Use QIODevice::readLineInto() instead of readLine() in loops

Most of the callers of QIODevice::readLine() are reading a device line
by line in a loop. Instead, use one QByteArray and modify it in every
iteration using QIODevice::readLineInto().

Use a QByteArrayView instead of QByteArray when calling trimmed() as
it's an expensive operation.

Fixes: QTBUG-103108
Change-Id: Ic1af487a2fbf352cc21d76a41717944d034d3709
Reviewed-by: Marc Mutz <[email protected]>
Reviewed-by: Thiago Macieira <[email protected]>

1 files changed, 5 insertions, 4 deletions

diff --git a/src/tools/androiddeployqt/main.cpp b/src/tools/androiddeployqt/main.cpp
index 98324ab5b25..cf13c5e781a 100644
--- a/src/tools/androiddeployqt/main.cpp
+++ b/src/tools/androiddeployqt/main.cpp
@@ -2837,8 +2837,9 @@ QStringList getLibraryProjectsInOutputFolder(const Options &options)
 
     QFile file(options.outputDirectory + "/project.properties"_L1);
     if (file.open(QIODevice::ReadOnly)) {
-        while (!file.atEnd()) {
-            QByteArray line = file.readLine().trimmed();
+        QByteArray lineArray;
+        while (file.readLineInto(&lineArray)) {
+            QByteArrayView line = QByteArrayView(lineArray).trimmed();
             if (line.startsWith("android.library.reference")) {
                 int equalSignIndex = line.indexOf('=');
                 if (equalSignIndex >= 0) {
@@ -2913,8 +2914,8 @@ static bool mergeGradleProperties(const QString &path, GradleProperties properti
 
     QFile oldFile(oldPathStr);
     if (oldFile.open(QIODevice::ReadOnly)) {
-        while (!oldFile.atEnd()) {
-            QByteArray line(oldFile.readLine());
+        QByteArray line;
+        while (oldFile.readLineInto(&line)) {
             QList<QByteArray> prop(line.split('='));
             if (prop.size() > 1) {
                 GradleProperties::iterator it = properties.find(prop.at(0).trimmed());