You are viewing a plain text version of this content. The canonical link for it is here.
Posted to commits@hbase.apache.org by mi...@apache.org on 2016/02/04 18:31:38 UTC
[18/23] hbase-site git commit: Published site at
2cf8af5bf1d501156cbb3b421cf75c1051ead7d9.
http://git-wip-us.apache.org/repos/asf/hbase-site/blob/32672884/devapidocs/src-html/org/apache/hadoop/hbase/io/hfile/ChecksumUtil.html
----------------------------------------------------------------------
diff --git a/devapidocs/src-html/org/apache/hadoop/hbase/io/hfile/ChecksumUtil.html b/devapidocs/src-html/org/apache/hadoop/hbase/io/hfile/ChecksumUtil.html
index b2afb36..a7a0401 100644
--- a/devapidocs/src-html/org/apache/hadoop/hbase/io/hfile/ChecksumUtil.html
+++ b/devapidocs/src-html/org/apache/hadoop/hbase/io/hfile/ChecksumUtil.html
@@ -33,172 +33,170 @@
<span class="sourceLineNo">025</span>import org.apache.commons.logging.LogFactory;<a name="line.25"></a>
<span class="sourceLineNo">026</span>import org.apache.hadoop.fs.ChecksumException;<a name="line.26"></a>
<span class="sourceLineNo">027</span>import org.apache.hadoop.hbase.classification.InterfaceAudience;<a name="line.27"></a>
-<span class="sourceLineNo">028</span>import org.apache.hadoop.fs.Path;<a name="line.28"></a>
-<span class="sourceLineNo">029</span>import org.apache.hadoop.hbase.util.ChecksumType;<a name="line.29"></a>
-<span class="sourceLineNo">030</span>import org.apache.hadoop.util.DataChecksum;<a name="line.30"></a>
-<span class="sourceLineNo">031</span><a name="line.31"></a>
-<span class="sourceLineNo">032</span>/**<a name="line.32"></a>
-<span class="sourceLineNo">033</span> * Utility methods to compute and validate checksums.<a name="line.33"></a>
-<span class="sourceLineNo">034</span> */<a name="line.34"></a>
-<span class="sourceLineNo">035</span>@InterfaceAudience.Private<a name="line.35"></a>
-<span class="sourceLineNo">036</span>public class ChecksumUtil {<a name="line.36"></a>
-<span class="sourceLineNo">037</span> public static final Log LOG = LogFactory.getLog(ChecksumUtil.class);<a name="line.37"></a>
-<span class="sourceLineNo">038</span><a name="line.38"></a>
-<span class="sourceLineNo">039</span> /** This is used to reserve space in a byte buffer */<a name="line.39"></a>
-<span class="sourceLineNo">040</span> private static byte[] DUMMY_VALUE = new byte[128 * HFileBlock.CHECKSUM_SIZE];<a name="line.40"></a>
-<span class="sourceLineNo">041</span><a name="line.41"></a>
-<span class="sourceLineNo">042</span> /** <a name="line.42"></a>
-<span class="sourceLineNo">043</span> * This is used by unit tests to make checksum failures throw an <a name="line.43"></a>
-<span class="sourceLineNo">044</span> * exception instead of returning null. Returning a null value from <a name="line.44"></a>
-<span class="sourceLineNo">045</span> * checksum validation will cause the higher layer to retry that <a name="line.45"></a>
-<span class="sourceLineNo">046</span> * read with hdfs-level checksums. Instead, we would like checksum <a name="line.46"></a>
-<span class="sourceLineNo">047</span> * failures to cause the entire unit test to fail.<a name="line.47"></a>
-<span class="sourceLineNo">048</span> */<a name="line.48"></a>
-<span class="sourceLineNo">049</span> private static boolean generateExceptions = false;<a name="line.49"></a>
-<span class="sourceLineNo">050</span><a name="line.50"></a>
-<span class="sourceLineNo">051</span> /**<a name="line.51"></a>
-<span class="sourceLineNo">052</span> * Generates a checksum for all the data in indata. The checksum is<a name="line.52"></a>
-<span class="sourceLineNo">053</span> * written to outdata.<a name="line.53"></a>
-<span class="sourceLineNo">054</span> * @param indata input data stream<a name="line.54"></a>
-<span class="sourceLineNo">055</span> * @param startOffset starting offset in the indata stream from where to<a name="line.55"></a>
-<span class="sourceLineNo">056</span> * compute checkums from<a name="line.56"></a>
-<span class="sourceLineNo">057</span> * @param endOffset ending offset in the indata stream upto<a name="line.57"></a>
-<span class="sourceLineNo">058</span> * which checksums needs to be computed<a name="line.58"></a>
