public class MinHashFilter extends TokenFilter
Modifier and Type | Class and Description |
---|---|
(package private) static class |
MinHashFilter.FixedSizeTreeSet<E extends java.lang.Comparable<E>> |
(package private) static class |
MinHashFilter.LongPair
128 bits of state
|
AttributeSource.State
Modifier and Type | Field and Description |
---|---|
private int |
bucketCount |
private int |
bucketPosition |
private long |
bucketSize |
private static MinHashFilter.LongPair[] |
cachedIntHashes |
static int |
DEFAULT_BUCKET_COUNT |
static int |
DEFAULT_HASH_COUNT |
static int |
DEFAULT_HASH_SET_SIZE |
private int |
endOffset |
private AttributeSource.State |
endState |
private boolean |
exhausted |
private static int |
HASH_CACHE_SIZE |
private int |
hashCount |
private int |
hashPosition |
private int |
hashSetSize |
(package private) static java.lang.String |
MIN_HASH_TYPE |
private java.util.List<java.util.List<MinHashFilter.FixedSizeTreeSet<MinHashFilter.LongPair>>> |
minHashSets |
private OffsetAttribute |
offsetAttribute |
private PositionIncrementAttribute |
posIncAttribute |
private PositionLengthAttribute |
posLenAttribute |
private boolean |
requiresInitialisation |
private CharTermAttribute |
termAttribute |
private TypeAttribute |
typeAttribute |
private boolean |
withRotation |
input
DEFAULT_TOKEN_ATTRIBUTE_FACTORY
Constructor and Description |
---|
MinHashFilter(TokenStream input,
int hashCount,
int bucketCount,
int hashSetSize,
boolean withRotation)
create a MinHash filter
|
Modifier and Type | Method and Description |
---|---|
private static MinHashFilter.LongPair |
combineOrdered(MinHashFilter.LongPair... hashCodes) |
private void |
doRest() |
void |
end()
This method is called by the consumer after the last token has been
consumed, after
TokenStream.incrementToken() returned false
(using the new TokenStream API). |
private static long |
fmix64(long k) |
(package private) static byte[] |
getBytes(int i) |
private static MinHashFilter.LongPair |
getIntHash(int i) |
private static long |
getLongLittleEndian(byte[] buf,
int offset)
Gets a long from a byte buffer in little endian byte order.
|
boolean |
incrementToken()
Consumers (i.e.,
IndexWriter ) use this method to advance the stream to
the next token. |
private static char |
int0(int x) |
private static char |
int1(int x) |
(package private) static boolean |
isLessThanUnsigned(long n1,
long n2) |
private static char |
long0(long x) |
private static char |
long1(long x) |
private static char |
long2(long x) |
private static char |
long3(long x) |
(package private) static void |
murmurhash3_x64_128(byte[] key,
int offset,
int len,
int seed,
MinHashFilter.LongPair out)
Returns the MurmurHash3_x64_128 hash, placing the result in "out".
|
void |
reset()
This method is called by a consumer before it begins consumption using
TokenStream.incrementToken() . |
close
addAttribute, addAttributeImpl, captureState, clearAttributes, cloneAttributes, copyTo, endAttributes, equals, getAttribute, getAttributeClassesIterator, getAttributeFactory, getAttributeImplsIterator, hasAttribute, hasAttributes, hashCode, reflectAsString, reflectWith, removeAllAttributes, restoreState, toString
private static final int HASH_CACHE_SIZE
private static final MinHashFilter.LongPair[] cachedIntHashes
public static final int DEFAULT_HASH_COUNT
public static final int DEFAULT_HASH_SET_SIZE
public static final int DEFAULT_BUCKET_COUNT
static final java.lang.String MIN_HASH_TYPE
private final java.util.List<java.util.List<MinHashFilter.FixedSizeTreeSet<MinHashFilter.LongPair>>> minHashSets
private int hashSetSize
private int bucketCount
private int hashCount
private boolean requiresInitialisation
private AttributeSource.State endState
private int hashPosition
private int bucketPosition
private long bucketSize
private final boolean withRotation
private int endOffset
private boolean exhausted
private final CharTermAttribute termAttribute
private final OffsetAttribute offsetAttribute
private final TypeAttribute typeAttribute
private final PositionIncrementAttribute posIncAttribute
private final PositionLengthAttribute posLenAttribute
public MinHashFilter(TokenStream input, int hashCount, int bucketCount, int hashSetSize, boolean withRotation)
input
- the token streamhashCount
- the no. of hashesbucketCount
- the no. of buckets for hashinghashSetSize
- the no. of min hashes to keepwithRotation
- whether rotate or not hashes while incrementing tokensstatic byte[] getBytes(int i)
public final boolean incrementToken() throws java.io.IOException
TokenStream
IndexWriter
) use this method to advance the stream to
the next token. Implementing classes must implement this method and update
the appropriate AttributeImpl
s with the attributes of the next
token.
The producer must make no assumptions about the attributes after the method
has been returned: the caller may arbitrarily change it. If the producer
needs to preserve the state for subsequent calls, it can use
AttributeSource.captureState()
to create a copy of the current attribute state.
This method is called for every token of a document, so an efficient
implementation is crucial for good performance. To avoid calls to
AttributeSource.addAttribute(Class)
and AttributeSource.getAttribute(Class)
,
references to all AttributeImpl
s that this stream uses should be
retrieved during instantiation.
To ensure that filters and consumers know which attributes are available,
the attributes must be added during instantiation. Filters and consumers
are not required to check for availability of attributes in
TokenStream.incrementToken()
.
incrementToken
in class TokenStream
java.io.IOException
private static MinHashFilter.LongPair getIntHash(int i)
public void end() throws java.io.IOException
TokenFilter
TokenStream.incrementToken()
returned false
(using the new TokenStream
API). Streams implementing the old API
should upgrade to use this feature.
This method can be used to perform any end-of-stream operations, such as setting the final offset of a stream. The final offset of a stream might differ from the offset of the last token eg in case one or more whitespaces followed after the last token, but a WhitespaceTokenizer was used.
Additionally any skipped positions (such as those removed by a stopfilter) can be applied to the position increment, or any adjustment of other attributes where the end-of-stream value may be important.
If you override this method, always call super.end()
.
NOTE:
The default implementation chains the call to the input TokenStream, so
be sure to call super.end()
first when overriding this method.
end
in class TokenFilter
java.io.IOException
- If an I/O error occurspublic void reset() throws java.io.IOException
TokenFilter
TokenStream.incrementToken()
.
Resets this stream to a clean state. Stateful implementations must implement this method so that they can be reused, just as if they had been created fresh.
If you override this method, always call super.reset()
, otherwise
some internal state will not be correctly reset (e.g., Tokenizer
will
throw IllegalStateException
on further usage).
NOTE:
The default implementation chains the call to the input TokenStream, so
be sure to call super.reset()
when overriding this method.
reset
in class TokenFilter
java.io.IOException
private void doRest()
private static char long0(long x)
private static char long1(long x)
private static char long2(long x)
private static char long3(long x)
private static char int0(int x)
private static char int1(int x)
static boolean isLessThanUnsigned(long n1, long n2)
private static MinHashFilter.LongPair combineOrdered(MinHashFilter.LongPair... hashCodes)
private static long getLongLittleEndian(byte[] buf, int offset)
static void murmurhash3_x64_128(byte[] key, int offset, int len, int seed, MinHashFilter.LongPair out)
private static long fmix64(long k)