com.facebook.buck.file.StackedDownloader.java Source code

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Here is the source code for com.facebook.buck.file.StackedDownloader.java

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/*
 * Copyright 2015-present Facebook, 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.facebook.buck.file;

import com.facebook.buck.cli.BuckConfig;
import com.facebook.buck.cli.DownloadConfig;
import com.facebook.buck.event.BuckEventBus;
import com.facebook.buck.log.Logger;
import com.facebook.buck.util.HumanReadableException;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableList;

import java.io.FileNotFoundException;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.PasswordAuthentication;
import java.net.Proxy;
import java.net.URI;
import java.net.URL;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Map;
import java.util.Optional;

/**
 * A {@link Downloader} which is composed of many other downloaders. When asked to download a
 * resource, these are each called in order until one succeeds or the final one fails.
 */
public class StackedDownloader implements Downloader {

    private static final Logger LOG = Logger.get(StackedDownloader.class);
    private final ImmutableList<Downloader> delegates;

    @VisibleForTesting
    StackedDownloader(ImmutableList<Downloader> delegates) {
        Preconditions.checkArgument(delegates.size() > 0);
        this.delegates = delegates;
    }

    public static Downloader createFromConfig(BuckConfig config, Optional<Path> androidSdkRoot) {
        ImmutableList.Builder<Downloader> downloaders = ImmutableList.builder();

        DownloadConfig downloadConfig = new DownloadConfig(config);
        Optional<Proxy> proxy = downloadConfig.getProxy();
        HttpDownloader httpDownloader = new HttpDownloader(proxy);

        for (Map.Entry<String, String> kv : downloadConfig.getAllMavenRepos().entrySet()) {
            String repo = kv.getValue();
            // Check the type.
            if (repo.startsWith("http:") || repo.startsWith("https://")) {
                String repoName = kv.getKey();
                Optional<PasswordAuthentication> credentials = downloadConfig.getRepoCredentials(repoName);
                downloaders.add(new RemoteMavenDownloader(httpDownloader, repo, credentials));
            } else if (repo.startsWith("file:")) {
                try {
                    URL url = new URL(repo);
                    Preconditions.checkNotNull(url.getPath());

                    downloaders.add(new OnDiskMavenDownloader(
                            config.resolvePathThatMayBeOutsideTheProjectFilesystem(Paths.get(url.getPath()))));
                } catch (FileNotFoundException e) {
                    throw new HumanReadableException(e,
                            "Error occurred when attempting to use %s "
                                    + "as a local Maven repository as configured in .buckconfig.  See "
                                    + "https://buckbuild.com/concept/buckconfig.html#maven_repositories for how to "
                                    + "configure this setting",
                            repo);
                } catch (MalformedURLException e) {
                    throw new HumanReadableException("Unable to determine path from %s", repo);
                }
            } else {
                try {
                    downloaders.add(new OnDiskMavenDownloader(
                            config.resolvePathThatMayBeOutsideTheProjectFilesystem(Paths.get(repo))));
                } catch (FileNotFoundException e) {
                    throw new HumanReadableException(e,
                            "Error occurred when attempting to use %s "
                                    + "as a local Maven repository as configured in .buckconfig.  See "
                                    + "https://buckbuild.com/concept/buckconfig.html#maven_repositories for how to "
                                    + "configure this setting",
                            repo);
                }
            }
        }

        if (androidSdkRoot.isPresent()) {
            Path androidMavenRepo = androidSdkRoot.get().resolve("extras/android/m2repository");
            try {
                downloaders.add(new OnDiskMavenDownloader(androidMavenRepo));
            } catch (FileNotFoundException e) {
                LOG.warn("Android Maven repo %s doesn't exist", androidMavenRepo.toString());
            }

            Path googleMavenRepo = androidSdkRoot.get().resolve("extras/google/m2repository");
            try {
                downloaders.add(new OnDiskMavenDownloader(googleMavenRepo));
            } catch (FileNotFoundException e) {
                LOG.warn("Google Maven repo '%s' doesn't exist", googleMavenRepo.toString());
            }

        }

        // Add a default downloader
        // TODO(shs96c): Remove the maven_repo check
        Optional<String> defaultMavenRepo = downloadConfig.getMavenRepo();
        if (defaultMavenRepo.isPresent()) {
            LOG.warn("Please configure maven repos by adding them to a 'maven_repositories' "
                    + "section in your buckconfig");
        }
        downloaders.add(downloadConfig.getMaxNumberOfRetries()
                .map(retries -> (Downloader) RetryingDownloader.from(httpDownloader, retries))
                .orElse(httpDownloader));

        return new StackedDownloader(downloaders.build());
    }

    @Override
    public boolean fetch(BuckEventBus eventBus, URI uri, Path output) throws IOException {
        for (Downloader downloader : delegates) {
            try {
                if (downloader.fetch(eventBus, uri, output)) {
                    return true;
                }
            } catch (IOException e) {
                LOG.debug(e, "Unable to download %s from %s", uri, downloader);
            }
        }

        return false;
    }
}