Package org.elasticsearch.index.store

Class StoreFileMetadata

java.lang.Object

org.elasticsearch.index.store.StoreFileMetadata

All Implemented Interfaces:

Writeable

public class StoreFileMetadata
extends Object
implements Writeable

Nested Class Summary

Nested classes/interfaces inherited from interface org.elasticsearch.common.io.stream.Writeable

Writeable.Reader<V>, Writeable.Writer<V>

Field Summary

Fields

Modifier and Type	Field	Description
static final org.apache.lucene.util.BytesRef	UNAVAILABLE_WRITER_UUID

Constructor Summary

Constructors

Constructor	Description
StoreFileMetadata(String name, long length, String checksum, String writtenBy)
StoreFileMetadata(String name, long length, String checksum, String writtenBy, org.apache.lucene.util.BytesRef hash, org.apache.lucene.util.BytesRef writerUuid)
StoreFileMetadata(StreamInput in)	Read from a stream.

Method Summary

Modifier and Type	Method	Description
String	checksum()	Returns a string representation of the files checksum.
org.apache.lucene.util.BytesRef	hash()	Returns a variable length hash of the file represented by this metadata object.
boolean	hashEqualsContents()	Checks if the bytes returned by hash() are the contents of the file that this instances refers to.
boolean	isSame(StoreFileMetadata other)	Returns true iff the length and the checksums are the same.
long	length()	the actual file size on "disk", if compressed, the compressed size
String	name()	Returns the name of this file
String	toString()
org.apache.lucene.util.BytesRef	writerUuid()	Returns the globally-unique ID that was assigned by the IndexWriter that originally wrote this file: - For `segments_N` files this is SegmentInfos.getId() which uniquely identifies the commit.
void	writeTo(StreamOutput out)	Write this into the StreamOutput.
String	writtenBy()	Returns a String representation of the Lucene version this file has been written by or null if unknown

Methods inherited from class java.lang.Object

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

Field Details

UNAVAILABLE_WRITER_UUID

public static final org.apache.lucene.util.BytesRef UNAVAILABLE_WRITER_UUID

Constructor Details

StoreFileMetadata

public StoreFileMetadata(String name,
 long length,
 String checksum,
 String writtenBy)

StoreFileMetadata

public StoreFileMetadata(String name,
 long length,
 String checksum,
 String writtenBy,
 org.apache.lucene.util.BytesRef hash,
 org.apache.lucene.util.BytesRef writerUuid)

StoreFileMetadata

public StoreFileMetadata(StreamInput in)
                  throws IOException

Read from a stream.

Throws:

IOException

Method Details

writeTo

public void writeTo(StreamOutput out)
             throws IOException

Description copied from interface: Writeable

Write this into the StreamOutput.

Specified by:

writeTo in interface Writeable

Throws:

IOException

name

public String name()

Returns the name of this file

length

public long length()

the actual file size on "disk", if compressed, the compressed size

checksum

public String checksum()

Returns a string representation of the files checksum. Since Lucene 4.8 this is a CRC32 checksum written by lucene.

hashEqualsContents

public boolean hashEqualsContents()

Checks if the bytes returned by hash() are the contents of the file that this instances refers to.

Returns:

true iff hash() will return the actual file contents

isSame

public boolean isSame(StoreFileMetadata other)

Returns true iff the length and the checksums are the same. otherwise false

toString

public String toString()

Overrides:

toString in class Object

writtenBy

public String writtenBy()

Returns a String representation of the Lucene version this file has been written by or null if unknown

hash

public org.apache.lucene.util.BytesRef hash()

Returns a variable length hash of the file represented by this metadata object. This can be the file itself if the file is small enough. If the length of the hash is 0 no hash value is available

writerUuid

public org.apache.lucene.util.BytesRef writerUuid()

Returns the globally-unique ID that was assigned by the IndexWriter that originally wrote this file: - For `segments_N` files this is SegmentInfos.getId() which uniquely identifies the commit. - For non-generational segment files this is SegmentInfo.getId() which uniquely identifies the segment. - For generational segment files (i.e. updated docvalues, liv files etc) this is SegmentCommitInfo.getId() which uniquely identifies the generation of the segment. This ID may be UNAVAILABLE_WRITER_UUID (i.e. zero-length) if unavilable, e.g.: - The file was written by a version of Lucene prior to Version.LUCENE_8_6_0. - The metadata came from a version of Elasticsearch prior to WRITER_UUID_MIN_VERSION). - The file is not one of the files listed above.