Package org.apache.lucene.util.compress
Class LZ4.HighCompressionHashTable
- java.lang.Object
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- org.apache.lucene.util.compress.LZ4.HashTable
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- org.apache.lucene.util.compress.LZ4.HighCompressionHashTable
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- Enclosing class:
- LZ4
public static final class LZ4.HighCompressionHashTable extends LZ4.HashTable
A higher-precisionLZ4.HashTable
. It stores up to 256 occurrences of 4-bytes sequences in the last2^16
bytes, which makes it much more likely to find matches thanLZ4.FastCompressionHashTable
.
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Field Summary
Fields Modifier and Type Field Description private int
attempts
private int
base
private byte[]
bytes
private short[]
chainTable
private int
end
private int[]
hashTable
private static int
MASK
private static int
MAX_ATTEMPTS
private int
next
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Constructor Summary
Constructors Constructor Description HighCompressionHashTable()
Sole constructor
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description private void
addHash(int off)
(package private) boolean
assertReset()
(package private) int
get(int off)
Advance the cursor tooff
and return an index that stored the same 4 bytes asb[o:o+4)
.(package private) void
initDictionary(int dictLen)
InitdictLen
bytes to be used as a dictionary.(package private) int
previous(int off)
Return an index that less thanoff
and stores the same 4 bytes.(package private) void
reset(byte[] bytes, int off, int len)
Reset this hash table in order to compress the given content.
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Field Detail
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MAX_ATTEMPTS
private static final int MAX_ATTEMPTS
- See Also:
- Constant Field Values
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MASK
private static final int MASK
- See Also:
- Constant Field Values
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bytes
private byte[] bytes
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base
private int base
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next
private int next
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end
private int end
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hashTable
private final int[] hashTable
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chainTable
private final short[] chainTable
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attempts
private int attempts
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Method Detail
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reset
void reset(byte[] bytes, int off, int len)
Description copied from class:LZ4.HashTable
Reset this hash table in order to compress the given content.- Specified by:
reset
in classLZ4.HashTable
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initDictionary
void initDictionary(int dictLen)
Description copied from class:LZ4.HashTable
InitdictLen
bytes to be used as a dictionary.- Specified by:
initDictionary
in classLZ4.HashTable
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get
int get(int off)
Description copied from class:LZ4.HashTable
Advance the cursor tooff
and return an index that stored the same 4 bytes asb[o:o+4)
. This may only be called on strictly increasing sequences of offsets. A return value of-1
indicates that no other index could be found.- Specified by:
get
in classLZ4.HashTable
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addHash
private void addHash(int off)
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previous
int previous(int off)
Description copied from class:LZ4.HashTable
Return an index that less thanoff
and stores the same 4 bytes. UnlikeLZ4.HashTable.get(int)
, it doesn't need to be called on increasing offsets. A return value of-1
indicates that no other index could be found.- Specified by:
previous
in classLZ4.HashTable
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assertReset
boolean assertReset()
- Specified by:
assertReset
in classLZ4.HashTable
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