Avoid code duplication by using checksum calculation from qtbase

Since qtbase supports checksum calculation defined in
ITU-V.41 an own implementation is not longer needed.

Change-Id: I0f62c872b4fb517493ba43a9bb7a6d35481fa40d
Reviewed-by: Alex Blasche <alexander.blasche@qt.io>

4 files changed, 20 insertions, 35 deletions

diff --git a/src/nfc/qnearfieldtarget.cpp b/src/nfc/qnearfieldtarget.cpp
index 274ef175..ecd845f6 100644
--- a/src/nfc/qnearfieldtarget.cpp
+++ b/src/nfc/qnearfieldtarget.cpp
@@ -126,15 +126,7 @@ QT_BEGIN_NAMESPACE
     \value CommandError             Failed to send a command to the target.
 */
 
-// Copied from qbytearray.cpp
-// Modified to initialize the crc with 0x6363 instead of 0xffff and to not invert the final result.
-static const quint16 crc_tbl[16] = {
-    0x0000, 0x1081, 0x2102, 0x3183,
-    0x4204, 0x5285, 0x6306, 0x7387,
-    0x8408, 0x9489, 0xa50a, 0xb58b,
-    0xc60c, 0xd68d, 0xe70e, 0xf78f
-};
-
+#if QT_DEPRECATED_SINCE(5, 9)
 /*!
     \relates QNearFieldTarget
 
@@ -142,17 +134,9 @@ static const quint16 crc_tbl[16] = {
 */
 quint16 qNfcChecksum(const char *data, uint len)
 {
-    quint16 crc = 0x6363;
-    uchar c;
-    const uchar *p = reinterpret_cast<const uchar *>(data);
-    while (len--) {
-        c = *p++;
-        crc = ((crc >> 4) & 0x0fff) ^ crc_tbl[((crc ^ c) & 15)];
-        c >>= 4;
-        crc = ((crc >> 4) & 0x0fff) ^ crc_tbl[((crc ^ c) & 15)];
-    }
-    return crc;
+    return qChecksum(data, len, Qt::ChecksumItuV41);
 }
+#endif
 
 /*!
     \fn void QNearFieldTarget::disconnected()
diff --git a/src/nfc/qnearfieldtarget.h b/src/nfc/qnearfieldtarget.h
index 620ea813..040b9719 100644
--- a/src/nfc/qnearfieldtarget.h
+++ b/src/nfc/qnearfieldtarget.h
@@ -40,9 +40,10 @@
 #ifndef QNEARFIELDTARGET_H
 #define QNEARFIELDTARGET_H
 
-#include <QtCore/QObject>
+#include <QtCore/QByteArray>
 #include <QtCore/QList>
 #include <QtCore/QMetaType>
+#include <QtCore/QObject>
 #include <QtCore/QSharedDataPointer>
 #include <QtNfc/qnfcglobal.h>
 
@@ -162,7 +163,9 @@ private:
     QNearFieldTargetPrivate *d_ptr;
 };
 
+#if QT_DEPRECATED_SINCE(5, 9)
 Q_NFC_EXPORT quint16 qNfcChecksum(const char * data, uint len);
+#endif
 
 Q_DECLARE_OPERATORS_FOR_FLAGS(QNearFieldTarget::AccessMethods)
 
diff --git a/src/nfc/qnearfieldtarget_emulator.cpp b/src/nfc/qnearfieldtarget_emulator.cpp
index 96462b0d..29b1f74d 100644
--- a/src/nfc/qnearfieldtarget_emulator.cpp
+++ b/src/nfc/qnearfieldtarget_emulator.cpp
@@ -40,11 +40,12 @@
 #include "qnearfieldtarget_emulator_p.h"
 #include "qnearfieldtarget_p.h"
 
-#include <QtCore/QDirIterator>
-#include <QtCore/QSettings>
-#include <QtCore/QMutex>
+#include <QtCore/QByteArray>
 #include <QtCore/QCoreApplication>
 #include <QtCore/QDateTime>
+#include <QtCore/QDirIterator>
+#include <QtCore/QMutex>
+#include <QtCore/QSettings>
 
 QT_BEGIN_NAMESPACE
 
@@ -87,7 +88,7 @@ QNearFieldTarget::RequestId TagType1::sendCommand(const QByteArray &command)
         return id;
     }
 
