rhi: Move to CBOR in QShader and expand the autotest

Binary JSON is said to become deprecated. Therefore, add support
for CBOR. Binary JSON is still supported for deserialization, so
all existing .qsb files will continue to work, as long as the
binaryjson feature is enabled in the Qt build.

Also makes QShaderDescription comparable. This is important for
tests in particular.

A nice side effect of using CBOR is that .qsb files become smaller.
For a typical Qt Quick material shader this can mean a reduction of
300 bytes or more.

Task-number: QTBUG-79576
Change-Id: I5547c0266e3e8128c9653e954e47487352267f71
Reviewed-by: Paul Olav Tvete <paul.tvete@qt.io>

4 files changed, 209 insertions, 12 deletions

diff --git a/src/gui/rhi/qshader.cpp b/src/gui/rhi/qshader.cpp
index c22b029dc8..14d780b4e4 100644
--- a/src/gui/rhi/qshader.cpp
+++ b/src/gui/rhi/qshader.cpp
@@ -214,9 +214,6 @@ QT_BEGIN_NAMESPACE
     QShader, it indicates no shader code was found for the requested key.
  */
 
-static const int QSB_VERSION = 2;
-static const int QSB_VERSION_WITHOUT_BINDINGS = 1;
-
 /*!
     Constructs a new, empty (and thus invalid) QShader instance.
  */
@@ -368,9 +365,9 @@ QByteArray QShader::serialized() const
     if (!buf.open(QIODevice::WriteOnly))
         return QByteArray();
 
-    ds << QSB_VERSION;
+    ds << QShaderPrivate::QSB_VERSION;
     ds << d->stage;
-    ds << d->desc.toBinaryJson();
+    ds << d->desc.toCbor();
     ds << d->shaders.count();
     for (auto it = d->shaders.cbegin(), itEnd = d->shaders.cend(); it != itEnd; ++it) {
         const QShaderKey &k(it.key());
@@ -429,9 +426,12 @@ QShader QShader::fromSerialized(const QByteArray &data)
     Q_ASSERT(d->ref.loadRelaxed() == 1); // must be detached
     int intVal;
     ds >> intVal;
-    const int qsbVersion = intVal;
-    if (qsbVersion != QSB_VERSION && qsbVersion != QSB_VERSION_WITHOUT_BINDINGS) {
-        qWarning("Attempted to deserialize QShader with unknown version %d.", qsbVersion);
+    d->qsbVersion = intVal;
+    if (d->qsbVersion != QShaderPrivate::QSB_VERSION
+            && d->qsbVersion != QShaderPrivate::QSB_VERSION_WITH_BINARY_JSON
+            && d->qsbVersion != QShaderPrivate::QSB_VERSION_WITHOUT_BINDINGS)
+    {
+        qWarning("Attempted to deserialize QShader with unknown version %d.", d->qsbVersion);
         return QShader();
     }
 
@@ -439,7 +439,10 @@ QShader QShader::fromSerialized(const QByteArray &data)
     d->stage = Stage(intVal);
     QByteArray descBin;
     ds >> descBin;
-    d->desc = QShaderDescription::fromBinaryJson(descBin);
+    if (d->qsbVersion > QShaderPrivate::QSB_VERSION_WITH_BINARY_JSON)
+        d->desc = QShaderDescription::fromCbor(descBin);
+    else
+        d->desc = QShaderDescription::fromBinaryJson(descBin);
     int count;
     ds >> count;
     for (int i = 0; i < count; ++i) {
@@ -454,7 +457,7 @@ QShader QShader::fromSerialized(const QByteArray &data)
         d->shaders[k] = shader;
     }
 
-    if (qsbVersion != QSB_VERSION_WITHOUT_BINDINGS) {
+    if (d->qsbVersion > QShaderPrivate::QSB_VERSION_WITHOUT_BINDINGS) {
         ds >> count;
         for (int i = 0; i < count; ++i) {
             QShaderKey k;
diff --git a/src/gui/rhi/qshader_p_p.h b/src/gui/rhi/qshader_p_p.h
index 4535e01491..8c89f2b45f 100644
--- a/src/gui/rhi/qshader_p_p.h
+++ b/src/gui/rhi/qshader_p_p.h
@@ -57,6 +57,10 @@ QT_BEGIN_NAMESPACE
 
 struct Q_GUI_EXPORT QShaderPrivate
 {
+    static const int QSB_VERSION = 3;
+    static const int QSB_VERSION_WITH_BINARY_JSON = 2;
+    static const int QSB_VERSION_WITHOUT_BINDINGS = 1;
+
     QShaderPrivate()
         : ref(1)
     {
@@ -64,6 +68,7 @@ struct Q_GUI_EXPORT QShaderPrivate
 
