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Posted to commits@hbase.apache.org by gi...@apache.org on 2018/08/02 19:52:16 UTC
[30/51] [partial] hbase-site git commit: Published site at
613d831429960348dc42c3bdb6ea5d31be15c81c.
http://git-wip-us.apache.org/repos/asf/hbase-site/blob/7cf6034b/devapidocs/src-html/org/apache/hadoop/hbase/io/hfile/HFileBlock.BlockDeserializer.html
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+<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
+<html lang="en">
+<head>
+<title>Source code</title>
+<link rel="stylesheet" type="text/css" href="../../../../../../../stylesheet.css" title="Style">
+</head>
+<body>
+<div class="sourceContainer">
+<pre><span class="sourceLineNo">001</span>/*<a name="line.1"></a>
+<span class="sourceLineNo">002</span> * Licensed to the Apache Software Foundation (ASF) under one<a name="line.2"></a>
+<span class="sourceLineNo">003</span> * or more contributor license agreements. See the NOTICE file<a name="line.3"></a>
+<span class="sourceLineNo">004</span> * distributed with this work for additional information<a name="line.4"></a>
+<span class="sourceLineNo">005</span> * regarding copyright ownership. The ASF licenses this file<a name="line.5"></a>
+<span class="sourceLineNo">006</span> * to you under the Apache License, Version 2.0 (the<a name="line.6"></a>
+<span class="sourceLineNo">007</span> * "License"); you may not use this file except in compliance<a name="line.7"></a>
+<span class="sourceLineNo">008</span> * with the License. You may obtain a copy of the License at<a name="line.8"></a>
+<span class="sourceLineNo">009</span> *<a name="line.9"></a>
+<span class="sourceLineNo">010</span> * http://www.apache.org/licenses/LICENSE-2.0<a name="line.10"></a>
+<span class="sourceLineNo">011</span> *<a name="line.11"></a>
+<span class="sourceLineNo">012</span> * Unless required by applicable law or agreed to in writing, software<a name="line.12"></a>
+<span class="sourceLineNo">013</span> * distributed under the License is distributed on an "AS IS" BASIS,<a name="line.13"></a>
+<span class="sourceLineNo">014</span> * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.<a name="line.14"></a>
+<span class="sourceLineNo">015</span> * See the License for the specific language governing permissions and<a name="line.15"></a>
+<span class="sourceLineNo">016</span> * limitations under the License.<a name="line.16"></a>
+<span class="sourceLineNo">017</span> */<a name="line.17"></a>
+<span class="sourceLineNo">018</span>package org.apache.hadoop.hbase.io.hfile;<a name="line.18"></a>
+<span class="sourceLineNo">019</span><a name="line.19"></a>
+<span class="sourceLineNo">020</span>import java.io.DataInputStream;<a name="line.20"></a>
+<span class="sourceLineNo">021</span>import java.io.DataOutput;<a name="line.21"></a>
+<span class="sourceLineNo">022</span>import java.io.DataOutputStream;<a name="line.22"></a>
+<span class="sourceLineNo">023</span>import java.io.IOException;<a name="line.23"></a>
+<span class="sourceLineNo">024</span>import java.io.InputStream;<a name="line.24"></a>
+<span class="sourceLineNo">025</span>import java.nio.ByteBuffer;<a name="line.25"></a>
+<span class="sourceLineNo">026</span>import java.util.concurrent.atomic.AtomicReference;<a name="line.26"></a>
+<span class="sourceLineNo">027</span>import java.util.concurrent.locks.Lock;<a name="line.27"></a>
+<span class="sourceLineNo">028</span>import java.util.concurrent.locks.ReentrantLock;<a name="line.28"></a>
+<span class="sourceLineNo">029</span><a name="line.29"></a>
+<span class="sourceLineNo">030</span>import org.apache.hadoop.fs.FSDataInputStream;<a name="line.30"></a>
+<span class="sourceLineNo">031</span>import org.apache.hadoop.fs.FSDataOutputStream;<a name="line.31"></a>
+<span class="sourceLineNo">032</span>import org.apache.hadoop.fs.Path;<a name="line.32"></a>
+<span class="sourceLineNo">033</span>import org.apache.hadoop.hbase.Cell;<a name="line.33"></a>
+<span class="sourceLineNo">034</span>import org.apache.hadoop.hbase.HConstants;<a name="line.34"></a>
+<span class="sourceLineNo">035</span>import org.apache.yetus.audience.InterfaceAudience;<a name="line.35"></a>
+<span class="sourceLineNo">036</span>import org.slf4j.Logger;<a name="line.36"></a>
+<span class="sourceLineNo">037</span>import org.slf4j.LoggerFactory;<a name="line.37"></a>
+<span class="sourceLineNo">038</span>import org.apache.hadoop.hbase.fs.HFileSystem;<a name="line.38"></a>
+<span class="sourceLineNo">039</span>import org.apache.hadoop.hbase.io.ByteArrayOutputStream;<a name="line.39"></a>
+<span class="sourceLineNo">040</span>import org.apache.hadoop.hbase.io.ByteBuffInputStream;<a name="line.40"></a>
+<span class="sourceLineNo">041</span>import org.apache.hadoop.hbase.io.ByteBufferWriterDataOutputStream;<a name="line.41"></a>
+<span class="sourceLineNo">042</span>import org.apache.hadoop.hbase.io.FSDataInputStreamWrapper;<a name="line.42"></a>
+<span class="sourceLineNo">043</span>import org.apache.hadoop.hbase.io.encoding.DataBlockEncoding;<a name="line.43"></a>
+<span class="sourceLineNo">044</span>import org.apache.hadoop.hbase.io.encoding.HFileBlockDecodingContext;<a name="line.44"></a>
+<span class="sourceLineNo">045</span>import org.apache.hadoop.hbase.io.encoding.HFileBlockDefaultDecodingContext;<a name="line.45"></a>