-<span class="sourceLineNo">059</span> * @param outdata the output buffer where checksum values are written<a name="line.59"></a>
-<span class="sourceLineNo">060</span> * @param outOffset the starting offset in the outdata where the<a name="line.60"></a>
-<span class="sourceLineNo">061</span> * checksum values are written<a name="line.61"></a>
-<span class="sourceLineNo">062</span> * @param checksumType type of checksum<a name="line.62"></a>
-<span class="sourceLineNo">063</span> * @param bytesPerChecksum number of bytes per checksum value<a name="line.63"></a>
-<span class="sourceLineNo">064</span> */<a name="line.64"></a>
-<span class="sourceLineNo">065</span> static void generateChecksums(byte[] indata, int startOffset, int endOffset,<a name="line.65"></a>
-<span class="sourceLineNo">066</span> byte[] outdata, int outOffset, ChecksumType checksumType,<a name="line.66"></a>
-<span class="sourceLineNo">067</span> int bytesPerChecksum) throws IOException {<a name="line.67"></a>
-<span class="sourceLineNo">068</span><a name="line.68"></a>
-<span class="sourceLineNo">069</span> if (checksumType == ChecksumType.NULL) {<a name="line.69"></a>
-<span class="sourceLineNo">070</span> return; // No checksum for this block.<a name="line.70"></a>
-<span class="sourceLineNo">071</span> }<a name="line.71"></a>
-<span class="sourceLineNo">072</span><a name="line.72"></a>
-<span class="sourceLineNo">073</span> DataChecksum checksum = DataChecksum.newDataChecksum(<a name="line.73"></a>
-<span class="sourceLineNo">074</span> checksumType.getDataChecksumType(), bytesPerChecksum);<a name="line.74"></a>
-<span class="sourceLineNo">075</span><a name="line.75"></a>
-<span class="sourceLineNo">076</span> checksum.calculateChunkedSums(<a name="line.76"></a>
-<span class="sourceLineNo">077</span> ByteBuffer.wrap(indata, startOffset, endOffset - startOffset),<a name="line.77"></a>
-<span class="sourceLineNo">078</span> ByteBuffer.wrap(outdata, outOffset, outdata.length - outOffset));<a name="line.78"></a>
-<span class="sourceLineNo">079</span> }<a name="line.79"></a>
-<span class="sourceLineNo">080</span><a name="line.80"></a>
-<span class="sourceLineNo">081</span> /**<a name="line.81"></a>
-<span class="sourceLineNo">082</span> * Validates that the data in the specified HFileBlock matches the<a name="line.82"></a>
-<span class="sourceLineNo">083</span> * checksum. Generates the checksum for the data and<a name="line.83"></a>
-<span class="sourceLineNo">084</span> * then validate that it matches the value stored in the header.<a name="line.84"></a>
-<span class="sourceLineNo">085</span> * If there is a checksum mismatch, then return false. Otherwise<a name="line.85"></a>
-<span class="sourceLineNo">086</span> * return true.<a name="line.86"></a>
-<span class="sourceLineNo">087</span> * The header is extracted from the specified HFileBlock while the<a name="line.87"></a>
-<span class="sourceLineNo">088</span> * data-to-be-verified is extracted from 'data'.<a name="line.88"></a>
-<span class="sourceLineNo">089</span> */<a name="line.89"></a>
-<span class="sourceLineNo">090</span> static boolean validateBlockChecksum(Path path, HFileBlock block,<a name="line.90"></a>
-<span class="sourceLineNo">091</span> byte[] data, int hdrSize) throws IOException {<a name="line.91"></a>
-<span class="sourceLineNo">092</span><a name="line.92"></a>
-<span class="sourceLineNo">093</span> // If this is an older version of the block that does not have<a name="line.93"></a>
-<span class="sourceLineNo">094</span> // checksums, then return false indicating that checksum verification<a name="line.94"></a>
-<span class="sourceLineNo">095</span> // did not succeed. Actually, this methiod should never be called<a name="line.95"></a>
-<span class="sourceLineNo">096</span> // when the minorVersion is 0, thus this is a defensive check for a<a name="line.96"></a>
-<span class="sourceLineNo">097</span> // cannot-happen case. Since this is a cannot-happen case, it is<a name="line.97"></a>
-<span class="sourceLineNo">098</span> // better to return false to indicate a checksum validation failure.<a name="line.98"></a>
