http://git-wip-us.apache.org/repos/asf/hbase-site/blob/e11cf2cb/devapidocs/src-html/org/apache/hadoop/hbase/wal/WAL.html
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@@ -31,277 +31,266 @@
<span class="sourceLineNo">023</span>import java.util.Set;<a
name="line.23"></a>
<span class="sourceLineNo">024</span>import
org.apache.hadoop.hbase.HConstants;<a name="line.24"></a>
<span class="sourceLineNo">025</span>import
org.apache.hadoop.hbase.client.RegionInfo;<a name="line.25"></a>
-<span class="sourceLineNo">026</span>import
org.apache.hadoop.hbase.regionserver.wal.CompressionContext;<a
name="line.26"></a>
-<span class="sourceLineNo">027</span>import
org.apache.hadoop.hbase.regionserver.wal.FailedLogCloseException;<a
name="line.27"></a>
-<span class="sourceLineNo">028</span>import
org.apache.hadoop.hbase.regionserver.wal.WALActionsListener;<a
name="line.28"></a>
-<span class="sourceLineNo">029</span>import
org.apache.hadoop.hbase.regionserver.wal.WALCoprocessorHost;<a
name="line.29"></a>
-<span class="sourceLineNo">030</span>import
org.apache.hadoop.hbase.replication.regionserver.WALFileLengthProvider;<a
name="line.30"></a>
-<span class="sourceLineNo">031</span>import
org.apache.yetus.audience.InterfaceAudience;<a name="line.31"></a>
-<span class="sourceLineNo">032</span>import
org.apache.yetus.audience.InterfaceStability;<a name="line.32"></a>
-<span class="sourceLineNo">033</span><a name="line.33"></a>
-<span class="sourceLineNo">034</span>import
org.apache.hbase.thirdparty.com.google.common.annotations.VisibleForTesting;<a
name="line.34"></a>
-<span class="sourceLineNo">035</span><a name="line.35"></a>
-<span class="sourceLineNo">036</span>/**<a name="line.36"></a>
-<span class="sourceLineNo">037</span> * A Write Ahead Log (WAL) provides
service for reading, writing waledits. This interface provides<a
name="line.37"></a>
-<span class="sourceLineNo">038</span> * APIs for WAL users (such as
RegionServer) to use the WAL (do append, sync, etc).<a name="line.38"></a>
-<span class="sourceLineNo">039</span> *<a name="line.39"></a>
-<span class="sourceLineNo">040</span> * Note that some internals, such as log
rolling and performance evaluation tools, will use<a name="line.40"></a>
-<span class="sourceLineNo">041</span> * WAL.equals to determine if they have
already seen a given WAL.<a name="line.41"></a>
-<span class="sourceLineNo">042</span> */<a name="line.42"></a>
-<span class="sourceLineNo">043</span>@InterfaceAudience.Private<a
name="line.43"></a>
-<span class="sourceLineNo">044</span>@InterfaceStability.Evolving<a
name="line.44"></a>
-<span class="sourceLineNo">045</span>public interface WAL extends Closeable,
WALFileLengthProvider {<a name="line.45"></a>
-<span class="sourceLineNo">046</span><a name="line.46"></a>
-<span class="sourceLineNo">047</span> /**<a name="line.47"></a>
-<span class="sourceLineNo">048</span> * Registers WALActionsListener<a
name="line.48"></a>
-<span class="sourceLineNo">049</span> */<a name="line.49"></a>
-<span class="sourceLineNo">050</span> void registerWALActionsListener(final
WALActionsListener listener);<a name="line.50"></a>
-<span class="sourceLineNo">051</span><a name="line.51"></a>
-<span class="sourceLineNo">052</span> /**<a name="line.52"></a>
-<span class="sourceLineNo">053</span> * Unregisters WALActionsListener<a
name="line.53"></a>
-<span class="sourceLineNo">054</span> */<a name="line.54"></a>
-<span class="sourceLineNo">055</span> boolean
unregisterWALActionsListener(final WALActionsListener listener);<a
name="line.55"></a>
-<span class="sourceLineNo">056</span><a name="line.56"></a>
-<span class="sourceLineNo">057</span> /**<a name="line.57"></a>
-<span class="sourceLineNo">058</span> * Roll the log writer. That is, start
writing log messages to a new file.<a name="line.58"></a>
-<span class="sourceLineNo">059</span> *<a name="line.59"></a>
-<span class="sourceLineNo">060</span> * <p><a name="line.60"></a>
-<span class="sourceLineNo">061</span> * The implementation is synchronized
in order to make sure there's one rollWriter<a name="line.61"></a>
-<span class="sourceLineNo">062</span> * running at any given time.<a
name="line.62"></a>
-<span class="sourceLineNo">063</span> *<a name="line.63"></a>
-<span class="sourceLineNo">064</span> * @return If lots of logs, flush the
returned regions so next time through we<a name="line.64"></a>
-<span class="sourceLineNo">065</span> * can clean logs. Returns null
if nothing to flush. Names are actual<a name="line.65"></a>
-<span class="sourceLineNo">066</span> * region names as returned by
{@link RegionInfo#getEncodedName()}<a name="line.66"></a>
-<span class="sourceLineNo">067</span> */<a name="line.67"></a>
-<span class="sourceLineNo">068</span> byte[][] rollWriter() throws
FailedLogCloseException, IOException;<a name="line.68"></a>
-<span class="sourceLineNo">069</span><a name="line.69"></a>
-<span class="sourceLineNo">070</span> /**<a name="line.70"></a>
-<span class="sourceLineNo">071</span> * Roll the log writer. That is, start
writing log messages to a new file.<a name="line.71"></a>
-<span class="sourceLineNo">072</span> *<a name="line.72"></a>
-<span class="sourceLineNo">073</span> * <p><a name="line.73"></a>
-<span class="sourceLineNo">074</span> * The implementation is synchronized
in order to make sure there's one rollWriter<a name="line.74"></a>
-<span class="sourceLineNo">075</span> * running at any given time.<a
name="line.75"></a>
-<span class="sourceLineNo">076</span> *<a name="line.76"></a>
-<span class="sourceLineNo">077</span> * @param force<a name="line.77"></a>
-<span class="sourceLineNo">078</span> * If true, force creation of
a new writer even if no entries have<a name="line.78"></a>
-<span class="sourceLineNo">079</span> * been written to the current
writer<a name="line.79"></a>
-<span class="sourceLineNo">080</span> * @return If lots of logs, flush the
returned regions so next time through we<a name="line.80"></a>