     QShaderPrivate(const QShaderPrivate *other)
         : ref(1),
+          qsbVersion(other->qsbVersion),
           stage(other->stage),
           desc(other->desc),
           shaders(other->shaders),
@@ -75,6 +80,7 @@ struct Q_GUI_EXPORT QShaderPrivate
     static const QShaderPrivate *get(const QShader *s) { return s->d; }
 
     QAtomicInt ref;
+    int qsbVersion = QSB_VERSION;
     QShader::Stage stage = QShader::VertexStage;
     QShaderDescription desc;
     QHash<QShaderKey, QShaderCode> shaders;
diff --git a/src/gui/rhi/qshaderdescription.cpp b/src/gui/rhi/qshaderdescription.cpp
index 179d5f3a07..d0f73f6aa7 100644
--- a/src/gui/rhi/qshaderdescription.cpp
+++ b/src/gui/rhi/qshaderdescription.cpp
@@ -38,6 +38,9 @@
 #include <QDebug>
 #include <QJsonObject>
 #include <QJsonArray>
+#include <QCborValue>
+#include <QCborMap>
+#include <QCborArray>
 
 QT_BEGIN_NAMESPACE
 
@@ -335,11 +338,27 @@ bool QShaderDescription::isValid() const
 /*!
     \return a serialized binary version of the data.
 
-    \sa toJson()
+    \sa toJson(), toCbor()
  */
 QByteArray QShaderDescription::toBinaryJson() const
 {
+#if QT_CONFIG(binaryjson)
     return d->makeDoc().toBinaryData();
+#else
+    qWarning("Cannot generate binary JSON from QShaderDescription due to disabled binaryjson feature");
+    return QByteArray();
+#endif
+}
+
+/*!
+   \return a serialized binary version of the data in CBOR (Concise Binary
+   Object Representation) format.
+
+   \sa QCborValue, toBinaryJson(), toJson()
+ */
+QByteArray QShaderDescription::toCbor() const
+{
+    return QCborValue::fromJsonValue(d->makeDoc().object()).toCbor();
 }
 
 /*!
@@ -347,7 +366,7 @@ QByteArray QShaderDescription::toBinaryJson() const
 
     \note There is no deserialization method provided for JSON text.
 
-    \sa toBinaryJson()
+    \sa toBinaryJson(), toCbor()
  */
 QByteArray QShaderDescription::toJson() const
 {
@@ -357,11 +376,38 @@ QByteArray QShaderDescription::toJson() const
 /*!
     Deserializes the given binary JSON \a data and returns a new
     QShaderDescription.
+
+    \sa fromCbor()
  */
 QShaderDescription QShaderDescription::fromBinaryJson(const QByteArray &data)
 {
     QShaderDescription desc;
+#if QT_CONFIG(binaryjson)
     QShaderDescriptionPrivate::get(&desc)->loadDoc(QJsonDocument::fromBinaryData(data));
+#else
+    Q_UNUSED(data);
+    qWarning("Cannot load QShaderDescription from binary JSON due to disabled binaryjson feature");
+#endif
+    return desc;
+}
+
+/*!
+    Deserializes the given CBOR \a data and returns a new QShaderDescription.
+
+    \sa fromBinaryJson()
+ */
+QShaderDescription QShaderDescription::fromCbor(const QByteArray &data)
+{
+    QShaderDescription desc;
+    const QCborValue cbor = QCborValue::fromCbor(data);
+    if (cbor.isMap()) {
+        const QJsonDocument doc(cbor.toMap().toJsonObject());
+        QShaderDescriptionPrivate::get(&desc)->loadDoc(doc);
+    }
+    if (cbor.isArray()) {
+        const QJsonDocument doc(cbor.toArray().toJsonArray());
+        QShaderDescriptionPrivate::get(&desc)->loadDoc(doc);
+    }
     return desc;
 }
 
