From d4db0dbbf1efbeee1eb5b37d4b2bae849a297d5c Mon Sep 17 00:00:00 2001
From: Samppa Saarela <samppa.saarela@mysema.com>
Date: Mon, 19 Sep 2011 10:49:58 +0300
Subject: [PATCH] getMap optimization

---
 .../com/mysema/query/support/GroupBy2.java    | 26 ++++++++++---
 .../mysema/query/support/GroupBy2Test.java    | 38 +++++++++----------
 2 files changed, 40 insertions(+), 24 deletions(-)

diff --git a/querydsl-core/src/test/java/com/mysema/query/support/GroupBy2.java b/querydsl-core/src/test/java/com/mysema/query/support/GroupBy2.java
index e1395d083..f9b5ec34f 100644
--- a/querydsl-core/src/test/java/com/mysema/query/support/GroupBy2.java
+++ b/querydsl-core/src/test/java/com/mysema/query/support/GroupBy2.java
@@ -10,6 +10,7 @@ import java.util.Arrays;
 import java.util.Iterator;
 import java.util.LinkedHashMap;
 import java.util.LinkedHashSet;
+import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -61,6 +62,10 @@ public class GroupBy2<S> implements ResultTransformer<Map<S, Group2>> {
         public List<Expression<?>> getArgs() {
             return Arrays.asList(key, value);
         }
+        
+        public boolean equals(Expression<?> keyExpr, Expression<?> valueExpr) {
+            return key.equals(keyExpr) && value.equals(valueExpr);
+        }
 
         @Override
         public Pair<K, V> newInstance(Object... args) {
@@ -283,13 +288,19 @@ public class GroupBy2<S> implements ResultTransformer<Map<S, Group2>> {
     
     private class GroupImpl implements Group2 {
         
-        private final Map<Expression<?>, GroupColumn<?>> groupColumns;
+        private final Map<Expression<?>, GroupColumn<?>> groupColumns = new LinkedHashMap<Expression<?>, GroupColumn<?>>();
+        
+        private final List<QPair<?, ?>> pairs = new LinkedList<GroupBy2.QPair<?,?>>(); 
         
         public GroupImpl() {
-            groupColumns = new LinkedHashMap<Expression<?>, GroupColumn<?>>();
             for (int i=0; i < columns.size(); i++) {
                 GroupColumnDefinition<?, ?> coldef = columns.get(i);
-                groupColumns.put(coldef.getExpression(), coldef.createGroupColumn());
+                Expression<?> expr = coldef.getExpression();
+                groupColumns.put(expr, coldef.createGroupColumn());
+                // Optimized map access
+                if (expr instanceof QPair) {
+                    pairs.add((QPair<?, ?>) expr);
+                }
             }
         }
 
@@ -321,10 +332,15 @@ public class GroupBy2<S> implements ResultTransformer<Map<S, Group2>> {
         }
         
         public <K, V> Map<K, V> getMap(Expression<K> key, Expression<V> value) {
-            return (Map<K, V>) groupColumns.get(new QPair<K, V>(key, value)).get();
+            for (QPair<?, ?> pair : pairs) {
+                if (pair.equals(key, value)) {
+                    return (Map<K, V>) groupColumns.get(pair).get();
+                }
+            }
+            return null;
         }
         
-        public void add(Object[] row) {
+        void add(Object[] row) {
             int i=0;
             for (GroupColumn<?> groupColumn : groupColumns.values()) {
                 groupColumn.add(row[i]);
diff --git a/querydsl-core/src/test/java/com/mysema/query/support/GroupBy2Test.java b/querydsl-core/src/test/java/com/mysema/query/support/GroupBy2Test.java
index 57536865e..3c36121e6 100644
--- a/querydsl-core/src/test/java/com/mysema/query/support/GroupBy2Test.java
+++ b/querydsl-core/src/test/java/com/mysema/query/support/GroupBy2Test.java
@@ -34,6 +34,24 @@ public class GroupBy2Test {
 
     private final StringExpression commentText = new StringPath("commentText");
 
+    private final GroupColumnDefinition<Integer, String> constant = new AbstractGroupColumnDefinition<Integer, String>(commentId) {
+
+        @Override
+        public GroupColumn<String> createGroupColumn() {
+            return new GroupColumn<String>() {
+
+                @Override
+                public void add(Object o) {
+                }
+
+                @Override
+                public String get() {
+                    return "constant";
+                }
+            };
+        }
+    };
+
     static class PostWithComments {
         public Integer id;
         public String name;
@@ -91,25 +109,7 @@ public class GroupBy2Test {
     }
     
     @Test
-    public void Custom_GroupColumnDefinition() {
-        GroupColumnDefinition<Integer, String> constant = new AbstractGroupColumnDefinition<Integer, String>(commentId) {
-
-            @Override
-            public GroupColumn<String> createGroupColumn() {
-                return new GroupColumn<String>() {
-
-                    @Override
-                    public void add(Object o) {
-                    }
-
-                    @Override
-                    public String get() {
-                        return "constant";
-                    }
-                };
-            }
-        };
-        
+    public void With_Constant_Column() {
         Map<Integer, Group2> results = 
             GroupBy2.groupBy(postId).withOne(postName).withGroup(constant).transform(BASIC_RESULTS);