org.elasticsearch.hadoop.serialization.ParsingUtils Maven / Gradle / Ivy

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 * Licensed to Elasticsearch under one or more contributor
 * license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright
 * ownership. Elasticsearch 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
 *
 *    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 org.elasticsearch.hadoop.serialization;

import java.util.ArrayList;
import java.util.List;

import org.elasticsearch.hadoop.serialization.Parser.Token;
import org.elasticsearch.hadoop.serialization.bulk.RawJson;
import org.elasticsearch.hadoop.serialization.json.JacksonJsonGenerator;
import org.elasticsearch.hadoop.util.FastByteArrayOutputStream;
import org.elasticsearch.hadoop.util.StringUtils;

public abstract class ParsingUtils {

    public static final String NOT_FOUND = "(not found)";

    /**
     * Seeks the field with the given name in the stream and positions (and returns) the parser to the next available token (value or not).
     * Return null if no token is found.
     *
     * @param path
     * @param parser
     * @return token associated with the given path or null if not found
     */
    public static Token seek(Parser parser, String path) {
        // return current token if no path is given
        if (!StringUtils.hasText(path)) {
            return null;
        }

        List tokens = StringUtils.tokenize(path, ".");
        return seek(parser, tokens.toArray(new String[tokens.size()]));
    }

    public static Token seek(Parser parser, String[] path1) {
        return seek(parser, path1, null);
    }

    public static Token seek(Parser parser, String[] path1, String[] path2) {
        return doSeekToken(parser, path1, 0, path2, 0);
    }

    private static Token doSeekToken(Parser parser, String[] path1, int index1, String[] path2, int index2) {
        Token token = null;

        String currentName;
        token = parser.currentToken();
        if (token == null) {
            token = parser.nextToken();
        }

        while ((token = parser.nextToken()) != null) {
            if (token == Token.START_OBJECT) {
                token = parser.nextToken();
            }
            if (token == Token.FIELD_NAME) {
                // found a node, go one level deep
                currentName = parser.currentName();
                if (path1 != null && currentName.equals(path1[index1])) {
                    if (index1 + 1 < path1.length) {
                        return doSeekToken(parser, path1, index1 + 1, null, 0);
                    }
                    else {
                        return parser.nextToken();
                    }
                }
                else if (path2 != null && currentName.equals(path2[index2])) {
                    if (index2 + 1 < path2.length) {
                        return doSeekToken(parser, null, 0, path2, index2 + 1);
                    }
                    else {
                        return parser.nextToken();
                    }
                }
                else {
                    // get field token (can be value, object or array)
                    parser.nextToken();
                    parser.skipChildren();
                }
            }
            else {
                break;
            }
        }

        return null;
    }

    private static class Matcher {
        private final List tokens;
        private final String path;
        private boolean matched = false;
        private Object value;

        Matcher(String path) {
            this.path = path;
            tokens = StringUtils.tokenize(path, ".");
        }

        // number of levels required for the matcher
        int nesting() {
            return tokens.size() - 1;
        }

        boolean matches(String key, int level) {
            if (level < tokens.size()) {
                return tokens.get(level).equals(key);
            }
            return false;
        }

        void value(Object value) {
            matched = true;
            this.value = value;
        }

        @Override
        public String toString() {
            return path;
        }
    }

    public static List