+<span class="sourceLineNo">046</span>import org.apache.hadoop.hbase.io.encoding.HFileBlockDefaultEncodingContext;<a name="line.46"></a>
+<span class="sourceLineNo">047</span>import org.apache.hadoop.hbase.io.encoding.HFileBlockEncodingContext;<a name="line.47"></a>
+<span class="sourceLineNo">048</span>import org.apache.hadoop.hbase.nio.ByteBuff;<a name="line.48"></a>
+<span class="sourceLineNo">049</span>import org.apache.hadoop.hbase.nio.MultiByteBuff;<a name="line.49"></a>
+<span class="sourceLineNo">050</span>import org.apache.hadoop.hbase.nio.SingleByteBuff;<a name="line.50"></a>
+<span class="sourceLineNo">051</span>import org.apache.hadoop.hbase.util.Bytes;<a name="line.51"></a>
+<span class="sourceLineNo">052</span>import org.apache.hadoop.hbase.util.ChecksumType;<a name="line.52"></a>
+<span class="sourceLineNo">053</span>import org.apache.hadoop.hbase.util.ClassSize;<a name="line.53"></a>
+<span class="sourceLineNo">054</span>import org.apache.hadoop.io.IOUtils;<a name="line.54"></a>
+<span class="sourceLineNo">055</span><a name="line.55"></a>
+<span class="sourceLineNo">056</span>import org.apache.hbase.thirdparty.com.google.common.annotations.VisibleForTesting;<a name="line.56"></a>
+<span class="sourceLineNo">057</span>import org.apache.hbase.thirdparty.com.google.common.base.Preconditions;<a name="line.57"></a>
+<span class="sourceLineNo">058</span><a name="line.58"></a>
+<span class="sourceLineNo">059</span>/**<a name="line.59"></a>
+<span class="sourceLineNo">060</span> * Cacheable Blocks of an {@link HFile} version 2 file.<a name="line.60"></a>
+<span class="sourceLineNo">061</span> * Version 2 was introduced in hbase-0.92.0.<a name="line.61"></a>
+<span class="sourceLineNo">062</span> *<a name="line.62"></a>
+<span class="sourceLineNo">063</span> * <p>Version 1 was the original file block. Version 2 was introduced when we changed the hbase file<a name="line.63"></a>
+<span class="sourceLineNo">064</span> * format to support multi-level block indexes and compound bloom filters (HBASE-3857). Support<a name="line.64"></a>
+<span class="sourceLineNo">065</span> * for Version 1 was removed in hbase-1.3.0.<a name="line.65"></a>
+<span class="sourceLineNo">066</span> *<a name="line.66"></a>
+<span class="sourceLineNo">067</span> * <h3>HFileBlock: Version 2</h3><a name="line.67"></a>
+<span class="sourceLineNo">068</span> * In version 2, a block is structured as follows:<a name="line.68"></a>
+<span class="sourceLineNo">069</span> * <ul><a name="line.69"></a>
+<span class="sourceLineNo">070</span> * <li><b>Header:</b> See Writer#putHeader() for where header is written; header total size is<a name="line.70"></a>
+<span class="sourceLineNo">071</span> * HFILEBLOCK_HEADER_SIZE<a name="line.71"></a>
+<span class="sourceLineNo">072</span> * <ul><a name="line.72"></a>
+<span class="sourceLineNo">073</span> * <li>0. blockType: Magic record identifying the {@link BlockType} (8 bytes):<a name="line.73"></a>
+<span class="sourceLineNo">074</span> * e.g. <code>DATABLK*</code><a name="line.74"></a>
+<span class="sourceLineNo">075</span> * <li>1. onDiskSizeWithoutHeader: Compressed -- a.k.a 'on disk' -- block size, excluding header,<a name="line.75"></a>
+<span class="sourceLineNo">076</span> * but including tailing checksum bytes (4 bytes)<a name="line.76"></a>
+<span class="sourceLineNo">077</span> * <li>2. uncompressedSizeWithoutHeader: Uncompressed block size, excluding header, and excluding<a name="line.77"></a>
+<span class="sourceLineNo">078</span> * checksum bytes (4 bytes)<a name="line.78"></a>
+<span class="sourceLineNo">079</span> * <li>3. prevBlockOffset: The offset of the previous block of the same type (8 bytes). This is<a name="line.79"></a>
+<span class="sourceLineNo">080</span> * used to navigate to the previous block without having to go to the block index<a name="line.80"></a>
+<span class="sourceLineNo">081</span> * <li>4: For minorVersions &gt;=1, the ordinal describing checksum type (1 byte)<a name="line.81"></a>
+<span class="sourceLineNo">082</span> * <li>5: For minorVersions &gt;=1, the number of data bytes/checksum chunk (4 bytes)<a name="line.82"></a>
+<span class="sourceLineNo">083</span> * <li>6: onDiskDataSizeWithHeader: For minorVersions &gt;=1, the size of data 'on disk', including<a name="line.83"></a>
+<span class="sourceLineNo">084</span> * header, excluding checksums (4 bytes)<a name="line.84"></a>
+<span class="sourceLineNo">085</span> * </ul><a name="line.85"></a>
+<span class="sourceLineNo">086</span> * </li><a name="line.86"></a>
+<span class="sourceLineNo">087</span> * <li><b>Raw/Compressed/Encrypted/Encoded data:</b> The compression<a name="line.87"></a>
+<span class="sourceLineNo">088</span> * algorithm is the same for all the blocks in an {@link HFile}. If compression is NONE, this is<a name="line.88"></a>
+<span class="sourceLineNo">089</span> * just raw, serialized Cells.<a name="line.89"></a>
+<span class="sourceLineNo">090</span> * <li><b>Tail:</b> For minorVersions &gt;=1, a series of 4 byte checksums, one each for<a name="line.90"></a>
+<span class="sourceLineNo">091</span> * the number of bytes specified by bytesPerChecksum.<a name="line.91"></a>
+<span class="sourceLineNo">092</span> * </ul><a name="line.92"></a>