-<span class="sourceLineNo">099</span> if (!block.getHFileContext().isUseHBaseChecksum()) {<a name="line.99"></a>
-<span class="sourceLineNo">100</span> return false;<a name="line.100"></a>
-<span class="sourceLineNo">101</span> }<a name="line.101"></a>
-<span class="sourceLineNo">102</span><a name="line.102"></a>
-<span class="sourceLineNo">103</span> // Get a checksum object based on the type of checksum that is<a name="line.103"></a>
-<span class="sourceLineNo">104</span> // set in the HFileBlock header. A ChecksumType.NULL indicates that <a name="line.104"></a>
-<span class="sourceLineNo">105</span> // the caller is not interested in validating checksums, so we<a name="line.105"></a>
-<span class="sourceLineNo">106</span> // always return true.<a name="line.106"></a>
-<span class="sourceLineNo">107</span> ChecksumType cktype = ChecksumType.codeToType(block.getChecksumType());<a name="line.107"></a>
-<span class="sourceLineNo">108</span> if (cktype == ChecksumType.NULL) {<a name="line.108"></a>
-<span class="sourceLineNo">109</span> return true; // No checksum validations needed for this block.<a name="line.109"></a>
-<span class="sourceLineNo">110</span> }<a name="line.110"></a>
-<span class="sourceLineNo">111</span><a name="line.111"></a>
-<span class="sourceLineNo">112</span> // read in the stored value of the checksum size from the header.<a name="line.112"></a>
-<span class="sourceLineNo">113</span> int bytesPerChecksum = block.getBytesPerChecksum();<a name="line.113"></a>
-<span class="sourceLineNo">114</span><a name="line.114"></a>
-<span class="sourceLineNo">115</span> DataChecksum dataChecksum = DataChecksum.newDataChecksum(<a name="line.115"></a>
-<span class="sourceLineNo">116</span> cktype.getDataChecksumType(), bytesPerChecksum);<a name="line.116"></a>
-<span class="sourceLineNo">117</span> assert dataChecksum != null;<a name="line.117"></a>
-<span class="sourceLineNo">118</span> int sizeWithHeader = block.getOnDiskDataSizeWithHeader();<a name="line.118"></a>
-<span class="sourceLineNo">119</span> if (LOG.isTraceEnabled()) {<a name="line.119"></a>
-<span class="sourceLineNo">120</span> LOG.info("length of data = " + data.length<a name="line.120"></a>
-<span class="sourceLineNo">121</span> + " OnDiskDataSizeWithHeader = " + sizeWithHeader<a name="line.121"></a>
-<span class="sourceLineNo">122</span> + " checksum type = " + cktype.getName()<a name="line.122"></a>
-<span class="sourceLineNo">123</span> + " file =" + path.toString()<a name="line.123"></a>
-<span class="sourceLineNo">124</span> + " header size = " + hdrSize<a name="line.124"></a>
-<span class="sourceLineNo">125</span> + " bytesPerChecksum = " + bytesPerChecksum);<a name="line.125"></a>
-<span class="sourceLineNo">126</span> }<a name="line.126"></a>
-<span class="sourceLineNo">127</span> try {<a name="line.127"></a>
-<span class="sourceLineNo">128</span> dataChecksum.verifyChunkedSums(ByteBuffer.wrap(data, 0, sizeWithHeader),<a name="line.128"></a>
-<span class="sourceLineNo">129</span> ByteBuffer.wrap(data, sizeWithHeader, data.length - sizeWithHeader),<a name="line.129"></a>
-<span class="sourceLineNo">130</span> path.toString(), 0);<a name="line.130"></a>
-<span class="sourceLineNo">131</span> } catch (ChecksumException e) {<a name="line.131"></a>
-<span class="sourceLineNo">132</span> return false;<a name="line.132"></a>
-<span class="sourceLineNo">133</span> }<a name="line.133"></a>
-<span class="sourceLineNo">134</span> return true; // checksum is valid<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> /**<a name="line.137"></a>
-<span class="sourceLineNo">138</span> * Returns the number of bytes needed to store the checksums for<a name="line.138"></a>
-<span class="sourceLineNo">139</span> * a specified data size<a name="line.139"></a>
-<span class="sourceLineNo">140</span> * @param datasize number of bytes of data<a name="line.140"></a>
-<span class="sourceLineNo">141</span> * @param bytesPerChecksum number of bytes in a checksum chunk<a name="line.141"></a>
-<span class="sourceLineNo">142</span> * @return The number of bytes needed to store the checksum values<a name="line.142"></a>