-<span class="sourceLineNo">081</span> * can clean logs. Returns null
if nothing to flush. Names are actual<a name="line.81"></a>
-<span class="sourceLineNo">082</span> * region names as returned by
{@link RegionInfo#getEncodedName()}<a name="line.82"></a>
-<span class="sourceLineNo">083</span> */<a name="line.83"></a>
-<span class="sourceLineNo">084</span> byte[][] rollWriter(boolean force)
throws FailedLogCloseException, IOException;<a name="line.84"></a>
-<span class="sourceLineNo">085</span><a name="line.85"></a>
-<span class="sourceLineNo">086</span> /**<a name="line.86"></a>
-<span class="sourceLineNo">087</span> * Stop accepting new writes. If we
have unsynced writes still in buffer, sync them.<a name="line.87"></a>
-<span class="sourceLineNo">088</span> * Extant edits are left in place in
backing storage to be replayed later.<a name="line.88"></a>
-<span class="sourceLineNo">089</span> */<a name="line.89"></a>
-<span class="sourceLineNo">090</span> void shutdown() throws IOException;<a
name="line.90"></a>
-<span class="sourceLineNo">091</span><a name="line.91"></a>
-<span class="sourceLineNo">092</span> /**<a name="line.92"></a>
-<span class="sourceLineNo">093</span> * Caller no longer needs any edits
from this WAL. Implementers are free to reclaim<a name="line.93"></a>
-<span class="sourceLineNo">094</span> * underlying resources after this
call; i.e. filesystem based WALs can archive or<a name="line.94"></a>
-<span class="sourceLineNo">095</span> * delete files.<a name="line.95"></a>
-<span class="sourceLineNo">096</span> */<a name="line.96"></a>
-<span class="sourceLineNo">097</span> @Override<a name="line.97"></a>
-<span class="sourceLineNo">098</span> void close() throws IOException;<a
name="line.98"></a>
-<span class="sourceLineNo">099</span><a name="line.99"></a>
-<span class="sourceLineNo">100</span> /**<a name="line.100"></a>
-<span class="sourceLineNo">101</span> * Append a set of edits to the WAL.
The WAL is not flushed/sync'd after this transaction<a name="line.101"></a>
-<span class="sourceLineNo">102</span> * completes BUT on return this edit
must have its region edit/sequence id assigned<a name="line.102"></a>
-<span class="sourceLineNo">103</span> * else it messes up our unification of
mvcc and sequenceid. On return <code>key</code> will<a
name="line.103"></a>
-<span class="sourceLineNo">104</span> * have the region edit/sequence id
filled in.<a name="line.104"></a>
-<span class="sourceLineNo">105</span> * @param info the regioninfo
associated with append<a name="line.105"></a>
-<span class="sourceLineNo">106</span> * @param key Modified by this call; we
add to it this edits region edit/sequence id.<a name="line.106"></a>
-<span class="sourceLineNo">107</span> * @param edits Edits to append. MAY
CONTAIN NO EDITS for case where we want to get an edit<a name="line.107"></a>
-<span class="sourceLineNo">108</span> * sequence id that is after all
currently appended edits.<a name="line.108"></a>
-<span class="sourceLineNo">109</span> * @param inMemstore Always true except
for case where we are writing a compaction completion<a name="line.109"></a>
-<span class="sourceLineNo">110</span> * record into the WAL; in this case
the entry is just so we can finish an unfinished compaction<a
name="line.110"></a>
-<span class="sourceLineNo">111</span> * -- it is not an edit for memstore.<a
name="line.111"></a>
-<span class="sourceLineNo">112</span> * @return Returns a 'transaction id'
and <code>key</code> will have the region edit/sequence id<a
name="line.112"></a>
-<span class="sourceLineNo">113</span> * in it.<a name="line.113"></a>
-<span class="sourceLineNo">114</span> */<a name="line.114"></a>
-<span class="sourceLineNo">115</span> long append(RegionInfo info, WALKeyImpl
key, WALEdit edits, boolean inMemstore) throws IOException;<a
name="line.115"></a>
-<span class="sourceLineNo">116</span><a name="line.116"></a>
-<span class="sourceLineNo">117</span> /**<a name="line.117"></a>
-<span class="sourceLineNo">118</span> * updates the seuence number of a
specific store.<a name="line.118"></a>
-<span class="sourceLineNo">119</span> * depending on the flag: replaces
current seq number if the given seq id is bigger,<a name="line.119"></a>
-<span class="sourceLineNo">120</span> * or even if it is lower than existing
one<a name="line.120"></a>
-<span class="sourceLineNo">121</span> * @param encodedRegionName<a
name="line.121"></a>
-<span class="sourceLineNo">122</span> * @param familyName<a
name="line.122"></a>
-<span class="sourceLineNo">123</span> * @param sequenceid<a
name="line.123"></a>
-<span class="sourceLineNo">124</span> * @param onlyIfGreater<a
name="line.124"></a>
-<span class="sourceLineNo">125</span> */<a name="line.125"></a>
-<span class="sourceLineNo">126</span> void updateStore(byte[]
encodedRegionName, byte[] familyName, Long sequenceid,<a name="line.126"></a>
-<span class="sourceLineNo">127</span> boolean onlyIfGreater);<a
name="line.127"></a>
-<span class="sourceLineNo">128</span><a name="line.128"></a>
-<span class="sourceLineNo">129</span> /**<a name="line.129"></a>
-<span class="sourceLineNo">130</span> * Sync what we have in the WAL.<a
name="line.130"></a>
-<span class="sourceLineNo">131</span> * @throws IOException<a
name="line.131"></a>
-<span class="sourceLineNo">132</span> */<a name="line.132"></a>
-<span class="sourceLineNo">133</span> void sync() throws IOException;<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> * Sync the WAL if the txId was not
already sync'd.<a name="line.136"></a>
-<span class="sourceLineNo">137</span> * @param txid Transaction id to sync
to.<a name="line.137"></a>
-<span class="sourceLineNo">138</span> * @throws IOException<a
name="line.138"></a>
-<span class="sourceLineNo">139</span> */<a name="line.139"></a>
-<span class="sourceLineNo">140</span> void sync(long txid) throws
IOException;<a name="line.140"></a>
-<span class="sourceLineNo">141</span><a name="line.141"></a>
