Package io.datarouter.bytes.compress.gzip

Class GzipBlockStream

java.lang.Object

io.datarouter.bytes.compress.gzip.GzipBlockStream

public class GzipBlockStream
extends Object

Gzip normally encodes and decodes in a single thread which underutilizes multi-threaded hardware. The data must be written to a single OutputStream and read from a single InputStream which is not parallelizable. Alternatively we can split the data into blocks and run the gzip encoding on each block in separate threads. This class splits the incoming bytes into blocks and gzips each block independently. Small tokens can be combined into GzipBlockStreamRow objects, where each row will be fully owned by one block. When writing, it prepends a block length header before writing each gzipped data block. When reading, the main thread can pull gzipped blocks from the InputStream and pass them to other threads to decode. Besides un-gzipping, blocks can further decoded in helper threads. Note that this is not compatible with the normal Gzip file format.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	GzipBlockStream.GzipBlockStreamEncodedBlock	Returned while encoding with convenience methods.
static final record	GzipBlockStream.GzipBlockStreamRow	One or more tokens that make up a "row" of data.

Constructor Summary

Constructors

Constructor	Description
GzipBlockStream()
GzipBlockStream(int blockSize)
GzipBlockStream(int blockSize, int encodeBufferSize, int gzipBufferSize, int decodeBufferSize)

Method Summary

Modifier and Type	Method	Description
io.datarouter.scanner.Scanner<byte[]>	decode(InputStream inputStream)	Convert an InputStream containing gzip blocks into a Scanner of raw blocks.
io.datarouter.scanner.Scanner<byte[]>	decodeParallel(InputStream inputStream, io.datarouter.scanner.Threads threads)	Convert an InputStream containing gzip blocks into a Scanner of raw blocks.
io.datarouter.scanner.Scanner<GzipBlockStream.GzipBlockStreamEncodedBlock>	encode(io.datarouter.scanner.Scanner<GzipBlockStream.GzipBlockStreamRow> rows)	Split the provided rows into larger blocks.
io.datarouter.scanner.Scanner<GzipBlockStream.GzipBlockStreamEncodedBlock>	encodeParallel(io.datarouter.scanner.Scanner<GzipBlockStream.GzipBlockStreamRow> rows, io.datarouter.scanner.Threads threads)	Split the provided rows into larger blocks.
long	getNumBlocksEncoded()
GzipBlockStream	resetCounters()

Methods inherited from class java.lang.Object

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

Constructor Details

GzipBlockStream

public GzipBlockStream()

GzipBlockStream

public GzipBlockStream(int blockSize)

GzipBlockStream

public GzipBlockStream(int blockSize,
 int encodeBufferSize,
 int gzipBufferSize,
 int decodeBufferSize)

Method Details

encode

public io.datarouter.scanner.Scanner<GzipBlockStream.GzipBlockStreamEncodedBlock> encode(io.datarouter.scanner.Scanner<GzipBlockStream.GzipBlockStreamRow> rows)

Split the provided rows into larger blocks. Encode the blocks to gzip.

encodeParallel

public io.datarouter.scanner.Scanner<GzipBlockStream.GzipBlockStreamEncodedBlock> encodeParallel(io.datarouter.scanner.Scanner<GzipBlockStream.GzipBlockStreamRow> rows,
 io.datarouter.scanner.Threads threads)

Split the provided rows into larger blocks. Pass each block to the provided executor for parallel encoding to gzip.

decode

public io.datarouter.scanner.Scanner<byte[]> decode(InputStream inputStream)

Convert an InputStream containing gzip blocks into a Scanner of raw blocks.

decodeParallel

public io.datarouter.scanner.Scanner<byte[]> decodeParallel(InputStream inputStream,
 io.datarouter.scanner.Threads threads)

Convert an InputStream containing gzip blocks into a Scanner of raw blocks. Offload the gzip decoding to the provided executor.

getNumBlocksEncoded

public long getNumBlocksEncoded()

resetCounters

public GzipBlockStream resetCounters()