com.facebook.buck.ide.intellij.lang.java.ParsingJavaPackageFinder.java Source code

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Here is the source code for com.facebook.buck.ide.intellij.lang.java.ParsingJavaPackageFinder.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.ide.intellij.lang.java;

import com.facebook.buck.io.ProjectFilesystem;
import com.facebook.buck.jvm.core.JavaPackageFinder;
import com.facebook.buck.jvm.java.DefaultJavaPackageFinder;
import com.facebook.buck.jvm.java.JavaFileParser;
import com.facebook.buck.model.BuildTarget;
import com.facebook.buck.util.Optionals;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.ImmutableSortedSet;
import java.io.File;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Comparator;
import java.util.Optional;

/** Finds the package for a given file by looking at its contents first. */
public abstract class ParsingJavaPackageFinder {

    /**
     * Creates a hybrid {@link JavaPackageFinder} which will resolve packages for the selected paths
     * based on parsing the source files and use the fallbackPackageFinder for everything else.
     *
     * @param javaFileParser parser to read Java sources with.
     * @param projectFilesystem filesystem.
     * @param filesToParse set of files to parse.
     * @param fallbackPackageFinder package finder to use when the package can't be inferred from
     *     source.
     * @return the described PackageFinder.
     */
    public static JavaPackageFinder preparse(final JavaFileParser javaFileParser,
            ProjectFilesystem projectFilesystem, ImmutableSet<Path> filesToParse,
            JavaPackageFinder fallbackPackageFinder) {
        JavaPackagePathCache packagePathCache = new JavaPackagePathCache();
        for (Path path : ImmutableSortedSet.copyOf(new PathComponentCountOrder(), filesToParse)) {
            Optional<String> packageNameFromSource = Optionals.bind(projectFilesystem.readFileIfItExists(path),
                    javaFileParser::getPackageNameFromSource);
            if (packageNameFromSource.isPresent()) {
                Path javaPackagePath = findPackageFolderWithJavaPackage(packageNameFromSource.get());
                packagePathCache.insert(path, javaPackagePath);
            }
        }
        return new CacheBasedPackageFinder(fallbackPackageFinder, packagePathCache);
    }

    private static Path findPackageFolderWithJavaPackage(String javaPackage) {
        return Paths.get(javaPackage.replace('.', File.separatorChar));
    }

    private static class CacheBasedPackageFinder implements JavaPackageFinder {
        private JavaPackageFinder fallbackPackageFinder;
        private JavaPackagePathCache packagePathCache;

        public CacheBasedPackageFinder(JavaPackageFinder fallbackPackageFinder,
                JavaPackagePathCache packagePathCache) {
            this.fallbackPackageFinder = fallbackPackageFinder;
            this.packagePathCache = packagePathCache;
        }

        @Override
        public Path findJavaPackageFolder(Path pathRelativeToProjectRoot) {
            Optional<Path> packageFolder = packagePathCache.lookup(pathRelativeToProjectRoot);
            if (!packageFolder.isPresent()) {
                packageFolder = Optional.of(fallbackPackageFinder.findJavaPackageFolder(pathRelativeToProjectRoot));
            }
            return packageFolder.get();
        }

        @Override
        public String findJavaPackage(Path pathRelativeToProjectRoot) {
            Path folder = findJavaPackageFolder(pathRelativeToProjectRoot);
            return DefaultJavaPackageFinder.findJavaPackageWithPackageFolder(folder);
        }

        @Override
        public String findJavaPackage(BuildTarget buildTarget) {
            return findJavaPackage(buildTarget.getBasePath().resolve("removed"));
        }
    }

    public static class PathComponentCountOrder implements Comparator<Path> {
        @Override
        public int compare(Path o1, Path o2) {
            int lengthCompare = Integer.compare(o2.getNameCount(), o1.getNameCount());
            if (lengthCompare == 0) {
                return o2.compareTo(o1);
            }
            return lengthCompare;
        }
    }
}