From 7fb1f1c146106d4a1ff36eb3cd49b963329fd70f Mon Sep 17 00:00:00 2001
From: Alexey Kudravtsev <cdr@intellij.com>
Date: Wed, 30 Nov 2016 18:22:11 +0300
Subject: [PATCH] memory optimisation: eliminate TIntArrayList slack

---
 .../intellij/vcs/log/data/CompressedRefs.java | 28 +++++++++----------
 1 file changed, 13 insertions(+), 15 deletions(-)

diff --git a/platform/vcs-log/impl/src/com/intellij/vcs/log/data/CompressedRefs.java b/platform/vcs-log/impl/src/com/intellij/vcs/log/data/CompressedRefs.java
index 772579231019..f0c04dcecf5d 100644
--- a/platform/vcs-log/impl/src/com/intellij/vcs/log/data/CompressedRefs.java
+++ b/platform/vcs-log/impl/src/com/intellij/vcs/log/data/CompressedRefs.java
@@ -27,10 +27,7 @@ import gnu.trove.TIntArrayList;
 import gnu.trove.TIntObjectHashMap;
 import org.jetbrains.annotations.NotNull;
 
-import java.util.AbstractCollection;
-import java.util.Collection;
-import java.util.Iterator;
-import java.util.Set;
+import java.util.*;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
@@ -38,16 +35,13 @@ public class CompressedRefs {
   @NotNull private final VcsLogStorage myHashMap;
 
   // maps each commit id to the list of tag ids on this commit
-  @NotNull private final TIntObjectHashMap<TIntArrayList> myTags;
+  @NotNull private final TIntObjectHashMap<TIntArrayList> myTags = new TIntObjectHashMap<>();
   // maps each commit id to the list of branches on this commit
-  @NotNull private final TIntObjectHashMap<SmartList<VcsRef>> myBranches;
+  @NotNull private final TIntObjectHashMap<List<VcsRef>> myBranches = new TIntObjectHashMap<>();
 
   public CompressedRefs(@NotNull Set<VcsRef> refs, @NotNull VcsLogStorage hashMap) {
     myHashMap = hashMap;
 
-    myTags = new TIntObjectHashMap<>();
-    myBranches = new TIntObjectHashMap<>();
-
     Ref<VirtualFile> root = new Ref<>();
 
     refs.forEach(ref -> {
@@ -61,12 +55,15 @@ public class CompressedRefs {
         putRefIndex(myTags, ref, myHashMap);
       }
     });
-
+    myTags.forEachValue(list -> {
+      list.trimToSize();
+      return true;
+    });
     myHashMap.flush();
   }
 
   @NotNull
-  public SmartList<VcsRef> refsToCommit(int index) {
+  SmartList<VcsRef> refsToCommit(int index) {
     SmartList<VcsRef> result = new SmartList<>();
     if (myBranches.containsKey(index)) result.addAll(myBranches.get(index));
     TIntArrayList tags = myTags.get(index);
@@ -80,7 +77,7 @@ public class CompressedRefs {
   }
 
   @NotNull
-  public Stream<VcsRef> streamBranches() {
+  Stream<VcsRef> streamBranches() {
     return TroveUtil.streamValues(myBranches).flatMap(Collection::stream);
   }
 
@@ -100,6 +97,7 @@ public class CompressedRefs {
       private final Supplier<Collection<VcsRef>> myLoadedRefs =
         Suppliers.memoize(() -> CompressedRefs.this.stream().collect(Collectors.toList()));
 
+      @NotNull
       @Override
       public Iterator<VcsRef> iterator() {
         return myLoadedRefs.get().iterator();
@@ -120,14 +118,14 @@ public class CompressedRefs {
     return result;
   }
 
-  public static void putRef(@NotNull TIntObjectHashMap<SmartList<VcsRef>> map, @NotNull VcsRef ref, @NotNull VcsLogStorage hashMap) {
+  private static void putRef(@NotNull TIntObjectHashMap<List<VcsRef>> map, @NotNull VcsRef ref, @NotNull VcsLogStorage hashMap) {
     int index = hashMap.getCommitIndex(ref.getCommitHash(), ref.getRoot());
-    SmartList<VcsRef> list = map.get(index);
+    List<VcsRef> list = map.get(index);
     if (list == null) map.put(index, list = new SmartList<>());
     list.add(ref);
   }
 
-  public static void putRefIndex(@NotNull TIntObjectHashMap<TIntArrayList> map, @NotNull VcsRef ref, @NotNull VcsLogStorage hashMap) {
+  private static void putRefIndex(@NotNull TIntObjectHashMap<TIntArrayList> map, @NotNull VcsRef ref, @NotNull VcsLogStorage hashMap) {
     int index = hashMap.getCommitIndex(ref.getCommitHash(), ref.getRoot());
     TIntArrayList list = map.get(index);
     if (list == null) map.put(index, list = new TIntArrayList());