ai.grakn.migration.base

Class AbstractMigrator

java.lang.Object

ai.grakn.migration.base.AbstractMigrator

All Implemented Interfaces:

Migrator, AutoCloseable

Direct Known Subclasses:

CSVMigrator, JsonMigrator, SQLMigrator

public abstract class AbstractMigrator
extends Object
implements Migrator

Abstract migrator class containing methods and functionality needed by all extending migrator classes.

Author:

alexandraorth

Field Summary

Fields

Modifier and Type	Field and Description
static int	ACTIVE_TASKS
static int	BATCH_SIZE

Constructor Summary

Constructors

Constructor and Description
AbstractMigrator()

Method Summary

Modifier and Type	Method and Description
void	load(String uri, String keyspace) Migrate data constrained by this migrator using a loader configured by the provided parameters.
void	load(String uri, String keyspace, int batchSize, int numberActiveTasks) Migrate data constrained by this migrator using a loader configured by the provided parameters.
AbstractMigrator	registerMacro(Macro macro) Register a macro to use in templating
protected <T> java.util.stream.Stream<T>	stream(Iterator<T> iterator) Partition a stream into a stream of collections, each with batchSize elements.
protected Optional<InsertQuery>	template(String template, Map<String,Object> data)
protected boolean	validValue(Object value) Test if an object is a valid Grakn value

Methods inherited from class java.lang.Object

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

Methods inherited from interface ai.grakn.migration.base.Migrator

migrate

Methods inherited from interface java.lang.AutoCloseable

close

Field Detail

BATCH_SIZE

public static final int BATCH_SIZE

See Also:

Constant Field Values

ACTIVE_TASKS

public static final int ACTIVE_TASKS

See Also:

Constant Field Values

Constructor Detail

AbstractMigrator

public AbstractMigrator()

Method Detail

registerMacro

public AbstractMigrator registerMacro(Macro macro)

Register a macro to use in templating

load

public void load(String uri,
                 String keyspace)

Migrate data constrained by this migrator using a loader configured by the provided parameters. Uses the default batch size and number of active tasks.

Specified by:

load in interface Migrator

Parameters:

uri - Uri where one instance of Grakn Engine is running

keyspace - The name of the keyspace where the data should be persisted

load

public void load(String uri,
                 String keyspace,
                 int batchSize,
                 int numberActiveTasks)

Migrate data constrained by this migrator using a loader configured by the provided parameters.

Specified by:

load in interface Migrator

Parameters:

uri - Uri where one instance of Grakn Engine is running

keyspace - The name of the keyspace where the data should be persisted

batchSize - The number of queries to execute in one transaction. Default is 25.

numberActiveTasks - Number of tasks running on the server at any one time. Consider this a safeguard to bot the system load. Default is 25.

template

protected Optional<InsertQuery> template(String template,
                                         Map<String,Object> data)

Parameters:

template - a string representing a templated graql query

data - data used in the template

Returns:

an insert query

stream

protected <T> java.util.stream.Stream<T> stream(Iterator<T> iterator)

Partition a stream into a stream of collections, each with batchSize elements.

Type Parameters:

T - Type of values of iterator

Parameters:

iterator - Iterator to partition

Returns:

Stream over a collection that are each of batchSize

validValue

protected boolean validValue(Object value)

Test if an object is a valid Grakn value

Parameters:

value - object to check

Returns:

if the value is valid