Consolidate debug string generation

Several QIODevice subclasses use the qt_prettyDebug() function to get
a printable representation of the buffer data for debug output.

Rather than having this feature statically implemented in each
respective file, this patch introduces a generic function in the
QtDebugUtils namespace. Accordingly, some inaccuracies in the
use-cases have been corrected.

Change-Id: I1a8465cab08c8acf5fdcdba5085182511b1cbb7b
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>

3 files changed, 20 insertions, 125 deletions

diff --git a/src/network/socket/qabstractsocket.cpp b/src/network/socket/qabstractsocket.cpp
index 16819404f4..56ffb678e4 100644
--- a/src/network/socket/qabstractsocket.cpp
+++ b/src/network/socket/qabstractsocket.cpp
@@ -483,6 +483,7 @@
 
 #ifdef QABSTRACTSOCKET_DEBUG
 #include <qdebug.h>
+#include <private/qdebug_p.h>
 #endif
 
 #include <time.h>
@@ -501,42 +502,6 @@ QT_BEGIN_NAMESPACE
 
 static const int DefaultConnectTimeout = 30000;
 
-#if defined QABSTRACTSOCKET_DEBUG
-QT_BEGIN_INCLUDE_NAMESPACE
-#include <qstring.h>
-#include <ctype.h>
-QT_END_INCLUDE_NAMESPACE
-
-/*
-    Returns a human readable representation of the first \a len
-    characters in \a data.
-*/
-static QByteArray qt_prettyDebug(const char *data, int len, int maxLength)
-{
-    if (!data) return "(null)";
-    QByteArray out;
-    for (int i = 0; i < qMin(len, maxLength); ++i) {
-        char c = data[i];
-        if (isprint(int(uchar(c)))) {
-            out += c;
-        } else switch (c) {
-        case '\n': out += "\\n"; break;
-        case '\r': out += "\\r"; break;
-        case '\t': out += "\\t"; break;
-        default:
-            QString tmp;
-            tmp.sprintf("\\%o", c);
-            out += tmp.toLatin1();
-        }
-    }
-
-    if (len < maxLength)
-        out += "...";
-
-    return out;
-}
-#endif
-
 static bool isProxyError(QAbstractSocket::SocketError error)
 {
     switch (error) {
@@ -2459,9 +2424,8 @@ qint64 QAbstractSocket::readData(char *data, qint64 maxSize)
     }
 
 #if defined (QABSTRACTSOCKET_DEBUG)
-    qDebug("QAbstractSocket::readData(%p \"%s\", %lli) == %lld [engine]",
-           data, qt_prettyDebug(data, 32, readBytes).data(), maxSize,
-           readBytes);
+    qDebug("QAbstractSocket::readData(%p \"%s\", %lli) == %lld [engine]", data,
+           QtDebugUtils::toPrintable(data, readBytes, 32).constData(), maxSize, readBytes);
 #endif
     return readBytes;
 }
@@ -2499,8 +2463,7 @@ qint64 QAbstractSocket::writeData(const char *data, qint64 size)
 
 #if defined (QABSTRACTSOCKET_DEBUG)
         qDebug("QAbstractSocket::writeData(%p \"%s\", %lli) == %lli", data,
-               qt_prettyDebug(data, qMin((int)size, 32), size).data(),
-               size, written);
+               QtDebugUtils::toPrintable(data, size, 32).constData(), size, written);
 #endif
         return written; // written = actually written + what has been buffered
     } else if (!d->isBuffered && d->socketType != TcpSocket) {
@@ -2511,8 +2474,7 @@ qint64 QAbstractSocket::writeData(const char *data, qint64 size)
 
 #if defined (QABSTRACTSOCKET_DEBUG)
     qDebug("QAbstractSocket::writeData(%p \"%s\", %lli) == %lli", data,
-           qt_prettyDebug(data, qMin((int)size, 32), size).data(),
-           size, written);
+           QtDebugUtils::toPrintable(data, size, 32).constData(), size, written);
 #endif
         if (written >= 0)
             d->emitBytesWritten(written);
@@ -2533,8 +2495,7 @@ qint64 QAbstractSocket::writeData(const char *data, qint64 size)
 
 #if defined (QABSTRACTSOCKET_DEBUG)
     qDebug("QAbstractSocket::writeData(%p \"%s\", %lli) == %lli", data,
-           qt_prettyDebug(data, qMin((int)size, 32), size).data(),
-           size, written);
+           QtDebugUtils::toPrintable(data, size, 32).constData(), size, written);
 #endif
     return written;
 }
diff --git a/src/network/socket/qnativesocketengine_unix.cpp b/src/network/socket/qnativesocketengine_unix.cpp
index 09d16fa908..e6704a3ca4 100644
--- a/src/network/socket/qnativesocketengine_unix.cpp
+++ b/src/network/socket/qnativesocketengine_unix.cpp
@@ -63,8 +63,7 @@
 #endif
 
