Optimization of Git status (in Commit dialog)

Speeds up GitClient.getStatus() by deferring expensive evaluation of object Ids, which often compute file content hash, to evaluate them lazily only when needed.

On Netbeans repository with a lot of files, this speeds up GitClient.getStatus() execution from 4 seconds to 1 second.

Author: OndroMih

ide/libs.git/src/org/netbeans/libs/git/jgit/commands/StatusCommand.java

@@ -33,6 +33,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.function.Supplier;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 import org.eclipse.jgit.diff.DiffEntry;
@@ -47,7 +48,9 @@
 import org.eclipse.jgit.lib.ObjectReader;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.revwalk.RevWalk;
-import org.eclipse.jgit.treewalk.*;
+import org.eclipse.jgit.treewalk.EmptyTreeIterator;
+import org.eclipse.jgit.treewalk.FileTreeIterator;
+import org.eclipse.jgit.treewalk.TreeWalk;
 import org.eclipse.jgit.treewalk.filter.AndTreeFilter;
 import org.eclipse.jgit.treewalk.filter.NotTreeFilter;
 import org.eclipse.jgit.treewalk.filter.OrTreeFilter;
@@ -189,7 +192,7 @@ protected void run () throws GitException {
                             Collection<TreeFilter> subTreeFilters = getSubtreeFilters(pathFilters, path);
                             if (!subTreeFilters.isEmpty()) {
                                 // caller requested a status for a file under an ignored folder
-                                treeWalk.setFilter(AndTreeFilter.create(treeWalk.getFilter(), OrTreeFilter.create(NotTreeFilter.create(PathFilter.create(path)), 
+                                treeWalk.setFilter(AndTreeFilter.create(treeWalk.getFilter(), OrTreeFilter.create(NotTreeFilter.create(PathFilter.create(path)),
                                         subTreeFilters.size() > 1 ? OrTreeFilter.create(subTreeFilters) : subTreeFilters.iterator().next())));
                                 treeWalk.enterSubtree();
                             }
@@ -217,11 +220,11 @@ protected void run () throws GitException {
                             } else {
                                 statusIndexWC = GitStatus.Status.STATUS_ADDED;
                             }
-                        } else if (!isExistingSymlink(mIndex, mWorking) && (differ(mIndex, mWorking, checkExecutable) 
+                        } else if (!isExistingSymlink(mIndex, mWorking) && (differ(mIndex, mWorking, checkExecutable)
                                 || (mWorking != 0 && mWorking != FileMode.TREE.getBits() && fti.isModified(indexEntry, true, od)))
                                 || GitStatus.Status.STATUS_MODIFIED == getGitlinkStatus(
-                                        mWorking, treeWalk.getObjectId(T_WORKSPACE),
-                                        mIndex, treeWalk.getObjectId(T_INDEX))) {
+                                        mWorking, () -> treeWalk.getObjectId(T_WORKSPACE),
+                                        mIndex, () -> treeWalk.getObjectId(T_INDEX))) {
                             statusIndexWC = GitStatus.Status.STATUS_MODIFIED;
                         } else {
                             statusIndexWC = GitStatus.Status.STATUS_NORMAL;
@@ -237,8 +240,8 @@ protected void run () throws GitException {
                                     && (statusIndexWC != GitStatus.Status.STATUS_NORMAL || statusHeadIndex != GitStatus.Status.STATUS_NORMAL)
                                     && !treeWalk.getObjectId(T_COMMIT).equals(fti.getEntryObjectId())))
                                 || GitStatus.Status.STATUS_MODIFIED == getGitlinkStatus(
-                                        mHead, treeWalk.getObjectId(T_WORKSPACE),
-                                        mHead, treeWalk.getObjectId(T_COMMIT))) {
+                                        mHead, () -> treeWalk.getObjectId(T_WORKSPACE),
+                                        mHead, () -> treeWalk.getObjectId(T_COMMIT))) {
                             statusHeadWC = GitStatus.Status.STATUS_MODIFIED;
                         } else {
                             statusHeadWC = GitStatus.Status.STATUS_NORMAL;
@@ -444,13 +447,13 @@ private void handleSymlink (List<GitStatus> symLinks, String workTreePath) {
         }
     }
 
-    private GitStatus.Status getGitlinkStatus (int mode1, ObjectId id1, int mode2, ObjectId id2) {
+    private GitStatus.Status getGitlinkStatus (int mode1, Supplier<ObjectId> id1, int mode2, Supplier<ObjectId> id2) {
         if (mode1 == FileMode.TYPE_GITLINK || mode2 == FileMode.TYPE_GITLINK) {
             if (mode1 == FileMode.TYPE_MISSING) {
                 return GitStatus.Status.STATUS_REMOVED;
             } else if (mode2 == FileMode.TYPE_MISSING) {
                 return GitStatus.Status.STATUS_ADDED;
-            } else if (!id1.equals(id2)) {
+            } else if (!id1.get().equals(id2.get())) {
                 return GitStatus.Status.STATUS_MODIFIED;
             }
         }