Introduce QGrpcMetadata

Introduce alias to std::multimap names QGrpcMetadata, to represent
additional HTTP headers, that can be added to channel and call options.
Then channel implementations can use QGrpcMetadata and append all
metadata do each call (TODO).

Task-number: QTBUG-111037
Change-Id: Ie16e658407a57a5f44bc1a0ff54dcb3ca8b06fe1
Reviewed-by: Alexey Edelev <alexey.edelev@qt.io>

examples/grpc/chat/client/simplechatengine.cpp

@@ -5,7 +5,6 @@
 #include "simplechatengine.h"
 
 #include <QGrpcHttp2Channel>
-#include <QGrpcUserPasswordCredentials>
 
 #include <QDebug>
 #include <QFile>

src/grpc/CMakeLists.txt

@@ -14,6 +14,7 @@ qt_internal_add_module(Grpc
         qgrpcuserpasswordcredentials.h qgrpcuserpasswordcredentials.cpp
         qgrpccalloptions.h qgrpccalloptions.cpp
         qgrpcchanneloptions.h qgrpcchanneloptions.cpp
+        qgrpcmetadata.h
         qtgrpcglobal.h qtgrpcglobal_p.h  qtgrpcglobal.cpp
     GENERATE_CPP_EXPORTS
     LIBRARIES

src/grpc/qgrpccalloptions.cpp

@@ -27,6 +27,7 @@ public:
     std::optional<std::chrono::milliseconds> deadline;
     std::shared_ptr<QGrpcCallCredentials> credentials;
     std::optional<qint64> maxRetryAttempts;
+    QGrpcMetadata metadata;
 };
 
 /*!
@@ -87,6 +88,15 @@ QGrpcCallOptions &QGrpcCallOptions::withMaxRetryAttempts(qint64 maxRetryAttempts
     return *this;
 }
 
+/*!
+    Sets \a metadata for a call and returns updated QGrpcCallOptions object.
+*/
+QGrpcCallOptions &QGrpcCallOptions::withMetadata(const QGrpcMetadata &metadata)
+{
+    dPtr->metadata = metadata;
+    return *this;
+}
+
 /*!
     Returns deadline value for a call.
 
@@ -117,4 +127,14 @@ std::optional<qint64> QGrpcCallOptions::maxRetryAttempts() const
     return dPtr->maxRetryAttempts;
 }
 
+/*!
+    Returns metadata used for a call.
+
+    If value was not set returns empty QGrpcMetadata.
+*/
+QGrpcMetadata QGrpcCallOptions::metadata() const
+{
+    return dPtr->metadata;
+}
+
 QT_END_NAMESPACE

src/grpc/qgrpccalloptions.h

@@ -6,6 +6,7 @@
 
 #include <QtCore/QUrl>
 #include <QtGrpc/QGrpcCallCredentials>
+#include <QtGrpc/qgrpcmetadata.h>
 #include <QtGrpc/qtgrpcglobal.h>
 
 #include <chrono>
@@ -28,10 +29,12 @@ public:
     QGrpcCallOptions &withDeadline(std::chrono::milliseconds deadline);
     QGrpcCallOptions &withCredentials(std::shared_ptr<QGrpcCallCredentials> credentials);
     QGrpcCallOptions &withMaxRetryAttempts(qint64 maxRetryAttempts);
+    QGrpcCallOptions &withMetadata(const QGrpcMetadata &metadata);
 
     std::optional<std::chrono::milliseconds> deadline() const;
     std::optional<QGrpcCredentialMap> credentials() const;
     std::optional<qint64> maxRetryAttempts() const;
+    QGrpcMetadata metadata() const;
 
 private:
     std::unique_ptr<QGrpcCallOptionsPrivate> dPtr;

src/grpc/qgrpcchanneloptions.cpp

@@ -27,6 +27,7 @@ public:
     std::optional<std::chrono::milliseconds> deadline;
     std::shared_ptr<QGrpcChannelCredentials> credentials;
     std::optional<QStringList> credentialList;
+    QGrpcMetadata metadata;
 #if QT_CONFIG(ssl)
     std::optional<QSslConfiguration> sslConfiguration;
 #endif
@@ -100,6 +101,15 @@ QGrpcChannelOptions &QGrpcChannelOptions::withCredentialList(const QStringList &
     return *this;
 }
 
