HADOOP-2599 Some minor improvements to changes in HADOOP-2443

git-svn-id: https://svn.apache.org/repos/asf/hadoop/core/trunk@617725 13f79535-47bb-0310-9956-ffa450edef68

src/contrib/hbase/CHANGES.txt

@@ -16,6 +16,8 @@ Trunk (unreleased changes)
    HADOOP-2731 Under load, regions become extremely large and eventually cause
                region servers to become unresponsive
    HADOOP-2693 NPE in getClosestRowBefore (Bryan Duxbury & Stack)
+   HADOOP-2599 Some minor improvements to changes in HADOOP-2443
+               (Bryan Duxbury & Stack)
 
   IMPROVEMENTS
    HADOOP-2555 Refactor the HTable#get and HTable#getRow methods to avoid

src/contrib/hbase/src/java/org/apache/hadoop/hbase/HConnectionManager.java

@@ -257,7 +257,7 @@ public class HConnectionManager implements HConstants {
           // open a scanner over the meta region
           scannerId = server.openScanner(
             metaLocation.getRegionInfo().getRegionName(),
-            COLUMN_FAMILY_ARRAY, EMPTY_START_ROW, LATEST_TIMESTAMP,
+            COLUMN_FAMILY_ARRAY, startRow, LATEST_TIMESTAMP,
             null);
           
           // iterate through the scanner, accumulating unique table names
@@ -296,7 +296,7 @@ public class HConnectionManager implements HConstants {
             server.close(scannerId);
           }
         }
-      } while (startRow.compareTo(EMPTY_START_ROW) != 0);
+      } while (startRow.compareTo(LAST_ROW) != 0);
       
       return uniqueTables.toArray(new HTableDescriptor[uniqueTables.size()]);
     }

src/contrib/hbase/src/java/org/apache/hadoop/hbase/HConstants.java

@@ -167,6 +167,12 @@ public interface HConstants {
    */
   static final Text EMPTY_START_ROW = EMPTY_TEXT;
 
+  /** 
+    * Used by scanners and others when they're trying to detect the end of a 
+    * table 
+    */
+  static final Text LAST_ROW = EMPTY_TEXT;
+  
   /** When we encode strings, we always specify UTF8 encoding */
   static final String UTF8_ENCODING = "UTF-8";