org.apache.gobblin.config.store.zip.ZipFileConfigStore.java Source code

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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.gobblin.config.store.zip;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.URI;
import java.nio.file.FileSystem;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.stream.Stream;

import org.apache.commons.lang.StringUtils;

import com.google.common.base.Charsets;
import com.google.common.base.Optional;
import com.google.common.base.Preconditions;
import com.sun.nio.zipfs.ZipFileSystem;
import com.typesafe.config.Config;
import com.typesafe.config.ConfigFactory;

import org.apache.gobblin.config.common.impl.SingleLinkedListConfigKeyPath;
import org.apache.gobblin.config.store.api.ConfigKeyPath;
import org.apache.gobblin.config.store.api.ConfigStore;
import org.apache.gobblin.config.store.api.VersionDoesNotExistException;
import org.apache.gobblin.config.store.hdfs.SimpleHadoopFilesystemConfigStore;

import lombok.extern.slf4j.Slf4j;

/**
 * {@link ConfigStore} that uses a zipped file containing all the config store paths.
 *
 * Similar to {@link SimpleHadoopFilesystemConfigStore} but using java APIs instead of Hadoop APIs for the Filesystem to
 * allow reading the file without unzipping.
 *
 * It is assumed that the version passed in the constructor will be the only version used.
 */
@Slf4j
public class ZipFileConfigStore implements ConfigStore {

    private final FileSystem fs;
    private final URI logicalStoreRoot;
    private String version;
    private String storePrefix;

    /**
     * Construct a ZipFileConfigStore
     *
     * @param fs A {@link ZipFileSystem} created using the zip file or jar containing the config store
     * @param logicalStoreRoot URI of this config store's root
     * @param version Config store version to use (only version allowed for lookups is the version passed here)
     * @param storePrefix Prefix to use if all paths in config store are under a parent directory
     */
    public ZipFileConfigStore(ZipFileSystem fs, URI logicalStoreRoot, String version, String storePrefix) {
        Preconditions.checkNotNull(fs);
        Preconditions.checkNotNull(logicalStoreRoot);
        Preconditions.checkNotNull(version);

        this.fs = fs;
        this.logicalStoreRoot = logicalStoreRoot;
        this.version = version;
        this.storePrefix = storePrefix;
    }

    @Override
    public String getCurrentVersion() {
        return this.version;
    }

    @Override
    public URI getStoreURI() {
        return this.logicalStoreRoot;
    }

    /**
     * Retrieves all the children of the given {@link ConfigKeyPath} using {@link Files#walk} to list files
     */
    @Override
    public Collection<ConfigKeyPath> getChildren(ConfigKeyPath configKey, String version)
            throws VersionDoesNotExistException {
        Preconditions.checkNotNull(configKey, "configKey cannot be null!");
        Preconditions.checkArgument(version.equals(getCurrentVersion()));

        List<ConfigKeyPath> children = new ArrayList<>();
        Path datasetDir = getDatasetDirForKey(configKey);

        try {

            if (!Files.exists(this.fs.getPath(datasetDir.toString()))) {
                return children;
            }

            Stream<Path> files = Files.walk(datasetDir, 1);

            for (Iterator<Path> it = files.iterator(); it.hasNext();) {
                Path path = it.next();

                if (Files.isDirectory(path) && !path.equals(datasetDir)) {
                    children.add(configKey
                            .createChild(StringUtils.removeEnd(path.getName(path.getNameCount() - 1).toString(),
                                    SingleLinkedListConfigKeyPath.PATH_DELIMETER)));
                }

            }
            return children;
        } catch (IOException e) {
            throw new RuntimeException(
                    String.format("Error while getting children for configKey: \"%s\"", configKey), e);
        }
    }

    /**
     * Retrieves all the {@link ConfigKeyPath}s that are imported by the given {@link ConfigKeyPath}. Similar to
     * {@link SimpleHadoopFilesystemConfigStore#getOwnImports}
     */
    @Override
    public List<ConfigKeyPath> getOwnImports(ConfigKeyPath configKey, String version) {
        return getOwnImports(configKey, version, Optional.<Config>absent());
    }

    public List<ConfigKeyPath> getOwnImports(ConfigKeyPath configKey, String version,
            Optional<Config> runtimeConfig) throws VersionDoesNotExistException {
        Preconditions.checkNotNull(configKey, "configKey cannot be null!");
        Preconditions.checkArgument(version.equals(getCurrentVersion()));

        List<ConfigKeyPath> configKeyPaths = new ArrayList<>();
        Path datasetDir = getDatasetDirForKey(configKey);
        Path includesFile = this.fs.getPath(datasetDir.toString(),
                SimpleHadoopFilesystemConfigStore.INCLUDES_CONF_FILE_NAME);

        try {
            if (!Files.exists(includesFile)) {
                return configKeyPaths;
            }

            if (!Files.isDirectory(includesFile)) {
                try (InputStream includesConfInStream = Files.newInputStream(includesFile)) {
                    configKeyPaths = SimpleHadoopFilesystemConfigStore
                            .getResolvedConfigKeyPaths(includesConfInStream, runtimeConfig);
                }
            }
        } catch (IOException e) {
            throw new RuntimeException(String.format("Error while getting config for configKey: \"%s\"", configKey),
                    e);
        }

        return configKeyPaths;
    }

    /**
     * Retrieves the {@link Config} for the given {@link ConfigKeyPath}. Similar to
     * {@link SimpleHadoopFilesystemConfigStore#getOwnConfig}
     */
    @Override
    public Config getOwnConfig(ConfigKeyPath configKey, String version) throws VersionDoesNotExistException {
        Preconditions.checkNotNull(configKey, "configKey cannot be null!");
        Preconditions.checkArgument(version.equals(getCurrentVersion()));

        Path datasetDir = getDatasetDirForKey(configKey);
        Path mainConfFile = this.fs.getPath(datasetDir.toString(),
                SimpleHadoopFilesystemConfigStore.MAIN_CONF_FILE_NAME);

        try {
            if (!Files.exists(mainConfFile)) {
                return ConfigFactory.empty();
            }

            if (!Files.isDirectory(mainConfFile)) {
                try (InputStream mainConfInputStream = Files.newInputStream(mainConfFile)) {
                    return ConfigFactory.parseReader(new InputStreamReader(mainConfInputStream, Charsets.UTF_8));
                }
            }
            return ConfigFactory.empty();
        } catch (IOException e) {
            throw new RuntimeException(String.format("Error while getting config for configKey: \"%s\"", configKey),
                    e);
        }
    }

    /**
     * Get path object using zipped file system and relative path
     */
    private Path getDatasetDirForKey(ConfigKeyPath configKey) throws VersionDoesNotExistException {
        return this.fs.getPath(this.storePrefix, configKey.getAbsolutePathString());
    }
}