-<span class="sourceLineNo">142</span> /**<a name="line.142"></a>
-<span class="sourceLineNo">143</span> * @param forceSync Flag to force sync
rather than flushing to the buffer. Example - Hadoop hflush<a
name="line.143"></a>
-<span class="sourceLineNo">144</span> * vs hsync.<a
name="line.144"></a>
-<span class="sourceLineNo">145</span> */<a name="line.145"></a>
-<span class="sourceLineNo">146</span> default void sync(boolean forceSync)
throws IOException {<a name="line.146"></a>
-<span class="sourceLineNo">147</span> sync();<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> /**<a name="line.150"></a>
-<span class="sourceLineNo">151</span> * @param txid Transaction id to sync
to.<a name="line.151"></a>
-<span class="sourceLineNo">152</span> * @param forceSync Flag to force sync
rather than flushing to the buffer. Example - Hadoop hflush<a
name="line.152"></a>
-<span class="sourceLineNo">153</span> * vs hsync.<a
name="line.153"></a>
-<span class="sourceLineNo">154</span> */<a name="line.154"></a>
-<span class="sourceLineNo">155</span> default void sync(long txid, boolean
forceSync) throws IOException {<a name="line.155"></a>
-<span class="sourceLineNo">156</span> sync(txid);<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> /**<a name="line.159"></a>
-<span class="sourceLineNo">160</span> * WAL keeps track of the sequence
numbers that are as yet not flushed im memstores<a name="line.160"></a>
-<span class="sourceLineNo">161</span> * in order to be able to do accounting
to figure which WALs can be let go. This method tells WAL<a name="line.161"></a>
-<span class="sourceLineNo">162</span> * that some region is about to flush.
The flush can be the whole region or for a column family<a name="line.162"></a>
-<span class="sourceLineNo">163</span> * of the region only.<a
name="line.163"></a>
-<span class="sourceLineNo">164</span> *<a name="line.164"></a>
-<span class="sourceLineNo">165</span> * <p>Currently, it is expected
that the update lock is held for the region; i.e. no<a name="line.165"></a>
-<span class="sourceLineNo">166</span> * concurrent appends while we set up
cache flush.<a name="line.166"></a>
-<span class="sourceLineNo">167</span> * @param families Families to flush.
May be a subset of all families in the region.<a name="line.167"></a>
-<span class="sourceLineNo">168</span> * @return Returns {@link
HConstants#NO_SEQNUM} if we are flushing the whole region OR if<a
name="line.168"></a>
-<span class="sourceLineNo">169</span> * we are flushing a subset of all
families but there are no edits in those families not<a name="line.169"></a>
-<span class="sourceLineNo">170</span> * being flushed; in other words, this
is effectively same as a flush of all of the region<a name="line.170"></a>
-<span class="sourceLineNo">171</span> * though we were passed a subset of
regions. Otherwise, it returns the sequence id of the<a name="line.171"></a>
-<span class="sourceLineNo">172</span> * oldest/lowest outstanding edit.<a
name="line.172"></a>
-<span class="sourceLineNo">173</span> * @see #completeCacheFlush(byte[])<a
name="line.173"></a>
-<span class="sourceLineNo">174</span> * @see #abortCacheFlush(byte[])<a
name="line.174"></a>
-<span class="sourceLineNo">175</span> */<a name="line.175"></a>
-<span class="sourceLineNo">176</span> Long startCacheFlush(final byte[]
encodedRegionName, Set<byte[]> families);<a name="line.176"></a>
-<span class="sourceLineNo">177</span><a name="line.177"></a>
-<span class="sourceLineNo">178</span> Long startCacheFlush(final byte[]
encodedRegionName, Map<byte[], Long> familyToSeq);<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> * Complete the cache flush.<a
name="line.181"></a>
-<span class="sourceLineNo">182</span> * @param encodedRegionName Encoded
region name.<a name="line.182"></a>
-<span class="sourceLineNo">183</span> * @see #startCacheFlush(byte[], Set)<a
name="line.183"></a>
-<span class="sourceLineNo">184</span> * @see #abortCacheFlush(byte[])<a
name="line.184"></a>
-<span class="sourceLineNo">185</span> */<a name="line.185"></a>
-<span class="sourceLineNo">186</span> void completeCacheFlush(final byte[]
encodedRegionName);<a name="line.186"></a>
-<span class="sourceLineNo">187</span><a name="line.187"></a>
-<span class="sourceLineNo">188</span> /**<a name="line.188"></a>
-<span class="sourceLineNo">189</span> * Abort a cache flush. Call if the
flush fails. Note that the only recovery<a name="line.189"></a>
-<span class="sourceLineNo">190</span> * for an aborted flush currently is a
restart of the regionserver so the<a name="line.190"></a>
-<span class="sourceLineNo">191</span> * snapshot content dropped by the
failure gets restored to the memstore.<a name="line.191"></a>
-<span class="sourceLineNo">192</span> * @param encodedRegionName Encoded
region name.<a name="line.192"></a>
-<span class="sourceLineNo">193</span> */<a name="line.193"></a>
-<span class="sourceLineNo">194</span> void abortCacheFlush(byte[]
encodedRegionName);<a name="line.194"></a>
-<span class="sourceLineNo">195</span><a name="line.195"></a>
-<span class="sourceLineNo">196</span> /**<a name="line.196"></a>
-<span class="sourceLineNo">197</span> * @return Coprocessor host.<a
name="line.197"></a>
-<span class="sourceLineNo">198</span> */<a name="line.198"></a>
-<span class="sourceLineNo">199</span> WALCoprocessorHost
getCoprocessorHost();<a name="line.199"></a>
-<span class="sourceLineNo">200</span><a name="line.200"></a>
-<span class="sourceLineNo">201</span> /**<a name="line.201"></a>
-<span class="sourceLineNo">202</span> * Gets the earliest unflushed sequence
id in the memstore for the region.<a name="line.202"></a>
-<span class="sourceLineNo">203</span> * @param encodedRegionName The region
to get the number for.<a name="line.203"></a>
-<span class="sourceLineNo">204</span> * @return The earliest/lowest/oldest
sequence id if present, HConstants.NO_SEQNUM if absent.<a name="line.204"></a>
-<span class="sourceLineNo">205</span> * @deprecated Since version 1.2.0.
