com.facebook.buck.core.module.impl.BuckModuleJarHashProvider.java Source code

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Here is the source code for com.facebook.buck.core.module.impl.BuckModuleJarHashProvider.java

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/*
 * Copyright 2017-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.core.module.impl;

import com.google.common.io.Resources;
import java.io.IOException;
import java.net.URL;
import java.nio.charset.Charset;
import org.pf4j.PluginWrapper;

public class BuckModuleJarHashProvider {

    private static final String MODULE_BINARY_HASH_LOCATION = "META-INF/module-binary-hash.txt";

    /** @return the hash of a jar that contains a Buck module. */
    public String getModuleHash(PluginWrapper modulePluginWrapper) {
        URL binaryHashLocation = modulePluginWrapper.getPluginClassLoader()
                .getResource(MODULE_BINARY_HASH_LOCATION);

        if (binaryHashLocation == null) {
            throw new IllegalStateException(createFailureMessage(modulePluginWrapper));
        }

        try {
            return Resources.toString(binaryHashLocation, Charset.defaultCharset());
        } catch (IOException e) {
            throw new RuntimeException(createFailureMessage(modulePluginWrapper), e);
        }
    }

    private String createFailureMessage(PluginWrapper modulePluginWrapper) {
        return String.format("Could not load module binary hash for module loaded in plugin %s",
                modulePluginWrapper);
    }
}