org.diirt.datasource

Interface DataSourceTypeAdapter<ConnectionPayload,MessagePayload>

Type Parameters:

ConnectionPayload - the type of payload given at connection

MessagePayload - the type of payload for each message

All Known Implementing Classes:

JCATypeAdapter, PVATypeAdapter

public interface DataSourceTypeAdapter<ConnectionPayload,MessagePayload>

Matches and fills a cache with the data from connection and message payloads. This optional class helps the writer of a datasource to manage the type matching and conversions.

Author:

carcassi

Method Summary

Modifier and Type	Method and Description
Object	getSubscriptionParameter(ValueCache<?> cache, ConnectionPayload connection) The parameters required to open a monitor for the channel.
int	match(ValueCache<?> cache, ConnectionPayload connection) Determines whether the converter can take values from the channel described by the connection payload and transform them in a type required by the cache.
boolean	updateCache(ValueCache<?> cache, ConnectionPayload connection, MessagePayload message) Takes the information in the message and updates the cache.

Method Detail

match

int match(ValueCache<?> cache,
          ConnectionPayload connection)

Determines whether the converter can take values from the channel described by the connection payload and transform them in a type required by the cache.

Parameters:

cache - the cache where data will need to be written

connection - the connection information

Returns:

zero if there is no match, or the position of the type matched

getSubscriptionParameter

Object getSubscriptionParameter(ValueCache<?> cache,
                                ConnectionPayload connection)

The parameters required to open a monitor for the channel. The type of the parameters will be datasource specific

For channels multiplexed on a single subscription, this method is never used.

Parameters:

cache - the cache where data will need to be written

connection - the connection information

Returns:

datasource specific subscription information

updateCache

boolean updateCache(ValueCache<?> cache,
                    ConnectionPayload connection,
                    MessagePayload message)

Takes the information in the message and updates the cache.

Parameters:

cache - cache to be updated

connection - the connection information

message - the payload of each message

Returns:

true if a new value was stored