com.palantir.baseline.services.JarClassHasher Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of gradle-baseline-java Show documentation
A Gradle plugin for applying Baseline-recommended build and IDE settings
The newest version!
/*
 * (c) Copyright 2021 Palantir Technologies Inc. All rights reserved.
 *
 * 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.palantir.baseline.services;

import com.github.benmanes.caffeine.cache.Cache;
import com.github.benmanes.caffeine.cache.Caffeine;
import com.google.common.base.Strings;
import com.google.common.collect.ImmutableListMultimap;
import com.google.common.collect.ImmutableSetMultimap;
import com.google.common.hash.HashCode;
import com.google.common.hash.Hashing;
import com.google.common.hash.HashingInputStream;
import com.google.common.io.ByteStreams;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.List;
import java.util.Map;
import java.util.jar.JarEntry;
import java.util.jar.JarInputStream;
import java.util.stream.Collectors;
import org.gradle.api.artifacts.ResolvedArtifact;
import org.gradle.api.services.BuildService;
import org.gradle.api.services.BuildServiceParameters;
import org.slf4j.Logger;

public abstract class JarClassHasher implements BuildService, AutoCloseable {

    private final Cache cache =
            Caffeine.newBuilder().build();

    public static final class Result {
        private final ImmutableSetMultimap hashesByClassName;

        private Result(ImmutableSetMultimap hashesByClassName) {
            this.hashesByClassName = hashesByClassName;
        }

        public ImmutableSetMultimap getHashesByClassName() {
            return hashesByClassName;
        }

        public static Result empty() {
            return new Result(ImmutableSetMultimap.of());
        }
    }

    public final Result hashClasses(ResolvedArtifact resolvedArtifact, Logger logger) {
        ClassUniquenessArtifactIdentifier key = ImmutableClassUniquenessArtifactIdentifier.builder()
                .moduleVersionIdentifier(resolvedArtifact.getModuleVersion().getId())
                .classifier(Strings.nullToEmpty(resolvedArtifact.getClassifier()))
                .build();
        return cache.get(key, _moduleId -> {
            File file = resolvedArtifact.getFile();
            if (!file.exists()) {
                return Result.empty();
            }

            ImmutableListMultimap.Builder hashesByClassName = ImmutableListMultimap.builder();
            try (FileInputStream fileInputStream = new FileInputStream(file);
                    JarInputStream jarInputStream = new JarInputStream(fileInputStream)) {
                JarEntry entry;
                while ((entry = jarInputStream.getNextJarEntry()) != null) {
                    if (entry.isDirectory() || !entry.getName().endsWith(".class")) {
                        continue;
                    }

                    if (isExcluded(entry.getName())) {
                        continue;
                    }

                    String className = entry.getName().replaceAll("/", ".").replaceAll("\\.class$", "");
                    HashingInputStream inputStream = new HashingInputStream(Hashing.sha256(), jarInputStream);
                    ByteStreams.exhaust(inputStream);

                    hashesByClassName.put(className, inputStream.hash());
                }
            } catch (IOException e) {
                throw new RuntimeException(e);
            }

            ImmutableListMultimap builtHashesByClassName = hashesByClassName.build();
            List keysWithDuplicateEntries = builtHashesByClassName.asMap().entrySet().stream()
                    .filter(entry -> entry.getValue().size() > 1)
                    .map(Map.Entry::getKey)
                    .sorted()
                    .collect(Collectors.toList());
            if (!keysWithDuplicateEntries.isEmpty()) {
                logger.warn(
                        "Warning: Gradle Baseline found a dependency jar that contains more than one zip entry for "
                                + "a class and is likely malformed: {}\n"
                                + "The following entries appear multiple times: {}\n"
                                + "This issue should be reported to the maintainer of the dependency.",
                        resolvedArtifact.getModuleVersion(),
                        keysWithDuplicateEntries);
            }

            return new Result(ImmutableSetMultimap.copyOf(builtHashesByClassName));
        });
    }

    @Override
    public final void close() {
        // Try to free up memory when this is no longer needed
        cache.invalidateAll();
        cache.cleanUp();
    }

    /**
     * Java 9 allows jars to have a module-info.class, we shouldn't complain about these.
     * Spark contains an 'UnusedStubClass' which generates many false positives, we shouldn't complain about this,
     * either.
     */
    private static boolean isExcluded(String path) {
        return path.endsWith("module-info.class") || path.equals("org/apache/spark/unused/UnusedStubClass.class");
    }
}