org.hawkular.inventory.impl.tinkerpop.spi

Interface GraphProvider

public interface GraphProvider

This is a service interface that the Tinkerpop implementation will use to get a configured and initialized instance of a blueprints graph.

This level of indirection is needed because many graph databases provide configuration and management features that are not accessible through plain Blueprints API.

Since:

0.0.1

Author:

Lukas Krejci

Method Summary

Modifier and Type	Method and Description
default void	commit(org.apache.tinkerpop.gremlin.structure.Graph graph) Commits the transaction in the graph.
void	ensureIndices(org.apache.tinkerpop.gremlin.structure.Graph graph, IndexSpec... indexSpecs) Makes sure all the indexes needed for good performance.
org.apache.tinkerpop.gremlin.structure.Graph	instantiateGraph(Configuration configuration) Given provided configuration, tries to instantiate a graph to be used by the inventory.
boolean	isPreferringBigTransactions()
default boolean	isTransactionRetryWarranted(org.apache.tinkerpop.gremlin.structure.Graph graph, Throwable t) Tries to determine if a transaction retry has a chance of recovering from a condition signified by the provided throwable.
boolean	isUniqueIndexSupported()
boolean	needsDraining() Some implementations need the pipeline to be fully drained in order to be able to reclaim backend resources.
default boolean	requiresRollbackAfterFailure(Throwable t) Checks the exception thrown during the commit and returns true if the backend requires explicit rollback after such failure occured or false if the failure caused the transaction to close itself automatically.
default void	rollback(org.apache.tinkerpop.gremlin.structure.Graph graph) Rolls back the transaction in the graph.
default org.apache.tinkerpop.gremlin.structure.Graph	startTransaction(org.apache.tinkerpop.gremlin.structure.Graph graph) Initializes new transaction for use with given graph.
default RuntimeException	translateException(RuntimeException inputException, org.hawkular.inventory.paths.CanonicalPath affectedPath) Translates the graph specific exception to an inventory exception.

Method Detail

isPreferringBigTransactions

boolean isPreferringBigTransactions()

needsDraining

boolean needsDraining()

Some implementations need the pipeline to be fully drained in order to be able to reclaim backend resources.

Returns:

true if the underlying graph needs pipelines drained in order to clean up.

isUniqueIndexSupported

boolean isUniqueIndexSupported()

See Also:

InventoryBackend

instantiateGraph

org.apache.tinkerpop.gremlin.structure.Graph instantiateGraph(Configuration configuration)

Given provided configuration, tries to instantiate a graph to be used by the inventory.

Parameters:

configuration - the configuration of the graph

Returns:

a configured instance of the graph or null if not possible

ensureIndices

void ensureIndices(org.apache.tinkerpop.gremlin.structure.Graph graph,
                   IndexSpec... indexSpecs)

Makes sure all the indexes needed for good performance.

The provided set of indexes is what the implementation thinks the indices should be. The graph provider is free to make more indexes if they choose so to support the "core" set of indices.

Parameters:

graph - the graph instance (coming from the instantiateGraph(Configuration) call) to index

indexSpecs - the core set of indices to define

startTransaction

default org.apache.tinkerpop.gremlin.structure.Graph startTransaction(org.apache.tinkerpop.gremlin.structure.Graph graph)

Initializes new transaction for use with given graph.

Parameters:

graph - the graph to start the transaction in

Returns:

a new transactional graph that is bound to a new transaction

commit

default void commit(org.apache.tinkerpop.gremlin.structure.Graph graph)

Commits the transaction in the graph.

The default implementation merely calls Transaction.commit().

Parameters:

graph - the graph to commit the transaction to

rollback

default void rollback(org.apache.tinkerpop.gremlin.structure.Graph graph)

Rolls back the transaction in the graph.

The default implementation merely calls Transaction.rollback().

Parameters:

graph - the graph to rollback the transaction from

translateException

default RuntimeException translateException(RuntimeException inputException,
                                            org.hawkular.inventory.paths.CanonicalPath affectedPath)

Translates the graph specific exception to an inventory exception.

The default implementation is an identity function.

Parameters:

inputException - an exception to convert

affectedPath - the canonical path of the entity affected by the exception

Returns:

converted exception

requiresRollbackAfterFailure

default boolean requiresRollbackAfterFailure(Throwable t)

Checks the exception thrown during the commit and returns true if the backend requires explicit rollback after such failure occured or false if the failure caused the transaction to close itself automatically.

Parameters:

t - the exception thrown during commit

Returns:

true to explictly roll back or false if the exception already caused the transaction to close

isTransactionRetryWarranted

default boolean isTransactionRetryWarranted(org.apache.tinkerpop.gremlin.structure.Graph graph,
                                            Throwable t)

Tries to determine if a transaction retry has a chance of recovering from a condition signified by the provided throwable.

Parameters:

graph -

t - a throwable that caused a transaction payload to fail.

Returns:

true if the transaction should be retried, false otherwise