svn commit: r936125 - /hadoop/hbase/branches/0.20/src/java/org/apache/hadoop/hbase/client/HTable.java

[ra...@apache.org]

Author: rawson
Date: Wed Apr 21 00:35:25 2010
New Revision: 936125

URL: http://svn.apache.org/viewvc?rev=936125&view=rev
Log:
HBASE-2248  (javadoc fix) Provide new non-copy mechanism to assure atomic reads in get and scan

Modified:
    hadoop/hbase/branches/0.20/src/java/org/apache/hadoop/hbase/client/HTable.java

Modified: hadoop/hbase/branches/0.20/src/java/org/apache/hadoop/hbase/client/HTable.java
URL: http://svn.apache.org/viewvc/hadoop/hbase/branches/0.20/src/java/org/apache/hadoop/hbase/client/HTable.java?rev=936125&r1=936124&r2=936125&view=diff
==============================================================================
--- hadoop/hbase/branches/0.20/src/java/org/apache/hadoop/hbase/client/HTable.java (original)
+++ hadoop/hbase/branches/0.20/src/java/org/apache/hadoop/hbase/client/HTable.java Wed Apr 21 00:35:25 2010
@@ -61,10 +61,16 @@ import org.apache.hadoop.hbase.util.Writ
 
 /**
  * Used to communicate with a single HBase table.
- * This class is not thread safe for writes.
- * Gets, puts, and deletes take out a row lock for the duration
- * of their operation.  Scans (currently) do not respect
- * row locking.
+ * This class is not thread safe. Use one instance per thread.
+ * 
+ * Puts, deletes, checkAndPut and incrementColumnValue are 
+ * done in an exclusive (and thus serial) fashion for each row. 
+ * These calls acquire a row lock which is shared with the lockRow
+ * calls. 
+ * 
+ * Gets and Scans will not return half written data. That is, 
+ * all mutation operations are atomic on a row basis with
+ * respect to other concurrent readers and writers. 
  */
 public class HTable {
   private final HConnection connection;