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>

src/corelib/io/qdebug.cpp

@@ -46,15 +46,63 @@
 #endif
 
 #include "qdebug.h"
+#include "private/qdebug_p.h"
 #include "qmetaobject.h"
 #include <private/qtextstream_p.h>
 #include <private/qtools_p.h>
+#include <ctype.h>
 
 QT_BEGIN_NAMESPACE
 
 using QtMiscUtils::toHexUpper;
+using QtMiscUtils::toHexLower;
 using QtMiscUtils::fromHex;
 
+/*
+    Returns a human readable representation of the first \a maxSize
+    characters in \a data.
+*/
+QByteArray QtDebugUtils::toPrintable(const char *data, int len, int maxSize)
+{
+    if (!data)
+        return "(null)";
+
+    QByteArray out;
+    for (int i = 0; i < qMin(len, maxSize); ++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: {
+                const char buf[] = {
+                    '\\',
+                    'x',
+                    toHexLower(uchar(c) / 16),
+                    toHexLower(uchar(c) % 16),
+                    0
+                };
+                out += buf;
+            }
+            }
+        }
+    }
+
+    if (maxSize < len)
+        out += "...";
+
+    return out;
+}
+
 // This file is needed to force compilation of QDebug into the kernel library.
 
 /*!

src/corelib/io/qdebug_p.h

@@ -55,11 +55,14 @@
 #include "QtCore/qdebug.h"
 #include "QtCore/qmetaobject.h"
 #include "QtCore/qflags.h"
+#include "QtCore/qbytearray.h"
 
 QT_BEGIN_NAMESPACE
 
 namespace QtDebugUtils {
 
+Q_CORE_EXPORT QByteArray toPrintable(const char *data, int len, int maxSize);
+
 // inline helpers for formatting basic classes.
 
 template <class Point>

src/corelib/io/qprocess.cpp

@@ -41,48 +41,11 @@
 //#define QPROCESS_DEBUG
 
 #include <qdebug.h>
+#include <private/qdebug_p.h>
 #include <qdir.h>
 #include <qscopedvaluerollback.h>
 #if defined(Q_OS_WIN)
 #include <qtimer.h>
-#endif
-#if defined QPROCESS_DEBUG
-#include <qstring.h>
-#include <ctype.h>
-
-QT_BEGIN_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 maxSize)
-{
-    if (!data) return "(null)";
-    QByteArray out;
-    for (int i = 0; i < len && i < maxSize; ++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:
-            char buf[5];
-            qsnprintf(buf, sizeof(buf), "\\%3o", c);
-            buf[4] = '\0';
-            out += QByteArray(buf);
-        }
-    }
-
-    if (len < maxSize)
-        out += "...";
-
-    return out;
-}
-
-QT_END_NAMESPACE
-
 #endif
 
 #include "qprocess.h"
@@ -1940,8 +1903,8 @@ qint64 QProcess::writeData(const char *data, qint64 len)
 
     if (d->stdinChannel.closed) {
 #if defined QPROCESS_DEBUG
-    qDebug("QProcess::writeData(%p \"%s\", %lld) == 0 (write channel closing)",
+        qDebug("QProcess::writeData(%p \"%s\", %lld) == 0 (write channel closing)",
-           data, qt_prettyDebug(data, len, 16).constData(), len);
+               data, QtDebugUtils::toPrintable(data, len, 16).constData(), len);
 #endif
         return 0;
     }
@@ -1965,7 +1928,7 @@ qint64 QProcess::writeData(const char *data, qint64 len)
 #endif
 #if defined QPROCESS_DEBUG
     qDebug("QProcess::writeData(%p \"%s\", %lld) == %lld (written to buffer)",
-           data, qt_prettyDebug(data, len, 16).constData(), len, len);
+           data, QtDebugUtils::toPrintable(data, len, 16).constData(), len, len);
 #endif
     return len;
 }

