diff options
author | Marc Mutz <marc.mutz@kdab.com> | 2019-05-19 23:25:12 +0200 |
---|---|---|
committer | Marc Mutz <marc.mutz@kdab.com> | 2019-05-21 21:57:20 +0200 |
commit | b03385f9cff7acc2b37933f493e3eff2d8bbef59 (patch) | |
tree | be519e92d527bc3878c2b58d3d006f099019dd83 /src/corelib/io/qfilesystemwatcher_inotify.cpp | |
parent | 4e026a2076dd6f612871e30fdcf49312b4647846 (diff) |
QFileSystemWatcherEngines: port some Java-style iterators to ranged-for
Java-style iterators are scheduled to be deprecated.
The general pattern used in the patch is that instead of copying an
input list, then iterating over the copy with some calls to
it.remove() (which leads to quadratic-complexity loops), we simply
copy conditionally (a la remove_copy_if instead of remove_if).
To make clearer what's going on, rename the outgoing list to
'unhandled'.
To avoid having to touch too much of the loops' structure, which
sometimes is quite convoluted, use qScopeGuard to do the append to
'unhandled', unless the original code removed the element.
Saves a surprising almost 5KiB in text size on GCC 9.1 optimized
AMD64 Linux builds.
Change-Id: Ifd861de9aa48d66b420858606998dd08a8401e03
Reviewed-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>
Diffstat (limited to 'src/corelib/io/qfilesystemwatcher_inotify.cpp')
-rw-r--r-- | src/corelib/io/qfilesystemwatcher_inotify.cpp | 25 |
1 files changed, 13 insertions, 12 deletions
diff --git a/src/corelib/io/qfilesystemwatcher_inotify.cpp b/src/corelib/io/qfilesystemwatcher_inotify.cpp index 9d008947ba..5fb5685f42 100644 --- a/src/corelib/io/qfilesystemwatcher_inotify.cpp +++ b/src/corelib/io/qfilesystemwatcher_inotify.cpp @@ -46,6 +46,7 @@ #include <qdebug.h> #include <qfile.h> #include <qfileinfo.h> +#include <qscopeguard.h> #include <qsocketnotifier.h> #include <qvarlengtharray.h> @@ -268,12 +269,11 @@ QStringList QInotifyFileSystemWatcherEngine::addPaths(const QStringList &paths, QStringList *files, QStringList *directories) { - QStringList p = paths; - QMutableListIterator<QString> it(p); - while (it.hasNext()) { - QString path = it.next(); + QStringList unhandled; + for (const QString &path : paths) { QFileInfo fi(path); bool isDir = fi.isDir(); + auto sg = qScopeGuard([&]{ unhandled.push_back(path); }); if (isDir) { if (directories->contains(path)) continue; @@ -305,7 +305,7 @@ QStringList QInotifyFileSystemWatcherEngine::addPaths(const QStringList &paths, continue; } - it.remove(); + sg.dismiss(); int id = isDir ? -wd : wd; if (id < 0) { @@ -318,19 +318,19 @@ QStringList QInotifyFileSystemWatcherEngine::addPaths(const QStringList &paths, idToPath.insert(id, path); } - return p; + return unhandled; } QStringList QInotifyFileSystemWatcherEngine::removePaths(const QStringList &paths, QStringList *files, QStringList *directories) { - QStringList p = paths; - QMutableListIterator<QString> it(p); - while (it.hasNext()) { - QString path = it.next(); + QStringList unhandled; + for (const QString &path : paths) { int id = pathToID.take(path); + auto sg = qScopeGuard([&]{ unhandled.push_back(path); }); + // Multiple paths could be associated to the same watch descriptor // when a file is moved and added with the new name. // So we should find and delete the correct one by using @@ -349,7 +349,8 @@ QStringList QInotifyFileSystemWatcherEngine::removePaths(const QStringList &path inotify_rm_watch(inotifyFd, wd); } - it.remove(); + sg.dismiss(); + if (id < 0) { directories->removeAll(path); } else { @@ -357,7 +358,7 @@ QStringList QInotifyFileSystemWatcherEngine::removePaths(const QStringList &path } } - return p; + return unhandled; } void QInotifyFileSystemWatcherEngine::readFromInotify() |