Add isValidUtf8() methods to QUtf8StringView and QByteArray{,View}

The new methods return true if the string contains valid UTF-8
encoded data, or false otherwise.

[ChangeLog][QtCore][QByteArray] Added isValidUtf8() method.

[ChangeLog][QtCore][QByteArrayView] Added isValidUtf8() method.

[ChangeLog][QtCore][QUtf8StringView] Added isValidUtf8() method.

Task-number: QTBUG-92021
Change-Id: I5d0cb613265d98b1f189c5f5cc09c1f7db302272
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>

7 files changed, 50 insertions, 0 deletions

diff --git a/src/corelib/text/qbytearray.cpp b/src/corelib/text/qbytearray.cpp
index a1b0f30d01..8a7db6ebe4 100644
--- a/src/corelib/text/qbytearray.cpp
+++ b/src/corelib/text/qbytearray.cpp
@@ -51,6 +51,7 @@
 #include "qstringalgorithms_p.h"
 #include "qscopedpointer.h"
 #include "qbytearray_p.h"
+#include "qstringconverter_p.h"
 #include <qdatastream.h>
 #include <qmath.h>
 
@@ -426,6 +427,14 @@ int QtPrivate::compareMemory(QByteArrayView lhs, QByteArrayView rhs)
     return lhs.size() == rhs.size() ? 0 : lhs.size() > rhs.size() ? 1 : -1;
 }
 
+/*!
+    \internal
+*/
+bool QtPrivate::isValidUtf8(QByteArrayView s) noexcept
+{
+    return QUtf8::isValidUtf8(s).isValidUtf8;
+}
+
 // the CRC table below is created by the following piece of code
 #if 0
 static void createCRC16Table()                        // build CRC16 lookup table
@@ -2784,6 +2793,15 @@ bool QByteArray::isLower() const
 }
 
 /*!
+    \fn QByteArray::isValidUtf8() const
+
+    Returns \c true if this byte array contains valid UTF-8 encoded data,
+    or \c false otherwise.
+
+    \since 6.3
+*/
+
+/*!
     Returns a byte array that contains the first \a len bytes of this byte
     array.
 
diff --git a/src/corelib/text/qbytearray.h b/src/corelib/text/qbytearray.h
index 4f29018f32..0a604f1594 100644
--- a/src/corelib/text/qbytearray.h
+++ b/src/corelib/text/qbytearray.h
@@ -200,6 +200,11 @@ public:
     bool isUpper() const;
     bool isLower() const;
 
+    [[nodiscard]] bool isValidUtf8() const noexcept
+    {
+        return QtPrivate::isValidUtf8(qToByteArrayViewIgnoringNull(*this));
+    }
+
     void truncate(qsizetype pos);
     void chop(qsizetype n);
 
diff --git a/src/corelib/text/qbytearrayalgorithms.h b/src/corelib/text/qbytearrayalgorithms.h
index a78e6e1709..b669f065b9 100644
--- a/src/corelib/text/qbytearrayalgorithms.h
+++ b/src/corelib/text/qbytearrayalgorithms.h
@@ -74,6 +74,8 @@ qsizetype count(QByteArrayView haystack, QByteArrayView needle) noexcept;
 
 [[nodiscard]] Q_CORE_EXPORT Q_DECL_PURE_FUNCTION QByteArrayView trimmed(QByteArrayView s) noexcept;
 
+[[nodiscard]] Q_CORE_EXPORT Q_DECL_PURE_FUNCTION bool isValidUtf8(QByteArrayView s) noexcept;
+
 } // namespace QtPrivate
 
 /*****************************************************************************
diff --git a/src/corelib/text/qbytearrayview.h b/src/corelib/text/qbytearrayview.h
index 1cd5b0333e..11db03c62f 100644
--- a/src/corelib/text/qbytearrayview.h
+++ b/src/corelib/text/qbytearrayview.h
@@ -288,6 +288,8 @@ public:
 
     inline int compare(QByteArrayView a, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept;
 
+    [[nodiscard]] inline bool isValidUtf8() const noexcept { return QtPrivate::isValidUtf8(*this); }
+
     //
     // STL compatibility API:
     //
diff --git a/src/corelib/text/qbytearrayview.qdoc b/src/corelib/text/qbytearrayview.qdoc
index 624b056744..96bb1ccb56 100644
--- a/src/corelib/text/qbytearrayview.qdoc
+++ b/src/corelib/text/qbytearrayview.qdoc
@@ -377,6 +377,15 @@
 */
 
 /*!
+    \fn QByteArrayView::isValidUtf8() const
+
+    Returns \c true if this byte array view contains valid UTF-8 encoded data,
+    or \c false otherwise.
+
+    \since 6.3
+*/
+
+/*!
     \fn QByteArrayView::const_iterator QByteArrayView::begin() const
 
     Returns a const \l{STL-style iterators}{STL-style iterator} pointing to the
diff --git a/src/corelib/text/qutf8stringview.h b/src/corelib/text/qutf8stringview.h
index eeab604fa8..a6930c2e0f 100644
--- a/src/corelib/text/qutf8stringview.h
+++ b/src/corelib/text/qutf8stringview.h
@@ -285,6 +285,11 @@ public:
     constexpr void chop(qsizetype n)
     { verify(n); m_size -= n; }
 
+    [[nodiscard]] inline bool isValidUtf8() const noexcept
+    {
+        return QByteArrayView(reinterpret_cast<const char *>(data()), size()).isValidUtf8();
+    }
+
     //
     // STL compatibility API:
     //
diff --git a/src/corelib/text/qutf8stringview.qdoc b/src/corelib/text/qutf8stringview.qdoc
index 683af4e423..deac0882fe 100644
--- a/src/corelib/text/qutf8stringview.qdoc
+++ b/src/corelib/text/qutf8stringview.qdoc
@@ -679,6 +679,15 @@
 */
 
 /*!
+    \fn QUtf8StringView::isValidUtf8() const
+
+    Returns \c true if this string contains valid UTF-8 encoded data,
+    or \c false otherwise.
+
+    \since 6.3
+*/
+
+/*!
     \fn template <typename QStringLike> qToUtf8StringViewIgnoringNull(const QStringLike &s);
     \relates QUtf8StringView
     \internal