org.apache.drill.exec.store.sys.ProfileJsonIterator.java Source code

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Here is the source code for org.apache.drill.exec.store.sys.ProfileJsonIterator.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.drill.exec.store.sys;

import java.io.IOException;
import java.util.Iterator;
import java.util.Map.Entry;

import javax.annotation.Nullable;

import org.apache.drill.exec.ops.ExecutorFragmentContext;
import org.apache.drill.exec.proto.UserBitShared;
import org.apache.drill.exec.proto.UserBitShared.QueryProfile;
import org.apache.drill.exec.serialization.InstanceSerializer;

import com.google.common.base.Function;
import com.google.common.collect.Iterators;

/**
 * System table listing completed profiles as JSON documents
 */
public class ProfileJsonIterator extends ProfileIterator {
    static final org.slf4j.Logger logger = org.slf4j.LoggerFactory.getLogger(ProfileJsonIterator.class);

    private final InstanceSerializer<QueryProfile> profileSerializer;
    private final Iterator<ProfileJson> itr;

    public ProfileJsonIterator(ExecutorFragmentContext context, int maxRecords) {
        super(context, maxRecords);
        //Holding a serializer (for JSON extract)
        this.profileSerializer = profileStoreContext.getProfileStoreConfig().getSerializer();
        this.itr = iterateProfileInfoJson();
    }

    @Override
    protected Iterator<Entry<String, QueryProfile>> getProfiles(int skip, int take) {
        return profileStoreContext.getCompletedProfileStore().getRange(skip, take);
    }

    //Returns an iterator for authorized profiles
    private Iterator<ProfileJson> iterateProfileInfoJson() {
        try {
            //Transform authorized profiles to iterator for ProfileInfoJson
            return transformJson(getAuthorizedProfiles(queryingUsername, isAdmin));

        } catch (Exception e) {
            logger.debug(e.getMessage(), e);
            return Iterators.singletonIterator(ProfileJson.getDefault());
        }
    }

    /**
     * Iterating persistentStore as a iterator of {@link org.apache.drill.exec.store.sys.ProfileJsonIterator.ProfileJson}.
     */
    private Iterator<ProfileJson> transformJson(Iterator<Entry<String, UserBitShared.QueryProfile>> all) {
        return Iterators.transform(all, new Function<Entry<String, UserBitShared.QueryProfile>, ProfileJson>() {
            @Nullable
            @Override
            public ProfileJson apply(@Nullable Entry<String, UserBitShared.QueryProfile> input) {
                if (input == null || input.getValue() == null) {
                    return ProfileJson.getDefault();
                }

                //Constructing ProfileInfo
                final String queryID = input.getKey();
                String profileJson;
                try {
                    profileJson = new String(profileSerializer.serialize(input.getValue()));
                } catch (IOException e) {
                    logger.debug("Failed to serialize profile for: " + queryID, e);
                    profileJson = "{ 'message' : 'error (unable to serialize profile: " + queryID + ")' }";
                }

                return new ProfileJson(queryID, profileJson);
            }
        });
    }

    @Override
    public boolean hasNext() {
        return itr.hasNext();
    }

    @Override
    public Object next() {
        return itr.next();
    }

    @Override
    public void remove() {
        throw new UnsupportedOperationException();
    }

    public static class ProfileJson {
        private static final String UNKNOWN_VALUE = "N/A";

        private static final ProfileJson DEFAULT = new ProfileJson();

        public final String queryId;
        public final String json;

        public ProfileJson(String query_id, String profileJson) {
            this.queryId = query_id;
            this.json = profileJson;
        }

        private ProfileJson() {
            this(UNKNOWN_VALUE, UNKNOWN_VALUE);
        }

        /**
         * If unable to get ProfileInfo, use this default instance instead.
         * @return the default instance
         */
        public static ProfileJson getDefault() {
            return DEFAULT;
        }
    }
}