| /* |
| * 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 |
| * |
| * 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.apache.hadoop.chukwa; |
| |
| |
| import java.io.DataOutput; |
| import java.io.IOException; |
| import org.apache.hadoop.chukwa.datacollection.adaptor.*; |
| |
| /** |
| * A chunk is a sequence of bytes at a particular logical offset in a stream, |
| * and containing one or more "records". Chunks have various metadata, such as |
| * source, format, and pointers to record boundaries within the chunk. |
| * |
| */ |
| public interface Chunk { |
| |
| // these conceptually are really network addresses |
| public String getSource(); |
| |
| public void setSource(String logSource); |
| |
| /** |
| * Get the name of the stream that this Chunk is a chunk of |
| * |
| * @return the name of this stream; e.g. file name |
| */ |
| public String getStreamName(); |
| |
| public void setStreamName(String streamName); |
| |
| // These describe the format of the data buffer |
| public String getDataType(); |
| |
| public void setDataType(String t); |
| |
| /** |
| * @return the user data in the chunk |
| */ |
| public byte[] getData(); |
| |
| /** |
| * @param logEvent the user data in the chunk |
| */ |
| public void setData(byte[] logEvent); |
| |
| /** |
| * get/set the <b>end</b> offsets of records in the buffer. |
| * |
| * We use end, rather than start offsets, since the first start offset is |
| * always 0, but the last end offset specifies how much of the buffer is |
| * valid. |
| * |
| * More precisely, offsets[i] is the offset in the Chunk of the last byte of |
| * record i in this chunk. |
| * |
| * @return a list of record end offsets |
| */ |
| public int[] getRecordOffsets(); |
| |
| public void setRecordOffsets(int[] offsets); |
| |
| /** |
| * @return the byte offset of the first byte not in this chunk. |
| * |
| * We pick this convention so that subtracting sequence IDs yields |
| * length. |
| * |
| * Furthermore, seqID - length = first byte pos. |
| */ |
| public long getSeqID(); |
| |
| public void setSeqID(long l); |
| |
| /** |
| * Retrieve a reference to the adaptor that sent this event. Used by |
| * LocalAgent and Connectors to deliver acks to the appropriate place. |
| * @return Adaptor |
| */ |
| public Adaptor getInitiator(); |
| |
| /** |
| * Estimate the size of this Chunk on the wire, assuming each char of metadata |
| * takes two bytes to serialize. This is pessimistic. |
| * |
| * @return size in bytes that this Chunk might take once serialized. |
| */ |
| public int getSerializedSizeEstimate(); |
| |
| /** |
| * @return tags. |
| * |
| */ |
| public String getTags(); |
| |
| /** |
| * Add tag. |
| * @param tag is a comma separated list |
| * |
| */ |
| public void addTag(String tag); |
| |
| /** |
| * Returns the value of a single tag, assuming tags are of the form |
| * tagname="val" |
| * @param tagName the tag to return |
| * @return null if not matched. |
| */ |
| public String getTag(String tagName); |
| |
| public void write(DataOutput data) throws IOException; |
| } |