From 809180eef2f86d7efab042487bb730de5668dfcb Mon Sep 17 00:00:00 2001
From: Michael Stack <stack@apache.org>
Date: Wed, 30 Jul 2008 04:37:06 +0000
Subject: [PATCH] HBASE-783 For single row, single family retrieval, getRow()
 works half as fast as getScanner().next()

git-svn-id: https://svn.apache.org/repos/asf/hadoop/hbase/trunk@680910 13f79535-47bb-0310-9956-ffa450edef68
---
 CHANGES.txt                                   |  2 ++
 .../hadoop/hbase/regionserver/HRegion.java    | 25 ++++++++++++++++---
 .../hadoop/hbase/regionserver/HStore.java     |  3 ++-
 3 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/CHANGES.txt b/CHANGES.txt
index b4ed15fd733..5d7f4025d02 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -324,6 +324,8 @@ Release 0.2.0
    HBASE-746   Batching row mutations via thrift (Tim Sell via Stack)
    HBASE-772   Up default lease period from 60 to 120 seconds
    HBASE-779   Test changing hbase.hregion.memcache.block.multiplier to 2
+   HBASE-783   For single row, single family retrieval, getRow() works half
+               as fast as getScanner().next() (Jean-Daniel Cryans via Stack)
 
   NEW FEATURES
    HBASE-47    Option to set TTL for columns in hbase
diff --git a/src/java/org/apache/hadoop/hbase/regionserver/HRegion.java b/src/java/org/apache/hadoop/hbase/regionserver/HRegion.java
index 1417e7c99a8..74cdc031ecb 100644
--- a/src/java/org/apache/hadoop/hbase/regionserver/HRegion.java
+++ b/src/java/org/apache/hadoop/hbase/regionserver/HRegion.java
@@ -1181,23 +1181,40 @@ public class HRegion implements HConstants {
     }
     HStoreKey key = new HStoreKey(row, ts);
     Integer lid = obtainRowLock(row);
+    HashSet<HStore> storeSet = new HashSet<HStore>();
     try {
       TreeMap<byte [], Cell> result =
         new TreeMap<byte [], Cell>(Bytes.BYTES_COMPARATOR);
-      for (HStore targetStore: stores.values()) {
-        targetStore.getFull(key, columns, result);
+      // Get the concerned columns or all of them
+      if (columns != null) {
+        for (byte[] bs : columns) {
+          HStore store = stores.get(Bytes.mapKey(HStoreKey.getFamily(bs)));
+          if (store != null) {
+            storeSet.add(store);
+          }
+        }
       }
-      // Previous step won't fetch whole families: HBASE-631.
+      else
+        storeSet.addAll(stores.values());
+      
       // For each column name that is just a column family, open the store
-      // related to it and fetch everything for that row. 
+      // related to it and fetch everything for that row. HBASE-631
+      // Also remove each store from storeSet so that these stores
+      // won't be opened for no reason. HBASE-783
       if (columns != null) {
         for (byte[] bs : columns) {
           if (HStoreKey.getFamilyDelimiterIndex(bs) == (bs.length - 1)) {
             HStore store = stores.get(Bytes.mapKey(HStoreKey.getFamily(bs)));
             store.getFull(key, null, result);
+            storeSet.remove(store);
           }
         }
       }
+      
+      for (HStore targetStore: storeSet) {
+        targetStore.getFull(key, columns, result);
+      }
+      
       return result;
     } finally {
       releaseRowLock(lid);
diff --git a/src/java/org/apache/hadoop/hbase/regionserver/HStore.java b/src/java/org/apache/hadoop/hbase/regionserver/HStore.java
index 1de27b9c61e..1908d0ea994 100644
--- a/src/java/org/apache/hadoop/hbase/regionserver/HStore.java
+++ b/src/java/org/apache/hadoop/hbase/regionserver/HStore.java
@@ -752,7 +752,8 @@ public class HStore implements HConstants {
         // last key of storefiles.
         maxId = this.storefiles.lastKey().longValue();
       }
-      if (!force && filesToCompact.size() < compactionThreshold) {
+      if (!force && !hasReferences(filesToCompact) &&
+          filesToCompact.size() < compactionThreshold) {
         return checkSplit();
       }
       if (!fs.exists(compactionDir) && !fs.mkdirs(compactionDir)) {