package com.tinkerpop.pipes.branch;
import com.tinkerpop.pipes.Pipe;
import com.tinkerpop.pipes.util.AbstractMetaPipe;
import com.tinkerpop.pipes.util.FastNoSuchElementException;
import com.tinkerpop.pipes.util.MetaPipe;
import com.tinkerpop.pipes.util.PipeHelper;
import java.util.List;
/**
* ExhaustiveMergePipe will drain its first internal pipe, then its second, so on until all internal pipes are drained.
*
* @author Marko A. Rodriguez (http://markorodriguez.com)
*/
public class ExhaustMergePipe<S> extends AbstractMetaPipe<S, S> implements MetaPipe {
private final List<Pipe> pipes;
int current = 0;
final int total;
public ExhaustMergePipe(final List<Pipe> pipes) {
this.pipes = pipes;
this.total = pipes.size();
}
public S processNextStart() {
while (true) {
final Pipe pipe = this.pipes.get(this.current);
if (pipe.hasNext()) {
return (S) pipe.next();
} else {
this.current = (this.current + 1) % this.total;
if (this.current == 0) {
throw FastNoSuchElementException.instance();
}
}
}
}
public List getCurrentPath() {
if (this.pathEnabled)
return this.pipes.get(this.current).getCurrentPath();
else
throw new RuntimeException(Pipe.NO_PATH_MESSAGE);
}
public List<Pipe> getPipes() {
return this.pipes;
}
public String toString() {
return PipeHelper.makePipeString(this, this.pipes);
}
}