svn commit: r1404177 - in /hadoop/common/trunk/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop: conf/Configuration.java util/StringInterner.java

[tgraves]

Author: tgraves
Date: Wed Oct 31 14:57:12 2012
New Revision: 1404177

URL: http://svn.apache.org/viewvc?rev=1404177&view=rev
Log:
MAPREDUCE-4752. Reduce MR AM memory usage through String Interning (Robert 
Evans via tgraves)

Modified:
    
hadoop/common/trunk/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/conf/Configuration.java
    
hadoop/common/trunk/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/StringInterner.java

Modified: 
hadoop/common/trunk/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/conf/Configuration.java
URL: 
http://svn.apache.org/viewvc/hadoop/common/trunk/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/conf/Configuration.java?rev=1404177&r1=1404176&r2=1404177&view=diff
==============================================================================
--- 
hadoop/common/trunk/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/conf/Configuration.java
 (original)
+++ 
hadoop/common/trunk/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/conf/Configuration.java
 Wed Oct 31 14:57:12 2012
@@ -75,6 +75,7 @@ import org.apache.hadoop.io.Writable;
 import org.apache.hadoop.io.WritableUtils;
 import org.apache.hadoop.net.NetUtils;
 import org.apache.hadoop.util.ReflectionUtils;
+import org.apache.hadoop.util.StringInterner;
 import org.apache.hadoop.util.StringUtils;
 import org.codehaus.jackson.JsonFactory;
 import org.codehaus.jackson.JsonGenerator;
@@ -2002,13 +2003,16 @@ public class Configuration implements It
             continue;
           Element field = (Element)fieldNode;
           if ("name".equals(field.getTagName()) && field.hasChildNodes())
-            attr = ((Text)field.getFirstChild()).getData().trim();
+            attr = StringInterner.weakIntern(
+                ((Text)field.getFirstChild()).getData().trim());
           if ("value".equals(field.getTagName()) && field.hasChildNodes())
-            value = ((Text)field.getFirstChild()).getData();
+            value = StringInterner.weakIntern(
+                ((Text)field.getFirstChild()).getData());
           if ("final".equals(field.getTagName()) && field.hasChildNodes())
             finalParameter = 
"true".equals(((Text)field.getFirstChild()).getData());
           if ("source".equals(field.getTagName()) && field.hasChildNodes())
-            source.add(((Text)field.getFirstChild()).getData());
+            source.add(StringInterner.weakIntern(
+                ((Text)field.getFirstChild()).getData()));
         }
         source.add(name);
         

Modified: 
hadoop/common/trunk/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/StringInterner.java
URL: 
http://svn.apache.org/viewvc/hadoop/common/trunk/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/StringInterner.java?rev=1404177&r1=1404176&r2=1404177&view=diff
==============================================================================
--- 
hadoop/common/trunk/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/StringInterner.java
 (original)
+++ 
hadoop/common/trunk/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/StringInterner.java
 Wed Oct 31 14:57:12 2012
@@ -59,6 +59,9 @@ public class StringInterner {
    * @return strong reference to interned string instance
    */
   public static String strongIntern(String sample) {
+    if (sample == null) {
+      return null;
+    }
     return strongInterner.intern(sample);
   }
   
@@ -72,6 +75,9 @@ public class StringInterner {
    * @return weak reference to interned string instance
    */
   public static String weakIntern(String sample) {
+    if (sample == null) {
+      return null;
+    }
     return weakInterner.intern(sample);
   }