Removing because not used and exposes subtle internal<a name="line.205"></a>
-<span class="sourceLineNo">206</span> * workings. Use {@link
#getEarliestMemStoreSeqNum(byte[], byte[])}<a name="line.206"></a>
-<span class="sourceLineNo">207</span> */<a name="line.207"></a>
-<span class="sourceLineNo">208</span> @VisibleForTesting<a
name="line.208"></a>
-<span class="sourceLineNo">209</span> @Deprecated<a name="line.209"></a>
-<span class="sourceLineNo">210</span> long getEarliestMemStoreSeqNum(byte[]
encodedRegionName);<a name="line.210"></a>
-<span class="sourceLineNo">211</span><a name="line.211"></a>
-<span class="sourceLineNo">212</span> /**<a name="line.212"></a>
-<span class="sourceLineNo">213</span> * Gets the earliest unflushed sequence
id in the memstore for the store.<a name="line.213"></a>
-<span class="sourceLineNo">214</span> * @param encodedRegionName The region
to get the number for.<a name="line.214"></a>
-<span class="sourceLineNo">215</span> * @param familyName The family to get
the number for.<a name="line.215"></a>
-<span class="sourceLineNo">216</span> * @return The earliest/lowest/oldest
sequence id if present, HConstants.NO_SEQNUM if absent.<a name="line.216"></a>
-<span class="sourceLineNo">217</span> */<a name="line.217"></a>
-<span class="sourceLineNo">218</span> long getEarliestMemStoreSeqNum(byte[]
encodedRegionName, byte[] familyName);<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> * Human readable identifying
information about the state of this WAL.<a name="line.221"></a>
-<span class="sourceLineNo">222</span> * Implementors are encouraged to
include information appropriate for debugging.<a name="line.222"></a>
-<span class="sourceLineNo">223</span> * Consumers are advised not to rely on
the details of the returned String; it does<a name="line.223"></a>
-<span class="sourceLineNo">224</span> * not have a defined structure.<a
name="line.224"></a>
-<span class="sourceLineNo">225</span> */<a name="line.225"></a>
-<span class="sourceLineNo">226</span> @Override<a name="line.226"></a>
-<span class="sourceLineNo">227</span> String toString();<a
name="line.227"></a>
-<span class="sourceLineNo">228</span><a name="line.228"></a>
-<span class="sourceLineNo">229</span> /**<a name="line.229"></a>
-<span class="sourceLineNo">230</span> * When outside clients need to consume
persisted WALs, they rely on a provided<a name="line.230"></a>
-<span class="sourceLineNo">231</span> * Reader.<a name="line.231"></a>
-<span class="sourceLineNo">232</span> */<a name="line.232"></a>
-<span class="sourceLineNo">233</span> interface Reader extends Closeable {<a
name="line.233"></a>
-<span class="sourceLineNo">234</span> Entry next() throws IOException;<a
name="line.234"></a>
-<span class="sourceLineNo">235</span> Entry next(Entry reuse) throws
IOException;<a name="line.235"></a>
-<span class="sourceLineNo">236</span> void seek(long pos) throws
IOException;<a name="line.236"></a>
-<span class="sourceLineNo">237</span> long getPosition() throws
IOException;<a name="line.237"></a>
-<span class="sourceLineNo">238</span> void reset() throws IOException;<a
name="line.238"></a>
-<span class="sourceLineNo">239</span> }<a name="line.239"></a>
-<span class="sourceLineNo">240</span><a name="line.240"></a>
-<span class="sourceLineNo">241</span> /**<a name="line.241"></a>
-<span class="sourceLineNo">242</span> * Utility class that lets us keep
track of the edit with it's key.<a name="line.242"></a>
-<span class="sourceLineNo">243</span> */<a name="line.243"></a>
-<span class="sourceLineNo">244</span> class Entry {<a name="line.244"></a>
-<span class="sourceLineNo">245</span> private final WALEdit edit;<a
name="line.245"></a>
-<span class="sourceLineNo">246</span> private final WALKeyImpl key;<a
name="line.246"></a>
-<span class="sourceLineNo">247</span><a name="line.247"></a>
-<span class="sourceLineNo">248</span> public Entry() {<a
name="line.248"></a>
-<span class="sourceLineNo">249</span> this(new WALKeyImpl(), new
WALEdit());<a name="line.249"></a>
-<span class="sourceLineNo">250</span> }<a name="line.250"></a>
-<span class="sourceLineNo">251</span><a name="line.251"></a>
-<span class="sourceLineNo">252</span> /**<a name="line.252"></a>
-<span class="sourceLineNo">253</span> * Constructor for both params<a
name="line.253"></a>
-<span class="sourceLineNo">254</span> *<a name="line.254"></a>
-<span class="sourceLineNo">255</span> * @param edit log's edit<a
name="line.255"></a>
-<span class="sourceLineNo">256</span> * @param key log's key<a
name="line.256"></a>
-<span class="sourceLineNo">257</span> */<a name="line.257"></a>
-<span class="sourceLineNo">258</span> public Entry(WALKeyImpl key, WALEdit
edit) {<a name="line.258"></a>
-<span class="sourceLineNo">259</span> this.key = key;<a
name="line.259"></a>
-<span class="sourceLineNo">260</span> this.edit = edit;<a
name="line.260"></a>
