Introduce QIODevice::skipData()

QIODevice::skip() called a virtual QIODevicePrivate::skip() to
implement an efficient skipping on I/O devices for the internal
subclasses. The user subclasses cannot inherit QIODevicePrivate, so
this functionality was not externally accessible.

This patch replaces QIODevicePrivate::skip() with a virtual protected
QIODevice::skipData(). While the basic implementation simply discards
the data by reading into a dummy buffer, users can reimplement this
function to improve the performance in their subclasses.

[ChangeLog][QtCore][QIODevice] Added virtual protected skipData().
Now, subclasses can implement device-specific skipping of data.

Change-Id: I9522f7f7ab9d03ac06e972a525f8ec2fa909a617
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

1 files changed, 7 insertions, 5 deletions

diff --git a/src/network/ssl/qsslsocket.cpp b/src/network/ssl/qsslsocket.cpp
index 66bcb79c4c..19ab903d36 100644
--- a/src/network/ssl/qsslsocket.cpp
+++ b/src/network/ssl/qsslsocket.cpp
@@ -2541,17 +2541,19 @@ QByteArray QSslSocketPrivate::peek(qint64 maxSize)
 }
 
 /*!
-    \internal
+    \reimp
 */
-qint64 QSslSocketPrivate::skip(qint64 maxSize)
+qint64 QSslSocket::skipData(qint64 maxSize)
 {
-    if (mode == QSslSocket::UnencryptedMode && !autoStartHandshake)
-        return plainSocket->skip(maxSize);
+    Q_D(QSslSocket);
+
+    if (d->mode == QSslSocket::UnencryptedMode && !d->autoStartHandshake)
+        return d->plainSocket->skip(maxSize);
 
     // In encrypted mode, the SSL backend writes decrypted data directly into the
     // QIODevice's read buffer. As this buffer is always emptied by the caller,
     // we need to wait for more incoming data.
-    return (state == QAbstractSocket::ConnectedState) ? Q_INT64_C(0) : Q_INT64_C(-1);
+    return (d->state == QAbstractSocket::ConnectedState) ? Q_INT64_C(0) : Q_INT64_C(-1);
 }
 
 /*!