Package org.apache.lucene.util.compress

Class LowercaseAsciiCompression

java.lang.Object

org.apache.lucene.util.compress.LowercaseAsciiCompression

public final class LowercaseAsciiCompression
extends java.lang.Object

Utility class that can efficiently compress arrays that mostly contain characters in the [0x1F,0x3F) or [0x5F,0x7F) ranges, which notably include all digits, lowercase characters, '.', '-' and '_'.

Constructor Summary

Constructors

Modifier	Constructor	Description
private	LowercaseAsciiCompression()

Method Summary

Modifier and Type	Method	Description
static boolean	compress(byte[] in, int len, byte[] tmp, DataOutput out)	Compress in[0:len] into out.
static void	decompress(DataInput in, byte[] out, int len)	Decompress data that has been compressed with compress(byte[], int, byte[], DataOutput).
private static boolean	isCompressible(int b)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

LowercaseAsciiCompression

private LowercaseAsciiCompression()

Method Detail

isCompressible

private static final boolean isCompressible(int b)

compress

public static boolean compress(byte[] in,
                               int len,
                               byte[] tmp,
                               DataOutput out)
                        throws java.io.IOException

Compress in[0:len] into out. This returns false if the content cannot be compressed. The number of bytes written is guaranteed to be less than len otherwise.

Throws:

java.io.IOException

decompress

public static void decompress(DataInput in,
                              byte[] out,
                              int len)
                       throws java.io.IOException

Decompress data that has been compressed with compress(byte[], int, byte[], DataOutput). len must be the original length, not the compressed length.

Throws:

java.io.IOException