-<span class="sourceLineNo">261</span> }<a name="line.261"></a>
-<span class="sourceLineNo">262</span><a name="line.262"></a>
-<span class="sourceLineNo">263</span> /**<a name="line.263"></a>
-<span class="sourceLineNo">264</span> * Gets the edit<a
name="line.264"></a>
-<span class="sourceLineNo">265</span> *<a name="line.265"></a>
-<span class="sourceLineNo">266</span> * @return edit<a name="line.266"></a>
-<span class="sourceLineNo">267</span> */<a name="line.267"></a>
-<span class="sourceLineNo">268</span> public WALEdit getEdit() {<a
name="line.268"></a>
-<span class="sourceLineNo">269</span> return edit;<a name="line.269"></a>
-<span class="sourceLineNo">270</span> }<a name="line.270"></a>
-<span class="sourceLineNo">271</span><a name="line.271"></a>
-<span class="sourceLineNo">272</span> /**<a name="line.272"></a>
-<span class="sourceLineNo">273</span> * Gets the key<a name="line.273"></a>
-<span class="sourceLineNo">274</span> *<a name="line.274"></a>
-<span class="sourceLineNo">275</span> * @return key<a name="line.275"></a>
-<span class="sourceLineNo">276</span> */<a name="line.276"></a>
-<span class="sourceLineNo">277</span> public WALKeyImpl getKey() {<a
name="line.277"></a>
-<span class="sourceLineNo">278</span> return key;<a name="line.278"></a>
-<span class="sourceLineNo">279</span> }<a name="line.279"></a>
-<span class="sourceLineNo">280</span><a name="line.280"></a>
-<span class="sourceLineNo">281</span> /**<a name="line.281"></a>
-<span class="sourceLineNo">282</span> * Set compression context for this
entry.<a name="line.282"></a>
-<span class="sourceLineNo">283</span> *<a name="line.283"></a>
-<span class="sourceLineNo">284</span> * @param compressionContext<a
name="line.284"></a>
-<span class="sourceLineNo">285</span> * Compression context<a
name="line.285"></a>
-<span class="sourceLineNo">286</span> */<a name="line.286"></a>
-<span class="sourceLineNo">287</span> public void
setCompressionContext(CompressionContext compressionContext) {<a
name="line.287"></a>
-<span class="sourceLineNo">288</span>
key.setCompressionContext(compressionContext);<a name="line.288"></a>
-<span class="sourceLineNo">289</span> }<a name="line.289"></a>
-<span class="sourceLineNo">290</span><a name="line.290"></a>
-<span class="sourceLineNo">291</span> @Override<a name="line.291"></a>
-<span class="sourceLineNo">292</span> public String toString() {<a
name="line.292"></a>
-<span class="sourceLineNo">293</span> return this.key + "=" +
this.edit;<a name="line.293"></a>
-<span class="sourceLineNo">294</span> }<a name="line.294"></a>
-<span class="sourceLineNo">295</span> }<a name="line.295"></a>
-<span class="sourceLineNo">296</span>}<a name="line.296"></a>
+<span class="sourceLineNo">026</span>import
org.apache.hadoop.hbase.regionserver.wal.FailedLogCloseException;<a
name="line.26"></a>
+<span class="sourceLineNo">027</span>import
org.apache.hadoop.hbase.regionserver.wal.WALActionsListener;<a
name="line.27"></a>
+<span class="sourceLineNo">028</span>import
org.apache.hadoop.hbase.regionserver.wal.WALCoprocessorHost;<a
name="line.28"></a>
+<span class="sourceLineNo">029</span>import
org.apache.hadoop.hbase.replication.regionserver.WALFileLengthProvider;<a
name="line.29"></a>
+<span class="sourceLineNo">030</span>import
org.apache.yetus.audience.InterfaceAudience;<a name="line.30"></a>
+<span class="sourceLineNo">031</span>import
org.apache.yetus.audience.InterfaceStability;<a name="line.31"></a>
+<span class="sourceLineNo">032</span><a name="line.32"></a>
+<span class="sourceLineNo">033</span>import
org.apache.hbase.thirdparty.com.google.common.annotations.VisibleForTesting;<a
name="line.33"></a>
+<span class="sourceLineNo">034</span><a name="line.34"></a>
+<span class="sourceLineNo">035</span>/**<a name="line.35"></a>
+<span class="sourceLineNo">036</span> * A Write Ahead Log (WAL) provides
service for reading, writing waledits. This interface provides<a
name="line.36"></a>
+<span class="sourceLineNo">037</span> * APIs for WAL users (such as
RegionServer) to use the WAL (do append, sync, etc).<a name="line.37"></a>
+<span class="sourceLineNo">038</span> *<a name="line.38"></a>
+<span class="sourceLineNo">039</span> * Note that some internals, such as log
rolling and performance evaluation tools, will use<a name="line.39"></a>
+<span class="sourceLineNo">040</span> * WAL.equals to determine if they have
already seen a given WAL.<a name="line.40"></a>
+<span class="sourceLineNo">041</span> */<a name="line.41"></a>
+<span class="sourceLineNo">042</span>@InterfaceAudience.Private<a
name="line.42"></a>
+<span class="sourceLineNo">043</span>@InterfaceStability.Evolving<a
name="line.43"></a>
+<span class="sourceLineNo">044</span>public interface WAL extends Closeable,
WALFileLengthProvider {<a name="line.44"></a>
+<span class="sourceLineNo">045</span><a name="line.45"></a>
+<span class="sourceLineNo">046</span> /**<a name="line.46"></a>
