freenet.support.compress

Interface Compressor

All Known Implementing Classes:

Bzip2Compressor, Compressor.COMPRESSOR_TYPE, GzipCompressor, NewLZMACompressor, OldLZMACompressor

public interface Compressor

A data compressor. Contains methods to get all data compressors. This is for single-file compression (gzip, bzip2) as opposed to archives.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	Compressor.COMPRESSOR_TYPE

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	DEFAULT_COMPRESSORDESCRIPTOR

Method Summary

Modifier and Type	Method and Description
Bucket	compress(Bucket data, BucketFactory bf, long maxReadLength, long maxWriteLength) Compress the data.
long	compress(java.io.InputStream input, java.io.OutputStream output, long maxReadLength, long maxWriteLength) Compress the data.
long	compress(java.io.InputStream input, java.io.OutputStream output, long maxReadLength, long maxWriteLength, long amountOfDataToCheckCompressionRatio, int minimumCompressionPercentage) Compress the data (@see compress(InputStream, OutputStream, long, long)) with checking of compression effect.
int	decompress(byte[] dbuf, int i, int j, byte[] output) Decompress in RAM only.
long	decompress(java.io.InputStream input, java.io.OutputStream output, long maxLength, long maxEstimateSizeLength) Decompress data.

Field Detail

DEFAULT_COMPRESSORDESCRIPTOR

static final java.lang.String DEFAULT_COMPRESSORDESCRIPTOR

Method Detail

compress

Bucket compress(Bucket data,
                BucketFactory bf,
                long maxReadLength,
                long maxWriteLength)
         throws java.io.IOException,
                CompressionOutputSizeException

Compress the data.

Parameters:

data - The bucket to read from.

bf - The means to create a new bucket.

maxReadLength - The maximum number of bytes to read from the input bucket.

maxWriteLength - The maximum number of bytes to write to the output bucket. If this is exceeded, throw a CompressionOutputSizeException.

Returns:

The compressed data.

Throws:

java.io.IOException - If an error occurs reading or writing data.

CompressionOutputSizeException - If the compressed data is larger than maxWriteLength.

compress

long compress(java.io.InputStream input,
              java.io.OutputStream output,
              long maxReadLength,
              long maxWriteLength)
       throws java.io.IOException,
              CompressionOutputSizeException

Compress the data.

Parameters:

input - The InputStream to read from.

output - The OutputStream to write to.

maxReadLength - The maximum number of bytes to read from the input bucket.

maxWriteLength - The maximum number of bytes to write to the output bucket. If this is exceeded, throw a CompressionOutputSizeException.

Returns:

The compressed data.

Throws:

java.io.IOException - If an error occurs reading or writing data.

CompressionOutputSizeException - If the compressed data is larger than maxWriteLength.

compress

long compress(java.io.InputStream input,
              java.io.OutputStream output,
              long maxReadLength,
              long maxWriteLength,
              long amountOfDataToCheckCompressionRatio,
              int minimumCompressionPercentage)
       throws java.io.IOException,
              CompressionRatioException

Compress the data (@see compress(InputStream, OutputStream, long, long)) with checking of compression effect.

Parameters:

amountOfDataToCheckCompressionRatio - The data amount after compression of which we will check whether we have got the desired effect.

minimumCompressionPercentage - The minimal desired compression effect, %. A value of 0 means that the compression effect will not be checked.

Throws:

CompressionRatioException - If the desired compression effect is not achieved.

java.io.IOException

decompress

long decompress(java.io.InputStream input,
                java.io.OutputStream output,
                long maxLength,
                long maxEstimateSizeLength)
         throws java.io.IOException,
                CompressionOutputSizeException

Decompress data.

Parameters:

input - Where to read the data to decompress from

output - Where to write the final product to

maxLength - The maximum length to decompress (we throw if more is present).

maxEstimateSizeLength - If the data is too big, and this is >0, read up to this many bytes in order to try to get the data size.

Returns:

Number of bytes copied

Throws:

java.io.IOException

CompressionOutputSizeException

decompress

int decompress(byte[] dbuf,
               int i,
               int j,
               byte[] output)
        throws CompressionOutputSizeException

Decompress in RAM only.

Parameters:

dbuf - Input buffer.

i - Offset to start reading from.

j - Number of bytes to read.

output - Output buffer.

Throws:

DecompressException

CompressionOutputSizeException