-<span class="sourceLineNo">143</span> */<a name="line.143"></a>
-<span class="sourceLineNo">144</span> static long numBytes(long datasize, int bytesPerChecksum) {<a name="line.144"></a>
-<span class="sourceLineNo">145</span> return numChunks(datasize, bytesPerChecksum) * <a name="line.145"></a>
-<span class="sourceLineNo">146</span> HFileBlock.CHECKSUM_SIZE;<a name="line.146"></a>
-<span class="sourceLineNo">147</span> }<a name="line.147"></a>
-<span class="sourceLineNo">148</span><a name="line.148"></a>
-<span class="sourceLineNo">149</span> /**<a name="line.149"></a>
-<span class="sourceLineNo">150</span> * Returns the number of checksum chunks needed to store the checksums for<a name="line.150"></a>
-<span class="sourceLineNo">151</span> * a specified data size<a name="line.151"></a>
-<span class="sourceLineNo">152</span> * @param datasize number of bytes of data<a name="line.152"></a>
-<span class="sourceLineNo">153</span> * @param bytesPerChecksum number of bytes in a checksum chunk<a name="line.153"></a>
-<span class="sourceLineNo">154</span> * @return The number of checksum chunks<a name="line.154"></a>
-<span class="sourceLineNo">155</span> */<a name="line.155"></a>
-<span class="sourceLineNo">156</span> static long numChunks(long datasize, int bytesPerChecksum) {<a name="line.156"></a>
-<span class="sourceLineNo">157</span> long numChunks = datasize/bytesPerChecksum;<a name="line.157"></a>
-<span class="sourceLineNo">158</span> if (datasize % bytesPerChecksum != 0) {<a name="line.158"></a>
-<span class="sourceLineNo">159</span> numChunks++;<a name="line.159"></a>
-<span class="sourceLineNo">160</span> }<a name="line.160"></a>
-<span class="sourceLineNo">161</span> return numChunks;<a name="line.161"></a>
-<span class="sourceLineNo">162</span> }<a name="line.162"></a>
-<span class="sourceLineNo">163</span><a name="line.163"></a>
-<span class="sourceLineNo">164</span> /**<a name="line.164"></a>
-<span class="sourceLineNo">165</span> * Write dummy checksums to the end of the specified bytes array<a name="line.165"></a>
-<span class="sourceLineNo">166</span> * to reserve space for writing checksums later<a name="line.166"></a>
-<span class="sourceLineNo">167</span> * @param baos OutputStream to write dummy checkum values<a name="line.167"></a>
-<span class="sourceLineNo">168</span> * @param numBytes Number of bytes of data for which dummy checksums<a name="line.168"></a>
-<span class="sourceLineNo">169</span> * need to be generated<a name="line.169"></a>
-<span class="sourceLineNo">170</span> * @param bytesPerChecksum Number of bytes per checksum value<a name="line.170"></a>
-<span class="sourceLineNo">171</span> */<a name="line.171"></a>
-<span class="sourceLineNo">172</span> static void reserveSpaceForChecksums(ByteArrayOutputStream baos,<a name="line.172"></a>
-<span class="sourceLineNo">173</span> int numBytes, int bytesPerChecksum) throws IOException {<a name="line.173"></a>
-<span class="sourceLineNo">174</span> long numChunks = numChunks(numBytes, bytesPerChecksum);<a name="line.174"></a>
-<span class="sourceLineNo">175</span> long bytesLeft = numChunks * HFileBlock.CHECKSUM_SIZE;<a name="line.175"></a>
-<span class="sourceLineNo">176</span> while (bytesLeft > 0) {<a name="line.176"></a>
-<span class="sourceLineNo">177</span> long count = Math.min(bytesLeft, DUMMY_VALUE.length);<a name="line.177"></a>
-<span class="sourceLineNo">178</span> baos.write(DUMMY_VALUE, 0, (int)count);<a name="line.178"></a>
-<span class="sourceLineNo">179</span> bytesLeft -= count;<a name="line.179"></a>
-<span class="sourceLineNo">180</span> }<a name="line.180"></a>
-<span class="sourceLineNo">181</span> }<a name="line.181"></a>
-<span class="sourceLineNo">182</span><a name="line.182"></a>
-<span class="sourceLineNo">183</span> /**<a name="line.183"></a>
-<span class="sourceLineNo">184</span> * Mechanism to throw an exception in case of hbase checksum<a name="line.184"></a>
-<span class="sourceLineNo">185</span> * failure. This is used by unit tests only.<a name="line.185"></a>