+<span class="sourceLineNo">047</span> * Registers WALActionsListener<a
name="line.47"></a>
+<span class="sourceLineNo">048</span> */<a name="line.48"></a>
+<span class="sourceLineNo">049</span> void registerWALActionsListener(final
WALActionsListener listener);<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> * Unregisters WALActionsListener<a
name="line.52"></a>
+<span class="sourceLineNo">053</span> */<a name="line.53"></a>
+<span class="sourceLineNo">054</span> boolean
unregisterWALActionsListener(final WALActionsListener listener);<a
name="line.54"></a>
+<span class="sourceLineNo">055</span><a name="line.55"></a>
+<span class="sourceLineNo">056</span> /**<a name="line.56"></a>
+<span class="sourceLineNo">057</span> * Roll the log writer. That is, start
writing log messages to a new file.<a name="line.57"></a>
+<span class="sourceLineNo">058</span> *<a name="line.58"></a>
+<span class="sourceLineNo">059</span> * <p><a name="line.59"></a>
+<span class="sourceLineNo">060</span> * The implementation is synchronized
in order to make sure there's one rollWriter<a name="line.60"></a>
+<span class="sourceLineNo">061</span> * running at any given time.<a
name="line.61"></a>
+<span class="sourceLineNo">062</span> *<a name="line.62"></a>
+<span class="sourceLineNo">063</span> * @return If lots of logs, flush the
returned regions so next time through we<a name="line.63"></a>
+<span class="sourceLineNo">064</span> * can clean logs. Returns null
if nothing to flush. Names are actual<a name="line.64"></a>
+<span class="sourceLineNo">065</span> * region names as returned by
{@link RegionInfo#getEncodedName()}<a name="line.65"></a>
+<span class="sourceLineNo">066</span> */<a name="line.66"></a>
+<span class="sourceLineNo">067</span> byte[][] rollWriter() throws
FailedLogCloseException, IOException;<a name="line.67"></a>
+<span class="sourceLineNo">068</span><a name="line.68"></a>
+<span class="sourceLineNo">069</span> /**<a name="line.69"></a>
+<span class="sourceLineNo">070</span> * Roll the log writer. That is, start
writing log messages to a new file.<a name="line.70"></a>
+<span class="sourceLineNo">071</span> *<a name="line.71"></a>
+<span class="sourceLineNo">072</span> * <p><a name="line.72"></a>
+<span class="sourceLineNo">073</span> * The implementation is synchronized
in order to make sure there's one rollWriter<a name="line.73"></a>
+<span class="sourceLineNo">074</span> * running at any given time.<a
name="line.74"></a>
+<span class="sourceLineNo">075</span> *<a name="line.75"></a>
+<span class="sourceLineNo">076</span> * @param force<a name="line.76"></a>
+<span class="sourceLineNo">077</span> * If true, force creation of
a new writer even if no entries have<a name="line.77"></a>
+<span class="sourceLineNo">078</span> * been written to the current
writer<a name="line.78"></a>
+<span class="sourceLineNo">079</span> * @return If lots of logs, flush the
returned regions so next time through we<a name="line.79"></a>
+<span class="sourceLineNo">080</span> * can clean logs. Returns null
if nothing to flush. Names are actual<a name="line.80"></a>
+<span class="sourceLineNo">081</span> * region names as returned by
{@link RegionInfo#getEncodedName()}<a name="line.81"></a>
+<span class="sourceLineNo">082</span> */<a name="line.82"></a>
+<span class="sourceLineNo">083</span> byte[][] rollWriter(boolean force)
throws FailedLogCloseException, IOException;<a name="line.83"></a>
+<span class="sourceLineNo">084</span><a name="line.84"></a>
+<span class="sourceLineNo">085</span> /**<a name="line.85"></a>
+<span class="sourceLineNo">086</span> * Stop accepting new writes. If we
have unsynced writes still in buffer, sync them.<a name="line.86"></a>
+<span class="sourceLineNo">087</span> * Extant edits are left in place in
backing storage to be replayed later.<a name="line.87"></a>
+<span class="sourceLineNo">088</span> */<a name="line.88"></a>
+<span class="sourceLineNo">089</span> void shutdown() throws IOException;<a
name="line.89"></a>
+<span class="sourceLineNo">090</span><a name="line.90"></a>
+<span class="sourceLineNo">091</span> /**<a name="line.91"></a>
+<span class="sourceLineNo">092</span> * Caller no longer needs any edits
from this WAL. Implementers are free to reclaim<a name="line.92"></a>
+<span class="sourceLineNo">093</span> * underlying resources after this
call; i.e. filesystem based WALs can archive or<a name="line.93"></a>
+<span class="sourceLineNo">094</span> * delete files.<a name="line.94"></a>
+<span class="sourceLineNo">095</span> */<a name="line.95"></a>
+<span class="sourceLineNo">096</span> @Override<a name="line.96"></a>
+<span class="sourceLineNo">097</span> void close() throws IOException;<a
name="line.97"></a>
+<span class="sourceLineNo">098</span><a name="line.98"></a>
+<span class="sourceLineNo">099</span> /**<a name="line.99"></a>
+<span class="sourceLineNo">100</span> * Append a set of edits to the WAL.
