BinaryDeltaCompressor Class

Oracle® Fusion Middleware .NET API Reference for Oracle Coherence
14c (14.1.1.0)
F23534-02

An IDeltaCompressor implementation that works with opaque (binary) values.

Inheritance Hierarchy

SystemObject
Tangosol.IOBinaryDeltaCompressor

Namespace: Tangosol.IO
Assembly: Coherence (in Coherence.dll) Version: 14.1.1.14 (14.1.1.14)

Syntax

Copy

public class BinaryDeltaCompressor : IDeltaCompressor

The BinaryDeltaCompressor type exposes the following members.

Constructors

	Name	Description
	BinaryDeltaCompressor	Initializes a new instance of the BinaryDeltaCompressor class

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Methods

	Name	Description
	ApplyDelta	Apply a delta to an old value in order to create a new value.
	CreateDelta	Actually create a delta in the binary delta format. This method is designed to be overridden by subclasses that have more intimate knowledge of the contents of the buffers.
	EnsureWriter	Make sure that a DataWriter exists if one doesn't already.
	Equals	Determines whether the specified object is equal to the current object. (Inherited from Object.)
	ExtractDelta	Compare an old value to a new value and generate a delta that represents the changes that must be made to the old value in order to transform it into the new value.
	Finalize	Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
	FinalizeDelta	Convert an open delta output stream into a finalized Binary delta.
	GetHashCode	Serves as the default hash function. (Inherited from Object.)
	GetType	Gets the Type of the current instance. (Inherited from Object.)
	MemberwiseClone	Creates a shallow copy of the current Object. (Inherited from Object.)
	ToString	Returns a string that represents the current object. (Inherited from Object.)
	WriteAppend	Encode a binary diff "append" operator to indicate that bytes should be appended from the delta stream to the new value.
	WriteExtract	Encode a binary diff "extract" operator to indicate that bytes should be copied from the old value to the new value.

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Fields

	Name	Description
	DELTA_TRUNCATE	A delta value that indicates an empty new value.
	FMT_BINDIFF	A format indicator (the first byte of the binary delta) that indicates that the new value is formed by applying a series of modifications to the old value. The possible modifications are defined by the OP_* constants.
	FMT_EMPTY	A format indicator (the first byte of the binary delta) that indicates that the new value is a zero-length binary value.
	FMT_REPLACE	A format indicator (the first byte of the binary delta) that indicates that the new value is found in its entirety in the delta value. In other words, other than the first byte, the delta is itself the new value.
	MIN_BLOCK	Minimum length of an "extract" block to encode.
	NO_BINARY	An empty Binary object.
	OP_APPEND	A binary delta operator that instructs the {@link #applyDelta} method to copy the following bytes from the delta value and append them to the new value. The format is the one-byte OP_APPEND indicator followed by a packed int length and then a series of bytes. The length indicates the length of the series of bytes to copy from the delta value and append to the new value.
	OP_EXTRACT	A binary delta operator that instructs the ApplyDelta(Binary, Binary) method to extract bytes from the old value and append them to the new value. The format is the one-byte OP_EXTRACT indicator followed by a packed int offset and packed int length. The offset and length indicate the region of the old value to extract and append to the new value.
	OP_TERM	A binary delta operator that instructs the {@link #applyDelta} method that the delta has been fully applied.

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Remarks

The delta format is composed of a leading byte that indicates the format; the format indicator byte is one of the FMT_* field values. If the delta value does not begin with one of the FMT_* indicators, then the delta value is itself the new value. If the delta is null, then it indicates no change. The grammar follows:

             BinaryDelta:
               FMT_EMPTY
               FMT_BINDIFF BinaryChangeList-opt OP_TERM
               FMT_REPLACE-opt Bytes
               null
            
             BinaryChangeList:
               OP_EXTRACT Offset Length BinaryChangeList-opt
               OP_APPEND Length Bytes BinaryChangeList-opt
            
             Offset:
             Length:
               packed-integer
            
             Bytes:
               byte Bytes-opt

Reference

Tangosol.IO Namespace