org.apache.drill.exec.coord.zk.PathUtils.java Source code

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Here is the source code for org.apache.drill.exec.coord.zk.PathUtils.java

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/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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
 * <p/>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p/>
 * 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 org.apache.drill.exec.coord.zk;

import com.google.common.base.Preconditions;
import org.apache.parquet.Strings;

/**
 * A convenience class used to expedite zookeeper paths manipulations.
 */
public final class PathUtils {

    /**
     * Returns a normalized, combined path out of the given path segments.
     *
     * @param parts  path segments to combine
     * @see #normalize(String)
     */
    public static final String join(final String... parts) {
        final StringBuilder sb = new StringBuilder();
        for (final String part : parts) {
            Preconditions.checkNotNull(part, "parts cannot contain null");
            if (!Strings.isNullOrEmpty(part)) {
                sb.append(part).append("/");
            }
        }
        if (sb.length() > 0) {
            sb.deleteCharAt(sb.length() - 1);
        }
        final String path = sb.toString();
        return normalize(path);
    }

    /**
     * Normalizes the given path eliminating repeated forward slashes.
     *
     * @return  normalized path
     */
    public static final String normalize(final String path) {
        if (Strings.isNullOrEmpty(Preconditions.checkNotNull(path))) {
            return path;
        }

        final StringBuilder builder = new StringBuilder();
        char last = path.charAt(0);
        builder.append(last);
        for (int i = 1; i < path.length(); i++) {
            char cur = path.charAt(i);
            if (last == '/' && cur == last) {
                continue;
            }
            builder.append(cur);
            last = cur;
        }
        return builder.toString();
    }

}