 #if defined QNATIVESOCKETENGINE_DEBUG
-#include <qstring.h>
-#include <ctype.h>
+#include <private/qdebug_p.h>
 #endif
 
 #include <netinet/tcp.h>
@@ -76,38 +75,6 @@
 
 QT_BEGIN_NAMESPACE
 
-#if defined QNATIVESOCKETENGINE_DEBUG
-
-/*
-    Returns a human readable representation of the first \a len
-    characters in \a data.
-*/
-static QByteArray qt_prettyDebug(const char *data, int len, int maxSize)
-{
-    if (!data) return "(null)";
-    QByteArray out;
-    for (int i = 0; i < len; ++i) {
-        char c = data[i];
-        if (isprint(c)) {
-            out += c;
-        } else switch (c) {
-        case '\n': out += "\\n"; break;
-        case '\r': out += "\\r"; break;
-        case '\t': out += "\\t"; break;
-        default:
-            QString tmp;
-            tmp.sprintf("\\%o", c);
-            out += tmp.toLatin1();
-        }
-    }
-
-    if (len < maxSize)
-        out += "...";
-
-    return out;
-}
-#endif
-
 /*
     Extracts the port and address from a sockaddr, and stores them in
     \a port and \a addr if they are non-null.
@@ -1063,7 +1030,7 @@ qint64 QNativeSocketEnginePrivate::nativeReceiveDatagram(char *data, qint64 maxS
 
 #if defined (QNATIVESOCKETENGINE_DEBUG)
     qDebug("QNativeSocketEnginePrivate::nativeReceiveDatagram(%p \"%s\", %lli, %s, %i) == %lli",
-           data, qt_prettyDebug(data, qMin(recvResult, ssize_t(16)), recvResult).data(), maxSize,
+           data, QtDebugUtils::toPrintable(data, recvResult, 16).constData(), maxSize,
            (recvResult != -1 && options != QAbstractSocketEngine::WantNone)
            ? header->senderAddress.toString().toLatin1().constData() : "(unknown)",
            (recvResult != -1 && options != QAbstractSocketEngine::WantNone)
@@ -1192,7 +1159,7 @@ qint64 QNativeSocketEnginePrivate::nativeSendDatagram(const char *data, qint64 l
 
 #if defined (QNATIVESOCKETENGINE_DEBUG)
     qDebug("QNativeSocketEngine::sendDatagram(%p \"%s\", %lli, \"%s\", %i) == %lli", data,
-           qt_prettyDebug(data, qMin<int>(len, 16), len).data(), len,
+           QtDebugUtils::toPrintable(data, len, 16).constData(), len,
            header.destinationAddress.toString().toLatin1().constData(),
            header.destinationPort, (qint64) sentBytes);
 #endif
@@ -1358,9 +1325,8 @@ qint64 QNativeSocketEnginePrivate::nativeWrite(const char *data, qint64 len)
     }
 
 #if defined (QNATIVESOCKETENGINE_DEBUG)
-    qDebug("QNativeSocketEnginePrivate::nativeWrite(%p \"%s\", %llu) == %i",
-           data, qt_prettyDebug(data, qMin((int) len, 16),
-                                (int) len).data(), len, (int) writtenBytes);
+    qDebug("QNativeSocketEnginePrivate::nativeWrite(%p \"%s\", %llu) == %i", data,
+           QtDebugUtils::toPrintable(data, len, 16).constData(), len, (int) writtenBytes);
 #endif
 
     return qint64(writtenBytes);
@@ -1409,9 +1375,8 @@ qint64 QNativeSocketEnginePrivate::nativeRead(char *data, qint64 maxSize)
     }
 
 #if defined (QNATIVESOCKETENGINE_DEBUG)
-    qDebug("QNativeSocketEnginePrivate::nativeRead(%p \"%s\", %llu) == %zd",
-           data, qt_prettyDebug(data, qMin(r, ssize_t(16)), r).data(),
-           maxSize, r);
+    qDebug("QNativeSocketEnginePrivate::nativeRead(%p \"%s\", %llu) == %zd", data,
+           QtDebugUtils::toPrintable(data, r, 16).constData(), maxSize, r);
 #endif
 
     return qint64(r);
diff --git a/src/network/socket/qnativesocketengine_win.cpp b/src/network/socket/qnativesocketengine_win.cpp
index ac4e725af0..7b5e674fbb 100644
--- a/src/network/socket/qnativesocketengine_win.cpp
+++ b/src/network/socket/qnativesocketengine_win.cpp
@@ -57,8 +57,7 @@
 
