com.facebook.buck.util.MorePaths.java Source code

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Here is the source code for com.facebook.buck.util.MorePaths.java

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/*
 * Copyright 2013-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.util;

import com.google.common.base.Function;
import com.google.common.base.Preconditions;
import com.google.common.base.Predicate;
import com.google.common.collect.FluentIterable;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.ImmutableSortedSet;

import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;

import javax.annotation.Nullable;

public class MorePaths {

    /** Utility class: do not instantiate. */
    private MorePaths() {
    }

    public static final Function<String, Path> TO_PATH = new Function<String, Path>() {
        @Override
        public Path apply(String path) {
            return Paths.get(path);
        }
    };

    public static Path newPathInstance(String path) {
        return separatorsToUnix(path);
    }

    public static Path newPathInstance(File file) {
        return separatorsToUnix(file.getPath());
    }

    /**
     * @return The path using UNIX path separators.
     */
    public static Path separatorsToUnix(String path) {
        if (!File.separator.equals("/")) {
            path = path.replace(File.separator, "/");
        }
        return Paths.get(path).normalize();
    }

    /**
     * @return The path using UNIX path separators.
     */
    public static Path separatorsToUnix(Path path) {
        return separatorsToUnix(path.toString());
    }

    /**
     * @param toMakeAbsolute The {@link Path} to act upon.
     * @return The Path, made absolute and normalized.
     */
    public static Path absolutify(Path toMakeAbsolute) {
        return Preconditions.checkNotNull(toMakeAbsolute).toAbsolutePath().normalize();
    }

    /**
     * Get the path of a file relative to a base directory.
     *
     * @param path must reference a file, not a directory.
     * @param baseDir must reference a directory that is relative to a common directory with the path.
     *     may be null if referencing the same directory as the path.
     * @return the relative path of path from the directory baseDir.
     */
    public static Path getRelativePath(Path path, @Nullable Path baseDir) {
        if (baseDir == null) {
            // This allows callers to use this method with "file.parent()" for files from the project
            // root dir.
            baseDir = Paths.get("");
        }
        Preconditions.checkArgument(!path.isAbsolute(), "Path must be relative: %s.", path);
        Preconditions.checkArgument(!baseDir.isAbsolute(), "Path must be relative: %s.", baseDir);
        return baseDir.relativize(path);
    }

    /**
     * Creates a symlink at
     * {@code projectFilesystem.getRootPath().resolve(pathToDesiredLinkUnderProjectRoot)} that
     * points to {@code projectFilesystem.getRootPath().resolve(pathToExistingFileUnderProjectRoot)}
     * using a relative symlink.
     *
     * @param pathToDesiredLinkUnderProjectRoot must reference a file, not a directory.
     * @param pathToExistingFileUnderProjectRoot must reference a file, not a directory.
     * @return the relative path from the new symlink that was created to the existing file.
     */
    public static Path createRelativeSymlink(Path pathToDesiredLinkUnderProjectRoot,
            Path pathToExistingFileUnderProjectRoot, ProjectFilesystem projectFilesystem) throws IOException {
        return createRelativeSymlink(pathToDesiredLinkUnderProjectRoot, pathToExistingFileUnderProjectRoot,
                projectFilesystem.getRootPath());
    }

    /**
     * Creates a symlink at {@code pathToProjectRoot.resolve(pathToDesiredLinkUnderProjectRoot)} that
     * points to {@code pathToProjectRoot.resolve(pathToExistingFileUnderProjectRoot)} using a
     * relative symlink. Both params must be relative to the project root.
     *
     * @param pathToDesiredLinkUnderProjectRoot must reference a file, not a directory.
     * @param pathToExistingFileUnderProjectRoot must reference a file, not a directory.
     * @return the relative path from the new symlink that was created to the existing file.
     */
    public static Path createRelativeSymlink(Path pathToDesiredLinkUnderProjectRoot,
            Path pathToExistingFileUnderProjectRoot, Path pathToProjectRoot) throws IOException {
        Path target = getRelativePath(pathToExistingFileUnderProjectRoot,
                pathToDesiredLinkUnderProjectRoot.getParent());
        Files.createSymbolicLink(pathToProjectRoot.resolve(pathToDesiredLinkUnderProjectRoot), target);
        return target;
    }

    /**
     * Convert a set of input file paths as strings to {@link Path} objects.
     */
    public static ImmutableSortedSet<Path> asPaths(Iterable<String> paths) {
        ImmutableSortedSet.Builder<Path> builder = ImmutableSortedSet.naturalOrder();
        for (String path : paths) {
            builder.add(Paths.get(path));
        }
        return builder.build();
    }

    /**
     * Filters out {@link Path} objects from {@code paths} that aren't a subpath of {@code root} and
     * returns a set of paths relative to {@code root}.
     */
    public static ImmutableSet<Path> filterForSubpaths(Iterable<Path> paths, final Path root) {
        final Path normalizedRoot = root.toAbsolutePath().normalize();
        return FluentIterable.from(paths).filter(new Predicate<Path>() {
            @Override
            public boolean apply(Path input) {
                if (input.isAbsolute()) {
                    return input.normalize().startsWith(normalizedRoot);
                } else {
                    return true;
                }
            }
        }).transform(new Function<Path, Path>() {
            @Override
            public Path apply(Path input) {
                if (input.isAbsolute()) {
                    return normalizedRoot.relativize(input.normalize());
                } else {
                    return input;
                }
            }
        }).toSet();
    }

    /**
     * @return Whether the input path directs to a file in the buck generated files folder.
     */
    public static boolean isGeneratedFile(Path pathRelativeToProjectRoot) {
        return pathRelativeToProjectRoot.startsWith(BuckConstant.GEN_PATH);
    }
}