QUuid: add a trivial structure to support exactly 128 bits

This is inspired by QBluetoothUuid's quint128, but with a better
name. It also matches systemd's sd_id128.

Change-Id: Id8e48e8f498c4a029619fffd172893dc1545adda
Reviewed-by: Ivan Solovev <ivan.solovev@qt.io>

1 files changed, 43 insertions, 1 deletions

diff --git a/src/corelib/plugin/quuid.h b/src/corelib/plugin/quuid.h
index bcd78d85e7..21833efe03 100644
--- a/src/corelib/plugin/quuid.h
+++ b/src/corelib/plugin/quuid.h
@@ -4,6 +4,7 @@
 #ifndef QUUID_H
 #define QUUID_H
 
+#include <QtCore/qendian.h>
 #include <QtCore/qstring.h>
 
 #if defined(Q_OS_WIN) || defined(Q_QDOC)
@@ -26,7 +27,6 @@ Q_FORWARD_DECLARE_OBJC_CLASS(NSUUID);
 
 QT_BEGIN_NAMESPACE
 
-
 class Q_CORE_EXPORT QUuid
 {
     QUuid(Qt::Initialization) {}
@@ -55,11 +55,24 @@ public:
         Id128           = 3
     };
 
+    union Id128Bytes {
+        quint8 data[16];
+        quint16 data16[8];
+        quint32 data32[4];
+        quint64 data64[2];
+
+        constexpr explicit operator QByteArrayView() const noexcept
+        {
+            return QByteArrayView(data, sizeof(data));
+        }
+    };
+
     constexpr QUuid() noexcept {}
 
     constexpr QUuid(uint l, ushort w1, ushort w2, uchar b1, uchar b2, uchar b3,
                            uchar b4, uchar b5, uchar b6, uchar b7, uchar b8) noexcept
         : data1(l), data2(w1), data3(w2), data4{b1, b2, b3, b4, b5, b6, b7, b8} {}
+    QUuid(Id128Bytes id128) noexcept;
 
     explicit QUuid(QAnyStringView string) noexcept
         : QUuid{fromString(string)} {}
@@ -73,11 +86,15 @@ public:
 #endif
     QString toString(StringFormat mode = WithBraces) const;
     QByteArray toByteArray(StringFormat mode = WithBraces) const;
+    Id128Bytes toBytes() const noexcept;
     QByteArray toRfc4122() const;
+
+    static QUuid fromBytes(const void *bytes) noexcept;
 #if QT_CORE_REMOVED_SINCE(6, 3)
     static QUuid fromRfc4122(const QByteArray &);
 #endif
     static QUuid fromRfc4122(QByteArrayView) noexcept;
+
     bool isNull() const noexcept;
 
     constexpr bool operator==(const QUuid &orig) const noexcept
@@ -177,6 +194,31 @@ Q_CORE_EXPORT QDebug operator<<(QDebug, const QUuid &);
 
 Q_CORE_EXPORT size_t qHash(const QUuid &uuid, size_t seed = 0) noexcept;
 
+inline QUuid::QUuid(Id128Bytes uuid) noexcept
+{
+    data1 = qFromBigEndian<quint32>(&uuid.data[0]);
+    data2 = qFromBigEndian<quint16>(&uuid.data[4]);
+    data3 = qFromBigEndian<quint16>(&uuid.data[6]);
+    memcpy(data4, &uuid.data[8], sizeof(data4));
+}
+
+inline QUuid::Id128Bytes QUuid::toBytes() const noexcept
+{
+    Id128Bytes result = {};
+    qToBigEndian(data1, &result.data[0]);
+    qToBigEndian(data2, &result.data[4]);
+    qToBigEndian(data3, &result.data[6]);
+    memcpy(&result.data[8], data4, sizeof(data4));
+    return result;
+}
+
+inline QUuid QUuid::fromBytes(const void *bytes) noexcept
+{
+    Id128Bytes result = {};
+    memcpy(result.data, bytes, sizeof(result));
+    return QUuid(result);
+}
+
 inline bool operator<=(const QUuid &lhs, const QUuid &rhs) noexcept
 { return !(rhs < lhs); }
 inline bool operator>=(const QUuid &lhs, const QUuid &rhs) noexcept