org.apache.iotdb.tsfile.compress

Interface ICompressor

All Superinterfaces:

Serializable

All Known Implementing Classes:

ICompressor.GZIPCompressor, ICompressor.IOTDBLZ4Compressor, ICompressor.NoCompressor, ICompressor.SnappyCompressor

public interface ICompressor
extends Serializable

compress data according to type in schema.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	ICompressor.GZIPCompress
static class	ICompressor.GZIPCompressor
static class	ICompressor.IOTDBLZ4Compressor
static class	ICompressor.NoCompressor NoCompressor will do nothing for data and return the input data directly.
static class	ICompressor.SnappyCompressor

Method Summary

Modifier and Type	Method and Description
byte[]	compress(byte[] data)
byte[]	compress(byte[] data, int offset, int length) abstract method of compress.
int	compress(byte[] data, int offset, int length, byte[] compressed) abstract method of compress.
int	compress(ByteBuffer data, ByteBuffer compressed) If the data is large, this function is better than byte[].
static ICompressor	getCompressor(CompressionType name) get Compressor according to CompressionType.
static ICompressor	getCompressor(String name)
int	getMaxBytesForCompression(int uncompressedDataSize) Get the maximum byte size needed for compressing data of the given byte size.
CompressionType	getType()

Method Detail

getCompressor

static ICompressor getCompressor(String name)

getCompressor

static ICompressor getCompressor(CompressionType name)

get Compressor according to CompressionType.

Parameters:

name - CompressionType

Returns:

the Compressor of specified CompressionType

compress

byte[] compress(byte[] data)
         throws IOException

Throws:

IOException

compress

byte[] compress(byte[] data,
                int offset,
                int length)
         throws IOException

abstract method of compress. this method has an important overhead due to the fact that it needs to allocate a byte array to compress into, and then needs to resize this buffer to the actual compressed length.

Returns:

byte array of compressed data.

Throws:

IOException

compress

int compress(byte[] data,
             int offset,
             int length,
             byte[] compressed)
      throws IOException

abstract method of compress.

Returns:

byte length of compressed data.

Throws:

IOException

compress

int compress(ByteBuffer data,
             ByteBuffer compressed)
      throws IOException

If the data is large, this function is better than byte[].

Parameters:

data - MUST be DirectByteBuffer for Snappy.

compressed - MUST be DirectByteBuffer for Snappy.

Returns:

byte length of compressed data.

Throws:

IOException

getMaxBytesForCompression

int getMaxBytesForCompression(int uncompressedDataSize)

Get the maximum byte size needed for compressing data of the given byte size. For GZIP, this method is insecure and may cause GZIPCompressOverflowException

Parameters:

uncompressedDataSize - byte size of the data to compress

Returns:

maximum byte size of the compressed data

getType

CompressionType getType()