-    quint16 crc = qNfcChecksum(command.constData(), command.length());
+    quint16 crc = qChecksum(command.constData(), command.length(), Qt::ChecksumItuV41);
 
     QByteArray response = m_tag->processCommand(command + char(crc & 0xff) + char(crc >> 8));
 
@@ -99,7 +100,7 @@ QNearFieldTarget::RequestId TagType1::sendCommand(const QByteArray &command)
     }
 
     // check crc
-    if (qNfcChecksum(response.constData(), response.length()) != 0) {
+    if (qChecksum(response.constData(), response.length(), Qt::ChecksumItuV41) != 0) {
         QMetaObject::invokeMethod(this, "error", Qt::QueuedConnection,
                                   Q_ARG(QNearFieldTarget::Error, ChecksumMismatchError),
                                   Q_ARG(QNearFieldTarget::RequestId, id));
@@ -157,7 +158,7 @@ QNearFieldTarget::RequestId TagType2::sendCommand(const QByteArray &command)
         return id;
     }
 
-    quint16 crc = qNfcChecksum(command.constData(), command.length());
+    quint16 crc = qChecksum(command.constData(), command.length(), Qt::ChecksumItuV41);
 
     QByteArray response = m_tag->processCommand(command + char(crc & 0xff) + char(crc >> 8));
 
@@ -166,7 +167,7 @@ QNearFieldTarget::RequestId TagType2::sendCommand(const QByteArray &command)
 
     if (response.length() > 1) {
         // check crc
-        if (qNfcChecksum(response.constData(), response.length()) != 0) {
+        if (qChecksum(response.constData(), response.length(), Qt::ChecksumItuV41) != 0) {
             QMetaObject::invokeMethod(this, "error", Qt::QueuedConnection,
                                       Q_ARG(QNearFieldTarget::Error, ChecksumMismatchError),
                                       Q_ARG(QNearFieldTarget::RequestId, id));
diff --git a/src/nfc/targetemulator.cpp b/src/nfc/targetemulator.cpp
index ffc2c1b5..80555593 100644
--- a/src/nfc/targetemulator.cpp
+++ b/src/nfc/targetemulator.cpp
@@ -44,9 +44,6 @@
 
 #include <QtCore/QDebug>
 
-// Implementation of qNfcChecksum
-#include "qnearfieldtarget.h"
-
 QT_BEGIN_NAMESPACE
 
 TagBase::TagBase()
@@ -157,7 +154,7 @@ QByteArray NfcTagType1::processCommand(const QByteArray &command)
         QByteArray uid = command.mid(3, 4);
 
         // check checksum
-        if (qNfcChecksum(command.constData(), command.length()) != 0)
+        if (qChecksum(command.constData(), command.length(), Qt::ChecksumItuV41) != 0)
             return QByteArray();
 
         // check UID
@@ -226,7 +223,7 @@ QByteArray NfcTagType1::processCommand(const QByteArray &command)
         QByteArray uid = command.mid(10, 4);
 
         // check checksum
-        if (qNfcChecksum(command.constData(), command.length()) != 0)
+        if (qChecksum(command.constData(), command.length(), Qt::ChecksumItuV41) != 0)
             return QByteArray();
 
         // check UID
@@ -280,7 +277,7 @@ QByteArray NfcTagType1::processCommand(const QByteArray &command)
     }
 
     if (!response.isEmpty()) {
-        quint16 crc = qNfcChecksum(response.constData(), response.length());
+        quint16 crc = qChecksum(response.constData(), response.length(), Qt::ChecksumItuV41);
         response.append(quint8(crc & 0xff));
         response.append(quint8(crc >> 8));
     }
@@ -324,7 +321,7 @@ QByteArray NfcTagType2::processCommand(const QByteArray &command)
     QByteArray response;
 
     // check checksum
-    if (qNfcChecksum(command.constData(), command.length()) != 0)
+    if (qChecksum(command.constData(), command.length(), Qt::ChecksumItuV41) != 0)
         return QByteArray();
 
     if (expectPacket2) {
@@ -381,7 +378,7 @@ QByteArray NfcTagType2::processCommand(const QByteArray &command)
     }
 
     if (!response.isEmpty()) {
-        quint16 crc = qNfcChecksum(response.constData(), response.length());
+        quint16 crc = qChecksum(response.constData(), response.length(), Qt::ChecksumItuV41);
         response.append(quint8(crc & 0xff));
         response.append(quint8(crc >> 8));
     }