitSet::size() const {
return wordsLength * BITS_PER_WORD;
}
BitSet& BitSet::operator&=(const BitSet& set) {
// Check for self-assignment!
if (this == &set) return *this;
while (wordsInUse > set.wordsInUse)
words[--wordsInUse] = 0;
// Perform logical AND on words in common
for (uint32 i = 0; i < wordsInUse; i++)
words[i] &= set.words[i];
recalculateWordsInUse();
return *this;
}
BitSet& BitSet::operator|=(const BitSet& set) {
// Check for self-assignment!
if (this == &set) return *this;
uint32 wordsInCommon = wordsInUse;
if(wordsInUse>set.wordsInUse) wordsInCommon = set.wordsInUse;
if (wordsInUse < set.wordsInUse) {
ensureCapacity(set.wordsInUse);
wordsInUse = set.wordsInUse;
}
// Perform logical OR on words in common
for (uint32 i =0; i < wordsInCommon; i++) {
words[i] |= set.words[i];
}
// Copy any remaining words
for(uint32 i=wordsInCommon; i<set.wordsInUse; ++i) {
words[i] = set.words[i];
}
// recalculateWordsInUse() is not needed
return *this;
}
BitSet& BitSet::operator^=(const BitSet& set) {
uint32 wordsInCommon = wordsInUse;
if(wordsInUse>set.wordsInUse) wordsInCommon = set.wordsInUse;
if (wordsInUse < set.wordsInUse) {
ensureCapacity(set.wordsInUse);
wordsInUse = set.wordsInUse;
}
// Perform logical OR on words in common
for (uint32 i =0; i < wordsInCommon; i++) {
words[i] ^= set.words[i];
}
// Copy any remaining words
for(uint32 i=wordsInCommon; i<set.wordsInUse; ++i) {
words[i] = set.words[i];
}
recalculateWordsInUse();
return *this;
}
BitSet& BitSet::operator=(const BitSet &set) {
// Check for self-assignment!
if (this == &set) return *this;
// we ensure that words array size is adequate (and not wordsInUse to ensure capacity to the future)
if (wordsLength < set.wordsLength)
{
if (words) delete[] words;
words = new uint64[set.wordsLength];
wordsLength = set.wordsLength;
}
memcpy(words, set.words, sizeof(uint64)*set.wordsInUse);
wordsInUse = set.wordsInUse;
return *this;
}
void BitSet::or_and(const BitSet& set1, const BitSet& set2) {
uint32 inUse = (set1.wordsInUse < set2.wordsInUse) ? set1.wordsInUse : set2.wordsInUse;
ensureCapacity(inUse);
wordsInUse = inUse;
// Perform logical AND on words in common
for (uint32 i = 0; i < inUse; i++)
words[i] |= (set1.words[i] & set2.words[i]);
// recalculateWordsInUse()...
}
bool BitSet::operator==(const BitSet &set) const
{
if (this == &set)
return true;
if (wordsInUse != set.wordsInUse)
return false;
// Check words in use by both BitSets
for (uint32 i = 0; i < wordsInUse; i++)
if (words[i] != set.words[i])
return false;
return true;
}
bool BitSet::operator!=(const BitSet &set) const
{
return !(*this == set);
}
void BitSet::toString(StringBuilder buffer, int /*indentLevel*/) const
{
*buffer += '{';
int32 i = nextSetBit(0);
char tmp[30];
if (i != -1) {
sprintf(tmp,"%d",(int)i); *buffer += tmp;
for (i = nextSetBit(i+1); i >= 0; i = nextSetBit(i+1)) {
int32 endOfRun = nextClearBit(i);
do { *buffer += ", "; sprintf(tmp,"%d",(int)i); *buffer += tmp; } while (++i < endOfRun);
}
}
*buffer += '}';
}
void BitSet::serialize(ByteBuffer* buffer, SerializableControl* flusher) const {
uint32 n = wordsInUse;
if (n == 0) {
SerializeHelper::writeSize(0, buffer, flusher);
return;
}
uint32 len = 8 * (n-1);
for (uint64 x = words[n - 1]; x != 0; x >>= 8)
len++;
SerializeHelper::writeSize(len, buffer, flusher);
flusher->ensureBuffer(len);
for (uint32 i = 0; i < n - 1; i++)
buffer->putLong(words[i]);
for (uint64 x = words[n - 1]; x != 0; x >>= 8)
buffer->putByte((int8) (x & 0xff));
}
void BitSet::deserialize(ByteBuffer* buffer, DeserializableControl* control) {
uint32 bytes = SerializeHelper::readSize(buffer, control); // in bytes
wordsInUse = (bytes + 7) / 8;
if (wordsInUse > wordsLength)
{
if (words) delete[] words;
words = new uint64[wordsInUse];
wordsLength = wordsInUse;
}
if (wordsInUse == 0)
return;
control->ensureData(bytes);
uint32 i = 0;
uint32 longs = bytes / 8;
while (i < longs)
words[i++] = buffer->getLong();
for (uint32 j = i; j < wordsInUse; j++)
words[j] = 0;
for (uint32 remaining = (bytes - longs * 8), j = 0; j < remaining; j++)
words[i] |= (buffer->getByte() & 0xffL) << (8 * j);
}
}};