Package org.scictrl.csshell.epics.server.application.orbitserver

Class ArchiveClient

java.lang.Object

org.scictrl.csshell.epics.server.application.orbitserver.ArchiveClient

public class ArchiveClient
extends Object

ArchiveClient class.

Author:

igor@scictrl.com

Field Summary

Fields

Modifier and Type	Field	Description
static org.apache.logging.log4j.Logger	log	Constant log
static final int	SAMPLES_SEARCH_COUNT	Constant SAMPLES_SEARCH_COUNT=50

Method Summary

Modifier and Type	Method	Description
static InputStream	getArchiveDataStream(String pvName, long tsStart, long tsEnd, int count, String archive_url)	Query JSON Archive Proxy server for PV data.
static Object[]	getClosestPVValue(Vector<Object[]> pvData, long targetTimestamp)	Find PV value in pvData whose timestamp is closest to targetTimestamp.
static Object[]	getClosestTimeValuePoint(InputStream jsonInputStream, long targetTime)	Parse InputStream with PV data in JSON format.
static Vector<Object[]>	getJsonPVValues(InputStream jsonInputStream)	Parse InputStream with PV data in JSON format.
static double[]	getTimeInstant(String[] pvs, long targetTime, long timeWindow, String archiver_url)	Retrieve PV values from JSON Archive Proxy server for PV names specified in pvs.

Methods inherited from class java.lang.Object

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

Field Details

SAMPLES_SEARCH_COUNT

public static final int SAMPLES_SEARCH_COUNT

Constant SAMPLES_SEARCH_COUNT=50

See Also:

• Constant Field Values

log

public static org.apache.logging.log4j.Logger log

Constant log

Method Details

getArchiveDataStream

public static InputStream getArchiveDataStream(String pvName,
 long tsStart,
 long tsEnd,
 int count,
 String archive_url)

Query JSON Archive Proxy server for PV data.

Parameters:

pvName - Name of PV we're querying the archiver for

tsStart - Start of time interval for PV data in nanosecond timestamp format

tsEnd - End of time interval for PV data in nanosecond timestamp format

count - Max. number of elements to retrieve from archive server

archive_url - a String object

Returns:

InputStream with JSON data, null if an error occurred

getJsonPVValues

public static Vector<Object[]> getJsonPVValues(InputStream jsonInputStream)

Parse InputStream with PV data in JSON format.

Parameters:

jsonInputStream - InputStream with PV data from Archive Proxy server in JSON format.

Returns:

Vector with PV data; each element is an 2-element array where [0] is Long nanosecond timestamp and [1] is Double PV value. Null is returned on error or if no data is found.

getClosestTimeValuePoint

public static Object[] getClosestTimeValuePoint(InputStream jsonInputStream,
 long targetTime)

Parse InputStream with PV data in JSON format.

Parameters:

jsonInputStream - InputStream with PV data from Archive Proxy server in JSON format.

targetTime - a long

Returns:

Vector with PV data; each element is an 2-element array where [0] is Long nanosecond timestamp and [1] is Double PV value. Null is returned on error or if no data is found.

getClosestPVValue

public static Object[] getClosestPVValue(Vector<Object[]> pvData,
 long targetTimestamp)

Find PV value in pvData whose timestamp is closest to targetTimestamp.

Parameters:

pvData - Vector containing arrays where [0] is Long nanosecond timestamp and [1] is Double PV value

targetTimestamp - target nanosecond timestamp

Returns:

Array element from pvData that is closest to targetTimestamp

getTimeInstant

public static double[] getTimeInstant(String[] pvs,
 long targetTime,
 long timeWindow,
 String archiver_url)

Retrieve PV values from JSON Archive Proxy server for PV names specified in pvs.

Parameters:

pvs - String array of PV names that will be queried from archiver

targetTime - in milliseconds

timeWindow - in milliseconds

archiver_url - a String object

Returns:

Double array with PV values from archiver