[historyView] Performance second part

This limits the number of commits to show in the history page to ten
thousand. This is a UI Preference available on the Git Preference
page. The user can set this to zero in order to see all commits.

The second thing is to hide the "tag sequence" by default. This is
very time and memory-consuming on big repositories. This is changeable
by another Git Preference.

In combination, this makes browsing the Linux 2.6 repository work
without too much waiting and memory overflow.

Bug: 337081
Change-Id: Ie2823c3c24c2ee9a1a9baf1a6c314901bf8b4a12
Signed-off-by: Mathias Kinzler <mathias.kinzler@sap.com>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

1 files changed, 21 insertions, 13 deletions

diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/history/GenerateHistoryJob.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/history/GenerateHistoryJob.java
index 768e655a3c..eb4cd0cb44 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/history/GenerateHistoryJob.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/history/GenerateHistoryJob.java
@@ -16,6 +16,7 @@ import org.eclipse.core.runtime.Status;
 import org.eclipse.core.runtime.jobs.Job;
 import org.eclipse.egit.ui.Activator;
 import org.eclipse.egit.ui.JobFamilies;
+import org.eclipse.egit.ui.UIPreferences;
 import org.eclipse.egit.ui.UIText;
 import org.eclipse.egit.ui.internal.trace.GitTraceLocation;
 import org.eclipse.osgi.util.NLS;
@@ -23,6 +24,9 @@ import org.eclipse.osgi.util.NLS;
 class GenerateHistoryJob extends Job {
 	private static final int BATCH_SIZE = 256;
 
+	private final int maxCommits = Activator.getDefault().getPreferenceStore()
+			.getInt(UIPreferences.HISTORY_MAX_NUM_COMMITS);
+
 	private final GitHistoryPage page;
 
 	private final SWTCommitList allCommits;
@@ -45,6 +49,7 @@ class GenerateHistoryJob extends Job {
 	@Override
 	protected IStatus run(final IProgressMonitor monitor) {
 		IStatus status = Status.OK_STATUS;
+		boolean incomplete = false;
 		try {
 			if (trace)
 				GitTraceLocation.getTrace().traceEntry(
@@ -60,27 +65,30 @@ class GenerateHistoryJob extends Job {
 								GitTraceLocation.HISTORYVIEW.getLocation(),
 								"Filling commit list"); //$NON-NLS-1$
 					allCommits.fillTo(oldsz + BATCH_SIZE - 1);
-					if (monitor.isCanceled() || oldsz == allCommits.size())
+					if (monitor.isCanceled()) {
+						page.setErrorMessage(NLS.bind(
+								UIText.GenerateHistoryJob_CancelMessage, page
+										.getName()));
+						return Status.CANCEL_STATUS;
+					}
+					if (maxCommits > 0 && allCommits.size() > maxCommits)
+						incomplete = true;
+					if (incomplete || oldsz == allCommits.size())
 						break;
 
+					monitor.setTaskName(NLS
+							.bind("Found {0} commits", Integer.valueOf(allCommits.size()))); //$NON-NLS-1$
 					final long now = System.currentTimeMillis();
 					if (now - lastUpdateAt < 2000 && lastUpdateCnt > 0)
 						continue;
-					updateUI();
+					updateUI(incomplete);
 					lastUpdateAt = now;
 				}
 			} catch (IOException e) {
 				status = new Status(IStatus.ERROR, Activator.getPluginId(),
 						UIText.GenerateHistoryJob_errorComputingHistory, e);
 			}
-
-			if (monitor.isCanceled()) {
-				page.setErrorMessage(NLS
-						.bind(UIText.GenerateHistoryJob_CancelMessage, page
-								.getName()));
-				return Status.CANCEL_STATUS;
-			}
-			updateUI();
+			updateUI(incomplete);
 		} finally {
 			monitor.done();
 			if (trace)
@@ -90,17 +98,17 @@ class GenerateHistoryJob extends Job {
 		return status;
 	}
 
-	void updateUI() {
+	void updateUI(boolean incomplete) {
 		if (trace)
 			GitTraceLocation.getTrace().traceEntry(
 					GitTraceLocation.HISTORYVIEW.getLocation());
 		try {
-			if (allCommits.size() == lastUpdateCnt)
+			if (!incomplete && allCommits.size() == lastUpdateCnt)
 				return;
 
 			final SWTCommit[] asArray = new SWTCommit[allCommits.size()];
 			allCommits.toArray(asArray);
-			page.showCommitList(this, allCommits, asArray);
+			page.showCommitList(this, allCommits, asArray, incomplete);
 			lastUpdateCnt = allCommits.size();
 		} finally {
 			if (trace)