org.apache.beam.runners.core.construction.PipelineResources.java Source code

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Here is the source code for org.apache.beam.runners.core.construction.PipelineResources.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.beam.runners.core.construction;

import static com.google.common.base.Preconditions.checkArgument;

import com.google.common.base.Strings;
import com.google.common.hash.Funnels;
import com.google.common.hash.Hasher;
import com.google.common.hash.Hashing;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.net.URISyntaxException;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;
import org.apache.beam.sdk.util.ZipFiles;

/** Utilities for working with classpath resources for pipelines. */
public class PipelineResources {

    /**
     * Attempts to detect all the resources the class loader has access to. This does not recurse to
     * class loader parents stopping it from pulling in resources from the system class loader.
     *
     * @param classLoader The URLClassLoader to use to detect resources to stage.
     * @throws IllegalArgumentException If either the class loader is not a URLClassLoader or one of
     *     the resources the class loader exposes is not a file resource.
     * @return A list of absolute paths to the resources the class loader uses.
     */
    public static List<String> detectClassPathResourcesToStage(ClassLoader classLoader) {
        if (!(classLoader instanceof URLClassLoader)) {
            String message = String.format("Unable to use ClassLoader to detect classpath elements. "
                    + "Current ClassLoader is %s, only URLClassLoaders are supported.", classLoader);
            throw new IllegalArgumentException(message);
        }

        List<String> files = new ArrayList<>();
        for (URL url : ((URLClassLoader) classLoader).getURLs()) {
            try {
                files.add(new File(url.toURI()).getAbsolutePath());
            } catch (IllegalArgumentException | URISyntaxException e) {
                String message = String.format("Unable to convert url (%s) to file.", url);
                throw new IllegalArgumentException(message, e);
            }
        }
        return files;
    }

    /**
     * Goes through the list of files that need to be staged on runner. Removes nonexistent
     * directories and packages existing ones. This is necessary for runners that require filesToStage
     * to be jars only.
     *
     * @param resourcesToStage list of resources that need to be staged
     * @param tmpJarLocation temporary directory to store the jars
     * @return A list of absolute paths to resources (jar files)
     */
    public static List<String> prepareFilesForStaging(List<String> resourcesToStage, String tmpJarLocation) {
        return resourcesToStage.stream().map(File::new).filter(File::exists)
                .map(file -> file.isDirectory() ? packageDirectoriesToStage(file, tmpJarLocation)
                        : file.getAbsolutePath())
                .collect(Collectors.toList());
    }

    private static String packageDirectoriesToStage(File directoryToStage, String tmpJarLocation) {
        String hash = calculateDirectoryContentHash(directoryToStage);
        String pathForJar = getUniqueJarPath(hash, tmpJarLocation);
        zipDirectory(directoryToStage, pathForJar);
        return pathForJar;
    }

    private static String calculateDirectoryContentHash(File directoryToStage) {
        Hasher hasher = Hashing.sha256().newHasher();
        try (OutputStream hashStream = Funnels.asOutputStream(hasher)) {
            ZipFiles.zipDirectory(directoryToStage, hashStream);
            return hasher.hash().toString();
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    private static String getUniqueJarPath(String contentHash, String tmpJarLocation) {
        checkArgument(!Strings.isNullOrEmpty(tmpJarLocation),
                "Please provide temporary location for storing the jar files.");

        return String.format("%s%s.jar", tmpJarLocation, contentHash);
    }

    private static void zipDirectory(File directoryToStage, String uniqueDirectoryPath) {
        try {
            ZipFiles.zipDirectory(directoryToStage, new FileOutputStream(uniqueDirectoryPath));
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }
}