Package org.apache.cassandra.io.tries

Class IncrementalTrieWriterSimple<VALUE>

java.lang.Object

org.apache.cassandra.io.tries.IncrementalTrieWriterBase<VALUE,DataOutputPlus,org.apache.cassandra.io.tries.IncrementalTrieWriterSimple.Node<VALUE>>

org.apache.cassandra.io.tries.IncrementalTrieWriterSimple<VALUE>

All Implemented Interfaces:

AutoCloseable, IncrementalTrieWriter<VALUE>

@NotThreadSafe
public class IncrementalTrieWriterSimple<VALUE>
extends IncrementalTrieWriterBase<VALUE,DataOutputPlus,org.apache.cassandra.io.tries.IncrementalTrieWriterSimple.Node<VALUE>>
implements IncrementalTrieWriter<VALUE>

Incremental builder of on-disk tries. Takes sorted input.

Incremental building is done by maintaining a stack of nodes in progress which follows the path to reach the last added entry. When a new entry is needed, comparison with the previous can tell us how much of the parents stack remains the same. The rest of the stack is complete as no new entry can affect them due to the input sorting. The completed nodes can be written to disk and discarded, keeping only a pointer to their location in the file (this pointer will be discarded too when the parent node is completed). This ensures that a very limited amount of data is kept in memory at all times.

Note: This class is currently unused (but tested) and stands only as form of documentation for IncrementalTrieWriterPageAware.

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.cassandra.io.tries.IncrementalTrieWriter

IncrementalTrieWriter.PartialTail

Field Summary

Fields inherited from class org.apache.cassandra.io.tries.IncrementalTrieWriterBase

dest, prev, serializer, stack

Constructor Summary

Constructors

Constructor	Description
IncrementalTrieWriterSimple(TrieSerializer<VALUE,? super DataOutputPlus> trieSerializer, DataOutputPlus dest)

Method Summary

Modifier and Type	Method	Description
protected void	complete(org.apache.cassandra.io.tries.IncrementalTrieWriterSimple.Node<VALUE> node)
IncrementalTrieWriter.PartialTail	makePartialRoot()	Make a temporary in-memory representation of the unwritten nodes that covers everything added to the trie until this point.
void	reset()

Methods inherited from class org.apache.cassandra.io.tries.IncrementalTrieWriterBase

add, close, complete, completeLast, count, reset

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.cassandra.io.tries.IncrementalTrieWriter

add, close, complete, count

Constructor Details

IncrementalTrieWriterSimple

public IncrementalTrieWriterSimple(TrieSerializer<VALUE,? super DataOutputPlus> trieSerializer,
 DataOutputPlus dest)

Method Details

complete

protected void complete(org.apache.cassandra.io.tries.IncrementalTrieWriterSimple.Node<VALUE> node)
                 throws IOException

Throws:

IOException

reset

public void reset()

Specified by:

reset in interface IncrementalTrieWriter<VALUE>

makePartialRoot

public IncrementalTrieWriter.PartialTail makePartialRoot()
                                                  throws IOException

Description copied from interface: IncrementalTrieWriter

Make a temporary in-memory representation of the unwritten nodes that covers everything added to the trie until this point. The object returned represents a "tail" for the file that needs to be attached at the "cutoff" point to the file (using e.g. TailOverridingRebufferer).

Specified by:

makePartialRoot in interface IncrementalTrieWriter<VALUE>

Specified by:

makePartialRoot in class IncrementalTrieWriterBase<VALUE,DataOutputPlus,org.apache.cassandra.io.tries.IncrementalTrieWriterSimple.Node<VALUE>>

Throws:

IOException