@@ -1119,4 +1165,106 @@ void QShaderDescriptionPrivate::loadDoc(const QJsonDocument &doc)
     }
 }
 
+/*!
+    Returns \c true if the two QShaderDescription objects \a lhs and \a rhs are
+    equal.
+
+    \relates QShaderDescription
+ */
+bool operator==(const QShaderDescription &lhs, const QShaderDescription &rhs) Q_DECL_NOTHROW
+{
+    if (lhs.d == rhs.d)
+        return true;
+
+    return lhs.d->inVars == rhs.d->inVars
+            && lhs.d->outVars == rhs.d->outVars
+            && lhs.d->uniformBlocks == rhs.d->uniformBlocks
+            && lhs.d->pushConstantBlocks == rhs.d->pushConstantBlocks
+            && lhs.d->storageBlocks == rhs.d->storageBlocks
+            && lhs.d->combinedImageSamplers == rhs.d->combinedImageSamplers
+            && lhs.d->storageImages == rhs.d->storageImages
+            && lhs.d->localSize == rhs.d->localSize;
+}
+
+/*!
+    Returns \c true if the two InOutVariable objects \a lhs and \a rhs are
+    equal.
+
+    \relates QShaderDescription::InOutVariable
+ */
+bool operator==(const QShaderDescription::InOutVariable &lhs, const QShaderDescription::InOutVariable &rhs) Q_DECL_NOTHROW
+{
+    return lhs.name == rhs.name
+            && lhs.type == rhs.type
+            && lhs.location == rhs.location
+            && lhs.binding == rhs.binding
+            && lhs.descriptorSet == rhs.descriptorSet
+            && lhs.imageFormat == rhs.imageFormat
+            && lhs.imageFlags == rhs.imageFlags;
+}
+
+/*!
+    Returns \c true if the two BlockVariable objects \a lhs and \a rhs are
+    equal.
+
+    \relates QShaderDescription::BlockVariable
+ */
+bool operator==(const QShaderDescription::BlockVariable &lhs, const QShaderDescription::BlockVariable &rhs) Q_DECL_NOTHROW
+{
+    return lhs.name == rhs.name
+            && lhs.type == rhs.type
+            && lhs.offset == rhs.offset
+            && lhs.size == rhs.size
+            && lhs.arrayDims == rhs.arrayDims
+            && lhs.arrayStride == rhs.arrayStride
+            && lhs.matrixStride == rhs.matrixStride
+            && lhs.matrixIsRowMajor == rhs.matrixIsRowMajor
+            && lhs.structMembers == rhs.structMembers;
+}
+
+/*!
+    Returns \c true if the two UniformBlock objects \a lhs and \a rhs are
+    equal.
+
+    \relates QShaderDescription::UniformBlock
+ */
+bool operator==(const QShaderDescription::UniformBlock &lhs, const QShaderDescription::UniformBlock &rhs) Q_DECL_NOTHROW
+{
+    return lhs.blockName == rhs.blockName
+            && lhs.structName == rhs.structName
+            && lhs.size == rhs.size
+            && lhs.binding == rhs.binding
+            && lhs.descriptorSet == rhs.descriptorSet
+            && lhs.members == rhs.members;
+}
+
+/*!
+    Returns \c true if the two PushConstantBlock objects \a lhs and \a rhs are
+    equal.
+
+    \relates QShaderDescription::PushConstantBlock
+ */
+bool operator==(const QShaderDescription::PushConstantBlock &lhs, const QShaderDescription::PushConstantBlock &rhs) Q_DECL_NOTHROW
+{
+    return lhs.name == rhs.name
+            && lhs.size == rhs.size
+            && lhs.members == rhs.members;
+}
+
+/*!
+    Returns \c true if the two StorageBlock objects \a lhs and \a rhs are
+    equal.
+
+    \relates QShaderDescription::StorageBlock
+ */
+bool operator==(const QShaderDescription::StorageBlock &lhs, const QShaderDescription::StorageBlock &rhs) Q_DECL_NOTHROW
+{
+    return lhs.blockName == rhs.blockName
+            && lhs.instanceName == rhs.instanceName
+            && lhs.knownSize == rhs.knownSize
+            && lhs.binding == rhs.binding
+            && lhs.descriptorSet == rhs.descriptorSet
+            && lhs.members == rhs.members;
+}
+
 QT_END_NAMESPACE
diff --git a/src/gui/rhi/qshaderdescription_p.h b/src/gui/rhi/qshaderdescription_p.h
index 5a63b998cd..e02a53dcb5 100644
--- a/src/gui/rhi/qshaderdescription_p.h
+++ b/src/gui/rhi/qshaderdescription_p.h
@@ -69,9 +69,11 @@ public:
     bool isValid() const;
 