+<span class="sourceLineNo">093</span> *<a name="line.93"></a>
+<span class="sourceLineNo">094</span> * <h3>Caching</h3><a name="line.94"></a>
+<span class="sourceLineNo">095</span> * Caches cache whole blocks with trailing checksums if any. We then tag on some metadata, the<a name="line.95"></a>
+<span class="sourceLineNo">096</span> * content of BLOCK_METADATA_SPACE which will be flag on if we are doing 'hbase'<a name="line.96"></a>
+<span class="sourceLineNo">097</span> * checksums and then the offset into the file which is needed when we re-make a cache key<a name="line.97"></a>
+<span class="sourceLineNo">098</span> * when we return the block to the cache as 'done'.<a name="line.98"></a>
+<span class="sourceLineNo">099</span> * See {@link Cacheable#serialize(ByteBuffer, boolean)} and {@link Cacheable#getDeserializer()}.<a name="line.99"></a>
+<span class="sourceLineNo">100</span> *<a name="line.100"></a>
+<span class="sourceLineNo">101</span> * <p>TODO: Should we cache the checksums? Down in Writer#getBlockForCaching(CacheConfig) where<a name="line.101"></a>
+<span class="sourceLineNo">102</span> * we make a block to cache-on-write, there is an attempt at turning off checksums. This is not the<a name="line.102"></a>
+<span class="sourceLineNo">103</span> * only place we get blocks to cache. We also will cache the raw return from an hdfs read. In this<a name="line.103"></a>
+<span class="sourceLineNo">104</span> * case, the checksums may be present. If the cache is backed by something that doesn't do ECC,<a name="line.104"></a>
+<span class="sourceLineNo">105</span> * say an SSD, we might want to preserve checksums. For now this is open question.<a name="line.105"></a>
+<span class="sourceLineNo">106</span> * <p>TODO: Over in BucketCache, we save a block allocation by doing a custom serialization.<a name="line.106"></a>
+<span class="sourceLineNo">107</span> * Be sure to change it if serialization changes in here. Could we add a method here that takes an<a name="line.107"></a>
+<span class="sourceLineNo">108</span> * IOEngine and that then serializes to it rather than expose our internals over in BucketCache?<a name="line.108"></a>
+<span class="sourceLineNo">109</span> * IOEngine is in the bucket subpackage. Pull it up? Then this class knows about bucketcache. Ugh.<a name="line.109"></a>
+<span class="sourceLineNo">110</span> */<a name="line.110"></a>
+<span class="sourceLineNo">111</span>@InterfaceAudience.Private<a name="line.111"></a>
+<span class="sourceLineNo">112</span>public class HFileBlock implements Cacheable {<a name="line.112"></a>
+<span class="sourceLineNo">113</span> private static final Logger LOG = LoggerFactory.getLogger(HFileBlock.class);<a name="line.113"></a>
+<span class="sourceLineNo">114</span><a name="line.114"></a>
+<span class="sourceLineNo">115</span> // Block Header fields.<a name="line.115"></a>
+<span class="sourceLineNo">116</span><a name="line.116"></a>
+<span class="sourceLineNo">117</span> // TODO: encapsulate Header related logic in this inner class.<a name="line.117"></a>
+<span class="sourceLineNo">118</span> static class Header {<a name="line.118"></a>
+<span class="sourceLineNo">119</span> // Format of header is:<a name="line.119"></a>
+<span class="sourceLineNo">120</span> // 8 bytes - block magic<a name="line.120"></a>
+<span class="sourceLineNo">121</span> // 4 bytes int - onDiskSizeWithoutHeader<a name="line.121"></a>
+<span class="sourceLineNo">122</span> // 4 bytes int - uncompressedSizeWithoutHeader<a name="line.122"></a>
+<span class="sourceLineNo">123</span> // 8 bytes long - prevBlockOffset<a name="line.123"></a>
+<span class="sourceLineNo">124</span> // The following 3 are only present if header contains checksum information<a name="line.124"></a>
+<span class="sourceLineNo">125</span> // 1 byte - checksum type<a name="line.125"></a>
+<span class="sourceLineNo">126</span> // 4 byte int - bytes per checksum<a name="line.126"></a>
+<span class="sourceLineNo">127</span> // 4 byte int - onDiskDataSizeWithHeader<a name="line.127"></a>
+<span class="sourceLineNo">128</span> static int BLOCK_MAGIC_INDEX = 0;<a name="line.128"></a>
+<span class="sourceLineNo">129</span> static int ON_DISK_SIZE_WITHOUT_HEADER_INDEX = 8;<a name="line.129"></a>
+<span class="sourceLineNo">130</span> static int UNCOMPRESSED_SIZE_WITHOUT_HEADER_INDEX = 12;<a name="line.130"></a>
+<span class="sourceLineNo">131</span> static int PREV_BLOCK_OFFSET_INDEX = 16;<a name="line.131"></a>
+<span class="sourceLineNo">132</span> static int CHECKSUM_TYPE_INDEX = 24;<a name="line.132"></a>
+<span class="sourceLineNo">133</span> static int BYTES_PER_CHECKSUM_INDEX = 25;<a name="line.133"></a>
+<span class="sourceLineNo">134</span> static int ON_DISK_DATA_SIZE_WITH_HEADER_INDEX = 29;<a name="line.134"></a>
+<span class="sourceLineNo">135</span> }<a name="line.135"></a>
+<span class="sourceLineNo">136</span><a name="line.136"></a>
+<span class="sourceLineNo">137</span> /** Type of block. Header field 0. */<a name="line.137"></a>
+<span class="sourceLineNo">138</span> private BlockType blockType;<a name="line.138"></a>
+<span class="sourceLineNo">139</span><a name="line.139"></a>
+<span class="sourceLineNo">140</span> /**<a name="line.140"></a>
+<span class="sourceLineNo">141</span> * Size on disk excluding header, including checksum. Header field 1.<a name="line.141"></a>