The WAL is not flushed/sync'd after this transaction<a name="line.100"></a>
+<span class="sourceLineNo">101</span> * completes BUT on return this edit
must have its region edit/sequence id assigned<a name="line.101"></a>
+<span class="sourceLineNo">102</span> * else it messes up our unification of
mvcc and sequenceid. On return <code>key</code> will<a
name="line.102"></a>
+<span class="sourceLineNo">103</span> * have the region edit/sequence id
filled in.<a name="line.103"></a>
+<span class="sourceLineNo">104</span> * @param info the regioninfo
associated with append<a name="line.104"></a>
+<span class="sourceLineNo">105</span> * @param key Modified by this call; we
add to it this edits region edit/sequence id.<a name="line.105"></a>
+<span class="sourceLineNo">106</span> * @param edits Edits to append. MAY
CONTAIN NO EDITS for case where we want to get an edit<a name="line.106"></a>
+<span class="sourceLineNo">107</span> * sequence id that is after all
currently appended edits.<a name="line.107"></a>
+<span class="sourceLineNo">108</span> * @param inMemstore Always true except
for case where we are writing a compaction completion<a name="line.108"></a>
+<span class="sourceLineNo">109</span> * record into the WAL; in this case
the entry is just so we can finish an unfinished compaction<a
name="line.109"></a>
+<span class="sourceLineNo">110</span> * -- it is not an edit for memstore.<a
name="line.110"></a>
+<span class="sourceLineNo">111</span> * @return Returns a 'transaction id'
and <code>key</code> will have the region edit/sequence id<a
name="line.111"></a>
+<span class="sourceLineNo">112</span> * in it.<a name="line.112"></a>
+<span class="sourceLineNo">113</span> */<a name="line.113"></a>
+<span class="sourceLineNo">114</span> long append(RegionInfo info, WALKeyImpl
key, WALEdit edits, boolean inMemstore) throws IOException;<a
name="line.114"></a>
+<span class="sourceLineNo">115</span><a name="line.115"></a>
+<span class="sourceLineNo">116</span> /**<a name="line.116"></a>
+<span class="sourceLineNo">117</span> * updates the seuence number of a
specific store.<a name="line.117"></a>
+<span class="sourceLineNo">118</span> * depending on the flag: replaces
current seq number if the given seq id is bigger,<a name="line.118"></a>
+<span class="sourceLineNo">119</span> * or even if it is lower than existing
one<a name="line.119"></a>
+<span class="sourceLineNo">120</span> * @param encodedRegionName<a
name="line.120"></a>
+<span class="sourceLineNo">121</span> * @param familyName<a
name="line.121"></a>
+<span class="sourceLineNo">122</span> * @param sequenceid<a
name="line.122"></a>
+<span class="sourceLineNo">123</span> * @param onlyIfGreater<a
name="line.123"></a>
+<span class="sourceLineNo">124</span> */<a name="line.124"></a>
+<span class="sourceLineNo">125</span> void updateStore(byte[]
encodedRegionName, byte[] familyName, Long sequenceid,<a name="line.125"></a>
+<span class="sourceLineNo">126</span> boolean onlyIfGreater);<a
name="line.126"></a>
+<span class="sourceLineNo">127</span><a name="line.127"></a>
+<span class="sourceLineNo">128</span> /**<a name="line.128"></a>
+<span class="sourceLineNo">129</span> * Sync what we have in the WAL.<a
name="line.129"></a>
+<span class="sourceLineNo">130</span> * @throws IOException<a
name="line.130"></a>
+<span class="sourceLineNo">131</span> */<a name="line.131"></a>
+<span class="sourceLineNo">132</span> void sync() throws IOException;<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> * Sync the WAL if the txId was not
already sync'd.<a name="line.135"></a>
+<span class="sourceLineNo">136</span> * @param txid Transaction id to sync
to.<a name="line.136"></a>
+<span class="sourceLineNo">137</span> * @throws IOException<a
name="line.137"></a>
+<span class="sourceLineNo">138</span> */<a name="line.138"></a>
+<span class="sourceLineNo">139</span> void sync(long txid) throws
IOException;<a name="line.139"></a>
+<span class="sourceLineNo">140</span><a name="line.140"></a>
+<span class="sourceLineNo">141</span> /**<a name="line.141"></a>
+<span class="sourceLineNo">142</span> * @param forceSync Flag to force sync
rather than flushing to the buffer. Example - Hadoop hflush<a
name="line.142"></a>
+<span class="sourceLineNo">143</span> * vs hsync.<a
name="line.143"></a>
+<span class="sourceLineNo">144</span> */<a name="line.144"></a>
+<span class="sourceLineNo">145</span> default void sync(boolean forceSync)
throws IOException {<a name="line.145"></a>
+<span class="sourceLineNo">146</span> sync();<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> * @param txid Transaction id to sync
to.<a name="line.150"></a>
+<span class="sourceLineNo">151</span> * @param forceSync Flag to force sync
rather than flushing to the buffer. Example - Hadoop hflush<a
name="line.151"></a>
+<span class="sourceLineNo">152</span> * vs hsync.<a
name="line.152"></a>
+<span class="sourceLineNo">153</span> */<a name="line.153"></a>
+<span class="sourceLineNo">154</span> default void sync(long txid, boolean
forceSync) throws IOException {<a name="line.154"></a>
+<span class="sourceLineNo">155</span> sync(txid);<a name="line.155"></a>
+<span class="sourceLineNo">156</span> }<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> * WAL keeps track of the sequence
numbers that are as yet not flushed im memstores<a name="line.159"></a>
+<span class="sourceLineNo">160</span> * in order to be able to do accounting
to figure which WALs can be let go. This method tells WAL<a name="line.160"></a>
+<span class="sourceLineNo">161</span> * that some region is about to flush.
The flush can be the whole region or for a column family<a name="line.161"></a>
+<span class="sourceLineNo">162</span> * of the region only.<a
name="line.162"></a>
+<span class="sourceLineNo">163</span> *<a name="line.163"></a>
+<span class="sourceLineNo">164</span> * <p>Currently, it is expected
that the update lock is held for the region; i.e. no<a name="line.164"></a>
+<span class="sourceLineNo">165</span> * concurrent appends while we set up
cache flush.<a name="line.165"></a>
+<span class="sourceLineNo">166</span> * @param families Families to flush.
