qt5base-lts/tests
Igor Kushnir d797e3c88e Optimize QMimeDatabase::mimeTypeForFile(f, MatchDefault)
Open the file only if matching on content is needed.

Use QFileInfo::filePath() instead of QFileInfo::absoluteFilePath() in
QMimeDatabase::mimeTypeForFile(). filePath() does much less work, and so
is faster. Thiago Macieira helpfully explained in a review comment why
the absolute path is not useful for correctness here: "Nothing needs
absolute paths within the same application that would resolve the
relative path to absolute. You only need an absolute path if you're
communicating with another application that may be in a different
directory."

QMimeDatabase::mimeTypeForFile() checks fileInfo.isDir(), so the
fileName.endsWith(QLatin1Char('/')) check in
QMimeDatabasePrivate::mimeTypeForFileNameAndData() was redundant when
called from this function. The other two callers of that function now
check this condition before opening IO devices. This improves
performance of the two QMimeDatabase::mimeTypeForFileNameAndData()
overloads in the corner case.

Refactor and optimize QMimeDatabasePrivate::findByFileName() and its
usages. Previously each caller constructed a QFileInfo object and passed
QFileInfo::fileName() into this function. Now the callers simply pass an
absolute or relative path to a file into this function, which then uses
QFileSystemEntry::fileName() to exclude the path. Constructing QFileInfo
is relatively expensive, so this change slightly improves performance.

Optimize QMimeDatabasePrivate::loadProviders() by calling static
QFileInfo::exists() instead of constructing a QFileInfo object and
calling the non-static QFileInfo::exists() overload. Note that the
QFileInfo object was always created, even if QFileInfo::exists() under
an `if` and an `#if` was never called.

The following table contains the average results of the added benchmark
tst_QMimeDatabase::benchMimeTypeForFile() on my GNU/Linux system before
and at this commit. The numbers denote milliseconds per iteration.

        data row tag                        before  at
MatchDefault:
        archive                             0.029   0.016
        OpenDocument Text                   0.029   0.015
        existent archive with extension     0.039   0.025
        existent C with extension           0.033   0.020
        existent text file with extension   0.033   0.020
        existent C w/o extension            0.076   0.074
        existent patch w/o extension        0.11    0.105
        existent archive w/o extension      0.069   0.066
MatchExtension:
        archive                             0.012   0.0115
        OpenDocument Text                   0.0115  0.011
        existent archive with extension     0.017   0.016
        existent C with extension           0.011   0.011
        existent text file with extension   0.011   0.011
        existent C w/o extension            0.016   0.0155
        existent patch w/o extension        0.013   0.012
        existent archive w/o extension      0.013   0.012
MatchContent:
        archive                             0.019   0.012
        OpenDocument Text                   0.019   0.012
        existent archive with extension     0.053   0.051
        existent C with extension           0.056   0.0545
        existent text file with extension   0.058   0.056
        existent C w/o extension            0.0605  0.059
        existent patch w/o extension        0.10    0.099
        existent archive w/o extension      0.057   0.054

Change-Id: Idb541656e073a2c4822ace3f4da412f29f2351f8
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: David Faure <david.faure@kdab.com>
2021-12-06 22:55:06 +02:00
..
auto QFontDatabase (Windows): Sanitize font requests early 2021-12-06 20:06:06 +01:00
baseline Never handle scrollbars styled with box or border changes as transient 2021-11-29 16:02:28 +01:00
benchmarks Optimize QMimeDatabase::mimeTypeForFile(f, MatchDefault) 2021-12-06 22:55:06 +02:00
global
libfuzzer CMake: Bump almost all cmake_minimum_required calls to 3.16 2021-09-22 19:36:49 +02:00
manual Rename and restructure the baseline (lancelot) testing code 2021-11-16 14:01:50 +01:00
shared QtBase: replace windows.h with qt_windows.h 2021-11-23 12:53:46 +08:00
testserver Network self-test: make it work with docker/containers 2020-11-17 19:56:06 +01:00
CMakeLists.txt CMake: Refactor optimization flag handling and add optimize_full 2020-10-06 10:07:05 +02:00
README

This directory contains autotests and benchmarks based on Qt Test. In order
to run the autotests reliably, you need to configure a desktop to match the
test environment that these tests are written for.

Linux X11:

   * The user must be logged in to an active desktop; you can't run the
     autotests without a valid DISPLAY that allows X11 connections.

   * The tests are run against a KDE3 or KDE4 desktop.

   * Window manager uses "click to focus", and not "focus follows mouse". Many
     tests move the mouse cursor around and expect this to not affect focus
     and activation.

   * Disable "click to activate", i.e., when a window is opened, the window
     manager should automatically activate it (give it input focus) and not
     wait for the user to click the window.