QUuid: add a way to get the string form without the braces

While we're at it, add a way to get it without the dashes too. I'm
calling it "id128", as in "128-bit ID", as seen in journald's sd_id128_t
type and the sd_id128_xxx() API.

[ChangeLog][QtCore][QUuid] Added a parameter to both toString() and
toByteArray() to allow controlling the use or not of the braces and
dashes in the string form.

Change-Id: I56b444f9d6274221a3b7fffd150cde706cfc5098
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
Reviewed-by: Olivier Goffart (Woboq GmbH) <ogoffart@woboq.com>

2 files changed, 121 insertions, 7 deletions

diff --git a/src/corelib/plugin/quuid.cpp b/src/corelib/plugin/quuid.cpp
index 3a1c0495fe..4d658e064c 100644
--- a/src/corelib/plugin/quuid.cpp
+++ b/src/corelib/plugin/quuid.cpp
@@ -83,21 +83,27 @@ bool _q_fromHex(const char *&src, Integral &value)
     return true;
 }
 
-static char *_q_uuidToHex(const QUuid &uuid, char *dst)
+static char *_q_uuidToHex(const QUuid &uuid, char *dst, QUuid::StringFormat mode = QUuid::WithBraces)
 {
-    *dst++ = '{';
+    if ((mode & QUuid::WithoutBraces) == 0)
+        *dst++ = '{';
     _q_toHex(dst, uuid.data1);
-    *dst++ = '-';
+    if ((mode & QUuid::Id128) != QUuid::Id128)
+        *dst++ = '-';
     _q_toHex(dst, uuid.data2);
-    *dst++ = '-';
+    if ((mode & QUuid::Id128) != QUuid::Id128)
+        *dst++ = '-';
     _q_toHex(dst, uuid.data3);
-    *dst++ = '-';
+    if ((mode & QUuid::Id128) != QUuid::Id128)
+        *dst++ = '-';
     for (int i = 0; i < 2; i++)
         _q_toHex(dst, uuid.data4[i]);
-    *dst++ = '-';
+    if ((mode & QUuid::Id128) != QUuid::Id128)
+        *dst++ = '-';
     for (int i = 2; i < 8; i++)
         _q_toHex(dst, uuid.data4[i]);
-    *dst++ = '}';
+    if ((mode & QUuid::WithoutBraces) == 0)
+        *dst++ = '}';
     return dst;
 }
 
@@ -307,6 +313,22 @@ static QUuid createFromName(const QUuid &ns, const QByteArray &baseData, QCrypto
 */
 
 /*!
+    \enum QUuid::StringFormat
+    \since 5.11
+
+    This enum is used by toString(StringFormat) to control the formatting of the
+    string representation. The possible values are:
+
+    \value WithBraces       The default, toString() will return five hex fields, separated by
+                            dashes and surrounded by braces. Example:
+                            {00000000-0000-0000-0000-000000000000}.
+    \value WithoutBraces    Only the five dash-separated fields, without the braces. Example:
+                            00000000-0000-0000-0000-000000000000.
+    \value Id128            Only the hex digits, without braces or dashes. Note that QUuid
+                            cannot parse this back again as input.
+*/
+
+/*!
     \fn QUuid::QUuid(const GUID &guid)
 
     Casts a Windows \a guid to a Qt QUuid.
@@ -592,6 +614,47 @@ QString QUuid::toString() const
 }
 
 /*!
+    \since 5.11
+
+    Returns the string representation of this QUuid, with the formattiong
+    controlled by the \a mode parameter. From left to right, the five hex
+    fields are obtained from the four public data members in QUuid as follows:
+
+    \table
+    \header
+    \li Field #
+    \li Source
+
+    \row
+    \li 1
+    \li data1
+
+    \row
+    \li 2
+    \li data2
+
+    \row
+    \li 3
+    \li data3
+
+    \row
+    \li 4
+    \li data4[0] .. data4[1]
+
+    \row
+    \li 5
+    \li data4[2] .. data4[7]
+
+    \endtable
+*/
+QString QUuid::toString(QUuid::StringFormat mode) const
+{
+    char latin1[MaxStringUuidLength];
+    const auto end = _q_uuidToHex(*this, latin1, mode);
+    return QString::fromLatin1(latin1, end - latin1);
+}
+
+/*!
     Returns the binary representation of this QUuid. The byte array is
     formatted as five hex fields separated by '-' and enclosed in
     curly braces, i.e., "{xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}" where
@@ -637,6 +700,48 @@ QByteArray QUuid::toByteArray() const
 }
 
 /*!
+    \since 5.11
+
+    Returns the string representation of this QUuid, with the formattiong
+    controlled by the \a mode parameter. From left to right, the five hex
+    fields are obtained from the four public data members in QUuid as follows:
+
+    \table
+    \header
+    \li Field #
+    \li Source
+
+    \row
+    \li 1
+    \li data1
+
+    \row
+    \li 2
+    \li data2
+
+    \row
+    \li 3
+    \li data3
+
+    \row
+    \li 4
+    \li data4[0] .. data4[1]
+
+    \row
+    \li 5
+    \li data4[2] .. data4[7]
+
+    \endtable
+*/
+QByteArray QUuid::toByteArray(QUuid::StringFormat mode) const
+{
+    QByteArray result(MaxStringUuidLength, Qt::Uninitialized);
+    const auto end = _q_uuidToHex(*this, const_cast<char*>(result.constData()), mode);
+    result.resize(end - result.constData());
+    return result;
+}
+
+/*!
     Returns the binary representation of this QUuid. The byte array is in big
     endian format, and formatted according to RFC 4122, section 4.1.2 -
     "Layout and byte order".
diff --git a/src/corelib/plugin/quuid.h b/src/corelib/plugin/quuid.h
index ee0a9f9dac..27a84b4e01 100644
--- a/src/corelib/plugin/quuid.h
+++ b/src/corelib/plugin/quuid.h
@@ -85,7 +85,14 @@ public:
         Sha1                 = 5 // 0 1 0 1
     };
 
+    enum StringFormat {
+        WithBraces      = 0,
+        WithoutBraces   = 1,
+        Id128           = 3
+    };
+
 #if defined(Q_COMPILER_UNIFORM_INIT) && !defined(Q_CLANG_QDOC)
+
     Q_DECL_CONSTEXPR QUuid() Q_DECL_NOTHROW : data1(0), data2(0), data3(0), data4{0,0,0,0,0,0,0,0} {}
 
     Q_DECL_CONSTEXPR QUuid(uint l, ushort w1, ushort w2, uchar b1, uchar b2, uchar b3,
@@ -121,8 +128,10 @@ public:
     static QUuid fromString(QLatin1String string) Q_DECL_NOTHROW;
     QUuid(const char *);
     QString toString() const;
+    QString toString(StringFormat mode) const; // ### Qt6: merge with previous
     QUuid(const QByteArray &);
     QByteArray toByteArray() const;
+    QByteArray toByteArray(StringFormat mode) const; // ### Qt6: merge with previous
     QByteArray toRfc4122() const;
     static QUuid fromRfc4122(const QByteArray &);
     bool isNull() const Q_DECL_NOTHROW;