src/corelib/io/qprocess_unix.cpp

@@ -41,49 +41,7 @@
 
 //#define QPROCESS_DEBUG
 #include "qdebug.h"
-
+#include <private/qdebug_p.h>
-#if QT_CONFIG(process) && defined(QPROCESS_DEBUG)
-#include "private/qtools_p.h"
-#include <ctype.h>
-
-/*
-    Returns a human readable representation of the first \a len
-    characters in \a data.
-*/
-QT_BEGIN_NAMESPACE
-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: {
-            const char buf[] =  {
-                '\\',
-                QtMiscUtils::toOct(uchar(c) / 64),
-                QtMiscUtils::toOct(uchar(c) % 64 / 8),
-                QtMiscUtils::toOct(uchar(c) % 8),
-                0
-            };
-            out += buf;
-            }
-        }
-    }
-
-    if (len < maxSize)
-        out += "...";
-
-    return out;
-}
-QT_END_NAMESPACE
-#endif
-
 #include "qplatformdefs.h"
 
 #include "qprocess.h"
@@ -676,7 +634,7 @@ qint64 QProcessPrivate::readFromChannel(const Channel *channel, char *data, qint
     int save_errno = errno;
     qDebug("QProcessPrivate::readFromChannel(%d, %p \"%s\", %lld) == %lld",
            int(channel - &stdinChannel),
-           data, qt_prettyDebug(data, bytesRead, 16).constData(), maxlen, bytesRead);
+           data, QtDebugUtils::toPrintable(data, bytesRead, 16).constData(), maxlen, bytesRead);
     errno = save_errno;
 #endif
     if (bytesRead == -1 && errno == EWOULDBLOCK)
@@ -691,8 +649,8 @@ bool QProcessPrivate::writeToStdin()
 
     qint64 written = qt_safe_write_nosignal(stdinChannel.pipe[1], data, bytesToWrite);
 #if defined QPROCESS_DEBUG
-    qDebug("QProcessPrivate::writeToStdin(), write(%p \"%s\", %lld) == %lld",
+    qDebug("QProcessPrivate::writeToStdin(), write(%p \"%s\", %lld) == %lld", data,
-           data, qt_prettyDebug(data, bytesToWrite, 16).constData(), bytesToWrite, written);
+           QtDebugUtils::toPrintable(data, bytesToWrite, 16).constData(), bytesToWrite, written);
     if (written == -1)
         qDebug("QProcessPrivate::writeToStdin(), failed to write (%ls)", qUtf16Printable(qt_error_string(errno)));
 #endif

src/corelib/serialization/qtextstream.cpp

@@ -230,6 +230,7 @@ static const int QTEXTSTREAM_BUFFERSIZE = 16384;
 #include "qfile.h"
 #include "qnumeric.h"
 #include "qvarlengtharray.h"
+#include <private/qdebug_p.h>
 
 #include <locale.h>
 #include "private/qlocale_p.h"
@@ -239,48 +240,6 @@ static const int QTEXTSTREAM_BUFFERSIZE = 16384;
 #include <limits.h>
 #include <new>
 
-#if defined QTEXTSTREAM_DEBUG
-#include <ctype.h>
-#include "private/qtools_p.h"
-
-QT_BEGIN_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 maxSize)
-{
-    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: {
-            const char buf[] = {
-                '\\',
-                'x',
-                QtMiscUtils::toHexLower(uchar(c) / 16),
-                QtMiscUtils::toHexLower(uchar(c) % 16),
-                0
-            };
-            out += buf;
-            }
-        }
-    }
-
-    if (len < maxSize)
-        out += "...";
-
-    return out;
-}
-QT_END_NAMESPACE
-
-#endif
-
 // A precondition macro
 #define Q_VOID
 #define CHECK_VALID_STREAM(x) do { \
@@ -448,7 +407,7 @@ bool QTextStreamPrivate::fillReadBuffer(qint64 maxBytes)
 
 #if defined (QTEXTSTREAM_DEBUG)
     qDebug("QTextStreamPrivate::fillReadBuffer(), device->read(\"%s\", %d) == %d",
-           qt_prettyDebug(buf, qMin(32,int(bytesRead)) , int(bytesRead)).constData(), int(sizeof(buf)), int(bytesRead));
+           QtDebugUtils::toPrintable(buf, bytesRead, 32).constData(), int(sizeof(buf)), int(bytesRead));
 #endif
 
     int oldReadBufferSize = readBuffer.size();
@@ -486,7 +445,7 @@ bool QTextStreamPrivate::fillReadBuffer(qint64 maxBytes)
 
