Rex.java

/*
 * Copyright 2013 Future Systems
 * 
 * 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 org.araqne.logdb.query.command;

import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.araqne.logdb.FieldOrdering;
import org.araqne.logdb.QueryCommand;
import org.araqne.logdb.Row;
import org.araqne.logdb.RowBatch;
import org.araqne.logdb.ThreadSafe;

public class Rex extends QueryCommand implements ThreadSafe, FieldOrdering {

	private final String field;
	private final Pattern p;
	private final ThreadLocal<Matcher> localMatcher;
	private final String[] names;

	// for query string generation convenience
	private String originalRegexToken;

	public Rex(String field, String originalRegexToken, Pattern p, String[] names) {
		this.field = field;
		this.p = p;
		this.names = names;
		this.localMatcher = new ThreadLocal<Matcher>() {
			@Override
			protected Matcher initialValue() {
				return Rex.this.p.matcher("");
			}
		};

		this.originalRegexToken = originalRegexToken;
	}

	@Override
	public String getName() {
		return "rex";
	}

	@Override
	public List<String> getFieldOrder() {
		List<String> l = new ArrayList<String>();
		for (String name : names)
			l.add(name);
		return l;
	}

	public String getInputField() {
		return field;
	}

	public Pattern getPattern() {
		return p;
	}

	public String[] getOutputNames() {
		return names;
	}

	@Override
	public void onPush(Row m) {
		Object o = m.get(field);
		if (o == null) {
			pushPipe(m);
			return;
		}

		String s = o.toString();

		Matcher matcher = localMatcher.get();
		matcher.reset(s);
		if (matcher.find())
			for (int i = 0; i < matcher.groupCount(); i++) {
				String value = matcher.group(i + 1);
				if (value != null)
					m.put(names[i], value);
			}

		pushPipe(m);
	}

	@Override
	public void onPush(RowBatch rowBatch) {
		Matcher matcher = localMatcher.get();
		if (rowBatch.selectedInUse) {
			for (int i = 0; i < rowBatch.size; i++) {
				int p = rowBatch.selected[i];
				Row row = rowBatch.rows[p];

				Object o = row.get(field);
				if (o == null)
					continue;

				String s = o.toString();

				matcher.reset(s);
				if (matcher.find()) {
					for (int g = 0; g < matcher.groupCount(); g++) {
						String value = matcher.group(g + 1);
						if (value != null)
							row.put(names[g], value);
					}
				}
			}
		} else {
			for (int i = 0; i < rowBatch.size; i++) {
				Row row = rowBatch.rows[i];

				Object o = row.get(field);
				if (o == null)
					continue;

				String s = o.toString();

				matcher.reset(s);
				if (matcher.find()) {
					for (int g = 0; g < matcher.groupCount(); g++) {
						String value = matcher.group(g + 1);
						if (value != null)
							row.put(names[g], value);
					}
				}
			}
		}

		pushPipe(rowBatch);
	}

	@Override
	public String toString() {
		return "rex field=" + field + " " + originalRegexToken;
	}
}