org.apache.maven.index.reader

Class IndexReader

java.lang.Object

org.apache.maven.index.reader.IndexReader

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, java.lang.Iterable<ChunkReader>

public class IndexReader
extends java.lang.Object
implements java.lang.Iterable<ChunkReader>, java.io.Closeable

Maven 2 Index reader that handles incremental updates if possible and provides one or more ChunkReaders, to read all the required records.

Since:

5.1.2

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private static class	IndexReader.ChunkReaderIterator Internal iterator implementation that lazily opens and closes the returned ChunkReaders as this iterator is being consumed.

Field Summary

Fields

Modifier and Type	Field and Description
private java.util.List<java.lang.String>	chunkNames
private boolean	incremental
private java.lang.String	indexId
private WritableResourceHandler	local
private java.util.Properties	localIndexProperties
private java.util.Date	publishedTimestamp
private ResourceHandler	remote
private java.util.Properties	remoteIndexProperties

Constructor Summary

Constructors

Constructor and Description
IndexReader(WritableResourceHandler local, ResourceHandler remote)

Method Summary

Modifier and Type	Method and Description
private java.util.List<java.lang.String>	calculateChunkNames() Calculates the chunk names that needs to be fetched.
private boolean	canRetrieveAllChunks() Verifies incremental update is possible, as all the diff chunks we need are still enlisted in remote properties.
void	close() Closes the underlying ResourceHandlers.
java.util.List<java.lang.String>	getChunkNames() Returns unmodifiable list of actual chunks that needs to be pulled from remote ResourceHandler.
java.lang.String	getIndexId() Returns the index context ID that published index has set.
java.util.Date	getPublishedTimestamp() Returns the Date when remote index was last published.
boolean	isIncremental() Returns true if incremental update is about to happen.
java.util.Iterator<ChunkReader>	iterator() Returns an Iterator of ChunkReaders, that if read in sequence, provide all the (incremental) updates from the index.
private void	syncLocalWithRemote() Stores the remote index properties into local index properties, preparing local WritableResourceHandler for future incremental updates.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Field Detail

local

private final WritableResourceHandler local

remote

private final ResourceHandler remote

localIndexProperties

private final java.util.Properties localIndexProperties

remoteIndexProperties

private final java.util.Properties remoteIndexProperties

indexId

private final java.lang.String indexId

publishedTimestamp

private final java.util.Date publishedTimestamp

incremental

private final boolean incremental

chunkNames

private final java.util.List<java.lang.String> chunkNames

Constructor Detail

IndexReader

public IndexReader(WritableResourceHandler local,
                   ResourceHandler remote)
            throws java.io.IOException

Throws:

java.io.IOException

Method Detail

getIndexId

public java.lang.String getIndexId()

Returns the index context ID that published index has set. Usually it is equal to "repository ID" used in Record.Type.DESCRIPTOR but does not have to be.

getPublishedTimestamp

public java.util.Date getPublishedTimestamp()

Returns the Date when remote index was last published.

isIncremental

public boolean isIncremental()

Returns true if incremental update is about to happen. If incremental update, the iterator() will return only the diff from the last update.

getChunkNames

public java.util.List<java.lang.String> getChunkNames()

Returns unmodifiable list of actual chunks that needs to be pulled from remote ResourceHandler. Those are incremental chunks or the big main file, depending on result of isIncremental(). Empty list means local index is up to date, and iterator() will return empty iterator.

close

public void close()
           throws java.io.IOException

Closes the underlying ResourceHandlers. In case of incremental update use, it also assumes that user consumed all the iterator and integrated it, hence, it will update the WritableResourceHandler contents to prepare it for future incremental update. If this is not desired (ie. due to aborted update), then this method should NOT be invoked, but rather the ResourceHandlers that caller provided in constructor of this class should be closed manually.

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Throws:

java.io.IOException

iterator

public java.util.Iterator<ChunkReader> iterator()

Returns an Iterator of ChunkReaders, that if read in sequence, provide all the (incremental) updates from the index. It is caller responsibility to either consume fully this iterator, or to close current ChunkReader if aborting.

Specified by:

iterator in interface java.lang.Iterable<ChunkReader>

syncLocalWithRemote

private void syncLocalWithRemote()
                          throws java.io.IOException

Stores the remote index properties into local index properties, preparing local WritableResourceHandler for future incremental updates.

Throws:

java.io.IOException

calculateChunkNames

private java.util.List<java.lang.String> calculateChunkNames()

Calculates the chunk names that needs to be fetched.

canRetrieveAllChunks

private boolean canRetrieveAllChunks()

Verifies incremental update is possible, as all the diff chunks we need are still enlisted in remote properties.