io.yawp.repository.pipes.Pipe Maven / Gradle / Ivy
package io.yawp.repository.pipes;
import io.yawp.commons.utils.ReflectionUtils;
import io.yawp.repository.Feature;
import io.yawp.repository.IdRef;
import io.yawp.repository.Repository;
import io.yawp.repository.pipes.pump.IdPump;
import io.yawp.repository.pipes.pump.PumpGenerator;
import io.yawp.repository.query.QueryBuilder;
import java.util.List;
import java.util.Set;
/**
* Pipe API
*
* The Pipe API is used to create an asynchronous information flow from
* one endpoint model (source) to another (sink). It can be used to
* create a variety of aggregation models without creating scalability
* bottle-necks.
*
* @param The source endpoint model type.
* @param The sink endpoint model type.
*/
public abstract class Pipe extends Feature {
private static final int BATCH_SIZE = 30;
private Class sourceClazz;
private Class sinkClazz;
private IdPump sourcePump;
private IdPump sinkPump;
public static Pipe newInstance(Repository r, Class pipeClazz) {
try {
Class sourceClazz = ReflectionUtils.getFeatureEndpointClazz(pipeClazz);
Class sinkClazz = ReflectionUtils.getFeatureTypeArgumentAt(pipeClazz, 1);
Pipe pipe = pipeClazz.newInstance();
pipe.setRepository(r);
pipe.init(sourceClazz, sinkClazz);
return pipe;
} catch (InstantiationException | IllegalAccessException e) {
throw new RuntimeException(e);
}
}
public final void init(Class sourceClazz, Class sinkClazz) {
this.sourceClazz = sourceClazz;
this.sinkClazz = sinkClazz;
this.sourcePump = new IdPump<>(sourceClazz, BATCH_SIZE);
this.sinkPump = new IdPump<>(sinkClazz, BATCH_SIZE);
}
/**
* Override this method to specify a custom queue for this pipe.
*
* @return Queue name
*/
public String getQueueName() {
return null;
}
/**
* Override this method to configure one or multiple sinks for a given source.
*
* Call {@link #addSinkId(IdRef)} for each sink you want to pipe the source.
*
* Note: the sinkIds should be retrieved in a strong consistent way
* (ancestor query or key fetch in GAE), otherwise the pipe may become
* inconsistent.
*
* @param source The source that needs to be piped to a sink.
*/
public abstract void configureSinks(T source);
/**
* Call this method from {@link #configureSinks(T)} to add a sink id for
* a given source.
*
* Note: the sink id should be retrieved in a strong consistent way
* (ancestor query or key fetch in GAE), otherwise the pipe may become
* inconsistent.
*
* @param id The sink id.
*/
public final void addSinkId(IdRef id) {
sinkPump.add(id);
}
/**
* Call this method from {@link #configureSinks(T)} to add list of sink ids
* for a given source.
*
* Note: the sink ids should be retrieved in a strong consistent way
* (ancestor query or key fetch in GAE), otherwise the pipe may become
* inconsistent.
*
* @param ids The sink ids.
*/
public final void addSinkIds(List> ids) {
sinkPump.addAll(ids);
}
/**
* Call this method from {@link #configureSinks(T)} to add a query of sink ids
* for a given source.
*
* Note: the sink ids should be retrieved in a strong consistent way
* (ancestor query or key fetch in GAE), otherwise the pipe may become
* inconsistent.
*
* @param query The {@link QueryBuilder} to query for sink ids.
*/
public final void addSinkIdsQuery(QueryBuilder query) {
sinkPump.addQuery(query);
}
/**
* Call this method from {@link #configureSinks(T)} to add a {@link PumpGenerator>}
* of sink ids for a given source.
*
* Note: the sink ids should be retrieved in a strong consistent way
* (ancestor query or key fetch in GAE), otherwise the pipe may become
* inconsistent.
*
* @param generator The generator.
*/
public final void addSinkIdsGenerator(PumpGenerator> generator) {
sinkPump.addGenerator(generator);
}
/**
* Override this method to flux information from the source to sink.
* This method will be invoked asynchronously when the source is created
* or updated and the source has been associated with the sink.
*
* @param source The source object.
* @param sink The sink object.
*/
public abstract void flux(T source, S sink);
/**
* Override this method to reflux source information from the sink.
* This method will be invoked asynchronously when the source is updated
* or destroyed and the source is no longer associated with the sink.
*
* @param source The source object.
* @param sink The sink object.
*/
public abstract void reflux(T source, S sink);
/**
* Override this method to decide if a sink needs to be reflowed after
* it is created or updated.
*
* The sink will be reflowed asynchronously by fluxing all sources
* configured in {@link #configureSources(S)}.
*
* @param newSink The sink object containing its new data.
* @param oldSink The sink object containing its previous data.
* It will be null if the sink is being created.
* @return Whether the sink needs to be reloaded.
*/
public boolean reflowCondition(S newSink, S oldSink) {
return false;
}
/**
* Override this method to define configure one or multiple source objects
* to be fluxed when the specified sink is reflowed.
*
* Call {@link #addSourceId(IdRef)}, {@link #addSourceIds(List)} or
* {@link #addSourceIdsQuery(QueryBuilder)} to specify which sources should be
* reflowed to the sink.
*
* Note: the sources should be retrieved in a strong consistent way
* (ancestor query in GAE), otherwise the pipe may become inconsistent.
*
* @param sink The sink object.
*/
public void configureSources(S sink) {
}
/**
* Call this method from {@link #configureSources(S)} to add
* source ids to be fluxed when the specified sink is reflowed.
*
* Note: the source should be retrieved in a strong consistent way
* (ancestor query or key fetch in GAE), otherwise the pipe may become
* inconsistent.
*
* @param source The source id.
*/
public void addSourceId(IdRef source) {
sourcePump.add(source);
}
/**
* Call this method from {@link #configureSources(S)} to add a list of
* source ids to be fluxed when the specified sink is reflowed.
*
* Note: the sources should be retrieved in a strong consistent way
* (ancestor query or key fetch in GAE), otherwise the pipe may become
* inconsistent.
*
* @param sources The list of source objects.
*/
public void addSourceIds(List> sources) {
sourcePump.addAll(sources);
}
/**
* Call this method from {@link #configureSources(S)} to add a query for
* source ids to be fluxed when the specified sink is reflowed.
*
* Note: this query should be strong consistent (ancestor query
* in GAE), otherwise the pipe may become inconsistent.
*
* @param query The {@link QueryBuilder} to query for sources.
*/
public void addSourceIdsQuery(QueryBuilder query) {
sourcePump.addQuery(query);
}
/**
* Call this method from {@link #configureSources(S)} to add a {@link PumpGenerator>}
* of source ids for a given sink.
*
* Note: the sources should be retrieved in a strong consistent way
* (ancestor query or key fetch in GAE), otherwise the pipe may become
* inconsistent.
*
* @param generator The generator.
*/
public void addSourceIdsGenerator(PumpGenerator> generator) {
sourcePump.addGenerator(generator);
}
/**
* Override this method to empty the sink before it is reloaded.
*
* @param sink The sink object.
*/
public void drain(S sink) {
}
public final Set> allSinks() {
return sinkPump.all();
}
public final boolean hasSinks() {
return sinkPump.hasMore();
}
public final void forceSink(IdRef sinkId) {
sinkPump = new IdPump<>(sinkClazz, BATCH_SIZE);
sinkPump.add(sinkId);
}
public IdPump getSourcePump() {
return sourcePump;
}
}
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