+<span class="sourceLineNo">142</span> * @see Writer#putHeader(byte[], int, int, int, int)<a name="line.142"></a>
+<span class="sourceLineNo">143</span> */<a name="line.143"></a>
+<span class="sourceLineNo">144</span> private int onDiskSizeWithoutHeader;<a name="line.144"></a>
+<span class="sourceLineNo">145</span><a name="line.145"></a>
+<span class="sourceLineNo">146</span> /**<a name="line.146"></a>
+<span class="sourceLineNo">147</span> * Size of pure data. Does not include header or checksums. Header field 2.<a name="line.147"></a>
+<span class="sourceLineNo">148</span> * @see Writer#putHeader(byte[], int, int, int, int)<a name="line.148"></a>
+<span class="sourceLineNo">149</span> */<a name="line.149"></a>
+<span class="sourceLineNo">150</span> private int uncompressedSizeWithoutHeader;<a name="line.150"></a>
+<span class="sourceLineNo">151</span><a name="line.151"></a>
+<span class="sourceLineNo">152</span> /**<a name="line.152"></a>
+<span class="sourceLineNo">153</span> * The offset of the previous block on disk. Header field 3.<a name="line.153"></a>
+<span class="sourceLineNo">154</span> * @see Writer#putHeader(byte[], int, int, int, int)<a name="line.154"></a>
+<span class="sourceLineNo">155</span> */<a name="line.155"></a>
+<span class="sourceLineNo">156</span> private long prevBlockOffset;<a name="line.156"></a>
+<span class="sourceLineNo">157</span><a name="line.157"></a>
+<span class="sourceLineNo">158</span> /**<a name="line.158"></a>
+<span class="sourceLineNo">159</span> * Size on disk of header + data. Excludes checksum. Header field 6,<a name="line.159"></a>
+<span class="sourceLineNo">160</span> * OR calculated from {@link #onDiskSizeWithoutHeader} when using HDFS checksum.<a name="line.160"></a>
+<span class="sourceLineNo">161</span> * @see Writer#putHeader(byte[], int, int, int, int)<a name="line.161"></a>
+<span class="sourceLineNo">162</span> */<a name="line.162"></a>
+<span class="sourceLineNo">163</span> private int onDiskDataSizeWithHeader;<a name="line.163"></a>
+<span class="sourceLineNo">164</span> // End of Block Header fields.<a name="line.164"></a>
+<span class="sourceLineNo">165</span><a name="line.165"></a>
+<span class="sourceLineNo">166</span> /**<a name="line.166"></a>
+<span class="sourceLineNo">167</span> * The in-memory representation of the hfile block. Can be on or offheap. Can be backed by<a name="line.167"></a>
+<span class="sourceLineNo">168</span> * a single ByteBuffer or by many. Make no assumptions.<a name="line.168"></a>
+<span class="sourceLineNo">169</span> *<a name="line.169"></a>
+<span class="sourceLineNo">170</span> * <p>Be careful reading from this <code>buf</code>. Duplicate and work on the duplicate or if<a name="line.170"></a>
+<span class="sourceLineNo">171</span> * not, be sure to reset position and limit else trouble down the road.<a name="line.171"></a>
+<span class="sourceLineNo">172</span> *<a name="line.172"></a>
+<span class="sourceLineNo">173</span> * <p>TODO: Make this read-only once made.<a name="line.173"></a>
+<span class="sourceLineNo">174</span> *<a name="line.174"></a>
+<span class="sourceLineNo">175</span> * <p>We are using the ByteBuff type. ByteBuffer is not extensible yet we need to be able to have<a name="line.175"></a>
+<span class="sourceLineNo">176</span> * a ByteBuffer-like API across multiple ByteBuffers reading from a cache such as BucketCache.<a name="line.176"></a>
+<span class="sourceLineNo">177</span> * So, we have this ByteBuff type. Unfortunately, it is spread all about HFileBlock. Would be<a name="line.177"></a>
+<span class="sourceLineNo">178</span> * good if could be confined to cache-use only but hard-to-do.<a name="line.178"></a>
+<span class="sourceLineNo">179</span> */<a name="line.179"></a>
+<span class="sourceLineNo">180</span> private ByteBuff buf;<a name="line.180"></a>
+<span class="sourceLineNo">181</span><a name="line.181"></a>
+<span class="sourceLineNo">182</span> /** Meta data that holds meta information on the hfileblock.<a name="line.182"></a>
+<span class="sourceLineNo">183</span> */<a name="line.183"></a>
+<span class="sourceLineNo">184</span> private HFileContext fileContext;<a name="line.184"></a>
+<span class="sourceLineNo">185</span><a name="line.185"></a>
+<span class="sourceLineNo">186</span> /**<a name="line.186"></a>
+<span class="sourceLineNo">187</span> * The offset of this block in the file. Populated by the reader for<a name="line.187"></a>
+<span class="sourceLineNo">188</span> * convenience of access. This offset is not part of the block header.<a name="line.188"></a>
+<span class="sourceLineNo">189</span> */<a name="line.189"></a>
+<span class="sourceLineNo">190</span> private long offset = UNSET;<a name="line.190"></a>
+<span class="sourceLineNo">191</span><a name="line.191"></a>
+<span class="sourceLineNo">192</span> private MemoryType memType = MemoryType.EXCLUSIVE;<a name="line.192"></a>
+<span class="sourceLineNo">193</span><a name="line.193"></a>
+<span class="sourceLineNo">194</span> /**<a name="line.194"></a>
+<span class="sourceLineNo">195</span> * The on-disk size of the next block, including the header and checksums if present.<a name="line.195"></a>
+<span class="sourceLineNo">196</span> * UNSET if unknown.<a name="line.196"></a>