-<span class="sourceLineNo">186</span> * @param value Setting this to true will cause hbase checksum<a name="line.186"></a>
-<span class="sourceLineNo">187</span> * verification failures to generate exceptions.<a name="line.187"></a>
-<span class="sourceLineNo">188</span> */<a name="line.188"></a>
-<span class="sourceLineNo">189</span> public static void generateExceptionForChecksumFailureForTest(boolean value) {<a name="line.189"></a>
-<span class="sourceLineNo">190</span> generateExceptions = value;<a name="line.190"></a>
-<span class="sourceLineNo">191</span> }<a name="line.191"></a>
-<span class="sourceLineNo">192</span>}<a name="line.192"></a>
-<span class="sourceLineNo">193</span><a name="line.193"></a>
+<span class="sourceLineNo">028</span>import org.apache.hadoop.hbase.util.ChecksumType;<a name="line.28"></a>
+<span class="sourceLineNo">029</span>import org.apache.hadoop.util.DataChecksum;<a name="line.29"></a>
+<span class="sourceLineNo">030</span><a name="line.30"></a>
+<span class="sourceLineNo">031</span>/**<a name="line.31"></a>
+<span class="sourceLineNo">032</span> * Utility methods to compute and validate checksums.<a name="line.32"></a>
+<span class="sourceLineNo">033</span> */<a name="line.33"></a>
+<span class="sourceLineNo">034</span>@InterfaceAudience.Private<a name="line.34"></a>
+<span class="sourceLineNo">035</span>public class ChecksumUtil {<a name="line.35"></a>
+<span class="sourceLineNo">036</span> public static final Log LOG = LogFactory.getLog(ChecksumUtil.class);<a name="line.36"></a>
+<span class="sourceLineNo">037</span><a name="line.37"></a>
+<span class="sourceLineNo">038</span> /** This is used to reserve space in a byte buffer */<a name="line.38"></a>
+<span class="sourceLineNo">039</span> private static byte[] DUMMY_VALUE = new byte[128 * HFileBlock.CHECKSUM_SIZE];<a name="line.39"></a>
+<span class="sourceLineNo">040</span><a name="line.40"></a>
+<span class="sourceLineNo">041</span> /** <a name="line.41"></a>
+<span class="sourceLineNo">042</span> * This is used by unit tests to make checksum failures throw an <a name="line.42"></a>
+<span class="sourceLineNo">043</span> * exception instead of returning null. Returning a null value from <a name="line.43"></a>
+<span class="sourceLineNo">044</span> * checksum validation will cause the higher layer to retry that <a name="line.44"></a>
+<span class="sourceLineNo">045</span> * read with hdfs-level checksums. Instead, we would like checksum <a name="line.45"></a>
+<span class="sourceLineNo">046</span> * failures to cause the entire unit test to fail.<a name="line.46"></a>
+<span class="sourceLineNo">047</span> */<a name="line.47"></a>
+<span class="sourceLineNo">048</span> private static boolean generateExceptions = false;<a name="line.48"></a>
+<span class="sourceLineNo">049</span><a name="line.49"></a>
+<span class="sourceLineNo">050</span> /**<a name="line.50"></a>
+<span class="sourceLineNo">051</span> * Generates a checksum for all the data in indata. The checksum is<a name="line.51"></a>
+<span class="sourceLineNo">052</span> * written to outdata.<a name="line.52"></a>
+<span class="sourceLineNo">053</span> * @param indata input data stream<a name="line.53"></a>
+<span class="sourceLineNo">054</span> * @param startOffset starting offset in the indata stream from where to<a name="line.54"></a>
+<span class="sourceLineNo">055</span> * compute checkums from<a name="line.55"></a>
+<span class="sourceLineNo">056</span> * @param endOffset ending offset in the indata stream upto<a name="line.56"></a>
+<span class="sourceLineNo">057</span> * which checksums needs to be computed<a name="line.57"></a>
+<span class="sourceLineNo">058</span> * @param outdata the output buffer where checksum values are written<a name="line.58"></a>
+<span class="sourceLineNo">059</span> * @param outOffset the starting offset in the outdata where the<a name="line.59"></a>
+<span class="sourceLineNo">060</span> * checksum values are written<a name="line.60"></a>
+<span class="sourceLineNo">061</span> * @param checksumType type of checksum<a name="line.61"></a>
+<span class="sourceLineNo">062</span> * @param bytesPerChecksum number of bytes per checksum value<a name="line.62"></a>
