C# 클래스 Lucene.Net.Codecs.CodecUtil

Utility class for reading and writing versioned headers.

Writing codec headers is useful to ensure that a file is in the format you think it is. @lucene.experimental

공개 프로퍼티들

프로퍼티	타입	설명
FOOTER_MAGIC	int

공개 메소드들

메소드	설명
CheckEOF ( IndexInput @in ) : void	Checks that the stream is positioned at the end, and throws exception if it is not.
CheckFooter ( Lucene.Net.Store.ChecksumIndexInput @in ) : long	Validates the codec footer previously written by #writeFooter.
CheckHeader ( DataInput @in, string codec, int minVersion, int maxVersion ) : int	Reads and validates a header previously written with #writeHeader(DataOutput, String, int). When reading a file, supply the expected `codec` and an expected version range (`minVersion to maxVersion`).
CheckHeaderNoMagic ( DataInput @in, string codec, int minVersion, int maxVersion ) : int	Like {@link #checkHeader(DataInput,String,int,int)} except this version assumes the first int has already been read and validated from the input.
ChecksumEntireFile ( IndexInput input ) : long	Clones the provided input, reads all bytes from the file, and calls #checkFooter Note that this method may be slow, as it must process the entire file. If you just need to extract the checksum value, call #retrieveChecksum.
FooterLength ( ) : int	Computes the length of a codec footer.
HeaderLength ( string codec ) : int	Computes the length of a codec header.
RetrieveChecksum ( IndexInput @in ) : long	Returns (but does not validate) the checksum previously written by #checkFooter.
WriteFooter ( Lucene.Net.Store.IndexOutput @out ) : void	Writes a codec footer, which records both a checksum algorithm ID and a checksum. this footer can be parsed and validated with #checkFooter(ChecksumIndexInput) checkFooter(). CodecFooter --> Magic,AlgorithmID,Checksum Magic --> DataOutput#writeInt Uint32. this identifies the start of the footer. It is always {@value #FOOTER_MAGIC}. AlgorithmID --> DataOutput#writeInt Uint32. this indicates the checksum algorithm used. Currently this is always 0, for zlib-crc32. Checksum --> DataOutput#writeLong Uint32. The actual checksum value for all previous bytes in the stream, including the bytes from Magic and AlgorithmID.
WriteHeader ( DataOutput @out, string codec, int version ) : void	Writes a codec header, which records both a string to identify the file and a version number. this header can be parsed and validated with #checkHeader(DataInput, String, int, int) checkHeader(). CodecHeader --> Magic,CodecName,Version Magic --> DataOutput#writeInt Uint32. this identifies the start of the header. It is always {@value #CODEC_MAGIC}. CodecName --> DataOutput#writeString String. this is a string to identify this file. Version --> DataOutput#writeInt Uint32. Records the version of the file. Note that the length of a codec header depends only upon the name of the codec, so this length can be computed at any time with #headerLength(String).

비공개 메소드들

메소드	설명
CodecUtil ( ) : Lucene.Net.Store
ValidateFooter ( IndexInput @in ) : void

메소드 상세

CheckEOF() 공개 정적인 메소드

Checks that the stream is positioned at the end, and throws exception if it is not.

public static CheckEOF ( IndexInput @in ) : void
@in	Lucene.Net.Store.IndexInput
리턴	void

CheckFooter() 공개 정적인 메소드

Validates the codec footer previously written by #writeFooter.

if the footer is invalid, if the checksum does not match, /// or if {@code in} is not properly positioned before the footer /// at the end of the stream.

public static CheckFooter ( Lucene.Net.Store.ChecksumIndexInput @in ) : long
@in	Lucene.Net.Store.ChecksumIndexInput
리턴	long

CheckHeader() 공개 정적인 메소드

Reads and validates a header previously written with #writeHeader(DataOutput, String, int).

When reading a file, supply the expected codec and an expected version range (minVersion to maxVersion).

If the first four bytes are not /// , or if the actual codec found is /// not codec. If the actual version is less /// than minVersion. If the actual version is greater /// than maxVersion. If there is an I/O error reading from the underlying medium.

public static CheckHeader ( DataInput @in, string codec, int minVersion, int maxVersion ) : int
@in	Lucene.Net.Store.DataInput
codec	string	The expected codec name.
minVersion	int	The minimum supported expected version number.
maxVersion	int	The maximum supported expected version number.
리턴	int

CheckHeaderNoMagic() 공개 정적인 메소드

Like {@link #checkHeader(DataInput,String,int,int)} except this version assumes the first int has already been read and validated from the input.

public static CheckHeaderNoMagic ( DataInput @in, string codec, int minVersion, int maxVersion ) : int
@in	Lucene.Net.Store.DataInput
codec	string
minVersion	int
maxVersion	int
리턴	int

ChecksumEntireFile() 공개 정적인 메소드

Clones the provided input, reads all bytes from the file, and calls #checkFooter

Note that this method may be slow, as it must process the entire file. If you just need to extract the checksum value, call #retrieveChecksum.

public static ChecksumEntireFile ( IndexInput input ) : long
input	Lucene.Net.Store.IndexInput
리턴	long

FooterLength() 공개 정적인 메소드

Computes the length of a codec footer.

public static FooterLength ( ) : int
리턴	int

HeaderLength() 공개 정적인 메소드

Computes the length of a codec header.

public static HeaderLength ( string codec ) : int
codec	string	Codec name.
리턴	int

RetrieveChecksum() 공개 정적인 메소드

Returns (but does not validate) the checksum previously written by #checkFooter.

if the footer is invalid

public static RetrieveChecksum ( IndexInput @in ) : long
@in	Lucene.Net.Store.IndexInput
리턴	long

WriteFooter() 공개 정적인 메소드

Writes a codec footer, which records both a checksum algorithm ID and a checksum. this footer can be parsed and validated with #checkFooter(ChecksumIndexInput) checkFooter().

CodecFooter --> Magic,AlgorithmID,Checksum

Magic --> DataOutput#writeInt Uint32. this identifies the start of the footer. It is always {@value #FOOTER_MAGIC}.
AlgorithmID --> DataOutput#writeInt Uint32. this indicates the checksum algorithm used. Currently this is always 0, for zlib-crc32.
Checksum --> DataOutput#writeLong Uint32. The actual checksum value for all previous bytes in the stream, including the bytes from Magic and AlgorithmID.

If there is an I/O error writing to the underlying medium.

public static WriteFooter ( Lucene.Net.Store.IndexOutput @out ) : void
@out	Lucene.Net.Store.IndexOutput
리턴	void

WriteHeader() 공개 정적인 메소드

Writes a codec header, which records both a string to identify the file and a version number. this header can be parsed and validated with #checkHeader(DataInput, String, int, int) checkHeader().

CodecHeader --> Magic,CodecName,Version

Magic --> DataOutput#writeInt Uint32. this identifies the start of the header. It is always {@value #CODEC_MAGIC}.
CodecName --> DataOutput#writeString String. this is a string to identify this file.
Version --> DataOutput#writeInt Uint32. Records the version of the file.

Note that the length of a codec header depends only upon the name of the codec, so this length can be computed at any time with #headerLength(String).

If there is an I/O error writing to the underlying medium.

public static WriteHeader ( DataOutput @out, string codec, int version ) : void
@out	Lucene.Net.Store.DataOutput
codec	string	String to identify this file. It should be simple ASCII, /// less than 128 characters in length.
version	int	Version number
리턴	void

프로퍼티 상세

FOOTER_MAGIC 공개적으로 정적으로 프로퍼티

Constant to identify the start of a codec footer.

public static int FOOTER_MAGIC
리턴	int