com.inductiveautomation.gateway.tsdb.historians

Class MemoryBackedHistorian

java.lang.Object

com.inductiveautomation.gateway.tsdb.historians.MemoryBackedHistorian

All Implemented Interfaces:

Historian, StorageSession, java.lang.AutoCloseable

public class MemoryBackedHistorian
extends java.lang.Object
implements Historian, StorageSession

A tag historian that stores data in memory. Supports max age and max size constraints, on the historian, and per-tag.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected class	MemoryBackedHistorian.Tag

Field Summary

Fields inherited from interface com.inductiveautomation.gateway.tsdb.api.Historian

QUALITY_NOT_FOUND

Constructor Summary

Constructors

Constructor and Description
MemoryBackedHistorian()

Method Summary

Modifier and Type	Method and Description
protected void	addNode(MemoryBackedHistorian.Tag node)
java.util.List<java.lang.String>	browse(java.util.Optional<java.lang.String> filter) Returns a list of paths with data stored, optionally matching a filter.
void	close()
StorageSession	createStorageSession() Used to store values to the historian.
void	delete(java.util.List<java.lang.String> paths) Deletes the tags and all data for the specified paths.
<T> T	getProperty(Property<T> prop) Returns the configured or status property requested, or the default value if no further info is available.
Status	getQueryStatus() Returns the status of the storage system.
Status	getStorageStatus() Returns the status of the storage system.
java.lang.Long	getTotalDataCount()
void	initialize(PropertySet properties)
protected void	performTimePruning(boolean force)
QueryResult	query(java.util.List<java.lang.String> tags, long startTime, long endTime, boolean includeBounding) Queries the values for the given paths over the specified span of time.
void	register(java.lang.String tag, PropertySet properties) Provides information about a path.
void	shutdown()
void	store(java.lang.String tag, java.lang.Object value, int quality, long timestamp) Stores a value for the given tag path.

Methods inherited from class java.lang.Object

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

Constructor Detail

MemoryBackedHistorian

public MemoryBackedHistorian()

Method Detail

initialize

public void initialize(PropertySet properties)
                throws java.lang.Exception

Specified by:

initialize in interface Historian

Throws:

java.lang.Exception

getProperty

public <T> T getProperty(Property<T> prop)

Description copied from interface: Historian

Returns the configured or status property requested, or the default value if no further info is available. Most of these properties are defined in HistorianProperties.

Specified by:

getProperty in interface Historian

getTotalDataCount

public java.lang.Long getTotalDataCount()

register

public void register(java.lang.String tag,
                     PropertySet properties)

Description copied from interface: Historian

Provides information about a path. May be called before or after values have been stored, will replace any previous information stored for a path. The property values are usually defined in HistorianProperties.

Specified by:

register in interface Historian

store

public void store(java.lang.String tag,
                  java.lang.Object value,
                  int quality,
                  long timestamp)
           throws java.lang.Exception

Description copied from interface: StorageSession

Stores a value for the given tag path.

Specified by:

store in interface StorageSession

Throws:

java.lang.Exception

performTimePruning

protected void performTimePruning(boolean force)

browse

public java.util.List<java.lang.String> browse(java.util.Optional<java.lang.String> filter)

Description copied from interface: Historian

Returns a list of paths with data stored, optionally matching a filter.

Specified by:

browse in interface Historian

Parameters:

filter - a wildcard ("Tag*") based string that will be used to filter tags. If empty, all paths will be returned.

delete

public void delete(java.util.List<java.lang.String> paths)

Description copied from interface: Historian

Deletes the tags and all data for the specified paths. Paths may be wildcards using "*". Only expected to work if the historian supports storage, as indicated by getStorageStatus().

Specified by:

delete in interface Historian

query

public QueryResult query(java.util.List<java.lang.String> tags,
                         long startTime,
                         long endTime,
                         boolean includeBounding)

Description copied from interface: Historian

Queries the values for the given paths over the specified span of time. The implementation will conform to the following rules:

1. If endTime is less than start time, results MAY be provided latest first. If that is not possible, the parameters will be swapped and values returned as normal.
2. The result will have a unique PathInfo item for EACH of the paths passed in. If a path is specified multiple times, it will be returned multiple times.
3. If a path is not valid, the query result will return ONE DataPoint for the query start time with a quality of 404 (NOT FOUND)
4. The timestamps for a given path will be ascending, though between paths they may not be.

Specified by:

query in interface Historian

includeBounding - if true, the closest value previous to the start time will be returned, as well as the closest value following the end time.

addNode

protected void addNode(MemoryBackedHistorian.Tag node)

getStorageStatus

public Status getStorageStatus()

Description copied from interface: Historian

Returns the status of the storage system. If the system does not support storage, NotAvailable will be returned. If this is the case, calls to createStorageSession will fail.

Specified by:

getStorageStatus in interface Historian

getQueryStatus

public Status getQueryStatus()

Description copied from interface: Historian

Returns the status of the storage system. If the system does not support querying, NotAvailable will be returned.

Specified by:

getQueryStatus in interface Historian

shutdown

public void shutdown()

Specified by:

shutdown in interface Historian

createStorageSession

public StorageSession createStorageSession()

Description copied from interface: Historian

Used to store values to the historian. Should be used for the immediate set of values and then closed. It should not be held open for longer than necessary.

It implements AutoClosable, and should often be used in a try-with-resources block, such as:
try(StorageSession s = historian.createStorageSession()){ s.store... }

Important: Not every historian will support storage, some are read-only. This can be checked by calling getStorageStatus() and checking the return for "NotSupported".

Specified by:

createStorageSession in interface Historian

close

public void close()
           throws java.io.IOException

Specified by:

close in interface java.lang.AutoCloseable

Throws:

java.io.IOException