+<span class="sourceLineNo">063</span> */<a name="line.63"></a>
+<span class="sourceLineNo">064</span> static void generateChecksums(byte[] indata, int startOffset, int endOffset,<a name="line.64"></a>
+<span class="sourceLineNo">065</span> byte[] outdata, int outOffset, ChecksumType checksumType,<a name="line.65"></a>
+<span class="sourceLineNo">066</span> int bytesPerChecksum) throws IOException {<a name="line.66"></a>
+<span class="sourceLineNo">067</span><a name="line.67"></a>
+<span class="sourceLineNo">068</span> if (checksumType == ChecksumType.NULL) {<a name="line.68"></a>
+<span class="sourceLineNo">069</span> return; // No checksum for this block.<a name="line.69"></a>
+<span class="sourceLineNo">070</span> }<a name="line.70"></a>
+<span class="sourceLineNo">071</span><a name="line.71"></a>
+<span class="sourceLineNo">072</span> DataChecksum checksum = DataChecksum.newDataChecksum(<a name="line.72"></a>
+<span class="sourceLineNo">073</span> checksumType.getDataChecksumType(), bytesPerChecksum);<a name="line.73"></a>
+<span class="sourceLineNo">074</span><a name="line.74"></a>
+<span class="sourceLineNo">075</span> checksum.calculateChunkedSums(<a name="line.75"></a>
+<span class="sourceLineNo">076</span> ByteBuffer.wrap(indata, startOffset, endOffset - startOffset),<a name="line.76"></a>
+<span class="sourceLineNo">077</span> ByteBuffer.wrap(outdata, outOffset, outdata.length - outOffset));<a name="line.77"></a>
+<span class="sourceLineNo">078</span> }<a name="line.78"></a>
+<span class="sourceLineNo">079</span><a name="line.79"></a>
+<span class="sourceLineNo">080</span> /**<a name="line.80"></a>
+<span class="sourceLineNo">081</span> * Validates that the data in the specified HFileBlock matches the<a name="line.81"></a>
+<span class="sourceLineNo">082</span> * checksum. Generates the checksum for the data and<a name="line.82"></a>
+<span class="sourceLineNo">083</span> * then validate that it matches the value stored in the header.<a name="line.83"></a>
+<span class="sourceLineNo">084</span> * If there is a checksum mismatch, then return false. Otherwise<a name="line.84"></a>
+<span class="sourceLineNo">085</span> * return true.<a name="line.85"></a>
+<span class="sourceLineNo">086</span> * The header is extracted from the specified HFileBlock while the<a name="line.86"></a>
+<span class="sourceLineNo">087</span> * data-to-be-verified is extracted from 'data'.<a name="line.87"></a>
+<span class="sourceLineNo">088</span> */<a name="line.88"></a>
+<span class="sourceLineNo">089</span> static boolean validateBlockChecksum(String pathName, HFileBlock block,<a name="line.89"></a>
+<span class="sourceLineNo">090</span> byte[] data, int hdrSize) throws IOException {<a name="line.90"></a>
+<span class="sourceLineNo">091</span><a name="line.91"></a>
+<span class="sourceLineNo">092</span> // If this is an older version of the block that does not have<a name="line.92"></a>
+<span class="sourceLineNo">093</span> // checksums, then return false indicating that checksum verification<a name="line.93"></a>
+<span class="sourceLineNo">094</span> // did not succeed. Actually, this methiod should never be called<a name="line.94"></a>
+<span class="sourceLineNo">095</span> // when the minorVersion is 0, thus this is a defensive check for a<a name="line.95"></a>
+<span class="sourceLineNo">096</span> // cannot-happen case. Since this is a cannot-happen case, it is<a name="line.96"></a>
+<span class="sourceLineNo">097</span> // better to return false to indicate a checksum validation failure.<a name="line.97"></a>
+<span class="sourceLineNo">098</span> if (!block.getHFileContext().isUseHBaseChecksum()) {<a name="line.98"></a>
+<span class="sourceLineNo">099</span> return false;<a name="line.99"></a>
+<span class="sourceLineNo">100</span> }<a name="line.100"></a>
+<span class="sourceLineNo">101</span><a name="line.101"></a>
+<span class="sourceLineNo">102</span> // Get a checksum object based on the type of checksum that is<a name="line.102"></a>
+<span class="sourceLineNo">103</span> // set in the HFileBlock header. A ChecksumType.NULL indicates that <a name="line.103"></a>
