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

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

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/*
 * Copyright 2014-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.event.BuckEventBus;
import com.facebook.buck.event.ConsoleEvent;
import com.facebook.buck.io.ProjectFilesystem;
import com.facebook.buck.step.ExecutionContext;
import com.facebook.buck.step.Step;
import com.facebook.buck.step.StepExecutionResult;
import com.facebook.buck.util.HumanReadableException;
import com.google.common.hash.HashCode;
import com.google.common.hash.Hashing;
import com.google.common.io.Files;

import java.io.IOException;
import java.net.URI;
import java.nio.file.Path;

/**
 * Download a file from a known location.
 */
public class DownloadStep implements Step {
    private final ProjectFilesystem filesystem;
    private final URI url;
    private final HashCode sha1;
    private final Path output;
    private final Downloader downloader;

    public DownloadStep(ProjectFilesystem filesystem, Downloader downloader, URI url, HashCode sha1, Path output) {
        this.filesystem = filesystem;
        this.downloader = downloader;
        this.url = url;
        this.sha1 = sha1;
        this.output = output;
    }

    @Override
    public StepExecutionResult execute(ExecutionContext context) throws InterruptedException {
        BuckEventBus eventBus = context.getBuckEventBus();
        try {
            Path resolved = filesystem.resolve(output);
            boolean success = downloader.fetch(eventBus, url, resolved);

            if (!success) {
                return StepExecutionResult.of(reportFailedDownload(eventBus));
            }

            HashCode readHash = Files.asByteSource(resolved.toFile()).hash(Hashing.sha1());
            if (!sha1.equals(readHash)) {
                eventBus.post(ConsoleEvent.severe(
                        "Unable to download %s (hashes do not match. Expected %s, saw %s)", url, sha1, readHash));
                return StepExecutionResult.of(-1);
            }
        } catch (IOException e) {
            return StepExecutionResult.of(reportFailedDownload(eventBus));
        } catch (HumanReadableException e) {
            eventBus.post(ConsoleEvent.severe(e.getHumanReadableErrorMessage(), e));
            return StepExecutionResult.of(-1);
        }

        return StepExecutionResult.SUCCESS;
    }

    private int reportFailedDownload(BuckEventBus eventBus) {
        eventBus.post(ConsoleEvent.severe("Unable to download: %s", url));
        return -1;
    }

    @Override
    public String getShortName() {
        return "curl";
    }

    @Override
    public String getDescription(ExecutionContext context) {
        return String.format("curl %s -o '%s'", url, output);
    }
}