com.aquenos.cassandra.pvarchiver.controlsystem

Class SampleBucketId

java.lang.Object

com.aquenos.cassandra.pvarchiver.controlsystem.SampleBucketId

public final class SampleBucketId
extends Object

Identifier for a sample bucket. Each sample bucket has a unique identifier consisting of the channel's data ID, the decimation level, and the start time of the bucket.

Author:

Sebastian Marsching

Constructor Summary

Constructors

Constructor and Description
SampleBucketId(UUID channelDataId, int decimationLevel, long bucketStartTime) Create an identifier for a sample bucket.

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object obj)
long	getBucketStartTime() Returns the start time of the sample bucket as the number of nanoseconds since epoch (January 1st, 1970, 00:00:00 UTC).
UUID	getChannelDataId() Returns the unique identifier that is associated with the data (samples) for the channel.
int	getDecimationLevel() Returns the decimation level for which the sample bucket stores data.
int	hashCode()
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

SampleBucketId

public SampleBucketId(UUID channelDataId,
                      int decimationLevel,
                      long bucketStartTime)

Create an identifier for a sample bucket. The sample bucket is identified by the channel's data ID, the decimation level, and the sample bucket's start time.

Parameters:

channelDataId - unique identifier associated with the data (samples) for the channel.

decimationLevel - decimation level for which the sample bucket stores data. The decimation level is identified by the number of seconds between two samples. A decimation level of zero specifies that this decimation level stores (undecimated) raw samples, which typically do not have a fixed period.

bucketStartTime - start time of the bucket. A bucket only stores samples that have a time stamp that is greater than or equal to the bucket's start-time. The start time is specified as the number of nanoseconds since epoch (January 1st, 1970, 00:00:00 UTC).

Method Detail

getBucketStartTime

public long getBucketStartTime()

Returns the start time of the sample bucket as the number of nanoseconds since epoch (January 1st, 1970, 00:00:00 UTC). A bucket only stores sample with time stamps equal to or greater than the bucket's start time and strictly less than the following bucket's start time.

Returns:

start time of the bucket as the number of nanoseconds since epoch.

getChannelDataId

public UUID getChannelDataId()

Returns the unique identifier that is associated with the data (samples) for the channel. While a channel's name might change due to renaming, the data ID will be permanent (until the channel is deleted), so even after renaming a channel, its associated data can still be found.

Returns:

unique identifier associated with the channel's data.

getDecimationLevel

public int getDecimationLevel()

Returns the decimation level for which the sample bucket stores data. The decimation level is identified by the number of seconds between two samples. A decimation level of zero specifies that this decimation level stores (undecimated) raw samples, which typically do not have a fixed period.

Returns:

decimation level of the bucket.

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

toString

public String toString()

Overrides:

toString in class Object