+<span class="sourceLineNo">104</span> // the caller is not interested in validating checksums, so we<a name="line.104"></a>
+<span class="sourceLineNo">105</span> // always return true.<a name="line.105"></a>
+<span class="sourceLineNo">106</span> ChecksumType cktype = ChecksumType.codeToType(block.getChecksumType());<a name="line.106"></a>
+<span class="sourceLineNo">107</span> if (cktype == ChecksumType.NULL) {<a name="line.107"></a>
+<span class="sourceLineNo">108</span> return true; // No checksum validations needed for this block.<a name="line.108"></a>
+<span class="sourceLineNo">109</span> }<a name="line.109"></a>
+<span class="sourceLineNo">110</span><a name="line.110"></a>
+<span class="sourceLineNo">111</span> // read in the stored value of the checksum size from the header.<a name="line.111"></a>
+<span class="sourceLineNo">112</span> int bytesPerChecksum = block.getBytesPerChecksum();<a name="line.112"></a>
+<span class="sourceLineNo">113</span><a name="line.113"></a>
+<span class="sourceLineNo">114</span> DataChecksum dataChecksum = DataChecksum.newDataChecksum(<a name="line.114"></a>
+<span class="sourceLineNo">115</span> cktype.getDataChecksumType(), bytesPerChecksum);<a name="line.115"></a>
+<span class="sourceLineNo">116</span> assert dataChecksum != null;<a name="line.116"></a>
+<span class="sourceLineNo">117</span> int sizeWithHeader = block.getOnDiskDataSizeWithHeader();<a name="line.117"></a>
+<span class="sourceLineNo">118</span> if (LOG.isTraceEnabled()) {<a name="line.118"></a>
+<span class="sourceLineNo">119</span> LOG.info("length of data = " + data.length<a name="line.119"></a>
+<span class="sourceLineNo">120</span> + " OnDiskDataSizeWithHeader = " + sizeWithHeader<a name="line.120"></a>
+<span class="sourceLineNo">121</span> + " checksum type = " + cktype.getName()<a name="line.121"></a>
+<span class="sourceLineNo">122</span> + " file =" + pathName<a name="line.122"></a>
+<span class="sourceLineNo">123</span> + " header size = " + hdrSize<a name="line.123"></a>
+<span class="sourceLineNo">124</span> + " bytesPerChecksum = " + bytesPerChecksum);<a name="line.124"></a>
+<span class="sourceLineNo">125</span> }<a name="line.125"></a>
+<span class="sourceLineNo">126</span> try {<a name="line.126"></a>
+<span class="sourceLineNo">127</span> dataChecksum.verifyChunkedSums(ByteBuffer.wrap(data, 0, sizeWithHeader),<a name="line.127"></a>
+<span class="sourceLineNo">128</span> ByteBuffer.wrap(data, sizeWithHeader, data.length - sizeWithHeader), pathName, 0);<a name="line.128"></a>
+<span class="sourceLineNo">129</span> } catch (ChecksumException e) {<a name="line.129"></a>
+<span class="sourceLineNo">130</span> return false;<a name="line.130"></a>
+<span class="sourceLineNo">131</span> }<a name="line.131"></a>
+<span class="sourceLineNo">132</span> return true; // checksum is valid<a name="line.132"></a>
+<span class="sourceLineNo">133</span> }<a name="line.133"></a>
+<span class="sourceLineNo">134</span><a name="line.134"></a>
+<span class="sourceLineNo">135</span> /**<a name="line.135"></a>
+<span class="sourceLineNo">136</span> * Returns the number of bytes needed to store the checksums for<a name="line.136"></a>
+<span class="sourceLineNo">137</span> * a specified data size<a name="line.137"></a>
+<span class="sourceLineNo">138</span> * @param datasize number of bytes of data<a name="line.138"></a>
+<span class="sourceLineNo">139</span> * @param bytesPerChecksum number of bytes in a checksum chunk<a name="line.139"></a>
+<span class="sourceLineNo">140</span> * @return The number of bytes needed to store the checksum values<a name="line.140"></a>
+<span class="sourceLineNo">141</span> */<a name="line.141"></a>
+<span class="sourceLineNo">142</span> static long numBytes(long datasize, int bytesPerChecksum) {<a name="line.142"></a>
+<span class="sourceLineNo">143</span> return numChunks(datasize, bytesPerChecksum) * <a name="line.143"></a>
+<span class="sourceLineNo">144</span> HFileBlock.CHECKSUM_SIZE;<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> /**<a name="line.147"></a>
