001/* 002 * Licensed to the Apache Software Foundation (ASF) under one 003 * or more contributor license agreements. See the NOTICE file 004 * distributed with this work for additional information 005 * regarding copyright ownership. The ASF licenses this file 006 * to you under the Apache License, Version 2.0 (the 007 * "License"); you may not use this file except in compliance 008 * with the License. You may obtain a copy of the License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, software 013 * distributed under the License is distributed on an "AS IS" BASIS, 014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 015 * See the License for the specific language governing permissions and 016 * limitations under the License. 017 */ 018package org.apache.hadoop.hbase.io.hfile; 019 020import java.io.DataOutput; 021import java.io.IOException; 022import org.apache.yetus.audience.InterfaceAudience; 023 024/** 025 * A way to write "inline" blocks into an {@link HFile}. Inline blocks are interspersed with data 026 * blocks. For example, Bloom filter chunks and leaf-level blocks of a multi-level block index are 027 * stored as inline blocks. 028 */ 029@InterfaceAudience.Private 030public interface InlineBlockWriter { 031 032 /** 033 * Determines whether there is a new block to be written out. whether the file is being closed, in 034 * which case we need to write out all available data and not wait to accumulate another block 035 */ 036 boolean shouldWriteBlock(boolean closing); 037 038 /** 039 * Writes the block to the provided stream. Must not write any magic records. Called only if 040 * {@link #shouldWriteBlock(boolean)} returned true. a stream (usually a compressing stream) to 041 * write the block to 042 */ 043 void writeInlineBlock(DataOutput out) throws IOException; 044 045 /** 046 * Called after a block has been written, and its offset, raw size, and compressed size have been 047 * determined. Can be used to add an entry to a block index. If this type of inline blocks needs a 048 * block index, the inline block writer is responsible for maintaining it. 049 * @param offset the offset of the block in the stream 050 * @param onDiskSize the on-disk size of the block 051 * @param uncompressedSize the uncompressed size of the block 052 */ 053 void blockWritten(long offset, int onDiskSize, int uncompressedSize); 054 055 /** 056 * The type of blocks this block writer produces. 057 */ 058 BlockType getInlineBlockType(); 059 060 /** Returns true if inline blocks produced by this writer should be cached */ 061 boolean getCacheOnWrite(); 062}