 #if defined (QTEXTSTREAM_DEBUG)
     qDebug("QTextStreamPrivate::fillReadBuffer() read %d bytes from device. readBuffer = [%s]", int(bytesRead),
-           qt_prettyDebug(readBuffer.toLatin1(), readBuffer.size(), readBuffer.size()).data());
+           QtDebugUtils::toPrintable(readBuffer.toLatin1(), readBuffer.size(), readBuffer.size()).constData());
 #endif
     return true;
 }
@@ -536,7 +495,7 @@ void QTextStreamPrivate::flushWriteBuffer()
     qint64 bytesWritten = device->write(data);
 #if defined (QTEXTSTREAM_DEBUG)
     qDebug("QTextStreamPrivate::flushWriteBuffer(), device->write(\"%s\") == %d",
-           qt_prettyDebug(data.constData(), qMin(data.size(),32), data.size()).constData(), int(bytesWritten));
+           QtDebugUtils::toPrintable(data.constData(), data.size(), 32).constData(), int(bytesWritten));
 #endif
 
 #if defined (Q_OS_WIN)

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]",
+    qDebug("QAbstractSocket::readData(%p \"%s\", %lli) == %lld [engine]", data,
-           data, qt_prettyDebug(data, 32, readBytes).data(), maxSize,
+           QtDebugUtils::toPrintable(data, readBytes, 32).constData(), maxSize, readBytes);
-           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(),
+               QtDebugUtils::toPrintable(data, size, 32).constData(), size, written);
-               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(),
+           QtDebugUtils::toPrintable(data, size, 32).constData(), size, written);
-           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(),
+           QtDebugUtils::toPrintable(data, size, 32).constData(), size, written);
-           size, written);
 #endif
     return written;
 }

src/network/socket/qnativesocketengine_unix.cpp

@@ -63,8 +63,7 @@
 #endif
 
 #if defined QNATIVESOCKETENGINE_DEBUG
-#include <qstring.h>
+#include <private/qdebug_p.h>
-#include <ctype.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",
+    qDebug("QNativeSocketEnginePrivate::nativeWrite(%p \"%s\", %llu) == %i", data,
-           data, qt_prettyDebug(data, qMin((int) len, 16),
+           QtDebugUtils::toPrintable(data, len, 16).constData(), len, (int) writtenBytes);
-                                (int) len).data(), 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",
+    qDebug("QNativeSocketEnginePrivate::nativeRead(%p \"%s\", %llu) == %zd", data,
-           data, qt_prettyDebug(data, qMin(r, ssize_t(16)), r).data(),
+           QtDebugUtils::toPrintable(data, r, 16).constData(), maxSize, r);
-           maxSize, r);
 #endif
 
     return qint64(r);

src/network/socket/qnativesocketengine_win.cpp

@@ -57,8 +57,7 @@
 
 //#define QNATIVESOCKETENGINE_DEBUG
 #if defined(QNATIVESOCKETENGINE_DEBUG)
-#   include <qstring.h>
+#include <private/qdebug_p.h>
-#   include <qbytearray.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,
+    qDebug("QNativeSocketEnginePrivate::nativeSendDatagram(%p \"%s\", %lli, \"%s\", %i) == %lli",
-           qt_prettyDebug(data, qMin<qint64>(len, 16), len).data(), len,
+           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",
+        qDebug("QNativeSocketEnginePrivate::nativeRead(%p \"%s\", %lli) == %lli", data,
-               data, qt_prettyDebug(data, qMin(int(bytesRead), 16), int(bytesRead)).data(), maxLength, ret);
+               QtDebugUtils::toPrintable(data, bytesRead, 16).constData(), maxLength, ret);
     } else {
         qDebug("QNativeSocketEnginePrivate::nativeRead(%p, %lli) == -2 (WOULD BLOCK)",
                data, maxLength);