+<span class="sourceLineNo">197</span> *<a name="line.197"></a>
+<span class="sourceLineNo">198</span> * Blocks try to carry the size of the next block to read in this data member. Usually<a name="line.198"></a>
+<span class="sourceLineNo">199</span> * we get block sizes from the hfile index but sometimes the index is not available:<a name="line.199"></a>
+<span class="sourceLineNo">200</span> * e.g. when we read the indexes themselves (indexes are stored in blocks, we do not<a name="line.200"></a>
+<span class="sourceLineNo">201</span> * have an index for the indexes). Saves seeks especially around file open when<a name="line.201"></a>
+<span class="sourceLineNo">202</span> * there is a flurry of reading in hfile metadata.<a name="line.202"></a>
+<span class="sourceLineNo">203</span> */<a name="line.203"></a>
+<span class="sourceLineNo">204</span> private int nextBlockOnDiskSize = UNSET;<a name="line.204"></a>
+<span class="sourceLineNo">205</span><a name="line.205"></a>
+<span class="sourceLineNo">206</span> /**<a name="line.206"></a>
+<span class="sourceLineNo">207</span> * On a checksum failure, do these many succeeding read requests using hdfs checksums before<a name="line.207"></a>
+<span class="sourceLineNo">208</span> * auto-reenabling hbase checksum verification.<a name="line.208"></a>
+<span class="sourceLineNo">209</span> */<a name="line.209"></a>
+<span class="sourceLineNo">210</span> static final int CHECKSUM_VERIFICATION_NUM_IO_THRESHOLD = 3;<a name="line.210"></a>
+<span class="sourceLineNo">211</span><a name="line.211"></a>
+<span class="sourceLineNo">212</span> private static int UNSET = -1;<a name="line.212"></a>
+<span class="sourceLineNo">213</span> public static final boolean FILL_HEADER = true;<a name="line.213"></a>
+<span class="sourceLineNo">214</span> public static final boolean DONT_FILL_HEADER = false;<a name="line.214"></a>
+<span class="sourceLineNo">215</span><a name="line.215"></a>
+<span class="sourceLineNo">216</span> // How to get the estimate correctly? if it is a singleBB?<a name="line.216"></a>
+<span class="sourceLineNo">217</span> public static final int MULTI_BYTE_BUFFER_HEAP_SIZE =<a name="line.217"></a>
+<span class="sourceLineNo">218</span> (int)ClassSize.estimateBase(MultiByteBuff.class, false);<a name="line.218"></a>
+<span class="sourceLineNo">219</span><a name="line.219"></a>
+<span class="sourceLineNo">220</span> /**<a name="line.220"></a>
+<span class="sourceLineNo">221</span> * Space for metadata on a block that gets stored along with the block when we cache it.<a name="line.221"></a>
+<span class="sourceLineNo">222</span> * There are a few bytes stuck on the end of the HFileBlock that we pull in from HDFS.<a name="line.222"></a>
+<span class="sourceLineNo">223</span> * 8 bytes are for the offset of this block (long) in the file. Offset is important because is is<a name="line.223"></a>
+<span class="sourceLineNo">224</span> * used when we remake the CacheKey when we return block to the cache when done. There is also<a name="line.224"></a>
+<span class="sourceLineNo">225</span> * a flag on whether checksumming is being done by hbase or not. See class comment for note on<a name="line.225"></a>
+<span class="sourceLineNo">226</span> * uncertain state of checksumming of blocks that come out of cache (should we or should we not?).<a name="line.226"></a>
+<span class="sourceLineNo">227</span> * Finally there are 4 bytes to hold the length of the next block which can save a seek on<a name="line.227"></a>
+<span class="sourceLineNo">228</span> * occasion if available.<a name="line.228"></a>
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+<span class="sourceLineNo">231</span> */<a name="line.231"></a>
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+<span class="sourceLineNo">238</span><a name="line.238"></a>
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+<span class="sourceLineNo">240</span> new byte[HConstants.HFILEBLOCK_HEADER_SIZE_NO_CHECKSUM];<a name="line.240"></a>
+<span class="sourceLineNo">241</span><a name="line.241"></a>
+<span class="sourceLineNo">242</span> /**<a name="line.242"></a>
+<span class="sourceLineNo">243</span> * Used deserializing blocks from Cache.<a name="line.243"></a>
+<span class="sourceLineNo">244</span> *<a name="line.244"></a>
+<span class="sourceLineNo">245</span> * <code><a name="line.245"></a>
+<span class="sourceLineNo">246</span> * ++++++++++++++<a name="line.246"></a>
+<span class="sourceLineNo">247</span> * + HFileBlock +<a name="line.247"></a>
+<span class="sourceLineNo">248</span> * ++++++++++++++<a name="line.248"></a>
+<span class="sourceLineNo">249</span> * + Checksums + <= Optional<a name="line.249"></a>
+<span class="sourceLineNo">250</span> * ++++++++++++++<a name="line.250"></a>
+<span class="sourceLineNo">251</span> * + Metadata! + <= See note on BLOCK_METADATA_SPACE above.<a name="line.251"></a>
+<span class="sourceLineNo">252</span> * ++++++++++++++<a name="line.252"></a>
+<span class="sourceLineNo">253</span> * </code><a name="line.253"></a>
+<span class="sourceLineNo">254</span> * @see #serialize(ByteBuffer, boolean)<a name="line.254"></a>
+<span class="sourceLineNo">255</span> */<a name="line.255"></a>
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+<span class="sourceLineNo">257</span><a name="line.257"></a>
