LUCENE-5277: Modify FixedBitSet copy constructor to take numBits to allow grow/shrink the new bitset

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1531627 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Shai Erera 2013-10-13 08:21:32 +00:00
parent 8b35981608
commit 544d997664
3 changed files with 62 additions and 12 deletions

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@ -146,6 +146,10 @@ API Changes:
* LUCENE-5275: Change AttributeSource.toString() to display the current
state of attributes. (Robert Muir)
* LUCENE-5277: Modify FixedBitSet copy constructor to take an additional
numBits parameter to allow growing/shrinking the copied bitset. You can
use FixedBitSet.clone() if you only need to clone the bitset. (Shai Erera)
Optimizations
* LUCENE-5225: The ToParentBlockJoinQuery only keeps tracks of the the child

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@ -35,7 +35,6 @@ import org.apache.lucene.search.DocIdSetIterator;
*
* @lucene.internal
**/
public final class FixedBitSet extends DocIdSet implements Bits {
private final long[] bits;
private final int numBits;
@ -65,12 +64,16 @@ public final class FixedBitSet extends DocIdSet implements Bits {
this.bits = storedBits;
}
/** Makes full copy. */
public FixedBitSet(FixedBitSet other) {
bits = new long[other.wordLength];
System.arraycopy(other.bits, 0, bits, 0, other.wordLength);
numBits = other.numBits;
wordLength = other.wordLength;
/**
* Makes a full copy of the bits, while allowing to expand/shrink the bitset.
* If {@code numBits < other.numBits}, then only the first {@code numBits}
* are copied from other.
*/
public FixedBitSet(FixedBitSet other, int numBits) {
wordLength = bits2words(numBits);
bits = new long[wordLength];
System.arraycopy(other.bits, 0, bits, 0, Math.min(other.wordLength, wordLength));
this.numBits = numBits;
}
@Override
@ -403,7 +406,7 @@ public final class FixedBitSet extends DocIdSet implements Bits {
@Override
public FixedBitSet clone() {
return new FixedBitSet(this);
return new FixedBitSet(this, numBits);
}
/** returns true if both sets have the same bits set */

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@ -328,7 +328,50 @@ public class TestFixedBitSet extends BaseDocIdSetTestCase<FixedBitSet> {
checkNextSetBitArray(new int[0], setBits.length + random().nextInt(10));
}
public void testGrow() {
FixedBitSet bits = new FixedBitSet(5);
bits.set(1);
bits.set(4);
FixedBitSet newBits = new FixedBitSet(bits, 8); // grow within the word
assertTrue(newBits.get(1));
assertTrue(newBits.get(4));
newBits = new FixedBitSet(bits, 72); // grow beyond one word
assertTrue(newBits.get(1));
assertTrue(newBits.get(4));
}
public void testShrink() {
FixedBitSet bits = new FixedBitSet(72);
bits.set(1);
bits.set(4);
bits.set(69);
FixedBitSet newBits = new FixedBitSet(bits, 66); // shrink within the word
assertTrue(newBits.get(1));
assertTrue(newBits.get(4));
boolean hitError = true;
try {
newBits.get(69);
hitError = false;
} catch (AssertionError e) {
hitError = true;
}
assertTrue(hitError);
newBits = new FixedBitSet(bits, 8); // shrink beyond one word
assertTrue(newBits.get(1));
assertTrue(newBits.get(4));
hitError = true;
try {
newBits.get(69);
hitError = false;
} catch (AssertionError e) {
hitError = true;
}
assertTrue(hitError);
}
}