com.google.gitiles.PathUtil.java Source code

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Here is the source code for com.google.gitiles.PathUtil.java

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// Copyright 2012 Google 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.google.gitiles;

import com.google.common.base.CharMatcher;
import com.google.common.base.Splitter;
import com.google.common.base.Strings;
import com.google.common.io.Files;

import java.util.StringTokenizer;

/** Static utilities for dealing with pathnames. */
class PathUtil {
    private static final CharMatcher MATCHER = CharMatcher.is('/');
    static final Splitter SPLITTER = Splitter.on(MATCHER);

    static String simplifyPathUpToRoot(String path, String root) {
        if (path.startsWith("/")) {
            return null;
        }

        root = Strings.nullToEmpty(root);
        // simplifyPath() normalizes "a/../../" to "a", so manually check whether
        // the path leads above the root.
        int depth = new StringTokenizer(root, "/").countTokens();
        for (String part : SPLITTER.split(path)) {
            if (part.equals("..")) {
                depth--;
                if (depth < 0) {
                    return null;
                }
            } else if (!part.isEmpty() && !part.equals(".")) {
                depth++;
            }
        }

        String result = Files.simplifyPath(!root.isEmpty() ? root + "/" + path : path);
        return !result.equals(".") ? result : "";
    }

    static String basename(String path) {
        path = MATCHER.trimTrailingFrom(path);
        int slash = path.lastIndexOf('/');
        if (slash < 0) {
            return path;
        }
        return path.substring(slash + 1);
    }

    private PathUtil() {
    }
}