Mercurial: Add cache for branch query

Change-Id: Ied6f2008324b80b9d4869ba17d67e6d55a91d08c
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>

src/plugins/mercurial/mercurialclient.cpp

@@ -39,6 +39,7 @@
 #include <utils/fileutils.h>
 #include <utils/qtcassert.h>
 
+#include <QDateTime>
 #include <QDir>
 #include <QFileInfo>
 #include <QTextCodec>
@@ -155,10 +156,12 @@ bool MercurialClient::synchronousPull(const QString &workingDir, const QString &
 
 QString MercurialClient::branchQuerySync(const QString &repositoryRoot)
 {
-    QByteArray output;
-    if (vcsFullySynchronousExec(repositoryRoot, QStringList(QLatin1String("branch")), &output))
-        return QTextCodec::codecForLocale()->toUnicode(output).trimmed();
-
+    QFile branchFile(repositoryRoot + QLatin1String("/.hg/branch"));
+    if (branchFile.open(QFile::ReadOnly)) {
+        const QByteArray branch = branchFile.readAll().trimmed();
+        if (!branch.isEmpty())
+            return QString::fromLocal8Bit(branch);
+    }
     return QLatin1String("Unknown Branch");
 }
 

src/plugins/mercurial/mercurialcontrol.cpp

@@ -33,6 +33,8 @@
 #include <vcsbase/vcsbaseclientsettings.h>
 #include <vcsbase/vcsbaseconstants.h>
 
+#include <coreplugin/vcsmanager.h>
+
 #include <QFileInfo>
 #include <QVariant>
 #include <QStringList>
@@ -40,8 +42,29 @@
 
 using namespace Mercurial::Internal;
 
+class MercurialTopicCache : public Core::IVersionControl::TopicCache
+{
+public:
+    MercurialTopicCache(MercurialClient *client) : m_client(client) {}
+
+protected:
+    QString trackFile(const QString &repository)
+    {
+        return repository + QLatin1String("/.hg/branch");
+    }
+
+    QString refreshTopic(const QString &repository)
+    {
+        return m_client->branchQuerySync(repository);
+    }
+
+private:
+    MercurialClient *m_client;
+};
+
 MercurialControl::MercurialControl(MercurialClient *client)
-    : mercurialClient(client)
+    : Core::IVersionControl(new MercurialTopicCache(client))
+    , mercurialClient(client)
 {
 }
 
@@ -136,11 +159,6 @@ bool MercurialControl::vcsAnnotate(const QString &file, int line)
     return true;
 }
 
-QString MercurialControl::vcsTopic(const QString &directory)
-{
-    return mercurialClient->branchQuerySync(directory);
-}
-
 bool MercurialControl::sccManaged(const QString &filename)
 {
     const QFileInfo fi(filename);

src/plugins/mercurial/mercurialcontrol.h

@@ -65,7 +65,6 @@ public:
     QString vcsGetRepositoryURL(const QString &directory);
     bool sccManaged(const QString &filename);
     bool vcsAnnotate(const QString &file, int line);
-    QString vcsTopic(const QString &directory);
 
 public slots:
     // To be connected to the HgTask's success signal to emit the repository/

src/plugins/mercurial/mercurialplugin.cpp

@@ -581,7 +581,7 @@ void MercurialPlugin::showCommitWidget(const QList<VcsBaseClient::StatusItem> &s
                         arg(QDir::toNativeSeparators(m_submitRepository));
     commitEditor->document()->setDisplayName(msg);
 
-    QString branch = m_client->branchQuerySync(m_submitRepository);
+    QString branch = versionControl()->vcsTopic(m_submitRepository);
     commitEditor->setFields(m_submitRepository, branch,
                             mercurialSettings.stringValue(MercurialSettings::userNameKey),
                             mercurialSettings.stringValue(MercurialSettings::userEmailKey), status);