org.metastatic.rsync
Class Rdiff

java.lang.Object
  |
  +--org.metastatic.rsync.Rdiff

public class Rdiff

extends Object

A re-implementation of the rdiff utility from librsync. For more info see the rproxy page.

Field Summary

protected int	blockLength The length of blocks to checksum.
static short	CHAR_OFFSET
static int	CHUNK_SIZE
static String	DELTA The `delta' command.
static int	DELTA_MAGIC Rdiff/rproxy delta magic.
protected static LongOpt[]	LONGOPTS The long options.
static byte	OP_COPY_N4_N4
static byte	OP_END
static byte	OP_LITERAL_N1
static byte	OP_LITERAL_N2
static byte	OP_LITERAL_N4
static byte	OP_LITERAL_N8
protected static String	OPTSTRING The short options.
static String	PATCH The `patch' command.
static String	PROGNAME The program name printed to the console.
static int	RDIFF_BLOCK_LENGTH Rdiff/rproxy default block length.
static int	RDIFF_STRONG_LENGTH Rdiff/rproxy default sum length.
static int	SIG_MAGIC Rdiff/rproxy signature magic.
static String	SIGNATURE The `signature' command.
protected int	strongSumLength The effective strong signature length.
static int	SUM_LENGTH The strong checksum length.
protected static boolean	verbose Whether or not to trace to System.err.

Constructor Summary

Rdiff()
Create an Rdiff object.

Method Summary

static void	main(String[] argv) Main entry point for console use.
List	makeDeltas(List sums, InputStream in) Make a collection of Deltas from the given sums and InputStream.
void	makeDeltas(List sums, InputStream in, OutputStream out)
List	makeSignatures(InputStream in) Make the signatures from data coming in through the input stream.
void	makeSignatures(InputStream in, OutputStream out) Generate and write the signatures.
List	readDeltas(InputStream in) Read a collection of Deltas from the InputStream.
List	readSignatures(InputStream in) Read the signatures from the input stream.
void	rebuildFile(File basis, InputStream deltas, OutputStream out)
void	rebuildFile(File basis, List deltas, OutputStream out) Patch the file basis using deltas, writing the patched file to out.
void	writeDeltas(List deltas, OutputStream out) Write deltas to an output stream.
void	writeSignatures(List sigs, OutputStream out) Write the signatures to the specified output stream.

Methods inherited from class java.lang.Object

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

Field Detail

OPTSTRING

protected static final String OPTSTRING

The short options.

See Also:

Constant Field Values

LONGOPTS

protected static final LongOpt[] LONGOPTS

The long options.

SUM_LENGTH

public static final int SUM_LENGTH

The strong checksum length.

See Also:

Constant Field Values

CHUNK_SIZE

public static final int CHUNK_SIZE

See Also:

Constant Field Values

RDIFF_BLOCK_LENGTH

public static final int RDIFF_BLOCK_LENGTH

Rdiff/rproxy default block length.

See Also:

Constant Field Values

RDIFF_STRONG_LENGTH

public static final int RDIFF_STRONG_LENGTH

Rdiff/rproxy default sum length.

See Also:

Constant Field Values

SIG_MAGIC

public static final int SIG_MAGIC

Rdiff/rproxy signature magic.

See Also:

Constant Field Values

DELTA_MAGIC

public static final int DELTA_MAGIC

Rdiff/rproxy delta magic.

See Also:

Constant Field Values

OP_END

public static final byte OP_END

See Also:

Constant Field Values

OP_LITERAL_N1

public static final byte OP_LITERAL_N1

See Also:

Constant Field Values

OP_LITERAL_N2

public static final byte OP_LITERAL_N2

See Also:

Constant Field Values

OP_LITERAL_N4

public static final byte OP_LITERAL_N4

See Also:

Constant Field Values

OP_LITERAL_N8

public static final byte OP_LITERAL_N8

See Also:

Constant Field Values

OP_COPY_N4_N4

public static final byte OP_COPY_N4_N4

See Also:

Constant Field Values

SIGNATURE

public static final String SIGNATURE

The `signature' command.

See Also:

Constant Field Values

DELTA

public static final String DELTA

The `delta' command.

See Also:

Constant Field Values

PATCH

public static final String PATCH

The `patch' command.

See Also:

Constant Field Values

PROGNAME

public static final String PROGNAME

The program name printed to the console.

See Also:

Constant Field Values

CHAR_OFFSET

public static final short CHAR_OFFSET

See Also:

Constant Field Values

verbose

protected static boolean verbose

Whether or not to trace to System.err.

blockLength

protected int blockLength

The length of blocks to checksum.

strongSumLength

protected int strongSumLength

The effective strong signature length.

Constructor Detail

Rdiff

public Rdiff()

Create an Rdiff object.

Method Detail

main

public static void main(String[] argv)
                 throws Throwable

Main entry point for console use.

Parameters:

argv - The argument vector.

Throwable

makeSignatures

public void makeSignatures(InputStream in,
                           OutputStream out)
                    throws IOException,
                           NoSuchAlgorithmException

Generate and write the signatures.

IOException

NoSuchAlgorithmException

writeSignatures

public void writeSignatures(List sigs,
                            OutputStream out)
                     throws IOException

Write the signatures to the specified output stream.

Parameters:

sigs - The signatures to write.

out - The OutputStream to write to.

Throws:

IOException - If writing fails.

makeSignatures

public List makeSignatures(InputStream in)
                    throws IOException,
                           NoSuchAlgorithmException

Make the signatures from data coming in through the input stream.

Parameters:

in - The input stream to generate signatures for.

Returns:

A List of signatures.

Throws:

IOException - If reading fails.

NoSuchAlgorithmException

readSignatures

public List readSignatures(InputStream in)
                    throws IOException

Read the signatures from the input stream.

Parameters:

in - The InputStream to read the signatures from.

Returns:

A collection of ChecksumPairs read.

Throws:

IOException - If the input stream is malformed.

makeDeltas

public void makeDeltas(List sums,
                       InputStream in,
                       OutputStream out)
                throws IOException,
                       NoSuchAlgorithmException

IOException

NoSuchAlgorithmException

writeDeltas

public void writeDeltas(List deltas,
                        OutputStream out)
                 throws IOException

Write deltas to an output stream.

Parameters:

deltas - A collection of Deltas to write.

out - The OutputStream to write to.

Throws:

IOException - If writing fails.

makeDeltas

public List makeDeltas(List sums,
                       InputStream in)
                throws IOException,
                       NoSuchAlgorithmException

Make a collection of Deltas from the given sums and InputStream.

Parameters:

sums - A collection of ChecksumPairs generated from the "old" file.

in - The InputStream for the "new" file.

Returns:

A collection of Deltas that will patch the old file to the new.

Throws:

IOException - If reading fails.

NoSuchAlgorithmException

readDeltas

public List readDeltas(InputStream in)
                throws IOException

Read a collection of Deltas from the InputStream.

Parameters:

in - The InputStream to read from.

Returns:

A collection of Deltas read.

Throws:

IOException - If the input stream is malformed.

rebuildFile

public void rebuildFile(File basis,
                        InputStream deltas,
                        OutputStream out)
                 throws IOException

IOException

rebuildFile

public void rebuildFile(File basis,
                        List deltas,
                        OutputStream out)
                 throws IOException

Patch the file basis using deltas, writing the patched file to out.

Parameters:

basis - The basis file.

deltas - The collection of Deltas to apply.

out - The OutputStream to write the patched file to.

Throws:

IOException - If reading/writing fails.