| /* |
| * Copyright 2012-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.Preconditions; |
| import com.google.common.base.Strings; |
| import com.google.common.collect.Iterables; |
| |
| import java.io.File; |
| |
| import javax.annotation.Nullable; |
| |
| public class Paths { |
| |
| private Paths() {} |
| |
| /** |
| * @param from must always refer to a directory (it should either be the empty string or end with |
| * a slash). |
| * @param to may refer to either a file or a directory |
| */ |
| public static String computeRelativePath(String from, String to) { |
| Preconditions.checkNotNull(from); |
| Preconditions.checkArgument(from.isEmpty() || from.endsWith("/"), |
| "Directory path must either be the empty string or end with a slash"); |
| Preconditions.checkNotNull(to); |
| |
| if (from.isEmpty()) { |
| return to; |
| } |
| |
| // Both from and to have the same string prefix through this character index. |
| int samePrefixIndex = 0; |
| while (true) { |
| int slashIndex = from.indexOf('/', samePrefixIndex); |
| if (slashIndex < 0) { |
| break; |
| } |
| |
| int indexIncludingSlash = slashIndex + 1; |
| if (indexIncludingSlash > to.length()) { |
| break; |
| } |
| |
| String fromPathElement = from.substring(samePrefixIndex, indexIncludingSlash); |
| String toPathElement = to.substring(samePrefixIndex, indexIncludingSlash); |
| if (fromPathElement.equals(toPathElement)) { |
| samePrefixIndex = indexIncludingSlash; |
| } else { |
| break; |
| } |
| } |
| |
| int directoryDepth = 0; |
| for (int charIndex = samePrefixIndex + 1; charIndex < from.length(); charIndex++) { |
| if (from.charAt(charIndex) == '/') { |
| directoryDepth++; |
| } |
| } |
| |
| return Strings.repeat("../", directoryDepth) + to.substring(samePrefixIndex); |
| } |
| |
| /** |
| * @return the path to the parent |
| */ |
| public static String getParentPath(String pathToFile) { |
| Preconditions.checkNotNull(pathToFile); |
| Preconditions.checkArgument(!pathToFile.isEmpty(), "path cannot be the empty string"); |
| |
| if (pathToFile.endsWith("/")) { |
| pathToFile = pathToFile.substring(0, pathToFile.length() - 1); |
| } |
| |
| int lastSlashIndex = pathToFile.lastIndexOf('/'); |
| if (lastSlashIndex < 0) { |
| return ""; |
| } else { |
| return pathToFile.substring(0, lastSlashIndex + 1); |
| } |
| } |
| |
| /** |
| * Mimic the UNIX command basename. |
| * @param path Filesystem path |
| * @param suffix Optional suffix (use null to exclude) that will be stripped from the basename if |
| * it is found. |
| * @return The file's name, with suffix removed if provided. |
| */ |
| public static String getBasename(String path, @Nullable String suffix) { |
| Preconditions.checkNotNull(path); |
| |
| String name = new File(path).getName(); |
| if (suffix != null && name.endsWith(suffix)) { |
| return name.substring(0, name.length() - suffix.length()); |
| } else { |
| return name; |
| } |
| } |
| |
| public static Iterable<File> transformPathToFile(Iterable<String> paths) { |
| return Iterables.transform(paths, Functions.PATH_TO_FILE); |
| } |
| |
| public static Iterable<String> transformFileToAbsolutePath(Iterable<File> files) { |
| return Iterables.transform(files, Functions.FILE_TO_ABSOLUTE_PATH); |
| } |
| } |