org.yamcs.yarch.rocksdb

Class AscendingRangeIterator

java.lang.Object

org.yamcs.yarch.rocksdb.AscendingRangeIterator

All Implemented Interfaces:

AutoCloseable, DbIterator

public class AscendingRangeIterator
extends Object
implements DbIterator

wrapper around a rocksdb iterator that only supports next() and is restricted to a range.

Author:

nm

Constructor Summary

Constructors

Constructor and Description
AscendingRangeIterator(org.rocksdb.RocksIterator it, byte[] rangeStart, boolean strictStart, byte[] rangeStop, boolean strictStop) Constructs an iterator restricted to a range.

Method Summary

Modifier and Type	Method and Description
void	close()
boolean	isValid()
byte[]	key()
void	next()
void	prev()
byte[]	value()

Methods inherited from class java.lang.Object

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

Constructor Detail

AscendingRangeIterator

public AscendingRangeIterator(org.rocksdb.RocksIterator it,
                              byte[] rangeStart,
                              boolean strictStart,
                              byte[] rangeStop,
                              boolean strictStop)

Constructs an iterator restricted to a range. Unlike the RocksDB standard iterators, if strictStart=true then the first rangeStart.length bytes of the key are compared with the rangeStart, if they are equal the record is skipped. same is valid for strictEnd So with the following DB: 1: 0x00 0x00 0x00 0x02 2: 0x01 0x01 0x01 0x00 3: 0x01 0x01 0x01 0x03 4: 0x01 0x01 0x02 0x00 and rangeStart = 0x01 0x01 0x01, strictStart=true the iterator will skip records 1,2 and 3 and start from record 4 To scan all records that start with a prefix, you can use rangeStart=rangeStop=prefix , strictStart=strictStop=false

Method Detail

isValid

public boolean isValid()

Specified by:

isValid in interface DbIterator

next

public void next()

Specified by:

next in interface DbIterator

key

public byte[] key()

Specified by:

key in interface DbIterator

value

public byte[] value()

Specified by:

value in interface DbIterator

close

public void close()

Specified by:

close in interface AutoCloseable

Specified by:

close in interface DbIterator

prev

public void prev()

Specified by:

prev in interface DbIterator