001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache license, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the license for the specific language governing permissions and
015 * limitations under the license.
016 */
017package org.apache.logging.log4j.core.net.server;
018
019import java.io.IOException;
020import java.io.InputStream;
021import java.nio.charset.Charset;
022
023import org.apache.logging.log4j.core.LogEvent;
024import org.apache.logging.log4j.core.LogEventListener;
025import org.apache.logging.log4j.core.impl.Log4jLogEvent;
026import org.apache.logging.log4j.util.Strings;
027
028import com.fasterxml.jackson.databind.ObjectMapper;
029import com.fasterxml.jackson.databind.ObjectReader;
030
031/**
032 * Reads and logs {@link LogEvent}s from an {@link InputStream}.
033 */
034public abstract class InputStreamLogEventBridge extends AbstractLogEventBridge<InputStream> {
035
036    private final int bufferSize;
037
038    private final Charset charset;
039
040    private final String eventEndMarker;
041    
042    private final ObjectReader objectReader;
043    
044    public InputStreamLogEventBridge(final ObjectMapper mapper, final int bufferSize, final Charset charset, final String eventEndMarker) {
045        this.bufferSize = bufferSize;
046        this.charset = charset;
047        this.eventEndMarker = eventEndMarker;
048        this.objectReader = mapper.reader(Log4jLogEvent.class);
049    }
050
051    abstract protected int[] getEventIndices(final String text, int beginIndex);
052
053    @Override
054    public void logEvents(final InputStream inputStream, final LogEventListener logEventListener) throws IOException {
055        String workingText = Strings.EMPTY;
056        try {
057            // Allocate buffer once
058            final byte[] buffer = new byte[bufferSize];
059            String textRemains = workingText = Strings.EMPTY;
060            while (true) {
061                // Process until the stream is EOF.
062                final int streamReadLength = inputStream.read(buffer);
063                if (streamReadLength == END) {
064                    // The input stream is EOF
065                    break;
066                }
067                final String text = workingText = textRemains + new String(buffer, 0, streamReadLength, charset);
068                int beginIndex = 0;
069                while (true) {
070                    // Extract and log all XML events in the buffer
071                    final int[] pair = getEventIndices(text, beginIndex);
072                    final int eventStartMarkerIndex = pair[0];
073                    if (eventStartMarkerIndex < 0) {
074                        // No more events or partial XML only in the buffer.
075                        // Save the unprocessed string part
076                        textRemains = text.substring(beginIndex);
077                        break;
078                    }
079                    final int eventEndMarkerIndex = pair[1];
080                    if (eventEndMarkerIndex > 0) {
081                        final int eventEndXmlIndex = eventEndMarkerIndex + eventEndMarker.length();
082                        final String textEvent = workingText = text.substring(eventStartMarkerIndex, eventEndXmlIndex);
083                        final LogEvent logEvent = unmarshal(textEvent);
084                        logEventListener.log(logEvent);
085                        beginIndex = eventEndXmlIndex;
086                    } else {
087                        // No more events or partial XML only in the buffer.
088                        // Save the unprocessed string part
089                        textRemains = text.substring(beginIndex);
090                        break;
091                    }
092                }
093            }
094        } catch (final IOException ex) {
095            logger.error(workingText, ex);
096        }
097    }
098
099    protected Log4jLogEvent unmarshal(final String jsonEvent) throws IOException {
100        return this.objectReader.readValue(jsonEvent);
101    }
102
103}