+<span class="sourceLineNo">258</span> public static final class BlockDeserializer implements CacheableDeserializer<Cacheable> {<a name="line.258"></a>
+<span class="sourceLineNo">259</span> private BlockDeserializer() {<a name="line.259"></a>
+<span class="sourceLineNo">260</span> }<a name="line.260"></a>
+<span class="sourceLineNo">261</span><a name="line.261"></a>
+<span class="sourceLineNo">262</span> @Override<a name="line.262"></a>
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+<span class="sourceLineNo">264</span> throws IOException {<a name="line.264"></a>
+<span class="sourceLineNo">265</span> // The buf has the file block followed by block metadata.<a name="line.265"></a>
+<span class="sourceLineNo">266</span> // Set limit to just before the BLOCK_METADATA_SPACE then rewind.<a name="line.266"></a>
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+<span class="sourceLineNo">268</span> // Get a new buffer to pass the HFileBlock for it to 'own'.<a name="line.268"></a>
+<span class="sourceLineNo">269</span> ByteBuff newByteBuff;<a name="line.269"></a>
+<span class="sourceLineNo">270</span> if (reuse) {<a name="line.270"></a>
+<span class="sourceLineNo">271</span> newByteBuff = buf.slice();<a name="line.271"></a>
+<span class="sourceLineNo">272</span> } else {<a name="line.272"></a>
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+<span class="sourceLineNo">274</span> newByteBuff = new SingleByteBuff(ByteBuffer.allocate(len));<a name="line.274"></a>
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+<span class="sourceLineNo">276</span> }<a name="line.276"></a>
+<span class="sourceLineNo">277</span> // Read out the BLOCK_METADATA_SPACE content and shove into our HFileBlock.<a name="line.277"></a>
+<span class="sourceLineNo">278</span> buf.position(buf.limit());<a name="line.278"></a>
+<span class="sourceLineNo">279</span> buf.limit(buf.limit() + HFileBlock.BLOCK_METADATA_SPACE);<a name="line.279"></a>
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+<span class="sourceLineNo">281</span> long offset = buf.getLong();<a name="line.281"></a>
+<span class="sourceLineNo">282</span> int nextBlockOnDiskSize = buf.getInt();<a name="line.282"></a>
+<span class="sourceLineNo">283</span> HFileBlock hFileBlock =<a name="line.283"></a>
+<span class="sourceLineNo">284</span> new HFileBlock(newByteBuff, usesChecksum, memType, offset, nextBlockOnDiskSize, null);<a name="line.284"></a>
+<span class="sourceLineNo">285</span> return hFileBlock;<a name="line.285"></a>
+<span class="sourceLineNo">286</span> }<a name="line.286"></a>
+<span class="sourceLineNo">287</span><a name="line.287"></a>
+<span class="sourceLineNo">288</span> @Override<a name="line.288"></a>
+<span class="sourceLineNo">289</span> public int getDeserialiserIdentifier() {<a name="line.289"></a>
+<span class="sourceLineNo">290</span> return DESERIALIZER_IDENTIFIER;<a name="line.290"></a>
+<span class="sourceLineNo">291</span> }<a name="line.291"></a>
+<span class="sourceLineNo">292</span><a name="line.292"></a>
+<span class="sourceLineNo">293</span> @Override<a name="line.293"></a>
+<span class="sourceLineNo">294</span> public HFileBlock deserialize(ByteBuff b) throws IOException {<a name="line.294"></a>
+<span class="sourceLineNo">295</span> // Used only in tests<a name="line.295"></a>
+<span class="sourceLineNo">296</span> return deserialize(b, false, MemoryType.EXCLUSIVE);<a name="line.296"></a>
+<span class="sourceLineNo">297</span> }<a name="line.297"></a>
+<span class="sourceLineNo">298</span> }<a name="line.298"></a>
+<span class="sourceLineNo">299</span><a name="line.299"></a>
+<span class="sourceLineNo">300</span> private static final int DESERIALIZER_IDENTIFIER;<a name="line.300"></a>
+<span class="sourceLineNo">301</span> static {<a name="line.301"></a>
+<span class="sourceLineNo">302</span> DESERIALIZER_IDENTIFIER =<a name="line.302"></a>
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+<span class="sourceLineNo">304</span> }<a name="line.304"></a>
+<span class="sourceLineNo">305</span><a name="line.305"></a>
+<span class="sourceLineNo">306</span> /**<a name="line.306"></a>
+<span class="sourceLineNo">307</span> * Copy constructor. Creates a shallow copy of {@code that}'s buffer.<a name="line.307"></a>
+<span class="sourceLineNo">308</span> */<a name="line.308"></a>
+<span class="sourceLineNo">309</span> private HFileBlock(HFileBlock that) {<a name="line.309"></a>
+<span class="sourceLineNo">310</span> this(that, false);<a name="line.310"></a>
+<span class="sourceLineNo">311</span> }<a name="line.311"></a>
+<span class="sourceLineNo">312</span><a name="line.312"></a>
+<span class="sourceLineNo">313</span> /**<a name="line.313"></a>
+<span class="sourceLineNo">314</span> * Copy constructor. Creates a shallow/deep copy of {@code that}'s buffer as per the boolean<a name="line.314"></a>
+<span class="sourceLineNo">315</span> * param.<a name="line.315"></a>
+<span class="sourceLineNo">316</span> */<a name="line.316"></a>
+<span class="sourceLineNo">317</span> private HFileBlock(HFileBlock that, boolean bufCopy) {<a name="line.317"></a>
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+<span class="sourceLineNo">319</span> that.uncompressedSizeWithoutHeader, that.prevBlockOffset,<a name="line.319"></a>
