From 97e9564ad6efb1312f4704b9cefce30671fedd95 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Timo=20Westk=C3=A4mper?= <timo.westkamper@mysema.com>
Date: Tue, 21 Apr 2009 09:53:09 +0000
Subject: [PATCH] added caching of Class constants

---
 .../query/grammar/types/ExprFactory.java      |  2 +
 .../grammar/types/SimpleExprFactory.java      | 46 +++++++++++++------
 2 files changed, 33 insertions(+), 15 deletions(-)

diff --git a/querydsl-core/src/main/java/com/mysema/query/grammar/types/ExprFactory.java b/querydsl-core/src/main/java/com/mysema/query/grammar/types/ExprFactory.java
index b58d62e96..1eabe48b8 100644
--- a/querydsl-core/src/main/java/com/mysema/query/grammar/types/ExprFactory.java
+++ b/querydsl-core/src/main/java/com/mysema/query/grammar/types/ExprFactory.java
@@ -21,6 +21,8 @@ public interface ExprFactory {
     
     Expr<Integer> createConstant(int i);
     
+    <A> Expr<Class<A>> createConstant(Class<A> obj);
+    
     <A> Expr<A> createConstant(A obj);
     
     EBoolean createBoolean(Op<Boolean> operator, Expr<?>... args);
diff --git a/querydsl-core/src/main/java/com/mysema/query/grammar/types/SimpleExprFactory.java b/querydsl-core/src/main/java/com/mysema/query/grammar/types/SimpleExprFactory.java
index 8f87f91dd..c48424141 100644
--- a/querydsl-core/src/main/java/com/mysema/query/grammar/types/SimpleExprFactory.java
+++ b/querydsl-core/src/main/java/com/mysema/query/grammar/types/SimpleExprFactory.java
@@ -5,6 +5,9 @@
  */
 package com.mysema.query.grammar.types;
 
+import java.util.HashMap;
+import java.util.Map;
+
 import com.mysema.query.grammar.Ops.Op;
 import com.mysema.query.grammar.types.Expr.EBoolean;
 import com.mysema.query.grammar.types.Expr.EComparable;
@@ -29,9 +32,7 @@ public class SimpleExprFactory implements ExprFactory{
 
     private static final ExprFactory instance = new SimpleExprFactory();
     
-    public static ExprFactory getInstance(){
-        return instance;
-    }
+    private final Map<Class<?>,Expr<?>> classToExpr = new HashMap<Class<?>,Expr<?>>();
     
     @SuppressWarnings("unchecked")
     private final Expr<Integer>[] integers = new Expr[256];
@@ -42,12 +43,16 @@ public class SimpleExprFactory implements ExprFactory{
         }
     }
     
-    public Expr<Integer> createConstant(int i){
-        if (i >= -128 && i <= 127) { 
-            return integers[i+128];
-        }else{
-            return new EConstant<Integer>(i);        
-        }
+    public static ExprFactory getInstance(){
+        return instance;
+    }
+    
+    public EBoolean createBoolean(Op<Boolean> operator, Expr<?>... args) {
+        return new OBoolean(Assert.notNull(operator), Assert.notNull(args));
+    }
+    
+    public <OpType, RT extends Comparable<?>> EComparable<RT> createComparable(Class<RT> type, Op<OpType> operator, Expr<?>... args) {
+        return new OComparable<OpType,RT>(type, Assert.notNull(operator), Assert.notNull(args));
     }
     
     @SuppressWarnings("unchecked")
@@ -59,22 +64,33 @@ public class SimpleExprFactory implements ExprFactory{
         }        
     }
     
-    public EBoolean createBoolean(Op<Boolean> operator, Expr<?>... args) {
-        return new OBoolean(Assert.notNull(operator), Assert.notNull(args));
+    @SuppressWarnings("unchecked")
+    public <A> Expr<Class<A>> createConstant(Class<A> obj) {
+        if (classToExpr.containsKey(obj)){
+            return (Expr<Class<A>>) classToExpr.get(obj);
+        }else{
+            Expr<Class<A>> expr = new EConstant<Class<A>>(obj);
+            classToExpr.put(obj, expr);
+            return expr;
+        }
     }
     
-    public <OpType, RT extends Comparable<?>> EComparable<RT> createComparable(Class<RT> type, Op<OpType> operator, Expr<?>... args) {
-        return new OComparable<OpType,RT>(type, Assert.notNull(operator), Assert.notNull(args));
+    public Expr<Integer> createConstant(int i){
+        if (i >= -128 && i <= 127) { 
+            return integers[i+128];
+        }else{
+            return new EConstant<Integer>(i);        
+        }
     }
     
     public <OpType extends Number,D extends Number & Comparable<?>> ENumber<D> createNumber(Class<? extends D> type, Op<OpType> operator, Expr<?>... args) {
         return new ONumber<OpType,D>(type, Assert.notNull(operator), Assert.notNull(args));
     }
-    
+
     public EString createString(Op<String> operator, Expr<?>... args) {
         return new OString(Assert.notNull(operator), Assert.notNull(args));
     }
-    
+
     public Expr<String[]> createStringArray(Op<String> operator, Expr<?>... args) {
         return new OStringArray(Assert.notNull(operator), Assert.notNull(args));
     }