From 083da84b79fd8e91730c1fe5b9a5d867331d8f18 Mon Sep 17 00:00:00 2001
From: peter <peter@jetbrains.com>
Date: Fri, 27 Sep 2013 12:26:18 +0200
Subject: [PATCH] use identity map for more efficient dfa state copy lookup

---
 .../intellij/codeInspection/dataFlow/StateMerger.java | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/StateMerger.java b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/StateMerger.java
index 5d1a0928cfeb..92fe226049db 100644
--- a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/StateMerger.java
+++ b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/StateMerger.java
@@ -38,7 +38,7 @@ import java.util.Set;
 class StateMerger {
   private final Map<DfaMemoryStateImpl, Map<DfaVariableValue, DfaConstValue>> myVarValues = ContainerUtil.newIdentityHashMap();
   private final Map<DfaMemoryStateImpl, List<UnorderedPair<DfaValue>>> myEqPairs = ContainerUtil.newIdentityHashMap();
-  private final Map<Pair<DfaMemoryStateImpl, DfaVariableValue>, DfaMemoryStateImpl> myCopyCache = ContainerUtil.newHashMap();
+  private final Map<DfaMemoryState, Map<DfaVariableValue, DfaMemoryStateImpl>> myCopyCache = ContainerUtil.newIdentityHashMap();
 
   @Nullable
   public List<DfaMemoryStateImpl> mergeByEquality(List<DfaMemoryStateImpl> states) {
@@ -197,12 +197,15 @@ class StateMerger {
   }
 
   private DfaMemoryStateImpl copyWithoutVar(DfaMemoryStateImpl state, DfaVariableValue var) {
-    Pair<DfaMemoryStateImpl, DfaVariableValue> key = Pair.create(state, var);
-    DfaMemoryStateImpl copy = myCopyCache.get(key);
+    Map<DfaVariableValue, DfaMemoryStateImpl> map = myCopyCache.get(state);
+    if (map == null) {
+      myCopyCache.put(state, map = ContainerUtil.newIdentityHashMap());
+    }
+    DfaMemoryStateImpl copy = map.get(var);
     if (copy == null) {
       copy = state.createCopy();
       copy.flushVariable(var);
-      myCopyCache.put(key, copy);
+      map.put(var, copy);
     }
     return copy;
   }