Package org.apache.lucene.util.compress
Class LZ4
- java.lang.Object
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- org.apache.lucene.util.compress.LZ4
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public final class LZ4 extends Object
LZ4 compression and decompression routines. https://github.com/lz4/lz4/tree/dev/lib http://fastcompression.blogspot.fr/p/lz4.html The high-compression option is a simpler version of the one of the original algorithm, and only retains a better hash table that remembers about more occurrences of a previous 4-bytes sequence, and removes all the logic about handling of the case when overlapping matches are found.
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Nested Class Summary
Nested Classes Modifier and Type Class Description static class
LZ4.FastCompressionHashTable
Simple lossyLZ4.HashTable
that only stores the last ocurrence for each hash on2^14
bytes of memory.static class
LZ4.HighCompressionHashTable
A higher-precisionLZ4.HashTable
.
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Method Summary
All Methods Static Methods Concrete Methods Modifier and Type Method Description static void
compress(byte[] bytes, int off, int len, DataOutput out, org.apache.lucene.util.compress.LZ4.HashTable ht)
Compressbytes[off:off+len]
intoout
using at most 16KB of memory.static int
decompress(DataInput compressed, int decompressedLen, byte[] dest)
Decompress at leastdecompressedLen
bytes intodest[dOff:]
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Method Detail
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decompress
public static int decompress(DataInput compressed, int decompressedLen, byte[] dest) throws IOException
Decompress at leastdecompressedLen
bytes intodest[dOff:]
. Please note thatdest
must be large enough to be able to hold all decompressed data (meaning that you need to know the total decompressed length).- Throws:
IOException
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compress
public static void compress(byte[] bytes, int off, int len, DataOutput out, org.apache.lucene.util.compress.LZ4.HashTable ht) throws IOException
Compressbytes[off:off+len]
intoout
using at most 16KB of memory.ht
shouldn't be shared across threads but can safely be reused.- Throws:
IOException
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