Java tutorial
/* * Copyright (c) 2011 LinkedIn, Inc * * 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.flaptor.indextank.storage; import java.io.IOException; import java.util.List; import org.apache.thrift.TException; import org.apache.thrift.transport.TTransportException; import com.flaptor.indextank.rpc.LogRecord; import com.flaptor.indextank.storage.Segment.MissingSegmentException; import com.flaptor.indextank.util.FormatLogger; import com.google.common.base.Preconditions; import com.google.common.collect.Iterables; import com.google.common.collect.Lists; public class RawLog { private static final FormatLogger logger = new FormatLogger(); public static final int DEFAULT_SEGMENT_SIZE = 1024 * 1024 * 50; private SegmentWriter writingHead; private LogRoot root; private final int segmentSize; private int records; private int segmentRecords; private long lastTime; public RawLog() { this(new LogRoot(), DEFAULT_SEGMENT_SIZE); } public RawLog(LogRoot root, int segmentSize) { this.root = root; this.segmentSize = segmentSize; this.root.getLiveLogPath().mkdirs(); this.root.getHistoryLogPath().mkdirs(); } public synchronized void write(LogRecord record) throws TException, IOException { Preconditions.checkState(!record.is_set_id(), "Can't insert records to the live log with an id"); Preconditions.checkState(record.is_set_index_code(), "Can't insert records to the live log without defining the index code"); if (writingHead == null) { writingHead = Segment.createRawHead(root, root.getLiveLogPath(), System.currentTimeMillis()); } record.set_timestamp_ms(System.currentTimeMillis()); writingHead.write(record); records++; segmentRecords++; if (System.currentTimeMillis() - lastTime > 5000) { logger.debug("%d records so far (current segment: %d, bytes: %d / %d)", records, segmentRecords, writingHead.length(), segmentSize); lastTime = System.currentTimeMillis(); } if (writingHead.length() > segmentSize) { logger.info("Closing a segment with %d records", segmentRecords); writingHead.release(); writingHead = null; segmentRecords = 0; } } public synchronized void flush() throws TTransportException { if (writingHead != null) { writingHead.flush(); } } public List<Segment> getLiveSegments() { List<Segment> live = Segment.getSegments(root, root.getLiveLogPath()); for (Segment s : live) { s.addAlternativeParent(root.getHistoryLogPath()); } return live; } public List<Segment> getAllSegments() { List<Segment> live = Segment.getSegments(root, root.getLiveLogPath()); List<Segment> history = Segment.getSegments(root, root.getHistoryLogPath()); for (Segment s : live) { s.addAlternativeParent(root.getHistoryLogPath()); } return Lists.newArrayList(Iterables.concat(history, live)); } public Segment getSegment(long timestamp) { Segment segment = Segment.getSegment(root, root.getLiveLogPath(), timestamp, false); if (segment == null) { segment = Segment.getSegment(root, root.getHistoryLogPath(), timestamp, false); } else { segment.addAlternativeParent(root.getHistoryLogPath()); } return segment; } public Segment getFirstSegment() { Segment segment = Iterables.get(Segment.iterateSegments(root, root.getHistoryLogPath()), 0, null); if (segment == null) { segment = Iterables.get(Segment.iterateSegments(root, root.getLiveLogPath()), 0, null); } return segment; } public Segment findFollowingSegment(long timestamp) throws MissingSegmentException { Segment segment = Segment.findNextSegment(root, timestamp, root.getHistoryLogPath(), root.getLiveLogPath()); if (segment != null && segment.parent.equals(root.getLiveLogPath())) { segment.addAlternativeParent(root.getHistoryLogPath()); } return segment; } }