net.quasardb.qdb.ts

Class Reader

java.lang.Object

net.quasardb.qdb.ts.Reader

All Implemented Interfaces:

AutoCloseable, Iterator<WritableRow>

public class Reader
extends Object
implements AutoCloseable, Iterator<WritableRow>

High-performance bulk reader for a QuasarDB timeseries table. This class follows the general Iterator pattern, and allows you to scan entire timeseries tables in bulk.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	Reader(Session session, Table table, TimeRange[] ranges)

Method Summary

Modifier and Type	Method and Description
void	close() Closes the timeseries table and local cache so that memory can be reclaimed.
protected void	finalize() Cleans up the internal representation of the local table.
Table	getTable()
boolean	hasNext() Check whether there is another row available for reading or not.
WritableRow	next() Modifies internal state to move forward to the next row.
java.util.stream.Stream<WritableRow>	stream() Provides stream-based access.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Iterator

forEachRemaining, remove

Constructor Detail

Reader

protected Reader(Session session,
                 Table table,
                 TimeRange[] ranges)

Method Detail

getTable

public Table getTable()

Returns:

The underlying table that is being written to.

finalize

protected void finalize()
                 throws Throwable

Cleans up the internal representation of the local table.

Overrides:

finalize in class Object

Throws:

Throwable

close

public void close()
           throws IOException

Closes the timeseries table and local cache so that memory can be reclaimed.

Specified by:

close in interface AutoCloseable

Throws:

IOException

hasNext

public boolean hasNext()

Check whether there is another row available for reading or not. When this function returns true, it is safe to call next.

Specified by:

hasNext in interface Iterator<WritableRow>

Returns:

Returns true when another row is available for reading.

next

public WritableRow next()
                 throws InvalidIteratorException

Modifies internal state to move forward to the next row. Make sure to check whether it is safe to read the next row using hasNext().

Specified by:

next in interface Iterator<WritableRow>

Returns:

The next row.

Throws:

InvalidIteratorException - Thrown when the iterator has reached the end and no next row is available.

stream

public java.util.stream.Stream<WritableRow> stream()

Provides stream-based access.