From 0a0d9310c3f61f1c971d993d7027bc5475d76920 Mon Sep 17 00:00:00 2001
From: ramkrishna <ramkrishna@unknown>
Date: Fri, 1 Mar 2013 16:37:57 +0000
Subject: [PATCH] HBASE-7928 Scanning .META. with startRow and/or stopRow is
 not giving proper results (Ram)

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1451643 13f79535-47bb-0310-9956-ffa450edef68
---
 .../apache/hadoop/hbase/client/HTable.java    | 21 ++++++++++++
 .../org/apache/hadoop/hbase/HConstants.java   |  2 ++
 .../apache/hadoop/hbase/client/TestAdmin.java | 32 +++++++++++++++++++
 3 files changed, 55 insertions(+)

diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/HTable.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/HTable.java
index bbf5e78ce9f..d75483e83de 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/HTable.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/HTable.java
@@ -529,9 +529,30 @@ public class HTable implements HTableInterface {
     if (scan.getCaching() <= 0) {
       scan.setCaching(getScannerCaching());
     }
+    if (Bytes.equals(this.getTableName(), HConstants.META_TABLE_NAME)) {
+      changeStartAndStopRowIfMeta(scan);
+    }
+
     return new ClientScanner(getConfiguration(), scan, getTableName(),
         this.connection);
   }
+  private void changeStartAndStopRowIfMeta(final Scan scan) {
+    if (scan.getStartRow() != null && scan.getStartRow().length != 0
+        && !isValidMetaTableRow(scan.getStartRow())) {
+      scan.setStartRow(Bytes.add(scan.getStartRow(), HConstants.META_ROW_DELIMITER_BYTES,
+          Bytes.toBytes(HConstants.ZEROES)));
+    }
+    if (scan.getStopRow() != null && scan.getStopRow().length != 0
+        && !isValidMetaTableRow(scan.getStopRow())) {
+      scan.setStopRow(Bytes.add(scan.getStopRow(), HConstants.META_ROW_DELIMITER_BYTES,
+          Bytes.toBytes(HConstants.NINES)));
+    }
+  }
+
+  private boolean isValidMetaTableRow(byte[] metaRow) {
+    return (com.google.common.primitives.Bytes
+        .indexOf(metaRow, HConstants.META_ROW_DELIMITER_BYTES) != -1);
+  }
 
   /**
    * {@inheritDoc}
diff --git a/hbase-common/src/main/java/org/apache/hadoop/hbase/HConstants.java b/hbase-common/src/main/java/org/apache/hadoop/hbase/HConstants.java
index 44d968aeeb7..21a445fd6f7 100644
--- a/hbase-common/src/main/java/org/apache/hadoop/hbase/HConstants.java
+++ b/hbase-common/src/main/java/org/apache/hadoop/hbase/HConstants.java
@@ -358,6 +358,8 @@ public final class HConstants {
 
   /** delimiter used between portions of a region name */
   public static final int META_ROW_DELIMITER = ',';
+  
+  public static final byte[] META_ROW_DELIMITER_BYTES = Bytes.toBytes(",,");
 
   /** The catalog family as a string*/
   public static final String CATALOG_FAMILY_STR = "info";
diff --git a/hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestAdmin.java b/hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestAdmin.java
index 7909f9833b3..2a902ee3428 100644
--- a/hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestAdmin.java
+++ b/hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestAdmin.java
@@ -536,6 +536,38 @@ public class TestAdmin {
       assertTrue(regionList.size() == min || regionList.size() == max);
     }
   }
+  
+  @Test
+  public void testHBASE7928() throws Exception {
+    final byte[] tableName = Bytes.toBytes("a");
+    final byte[] tableName1 = Bytes.toBytes("b");
+    final byte[] tableName2 = Bytes.toBytes("c");
+    try {
+
+      TEST_UTIL.createTable(tableName, HConstants.CATALOG_FAMILY).close();
+
+      TEST_UTIL.createTable(tableName1, HConstants.CATALOG_FAMILY).close();
+
+      TEST_UTIL.createTable(tableName2, HConstants.CATALOG_FAMILY).close();
+      while (!admin.isTableAvailable(tableName2)) {
+        Thread.sleep(1);
+      }
+      Scan s = new Scan();
+      s.setStartRow(Bytes.toBytes("a1"));
+      s.setStopRow(Bytes.toBytes("b1"));
+      HTable table = new HTable(admin.getConfiguration(), HConstants.META_TABLE_NAME);
+      ResultScanner scanner = table.getScanner(s);
+      Result[] result = scanner.next(5);
+      assertEquals("Only one row should be selected", 1, result.length);
+    } finally {
+      admin.disableTable(tableName);
+      admin.deleteTable(tableName);
+      admin.disableTable(tableName1);
+      admin.deleteTable(tableName1);
+      admin.disableTable(tableName2);
+      admin.deleteTable(tableName2);
+    }
+  }
 
   @Test
   public void testCreateTableWithRegions() throws IOException, InterruptedException {