org.opennms.features.distributed.kvstore.pgshared

Class AbstractPostgresKeyValueStore<T,S>

java.lang.Object

org.opennms.features.distributed.kvstore.api.AbstractKeyValueStore<T>

org.opennms.features.distributed.kvstore.api.AbstractAsyncKeyValueStore<T>

org.opennms.features.distributed.kvstore.pgshared.AbstractPostgresKeyValueStore<T,S>

Type Parameters:

T - the type this store persists

S - the SQL type this store persists if the value type must be wrapped with an SQL type

All Implemented Interfaces:

KeyValueStore<T>

Direct Known Subclasses:

PostgresBlobStore, PostgresJsonStore

public abstract class AbstractPostgresKeyValueStore<T,S>
extends AbstractAsyncKeyValueStore<T>

A KeyValueStore backed by Postgres.

Postgres key value stores should implement this class with concrete types.

Constructor Summary

Constructors

Constructor and Description
AbstractPostgresKeyValueStore(DataSource dataSource)

Method Summary

Modifier and Type	Method and Description
void	delete(String key, String context)
Map<String,T>	enumerateContext(String context)
Optional<T>	get(String key, String context)
Optional<Optional<T>>	getIfStale(String key, String context, long timestamp)
OptionalLong	getLastUpdated(String key, String context)
String	getName()
protected abstract String	getPkConstraintName()
protected S	getSQLTypeFromValueType(T value) Sub classes should override this method to provide handling for converting from type T to a JDBC type if type T is not a native JDBC type.
protected abstract String	getTableName()
protected String	getValueStatementPlaceholder() Sub classes should override this to add additional specificity to the SQL placeholder in the prepared statements if necessary.
protected abstract T	getValueTypeFromSQLType(ResultSet resultSet, String columnName) Sub classes must override this method to provide handling for converting from the JDBC result to type T.
long	put(String key, T value, String context, Integer ttlInSeconds) Put a value with a suggested time-to-live after which the value should be expired and removed from the store.
void	truncateContext(String context) A default truncate implementation.

Methods inherited from class org.opennms.features.distributed.kvstore.api.AbstractAsyncKeyValueStore

deleteAsync, enumerateContextAsync, getAsync, getIfStaleAsync, getLastUpdatedAsync, putAsync, truncateContextAsync

Methods inherited from class org.opennms.features.distributed.kvstore.api.AbstractKeyValueStore

put, putAsync

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractPostgresKeyValueStore

public AbstractPostgresKeyValueStore(DataSource dataSource)

Method Detail

put

public long put(String key,
                T value,
                String context,
                Integer ttlInSeconds)

Description copied from interface: KeyValueStore

Put a value with a suggested time-to-live after which the value should be expired and removed from the store.

Records are expired on a best effort basis and depending on the implementation it is possible to get an expired record.

context - a context used to differentiate between keys with the same name (forms a compound key)

ttlInSeconds - the time to live in seconds for this key or no ttl if null

Returns:

the timestamp the value was persisted with

get

public Optional<T> get(String key,
                       String context)

context - a context used to differentiate between keys with the same name (forms a compound key)

Returns:

an optional containing the value if present or empty if the key did not exist

getIfStale

public Optional<Optional<T>> getIfStale(String key,
                                        String context,
                                        long timestamp)

context - a context used to differentiate between keys with the same name (forms a compound key)

timestamp - the timestamp of the last known state such that if an record with a more recent timestamp is found the provided timestamp will be considered stale and the new record will be returned

Returns:

an optional that will be empty if the key was not found or will contain another optional that will be empty if not stale or contain the value if stale

getLastUpdated

public OptionalLong getLastUpdated(String key,
                                   String context)

context - a context used to differentiate between keys with the same name (forms a compound key)

Returns:

an optional containing the timestamp the key's value was last updated or empty if the key did not exist

enumerateContext

public Map<String,T> enumerateContext(String context)

Parameters:

context - a context used to differentiate between keys with the same name (forms a compound key)

Returns:

a map of all the records matching the given context where the map's key is the record's key and the map's value is the records value

delete

public void delete(String key,
                   String context)

context - a context used to differentiate between keys with the same name (forms a compound key)

truncateContext

public void truncateContext(String context)

Description copied from class: AbstractKeyValueStore

A default truncate implementation.

Specified by:

truncateContext in interface KeyValueStore<T>

Overrides:

truncateContext in class AbstractKeyValueStore<T>

Parameters:

context - a context used to differentiate between keys with the same name (forms a compound key)

getSQLTypeFromValueType

protected S getSQLTypeFromValueType(T value)

Sub classes should override this method to provide handling for converting from type T to a JDBC type if type T is not a native JDBC type.

getValueTypeFromSQLType

protected abstract T getValueTypeFromSQLType(ResultSet resultSet,
                                             String columnName)
                                      throws SQLException

Sub classes must override this method to provide handling for converting from the JDBC result to type T.

Throws:

SQLException

getValueStatementPlaceholder

protected String getValueStatementPlaceholder()

Sub classes should override this to add additional specificity to the SQL placeholder in the prepared statements if necessary.

getTableName

protected abstract String getTableName()

Returns:

the name of the table for this store

getPkConstraintName

protected abstract String getPkConstraintName()

Returns:

the name of the primary key constraint for the table this store persists to

getName

public String getName()

Returns:

the name of the backing implementation