co.cask.tigon.internal.app.queue.AbstractQueueSpecificationGenerator.java Source code

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Here is the source code for co.cask.tigon.internal.app.queue.AbstractQueueSpecificationGenerator.java

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/*
 * Copyright  2014 Cask Data, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */

package co.cask.tigon.internal.app.queue;

import co.cask.tigon.api.flow.FlowletConnection;
import co.cask.tigon.api.flow.FlowletDefinition;
import co.cask.tigon.app.queue.QueueSpecification;
import co.cask.tigon.app.queue.QueueSpecificationGenerator;
import co.cask.tigon.data.queue.QueueName;
import co.cask.tigon.internal.app.SchemaFinder;
import co.cask.tigon.internal.io.Schema;
import co.cask.tigon.utils.ImmutablePair;
import com.google.common.base.Objects;
import com.google.common.collect.ImmutableSet;

import java.util.Map;
import java.util.Set;

/**
 * AbstractQueueSpecification builder for extracting commanality across
 * different implementation. We don't know how it would look for this yet :-)
 */
public abstract class AbstractQueueSpecificationGenerator implements QueueSpecificationGenerator {

    /**
     * Finds a equal or compatible schema connection between <code>source</code> and <code>target</code>
     * flowlet.
     */
    protected Set<QueueSpecification> generateQueueSpecification(String flow, FlowletConnection connection,
            Map<String, Set<Schema>> inputSchemas, Map<String, Set<Schema>> outputSchemas) {

        ImmutableSet.Builder<QueueSpecification> builder = ImmutableSet.builder();

        // Iterate through all the outputs and look for an input with compatible schema.
        // If no such input is found, look for one with ANY_INPUT.
        // If there is exact match of schema then we pick that over the compatible one.
        for (Map.Entry<String, Set<Schema>> entryOutput : outputSchemas.entrySet()) {
            String outputName = entryOutput.getKey();

            Set<Schema> nameOutputSchemas = inputSchemas.get(outputName);
            ImmutablePair<Schema, Schema> schemas = (nameOutputSchemas == null) ? null
                    : SchemaFinder.findSchema(entryOutput.getValue(), nameOutputSchemas);

            if (schemas == null) {
                // Try ANY_INPUT
                Set<Schema> anyInputSchemas = inputSchemas.get(FlowletDefinition.ANY_INPUT);
                if (anyInputSchemas != null) {
                    schemas = SchemaFinder.findSchema(entryOutput.getValue(), anyInputSchemas);
                }
            }

            if (schemas == null) {
                continue;
            }

            if (connection.getSourceType() == FlowletConnection.Type.STREAM) {
                builder.add(createSpec(QueueName.fromStream(outputName), schemas.getFirst(), schemas.getSecond()));
            } else {
                builder.add(createSpec(QueueName.fromFlowlet(flow, flow, connection.getSourceName(), outputName),
                        schemas.getFirst(), schemas.getSecond()));
            }
        }

        return builder.build();
    }

    /**
     * @return An instance of {@link QueueSpecification} containing the URI for the queue
     * and the matching {@link Schema}
     */
    protected QueueSpecification createSpec(final QueueName queueName, final Schema outputSchema,
            final Schema inputSchema) {
        return new QueueSpecification() {
            @Override
            public QueueName getQueueName() {
                return queueName;
            }

            @Override
            public Schema getInputSchema() {
                return inputSchema;
            }

            @Override
            public Schema getOutputSchema() {
                return outputSchema;
            }

            @Override
            public int hashCode() {
                return Objects.hashCode(getQueueName(), getInputSchema(), getOutputSchema());
            }

            @Override
            public boolean equals(Object obj) {
                if (obj == null || !(obj instanceof QueueSpecification)) {
                    return false;
                }
                QueueSpecification other = (QueueSpecification) obj;
                return Objects.equal(getQueueName(), other.getQueueName())
                        && Objects.equal(getInputSchema(), other.getInputSchema())
                        && Objects.equal(getOutputSchema(), other.getOutputSchema());
            }

            @Override
            public String toString() {
                return queueName.toString();
            }
        };
    }
}