     QByteArray toBinaryJson() const;
+    QByteArray toCbor() const;
     QByteArray toJson() const;
 
     static QShaderDescription fromBinaryJson(const QByteArray &data);
+    static QShaderDescription fromCbor(const QByteArray &data);
 
     enum VariableType {
         Unknown = 0,
@@ -263,6 +265,7 @@ private:
 #ifndef QT_NO_DEBUG_STREAM
     friend Q_GUI_EXPORT QDebug operator<<(QDebug, const QShaderDescription &);
 #endif
+    friend Q_GUI_EXPORT bool operator==(const QShaderDescription &lhs, const QShaderDescription &rhs) Q_DECL_NOTHROW;
 };
 
 Q_DECLARE_OPERATORS_FOR_FLAGS(QShaderDescription::ImageFlags)
@@ -276,6 +279,43 @@ Q_GUI_EXPORT QDebug operator<<(QDebug, const QShaderDescription::PushConstantBlo
 Q_GUI_EXPORT QDebug operator<<(QDebug, const QShaderDescription::StorageBlock &);
 #endif
 
+Q_GUI_EXPORT bool operator==(const QShaderDescription &lhs, const QShaderDescription &rhs) Q_DECL_NOTHROW;
+Q_GUI_EXPORT bool operator==(const QShaderDescription::InOutVariable &lhs, const QShaderDescription::InOutVariable &rhs) Q_DECL_NOTHROW;
+Q_GUI_EXPORT bool operator==(const QShaderDescription::BlockVariable &lhs, const QShaderDescription::BlockVariable &rhs) Q_DECL_NOTHROW;
+Q_GUI_EXPORT bool operator==(const QShaderDescription::UniformBlock &lhs, const QShaderDescription::UniformBlock &rhs) Q_DECL_NOTHROW;
+Q_GUI_EXPORT bool operator==(const QShaderDescription::PushConstantBlock &lhs, const QShaderDescription::PushConstantBlock &rhs) Q_DECL_NOTHROW;
+Q_GUI_EXPORT bool operator==(const QShaderDescription::StorageBlock &lhs, const QShaderDescription::StorageBlock &rhs) Q_DECL_NOTHROW;
+
+inline bool operator!=(const QShaderDescription &lhs, const QShaderDescription &rhs) Q_DECL_NOTHROW
+{
+    return !(lhs == rhs);
+}
+
+inline bool operator!=(const QShaderDescription::InOutVariable &lhs, const QShaderDescription::InOutVariable &rhs) Q_DECL_NOTHROW
+{
+    return !(lhs == rhs);
+}
+
+inline bool operator!=(const QShaderDescription::BlockVariable &lhs, const QShaderDescription::BlockVariable &rhs) Q_DECL_NOTHROW
+{
+    return !(lhs == rhs);
+}
+
+inline bool operator!=(const QShaderDescription::UniformBlock &lhs, const QShaderDescription::UniformBlock &rhs) Q_DECL_NOTHROW
+{
+    return !(lhs == rhs);
+}
+
+inline bool operator!=(const QShaderDescription::PushConstantBlock &lhs, const QShaderDescription::PushConstantBlock &rhs) Q_DECL_NOTHROW
+{
+    return !(lhs == rhs);
+}
+
+inline bool operator!=(const QShaderDescription::StorageBlock &lhs, const QShaderDescription::StorageBlock &rhs) Q_DECL_NOTHROW
+{
+    return !(lhs == rhs);
+}
+
 QT_END_NAMESPACE
 
 #endif