+<span class="sourceLineNo">148</span> * Returns the number of checksum chunks needed to store the checksums for<a name="line.148"></a>
+<span class="sourceLineNo">149</span> * a specified data size<a name="line.149"></a>
+<span class="sourceLineNo">150</span> * @param datasize number of bytes of data<a name="line.150"></a>
+<span class="sourceLineNo">151</span> * @param bytesPerChecksum number of bytes in a checksum chunk<a name="line.151"></a>
+<span class="sourceLineNo">152</span> * @return The number of checksum chunks<a name="line.152"></a>
+<span class="sourceLineNo">153</span> */<a name="line.153"></a>
+<span class="sourceLineNo">154</span> static long numChunks(long datasize, int bytesPerChecksum) {<a name="line.154"></a>
+<span class="sourceLineNo">155</span> long numChunks = datasize/bytesPerChecksum;<a name="line.155"></a>
+<span class="sourceLineNo">156</span> if (datasize % bytesPerChecksum != 0) {<a name="line.156"></a>
+<span class="sourceLineNo">157</span> numChunks++;<a name="line.157"></a>
+<span class="sourceLineNo">158</span> }<a name="line.158"></a>
+<span class="sourceLineNo">159</span> return numChunks;<a name="line.159"></a>
+<span class="sourceLineNo">160</span> }<a name="line.160"></a>
+<span class="sourceLineNo">161</span><a name="line.161"></a>
+<span class="sourceLineNo">162</span> /**<a name="line.162"></a>
+<span class="sourceLineNo">163</span> * Write dummy checksums to the end of the specified bytes array<a name="line.163"></a>
+<span class="sourceLineNo">164</span> * to reserve space for writing checksums later<a name="line.164"></a>
+<span class="sourceLineNo">165</span> * @param baos OutputStream to write dummy checkum values<a name="line.165"></a>
+<span class="sourceLineNo">166</span> * @param numBytes Number of bytes of data for which dummy checksums<a name="line.166"></a>
+<span class="sourceLineNo">167</span> * need to be generated<a name="line.167"></a>
+<span class="sourceLineNo">168</span> * @param bytesPerChecksum Number of bytes per checksum value<a name="line.168"></a>
+<span class="sourceLineNo">169</span> */<a name="line.169"></a>
+<span class="sourceLineNo">170</span> static void reserveSpaceForChecksums(ByteArrayOutputStream baos,<a name="line.170"></a>
+<span class="sourceLineNo">171</span> int numBytes, int bytesPerChecksum) throws IOException {<a name="line.171"></a>
+<span class="sourceLineNo">172</span> long numChunks = numChunks(numBytes, bytesPerChecksum);<a name="line.172"></a>
+<span class="sourceLineNo">173</span> long bytesLeft = numChunks * HFileBlock.CHECKSUM_SIZE;<a name="line.173"></a>
+<span class="sourceLineNo">174</span> while (bytesLeft > 0) {<a name="line.174"></a>
+<span class="sourceLineNo">175</span> long count = Math.min(bytesLeft, DUMMY_VALUE.length);<a name="line.175"></a>
+<span class="sourceLineNo">176</span> baos.write(DUMMY_VALUE, 0, (int)count);<a name="line.176"></a>
+<span class="sourceLineNo">177</span> bytesLeft -= count;<a name="line.177"></a>
+<span class="sourceLineNo">178</span> }<a name="line.178"></a>
+<span class="sourceLineNo">179</span> }<a name="line.179"></a>
+<span class="sourceLineNo">180</span><a name="line.180"></a>
+<span class="sourceLineNo">181</span> /**<a name="line.181"></a>
+<span class="sourceLineNo">182</span> * Mechanism to throw an exception in case of hbase checksum<a name="line.182"></a>
+<span class="sourceLineNo">183</span> * failure. This is used by unit tests only.<a name="line.183"></a>
+<span class="sourceLineNo">184</span> * @param value Setting this to true will cause hbase checksum<a name="line.184"></a>
+<span class="sourceLineNo">185</span> * verification failures to generate exceptions.<a name="line.185"></a>
+<span class="sourceLineNo">186</span> */<a name="line.186"></a>
+<span class="sourceLineNo">187</span> public static void generateExceptionForChecksumFailureForTest(boolean value) {<a name="line.187"></a>
+<span class="sourceLineNo">188</span> generateExceptions = value;<a name="line.188"></a>
+<span class="sourceLineNo">189</span> }<a name="line.189"></a>
+<span class="sourceLineNo">190</span>}<a name="line.190"></a>
+<span class="sourceLineNo">191</span><a name="line.191"></a>