 //#define QNATIVESOCKETENGINE_DEBUG
 #if defined(QNATIVESOCKETENGINE_DEBUG)
-#   include <qstring.h>
-#   include <qbytearray.h>
+#include <private/qdebug_p.h>
 #endif
 
 QT_BEGIN_NAMESPACE
@@ -127,36 +126,6 @@ void verboseWSErrorDebug(int r)
     qErrnoWarning(r, "more details");
 }
 
-/*
-    Returns a human readable representation of the first \a len
-    characters in \a data.
-*/
-static QByteArray qt_prettyDebug(const char *data, int len, int maxLength)
-{
-    if (!data) return "(null)";
-    QByteArray out;
-    for (int i = 0; i < len; ++i) {
-        char c = data[i];
-        if (isprint(int(uchar(c)))) {
-            out += c;
-        } else switch (c) {
-        case '\n': out += "\\n"; break;
-        case '\r': out += "\\r"; break;
-        case '\t': out += "\\t"; break;
-        default:
-            QString tmp;
-            tmp.sprintf("\\%o", c);
-            out += tmp.toLatin1().constData();
-        }
-    }
-
-    if (len < maxLength)
-        out += "...";
-
-    return out;
-}
-
-
 #define WS_ERROR_DEBUG(x) verboseWSErrorDebug(x)
 
 #else
@@ -1279,7 +1248,7 @@ qint64 QNativeSocketEnginePrivate::nativeReceiveDatagram(char *data, qint64 maxL
 #if defined (QNATIVESOCKETENGINE_DEBUG)
     bool printSender = (ret != -1 && (options & QNativeSocketEngine::WantDatagramSender) != 0);
     qDebug("QNativeSocketEnginePrivate::nativeReceiveDatagram(%p \"%s\", %lli, %s, %i) == %lli",
-           data, qt_prettyDebug(data, qMin<qint64>(ret, 16), ret).data(), maxLength,
+           data, QtDebugUtils::toPrintable(data, ret, 16).constData(), maxLength,
            printSender ? header->senderAddress.toString().toLatin1().constData() : "(unknown)",
            printSender ? header->senderPort : 0, ret);
 #endif
@@ -1412,8 +1381,8 @@ qint64 QNativeSocketEnginePrivate::nativeSendDatagram(const char *data, qint64 l
     }
 
 #if defined (QNATIVESOCKETENGINE_DEBUG)
-    qDebug("QNativeSocketEnginePrivate::nativeSendDatagram(%p \"%s\", %lli, \"%s\", %i) == %lli", data,
-           qt_prettyDebug(data, qMin<qint64>(len, 16), len).data(), len,
+    qDebug("QNativeSocketEnginePrivate::nativeSendDatagram(%p \"%s\", %lli, \"%s\", %i) == %lli",
+           data, QtDebugUtils::toPrintable(data, len, 16).constData(), len,
            header.destinationAddress.toString().toLatin1().constData(),
            header.destinationPort, ret);
 #endif
@@ -1472,7 +1441,7 @@ qint64 QNativeSocketEnginePrivate::nativeWrite(const char *data, qint64 len)
 
 #if defined (QNATIVESOCKETENGINE_DEBUG)
     qDebug("QNativeSocketEnginePrivate::nativeWrite(%p \"%s\", %lli) == %lli",
-           data, qt_prettyDebug(data, qMin(int(ret), 16), int(ret)).data(), len, ret);
+           data, QtDebugUtils::toPrintable(data, ret, 16).constData(), len, ret);
 #endif
 
     return ret;
@@ -1514,8 +1483,8 @@ qint64 QNativeSocketEnginePrivate::nativeRead(char *data, qint64 maxLength)
 
 #if defined (QNATIVESOCKETENGINE_DEBUG)
     if (ret != -2) {
-        qDebug("QNativeSocketEnginePrivate::nativeRead(%p \"%s\", %lli) == %lli",
-               data, qt_prettyDebug(data, qMin(int(bytesRead), 16), int(bytesRead)).data(), maxLength, ret);
+        qDebug("QNativeSocketEnginePrivate::nativeRead(%p \"%s\", %lli) == %lli", data,
+               QtDebugUtils::toPrintable(data, bytesRead, 16).constData(), maxLength, ret);
     } else {
         qDebug("QNativeSocketEnginePrivate::nativeRead(%p, %lli) == -2 (WOULD BLOCK)",
                data, maxLength);