[Bigdata-commit] SF.net SVN: bigdata:[3685] branches/QUADS_QUERY_BRANCH/bigdata/src/java/com /bigdata/bop

[<tho...@us...>]

Revision: 3685
          http://bigdata.svn.sourceforge.net/bigdata/?rev=3685&view=rev
Author:   thompsonbry
Date:     2010-09-29 19:55:30 +0000 (Wed, 29 Sep 2010)

Log Message:
-----------
Added NOARGS and NOANNS for BOPs that we create a lot of.  These are a singleton empty array and empty map respectively.

Modified Paths:
--------------
    branches/QUADS_QUERY_BRANCH/bigdata/src/java/com/bigdata/bop/BOpBase.java
    branches/QUADS_QUERY_BRANCH/bigdata/src/java/com/bigdata/bop/Constant.java
    branches/QUADS_QUERY_BRANCH/bigdata/src/java/com/bigdata/bop/Var.java

Modified: branches/QUADS_QUERY_BRANCH/bigdata/src/java/com/bigdata/bop/BOpBase.java
===================================================================
--- branches/QUADS_QUERY_BRANCH/bigdata/src/java/com/bigdata/bop/BOpBase.java	2010-09-29 19:54:27 UTC (rev 3684)
+++ branches/QUADS_QUERY_BRANCH/bigdata/src/java/com/bigdata/bop/BOpBase.java	2010-09-29 19:55:30 UTC (rev 3685)
@@ -71,6 +71,20 @@
     private static final long serialVersionUID = 1L;
 
     /**
+     * An empty array.
+     */
+    static protected final transient BOp[] NOARGS = new BOp[] {};
+
+    /**
+     * An empty immutable annotations map.
+     * 
+     * @todo This is for things like {@link Constant} and {@link Var} which are
+     *       never annotated. However, i'm not sure if this is a good idea or
+     *       not. A "copy on write" map might be better.
+     */
+    static protected final transient Map<String,Object> NOANNS = Collections.emptyMap();
+    
+    /**
      * The argument values - <strong>direct access to this field is
      * discouraged</strong> - the field is protected to support
      * <em>mutation</em> APIs and should not be relied on for other purposes.
@@ -288,6 +302,10 @@
 
     /** deep copy the arguments. */
     static protected BOp[] deepCopy(final BOp[] a) {
+        if (a == NOARGS) {
+            // fast path for zero arity operators.
+            return a;
+        }
         final BOp[] t = new BOp[a.length];
         for (int i = 0; i < a.length; i++) {
             t[i] = a[i] == null ? null : a[i].clone();
@@ -311,7 +329,11 @@
      *       containing an ontology or some conditional assertions with a query
      *       plan.
      */
-    static protected Map<String,Object> deepCopy(final Map<String,Object> a) {
+    static protected Map<String, Object> deepCopy(final Map<String, Object> a) {
+        if (a == NOANNS) {
+            // Fast past for immutable, empty annotations.
+            return a;
+        }
         // allocate map.
         final Map<String, Object> t = new LinkedHashMap<String, Object>(a
                 .size());

Modified: branches/QUADS_QUERY_BRANCH/bigdata/src/java/com/bigdata/bop/Constant.java
===================================================================
--- branches/QUADS_QUERY_BRANCH/bigdata/src/java/com/bigdata/bop/Constant.java	2010-09-29 19:54:27 UTC (rev 3684)
+++ branches/QUADS_QUERY_BRANCH/bigdata/src/java/com/bigdata/bop/Constant.java	2010-09-29 19:55:30 UTC (rev 3685)
@@ -66,13 +66,16 @@
      * @param op
      */
     public Constant(final Constant<E> op) {
+
         super(op);
+        
         this.value = op.value;
+        
     }
     
     public Constant(final E value) {
         
-        super(new BOp[] {}, null/* annotations */);
+        super(NOARGS, NOANNS);
         
         if (value == null)
             throw new IllegalArgumentException();

Modified: branches/QUADS_QUERY_BRANCH/bigdata/src/java/com/bigdata/bop/Var.java
===================================================================
--- branches/QUADS_QUERY_BRANCH/bigdata/src/java/com/bigdata/bop/Var.java	2010-09-29 19:54:27 UTC (rev 3684)
+++ branches/QUADS_QUERY_BRANCH/bigdata/src/java/com/bigdata/bop/Var.java	2010-09-29 19:55:30 UTC (rev 3685)
@@ -58,7 +58,8 @@
      */
     private Var(final String name) {
 
-        super(new BOp[] {}, null/* annotations */);
+//        super(new BOp[] {}, null/* annotations */);
+        super(NOARGS, NOANNS);
         
         assert name != null;
 


This was sent by the SourceForge.net collaborative development platform, the world's largest Open Source development site.