+<span class="sourceLineNo">320</span> that.offset, that.onDiskDataSizeWithHeader, that.nextBlockOnDiskSize, that.fileContext);<a name="line.320"></a>
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+<span class="sourceLineNo">323</span> } else {<a name="line.323"></a>
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+<span class="sourceLineNo">325</span> }<a name="line.325"></a>
+<span class="sourceLineNo">326</span> }<a name="line.326"></a>
+<span class="sourceLineNo">327</span><a name="line.327"></a>
+<span class="sourceLineNo">328</span> /**<a name="line.328"></a>
+<span class="sourceLineNo">329</span> * Creates a new {@link HFile} block from the given fields. This constructor<a name="line.329"></a>
+<span class="sourceLineNo">330</span> * is used only while writing blocks and caching,<a name="line.330"></a>
+<span class="sourceLineNo">331</span> * and is sitting in a byte buffer and we want to stuff the block into cache.<a name="line.331"></a>
+<span class="sourceLineNo">332</span> *<a name="line.332"></a>
+<span class="sourceLineNo">333</span> * <p>TODO: The caller presumes no checksumming<a name="line.333"></a>
+<span class="sourceLineNo">334</span> * required of this block instance since going into cache; checksum already verified on<a name="line.334"></a>
+<span class="sourceLineNo">335</span> * underlying block data pulled in from filesystem. Is that correct? What if cache is SSD?<a name="line.335"></a>
+<span class="sourceLineNo">336</span> *<a name="line.336"></a>
+<span class="sourceLineNo">337</span> * @param blockType the type of this block, see {@link BlockType}<a name="line.337"></a>
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+<span class="sourceLineNo">339</span> * @param uncompressedSizeWithoutHeader see {@link #uncompressedSizeWithoutHeader}<a name="line.339"></a>
+<span class="sourceLineNo">340</span> * @param prevBlockOffset see {@link #prevBlockOffset}<a name="line.340"></a>
+<span class="sourceLineNo">341</span> * @param b block header ({@link HConstants#HFILEBLOCK_HEADER_SIZE} bytes)<a name="line.341"></a>
+<span class="sourceLineNo">342</span> * @param fillHeader when true, write the first 4 header fields into passed buffer.<a name="line.342"></a>
+<span class="sourceLineNo">343</span> * @param offset the file offset the block was read from<a name="line.343"></a>
+<span class="sourceLineNo">344</span> * @param onDiskDataSizeWithHeader see {@link #onDiskDataSizeWithHeader}<a name="line.344"></a>
+<span class="sourceLineNo">345</span> * @param fileContext HFile meta data<a name="line.345"></a>
+<span class="sourceLineNo">346</span> */<a name="line.346"></a>
+<span class="sourceLineNo">347</span> @VisibleForTesting<a name="line.347"></a>
+<span class="sourceLineNo">348</span> public HFileBlock(BlockType blockType, int onDiskSizeWithoutHeader,<a name="line.348"></a>
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+<span class="sourceLineNo">350</span> long offset, final int nextBlockOnDiskSize, int onDiskDataSizeWithHeader,<a name="line.350"></a>
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+<span class="sourceLineNo">354</span> this.buf = new SingleByteBuff(b);<a name="line.354"></a>
+<span class="sourceLineNo">355</span> if (fillHeader) {<a name="line.355"></a>
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+<span class="sourceLineNo">358</span> this.buf.rewind();<a name="line.358"></a>
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+<span class="sourceLineNo">360</span><a name="line.360"></a>
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+<span class="sourceLineNo">363</span> * and takes ownership of the buffer. By definition of rewind, ignores the<a name="line.363"></a>
+<span class="sourceLineNo">364</span> * buffer position, but if you slice the buffer beforehand, it will rewind<a name="line.364"></a>
+<span class="sourceLineNo">365</span> * to that point.<a name="line.365"></a>
+<span class="sourceLineNo">366</span> * @param buf Has header, content, and trailing checksums if present.<a name="line.366"></a>
+<span class="sourceLineNo">367</span> */<a name="line.367"></a>
+<span class="sourceLineNo">368</span> HFileBlock(ByteBuff buf, boolean usesHBaseChecksum, MemoryType memType, final long offset,<a name="line.368"></a>
+<span class="sourceLineNo">369</span> final int nextBlockOnDiskSize, HFileContext fileContext) throws IOException {<a name="line.369"></a>
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+<span class="sourceLineNo">371</span> final BlockType blockType = BlockType.read(buf);<a name="line.371"></a>
+<span class="sourceLineNo">372</span> final int onDiskSizeWithoutHeader = buf.getInt(Header.ON_DISK_SIZE_WITHOUT_HEADER_INDEX);<a name="line.372"></a>
+<span class="sourceLineNo">373</span> final int uncompressedSizeWithoutHeader =<a name="line.373"></a>
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+<span class="sourceLineNo">375</span> final long prevBlockOffset = buf.getLong(Header.PREV_BLOCK_OFFSET_INDEX);<a name="line.375"></a>
+<span class="sourceLineNo">376</span> // This constructor is called when we deserialize a block from cache and when we read a block in<a name="line.376"></a>
+<span class="sourceLineNo">377</span> // from the fs. fileCache is null when deserialized from cache so need to make up one.<a name="line.377"></a>
