com.cloudera.cdk.morphline.stdlib.GenerateUUIDBuilder.java Source code

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Here is the source code for com.cloudera.cdk.morphline.stdlib.GenerateUUIDBuilder.java

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/*
 * Copyright 2013 Cloudera 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 com.cloudera.cdk.morphline.stdlib;

import java.security.SecureRandom;
import java.util.Collection;
import java.util.Collections;
import java.util.Random;
import java.util.UUID;

import com.cloudera.cdk.morphline.api.Command;
import com.cloudera.cdk.morphline.api.CommandBuilder;
import com.cloudera.cdk.morphline.api.MorphlineContext;
import com.cloudera.cdk.morphline.api.Record;
import com.cloudera.cdk.morphline.base.AbstractCommand;
import com.cloudera.cdk.morphline.base.Fields;
import com.cloudera.cdk.morphline.base.Validator;
import com.cloudera.cdk.morphline.shaded.org.apache.commons.math3.random.RandomGenerator;
import com.cloudera.cdk.morphline.shaded.org.apache.commons.math3.random.Well19937c;
import com.typesafe.config.Config;

/**
 * A command that sets a universally unique identifier on all records that are intercepted. By
 * default this event header is named "id".
 */
public final class GenerateUUIDBuilder implements CommandBuilder {

    public static final String FIELD_NAME = "field";
    public static final String PRESERVE_EXISTING_NAME = "preserveExisting";
    public static final String PREFIX_NAME = "prefix";

    @Override
    public Collection<String> getNames() {
        return Collections.singletonList("generateUUID");
    }

    @Override
    public Command build(Config config, Command parent, Command child, MorphlineContext context) {
        return new GenerateUUID(this, config, parent, child, context);
    }

    ///////////////////////////////////////////////////////////////////////////////
    // Nested classes:
    ///////////////////////////////////////////////////////////////////////////////
    private static final class GenerateUUID extends AbstractCommand {

        private final String fieldName;
        private final boolean preserveExisting;
        private final String prefix;
        private final RandomGenerator prng;

        public GenerateUUID(CommandBuilder builder, Config config, Command parent, Command child,
                MorphlineContext context) {
            super(builder, config, parent, child, context);
            this.fieldName = getConfigs().getString(config, FIELD_NAME, Fields.ID);
            this.preserveExisting = getConfigs().getBoolean(config, PRESERVE_EXISTING_NAME, true);
            this.prefix = getConfigs().getString(config, PREFIX_NAME, "");
            Type type = new Validator<Type>().validateEnum(config,
                    getConfigs().getString(config, "type", Type.secure.toString()), Type.class);
            if (type == Type.secure) {
                prng = null; // secure & slow
            } else {
                Random rand = new SecureRandom();
                int[] seed = new int[624];
                for (int i = 0; i < seed.length; i++) {
                    seed[i] = rand.nextInt();
                }
                prng = new Well19937c(seed); // non-secure & fast
            }
            validateArguments();
        }

        @Override
        protected boolean doProcess(Record record) {
            if (preserveExisting && record.getFields().containsKey(fieldName)) {
                ; // we must preserve the existing id
            } else {
                record.replaceValues(fieldName, generateUUID());
            }
            return super.doProcess(record);
        }

        protected String getPrefix() {
            return prefix;
        }

        protected String generateUUID() {
            UUID uuid;
            if (prng == null) {
                uuid = UUID.randomUUID(); // secure & slow
            } else {
                uuid = new UUID(prng.nextLong(), prng.nextLong()); // non-secure & fast
            }
            return getPrefix() + uuid.toString();
        }

    }

    ///////////////////////////////////////////////////////////////////////////////
    // Nested classes:
    ///////////////////////////////////////////////////////////////////////////////
    private static enum Type {
        secure, nonSecure
    }

}