Merge branch 'master' of feistymeow.org:feisty_meow

[feisty_meow.git] / kona / src / org / gffs / application / MemoryFootprint.java

diff --git a/kona/src/org/gffs/application/MemoryFootprint.java b/kona/src/org/gffs/application/MemoryFootprint.java
new file mode 100644 (file)
index 0000000..6b2ac28
--- /dev/null
+++ b/kona/src/org/gffs/application/MemoryFootprint.java
@@ -0,0 +1,59 @@
+package org.gffs.application;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
+import net.sourceforge.sizeof.SizeOf;
+
+/**
+ * can retrieve the size of java objects to assist tuning of caches and memory usage. this requires the SizeOf jar and -javaagent setting to
+ * point at that jar. this is the project page: https://sourceforge.net/projects/sizeof/?source=typ_redirect
+ */
+public class MemoryFootprint
+{
+       static private Log _logger = LogFactory.getLog(MemoryFootprint.class);
+
+       // static SizeOf _sizeEstimater = new SizeOf();
+       static {
+               // don't count statics in the memory size.
+               SizeOf.skipStaticField(true);
+               // only complain about large objects if they're bigger than the limit below.
+               SizeOf.setMinSizeToLog(5 * 1024 * 1024);
+       }
+
+       /**
+        * can report the size of the object 'o' if instrumentation has been set up. if instrumentation is absent, all object sizes will be
+        * reported as zero.
+        */
+       public static long getFootprint(Object o)
+       {
+               if (!_logger.isDebugEnabled()) {
+                       _logger.error("abusive memory footprint called when not in debug mode.  a logging statement is wrong.");
+                       return 0;
+               }
+               try {
+                       return SizeOf.sizeOf(o);
+               } catch (Exception e) {
+                       _logger.debug("error retrieving SizeOf object; is SizeOf.jar in javaagent?");
+                       return 0;
+               }
+       }
+
+       /**
+        * reports the size of the object 'o' plus the size of all other objects reachable from it.
+        */
+       public static long getDeepFootprint(Object o)
+       {
+               if (!_logger.isDebugEnabled()) {
+                       _logger.error("abusive memory footprint called when not in debug mode.  a logging statement is wrong.");
+                       return 0;
+               }
+
+               try {
+                       return SizeOf.deepSizeOf(o);
+               } catch (Exception e) {
+                       _logger.debug("error retrieving SizeOf object; is SizeOf.jar in javaagent?");
+                       return 0;
+               }
+       }
+}