+<span class="sourceLineNo">378</span> HFileContextBuilder fileContextBuilder = fileContext != null?<a name="line.378"></a>
+<span class="sourceLineNo">379</span> new HFileContextBuilder(fileContext): new HFileContextBuilder();<a name="line.379"></a>
+<span class="sourceLineNo">380</span> fileContextBuilder.withHBaseCheckSum(usesHBaseChecksum);<a name="line.380"></a>
+<span class="sourceLineNo">381</span> int onDiskDataSizeWithHeader;<a name="line.381"></a>
+<span class="sourceLineNo">382</span> if (usesHBaseChecksum) {<a name="line.382"></a>
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+<span class="sourceLineNo">384</span> int bytesPerChecksum = buf.getInt(Header.BYTES_PER_CHECKSUM_INDEX);<a name="line.384"></a>
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+<span class="sourceLineNo">386</span> // Use the checksum type and bytes per checksum from header, not from filecontext.<a name="line.386"></a>
+<span class="sourceLineNo">387</span> fileContextBuilder.withChecksumType(ChecksumType.codeToType(checksumType));<a name="line.387"></a>
+<span class="sourceLineNo">388</span> fileContextBuilder.withBytesPerCheckSum(bytesPerChecksum);<a name="line.388"></a>
+<span class="sourceLineNo">389</span> } else {<a name="line.389"></a>
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+<span class="sourceLineNo">391</span> fileContextBuilder.withBytesPerCheckSum(0);<a name="line.391"></a>
+<span class="sourceLineNo">392</span> // Need to fix onDiskDataSizeWithHeader; there are not checksums after-block-data<a name="line.392"></a>
+<span class="sourceLineNo">393</span> onDiskDataSizeWithHeader = onDiskSizeWithoutHeader + headerSize(usesHBaseChecksum);<a name="line.393"></a>
+<span class="sourceLineNo">394</span> }<a name="line.394"></a>
+<span class="sourceLineNo">395</span> fileContext = fileContextBuilder.build();<a name="line.395"></a>
+<span class="sourceLineNo">396</span> assert usesHBaseChecksum == fileContext.isUseHBaseChecksum();<a name="line.396"></a>
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+<span class="sourceLineNo">400</span> this.offset = offset;<a name="line.400"></a>
+<span class="sourceLineNo">401</span> this.buf = buf;<a name="line.401"></a>
+<span class="sourceLineNo">402</span> this.buf.rewind();<a name="line.402"></a>
+<span class="sourceLineNo">403</span> }<a name="line.403"></a>
+<span class="sourceLineNo">404</span><a name="line.404"></a>
+<span class="sourceLineNo">405</span> /**<a name="line.405"></a>
+<span class="sourceLineNo">406</span> * Called from constructors.<a name="line.406"></a>
+<span class="sourceLineNo">407</span> */<a name="line.407"></a>
+<span class="sourceLineNo">408</span> private void init(BlockType blockType, int onDiskSizeWithoutHeader,<a name="line.408"></a>
+<span class="sourceLineNo">409</span> int uncompressedSizeWithoutHeader, long prevBlockOffset,<a name="line.409"></a>
+<span class="sourceLineNo">410</span> long offset, int onDiskDataSizeWithHeader, final int nextBlockOnDiskSize,<a name="line.410"></a>
+<span class="sourceLineNo">411</span> HFileContext fileContext) {<a name="line.411"></a>
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+<span class="sourceLineNo">413</span> this.onDiskSizeWithoutHeader = onDiskSizeWithoutHeader;<a name="line.413"></a>
+<span class="sourceLineNo">414</span> this.uncompressedSizeWithoutHeader = uncompressedSizeWithoutHeader;<a name="line.414"></a>
+<span class="sourceLineNo">415</span> this.prevBlockOffset = prevBlockOffset;<a name="line.415"></a>
+<span class="sourceLineNo">416</span> this.offset = offset;<a name="line.416"></a>
+<span class="sourceLineNo">417</span> this.onDiskDataSizeWithHeader = onDiskDataSizeWithHeader;<a name="line.417"></a>
+<span class="sourceLineNo">418</span> this.nextBlockOnDiskSize = nextBlockOnDiskSize;<a name="line.418"></a>
+<span class="sourceLineNo">419</span> this.fileContext = fileContext;<a name="line.419"></a>
+<span class="sourceLineNo">420</span> }<a name="line.420"></a>
+<span class="sourceLineNo">421</span><a name="line.421"></a>
+<span class="sourceLineNo">422</span> /**<a name="line.422"></a>
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+<span class="sourceLineNo">425</span> * @param verifyChecksum true if checksum verification is in use.<a name="line.425"></a>
+<span class="sourceLineNo">426</span> * @return Size of the block with header included.<a name="line.426"></a>
+<span class="sourceLineNo">427</span> */<a name="line.427"></a>
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+<span class="sourceLineNo">431</span> headerSize(verifyChecksum);<a name="line.431"></a>
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+<span class="sourceLineNo">433</span><a name="line.433"></a>
+<span class="sourceLineNo">434</span> /**<a name="line.434"></a>
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+<span class="sourceLineNo">437</span> * a read of the next block when scanning or running over a file.<a name="line.437"></a>
+<span class="sourceLineNo">438</span> */<a name="line.438"></a>
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+<span class="sourceLineNo">442</span><a name="line.442"></a>
+<span class="sourceLineNo">443</span> @Override<a name="line.443"></a>
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