May be a subset of all families in the region.<a name="line.166"></a>
+<span class="sourceLineNo">167</span> * @return Returns {@link
HConstants#NO_SEQNUM} if we are flushing the whole region OR if<a
name="line.167"></a>
+<span class="sourceLineNo">168</span> * we are flushing a subset of all
families but there are no edits in those families not<a name="line.168"></a>
+<span class="sourceLineNo">169</span> * being flushed; in other words, this
is effectively same as a flush of all of the region<a name="line.169"></a>
+<span class="sourceLineNo">170</span> * though we were passed a subset of
regions. Otherwise, it returns the sequence id of the<a name="line.170"></a>
+<span class="sourceLineNo">171</span> * oldest/lowest outstanding edit.<a
name="line.171"></a>
+<span class="sourceLineNo">172</span> * @see #completeCacheFlush(byte[])<a
name="line.172"></a>
+<span class="sourceLineNo">173</span> * @see #abortCacheFlush(byte[])<a
name="line.173"></a>
+<span class="sourceLineNo">174</span> */<a name="line.174"></a>
+<span class="sourceLineNo">175</span> Long startCacheFlush(final byte[]
encodedRegionName, Set<byte[]> families);<a name="line.175"></a>
+<span class="sourceLineNo">176</span><a name="line.176"></a>
+<span class="sourceLineNo">177</span> Long startCacheFlush(final byte[]
encodedRegionName, Map<byte[], Long> familyToSeq);<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> * Complete the cache flush.<a
name="line.180"></a>
+<span class="sourceLineNo">181</span> * @param encodedRegionName Encoded
region name.<a name="line.181"></a>
+<span class="sourceLineNo">182</span> * @see #startCacheFlush(byte[], Set)<a
name="line.182"></a>
+<span class="sourceLineNo">183</span> * @see #abortCacheFlush(byte[])<a
name="line.183"></a>
+<span class="sourceLineNo">184</span> */<a name="line.184"></a>
+<span class="sourceLineNo">185</span> void completeCacheFlush(final byte[]
encodedRegionName);<a name="line.185"></a>
+<span class="sourceLineNo">186</span><a name="line.186"></a>
+<span class="sourceLineNo">187</span> /**<a name="line.187"></a>
+<span class="sourceLineNo">188</span> * Abort a cache flush. Call if the
flush fails. Note that the only recovery<a name="line.188"></a>
+<span class="sourceLineNo">189</span> * for an aborted flush currently is a
restart of the regionserver so the<a name="line.189"></a>
+<span class="sourceLineNo">190</span> * snapshot content dropped by the
failure gets restored to the memstore.<a name="line.190"></a>
+<span class="sourceLineNo">191</span> * @param encodedRegionName Encoded
region name.<a name="line.191"></a>
+<span class="sourceLineNo">192</span> */<a name="line.192"></a>
+<span class="sourceLineNo">193</span> void abortCacheFlush(byte[]
encodedRegionName);<a name="line.193"></a>
+<span class="sourceLineNo">194</span><a name="line.194"></a>
+<span class="sourceLineNo">195</span> /**<a name="line.195"></a>
+<span class="sourceLineNo">196</span> * @return Coprocessor host.<a
name="line.196"></a>
+<span class="sourceLineNo">197</span> */<a name="line.197"></a>
+<span class="sourceLineNo">198</span> WALCoprocessorHost
getCoprocessorHost();<a name="line.198"></a>
+<span class="sourceLineNo">199</span><a name="line.199"></a>
+<span class="sourceLineNo">200</span> /**<a name="line.200"></a>
+<span class="sourceLineNo">201</span> * Gets the earliest unflushed sequence
id in the memstore for the region.<a name="line.201"></a>
+<span class="sourceLineNo">202</span> * @param encodedRegionName The region
to get the number for.<a name="line.202"></a>
+<span class="sourceLineNo">203</span> * @return The earliest/lowest/oldest
sequence id if present, HConstants.NO_SEQNUM if absent.<a name="line.203"></a>
+<span class="sourceLineNo">204</span> * @deprecated Since version 1.2.0.
Removing because not used and exposes subtle internal<a name="line.204"></a>
+<span class="sourceLineNo">205</span> * workings. Use {@link
#getEarliestMemStoreSeqNum(byte[], byte[])}<a name="line.205"></a>
+<span class="sourceLineNo">206</span> */<a name="line.206"></a>
+<span class="sourceLineNo">207</span> @VisibleForTesting<a
name="line.207"></a>
+<span class="sourceLineNo">208</span> @Deprecated<a name="line.208"></a>
+<span class="sourceLineNo">209</span> long getEarliestMemStoreSeqNum(byte[]
encodedRegionName);<a name="line.209"></a>
+<span class="sourceLineNo">210</span><a name="line.210"></a>
+<span class="sourceLineNo">211</span> /**<a name="line.211"></a>
+<span class="sourceLineNo">212</span> * Gets the earliest unflushed sequence
id in the memstore for the store.<a name="line.212"></a>
+<span class="sourceLineNo">213</span> * @param encodedRegionName The region
to get the number for.<a name="line.213"></a>
+<span class="sourceLineNo">214</span> * @param familyName The family to get
the number for.<a name="line.214"></a>
+<span class="sourceLineNo">215</span> * @return The earliest/lowest/oldest
sequence id if present, HConstants.NO_SEQNUM if absent.<a name="line.215"></a>
+<span class="sourceLineNo">216</span> */<a name="line.216"></a>
+<span class="sourceLineNo">217</span> long getEarliestMemStoreSeqNum(byte[]
encodedRegionName, byte[] familyName);<a name="line.217"></a>
+<span class="sourceLineNo">218</span><a name="line.218"></a>
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+<span class="sourceLineNo">265</span> * @return edit<a name="line.265"></a>
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+<span class="sourceLineNo">273</span> *<a name="line.273"></a>
+<span class="sourceLineNo">274</span> * @return key<a name="line.274"></a>
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+<span class="sourceLineNo">279</span><a name="line.279"></a>
+<span class="sourceLineNo">280</span> @Override<a name="line.280"></a>
+<span class="sourceLineNo">281</span> public String toString() {<a
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+<span class="sourceLineNo">282</span> return this.key + "=" +
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+<span class="sourceLineNo">283</span> }<a name="line.283"></a>
+<span class="sourceLineNo">284</span> }<a name="line.284"></a>
+<span class="sourceLineNo">285</span>}<a name="line.285"></a>
