com.davidehrmann.vcdiff

Interface VCDiffCodeTableWriter<OUT>

All Known Implementing Classes:

JSONCodeTableWriter, VCDiffCodeTableWriterImpl

public interface VCDiffCodeTableWriter<OUT>

Author:

David Ehrmann The method calls after construction should follow this pattern: {{add|copy|run}* output}* output() will produce an encoding using the given series of add, copy, and/or run instructions. One implementation of the interface (VCDiffCodeTableWriter) produces a VCDIFF delta window, but other implementations may be used to produce other output formats, or as test mocks, or to gather encoding statistics.

Method Summary

Modifier and Type	Method and Description
void	add(byte[] data, int offset, int length) encode an ADD opcode with the "size" length starting at offset
void	addChecksum(int checksum) add a checksum to the code table
void	copy(int offset, int size) encode a COPY opcode with args "offset" (into dictionary) and "size" bytes.
void	finishEncoding(OUT out) Finishes encoding.
void	init(int dictionarySize) Initializes the constructed object for use.
void	output(OUT out) Appends the encoded delta window to the output string.
void	run(int size, byte b) encode a RUN opcode for "size" copies of the value "b".
void	writeHeader(OUT out, EnumSet<VCDiffFormatExtension> formatExtensions) Writes the header to the output string.

Method Detail

init

void init(int dictionarySize)
   throws IOException

Initializes the constructed object for use. It will return false if there was an error initializing the object, or true if it was successful. After the object has been initialized and used, init() can be called again to restore the initial state of the object.

Parameters:

dictionarySize - size of the dictionary being used

Throws:

IOException - if the CodeTableWriter failed to initialize

writeHeader

void writeHeader(OUT out,
                 EnumSet<VCDiffFormatExtension> formatExtensions)
          throws IOException

Writes the header to the output string.

Parameters:

out - writer mechanism to write to

formatExtensions - Flags for enabling features that are extensions to the format

Throws:

IOException - if there's an exception writing to out

add

void add(byte[] data,
         int offset,
         int length)

encode an ADD opcode with the "size" length starting at offset

Parameters:

data - data to add

offset - offset in data to start from

length - total bytes to add

copy

void copy(int offset,
          int size)

encode a COPY opcode with args "offset" (into dictionary) and "size" bytes.

Parameters:

offset - offset into the dictionary to copy data from

size - number of bytes to copy from dictionary

run

void run(int size,
         byte b)

encode a RUN opcode for "size" copies of the value "b".

Parameters:

size - number of copies of the value to write

b - byte value to write

addChecksum

void addChecksum(int checksum)

add a checksum to the code table

Parameters:

checksum - checksum to write to the writer

output

void output(OUT out)
     throws IOException

Appends the encoded delta window to the output string.

Parameters:

out - writer mechanism to write to

Throws:

IOException - if there's an exception writing to out

finishEncoding

void finishEncoding(OUT out)
             throws IOException

Finishes encoding.

Parameters:

out - writer mechanism to write to

Throws:

IOException - if there's an exception writing to out