1 files changed, 146 insertions, 0 deletions
diff --git a/tests/benchmarks/corelib/mimetypes/qmimedatabase/tst_bench_qmimedatabase.cpp b/tests/benchmarks/corelib/mimetypes/qmimedatabase/tst_bench_qmimedatabase.cpp
new file mode 100644
index 0000000000..ffc65e7949
--- /dev/null
+++ b/tests/benchmarks/corelib/mimetypes/qmimedatabase/tst_bench_qmimedatabase.cpp
@@ -0,0 +1,146 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// Copyright (C) 2021 Igor Kushnir <igorkuo@gmail.com>
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
+
+#include <QTest>
+#include <QMimeDatabase>
+
+using namespace Qt::StringLiterals;
+
+namespace {
+struct MatchModeInfo
+{
+    QMimeDatabase::MatchMode mode;
+    const char *name;
+};
+
+constexpr MatchModeInfo matchModes[] = { { QMimeDatabase::MatchDefault, "Default" },
+                                         { QMimeDatabase::MatchExtension, "Extension" },
+                                         { QMimeDatabase::MatchContent, "Content" } };
+
+void addFileRows(const char *tag, const QString &fileName, const QStringList &expectedMimeNames)
+{
+    QCOMPARE(static_cast<std::size_t>(expectedMimeNames.size()), std::size(matchModes));
+    for (int i = 0; i < expectedMimeNames.size(); ++i) {
+        QTest::addRow(qPrintable(tag + QStringLiteral(" - %s")), matchModes[i].name)
+                << fileName << matchModes[i].mode << expectedMimeNames[i];
+    }
+}
+
+void addExistentFileRows(const char *tag, const QString &fileName,
+                         const QStringList &expectedMimeNames)
+{
+    const QString filePath = QFINDTESTDATA("files/" + fileName);
+    QVERIFY2(!filePath.isEmpty(),
+             qPrintable(QStringLiteral("Cannot find test file %1 in files/").arg(fileName)));
+    addFileRows(tag, filePath, expectedMimeNames);
+}
+}
+
+class tst_QMimeDatabase: public QObject
+{
+
+    Q_OBJECT
+
+private slots:
+    void inheritsPerformance();
+    void benchMimeTypeForName();
+    void benchMimeTypeForFile_data();
+    void benchMimeTypeForFile();
+};
+
+void tst_QMimeDatabase::inheritsPerformance()
+{
+    // Check performance of inherits().
+    // This benchmark (which started in 2009 in kmimetypetest.cpp) uses 40 mimetypes.
+    // (eight groups of five unique ones)
+    const QString uniqueMimeTypes[] = {
+        u"image/jpeg"_s,
+        u"image/png"_s,
+        u"image/tiff"_s,
+        u"text/plain"_s,
+        u"text/html"_s,
+    };
+    constexpr size_t NumOuterLoops = 40 / std::size(uniqueMimeTypes);
+    QMimeDatabase db;
+    const QMimeType mime = db.mimeTypeForName(u"text/x-chdr"_s);
+    QVERIFY(mime.isValid());
+    QString match;
+    QBENCHMARK {
+        for (size_t i = 0; i < NumOuterLoops; ++i) {
+            for (const QString &mt : uniqueMimeTypes) {
+                if (mime.inherits(mt)) {
+                    match = mt;
+                    // of course there would normally be a "break" here, but
+                    // we're testing worse-case performance here
+                }
+            }
+        }
+    }
+    QCOMPARE(match, u"text/plain"_s);
+    // Numbers from 2011, in release mode:
+    // KDE 4.7 numbers: 0.21 msec / 494,000 ticks / 568,345 instr. loads per iteration
+    // QMimeBinaryProvider (with Qt 5): 0.16 msec / NA / 416,049 instr. reads per iteration
+    // QMimeXmlProvider (with Qt 5): 0.062 msec / NA / 172,889 instr. reads per iteration
+    //   (but the startup time is way higher)
+    // And memory usage is flat at 200K with QMimeBinaryProvider, while it peaks at 6 MB when
+    // parsing XML, and then keeps being around 4.5 MB for all the in-memory hashes.
+}
+
+void tst_QMimeDatabase::benchMimeTypeForName()
+{
+    QMimeDatabase db;
+
+    QBENCHMARK {
+        const auto s = db.mimeTypeForName(QStringLiteral("text/plain"));
+        QVERIFY(s.isValid());
+    }
+}
+
+void tst_QMimeDatabase::benchMimeTypeForFile_data()
+{
+    QTest::addColumn<QString>("fileName");
+    QTest::addColumn<QMimeDatabase::MatchMode>("mode");
+    QTest::addColumn<QString>("expectedMimeName");
+
+    addFileRows("archive", "a.tar.gz",
+                { "application/x-compressed-tar",
+                  "application/x-compressed-tar",
+                  "application/octet-stream" });
+    addFileRows("OpenDocument Text", "b.odt",
+                { "application/vnd.oasis.opendocument.text",
+                  "application/vnd.oasis.opendocument.text",
+                  "application/octet-stream" });
+
+    addExistentFileRows(
+            "existent archive with extension", "N.tar.gz",
+            { "application/x-compressed-tar", "application/x-compressed-tar", "application/gzip" });
+    addExistentFileRows("existent C with extension", "t.c",
+                        { "text/x-csrc", "text/x-csrc", "text/plain" });
+    addExistentFileRows("existent text file with extension", "u.txt",
+                        { "text/plain", "text/plain", "text/plain" });
+    addExistentFileRows("existent C w/o extension", "X",
+                        { "text/x-csrc", "application/octet-stream", "text/x-csrc" });
+    addExistentFileRows("existent patch w/o extension", "y",
+                        { "text/x-patch", "application/octet-stream", "text/x-patch" });
+    addExistentFileRows("existent archive w/o extension", "z",
+                        { "application/gzip", "application/octet-stream", "application/gzip" });
+}
+
+void tst_QMimeDatabase::benchMimeTypeForFile()
+{
+    QFETCH(const QString, fileName);
+    QFETCH(const QMimeDatabase::MatchMode, mode);
+    QFETCH(const QString, expectedMimeName);
+
+    QMimeDatabase db;
+
+    QBENCHMARK {
+        const auto mimeType = db.mimeTypeForFile(fileName, mode);
+        QCOMPARE(mimeType.name(), expectedMimeName);
+    }
+}
+
+QTEST_MAIN(tst_QMimeDatabase)
+
+#include "tst_bench_qmimedatabase.moc"