+/*!
+    Sets \a metadata for a call and returns updated QGrpcCallOptions object.
+*/
+QGrpcChannelOptions &QGrpcChannelOptions::withMetadata(const QGrpcMetadata &metadata)
+{
+    dPtr->metadata = metadata;
+    return *this;
+}
+
 /*!
     Returns deadline value for every call on the channel.
 
@@ -140,6 +150,16 @@ std::optional<QStringList> QGrpcChannelOptions::credentialList() const
 }
 
 #if QT_CONFIG(ssl)
+/*!
+    Returns metadata used for a call.
+
+    If value was not set returns empty QGrpcMetadata.
+*/
+QGrpcMetadata QGrpcChannelOptions::metadata() const
+{
+    return dPtr->metadata;
+}
+
 /*!
     Sets SSL configuration with \a sslConfiguration and returns updated QGrpcChannelOptions object.
 */

src/grpc/qgrpcchanneloptions.h

@@ -6,6 +6,7 @@
 
 #include <QtCore/QUrl>
 #include <QtGrpc/QGrpcChannelCredentials>
+#include <QtGrpc/qgrpcmetadata.h>
 #include <QtGrpc/qtgrpcglobal.h>
 
 #if QT_CONFIG(ssl)
@@ -34,11 +35,13 @@ public:
     QGrpcChannelOptions &withDeadline(std::chrono::milliseconds deadline);
     QGrpcChannelOptions &withCredentials(std::shared_ptr<QGrpcChannelCredentials> credentials);
     QGrpcChannelOptions &withCredentialList(const QStringList &credentialList);
+    QGrpcChannelOptions &withMetadata(const QGrpcMetadata &metadata);
 
     QUrl host() const;
     std::optional<std::chrono::milliseconds> deadline() const;
     std::optional<QGrpcCredentialMap> credentials() const;
     std::optional<QStringList> credentialList() const;
+    QGrpcMetadata metadata() const;
 
 #if QT_CONFIG(ssl)
     QGrpcChannelOptions &withSslConfiguration(const QSslConfiguration &sslConfiguration);

src/grpc/qgrpchttp2channel.cpp

@@ -86,6 +86,19 @@ constexpr char GrpcStatusHeader[] = "grpc-status";
 constexpr char GrpcStatusMessageHeader[] = "grpc-message";
 constexpr qsizetype GrpcMessageSizeHeaderSize = 5;
 
+static void addMetadataToRequest(QNetworkRequest *request, const QGrpcMetadata &channelMetadata,
+                                 const QGrpcMetadata &callMetadata)
+{
+    auto iterateMetadata = [&request](const auto &metadata) {
+        for (const auto &[key, value] : std::as_const(metadata)) {
+            request->setRawHeader(key, value);
+        }
+    };
+
+    iterateMetadata(channelMetadata);
+    iterateMetadata(callMetadata);
+}
+
 struct QGrpcHttp2ChannelPrivate
 {
     struct ExpectedData
@@ -121,6 +134,8 @@ struct QGrpcHttp2ChannelPrivate
             for (const auto &[key, value] : credentials->toStdMap())
                 request.setRawHeader(key, value.toString().toUtf8());
         }
+        addMetadataToRequest(&request, channelOptions.metadata(), callOptions.metadata());
+
         request.setAttribute(QNetworkRequest::Http2DirectAttribute, true);
 
         QByteArray msg(GrpcMessageSizeHeaderSize, '\0');

src/grpc/qgrpcmetadata.h

@@ -0,0 +1,17 @@
+// Copyright (C) 2023 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
+
+#ifndef QGRPCMETADATA_H
+#define QGRPCMETADATA_H
+
+#include <QtGrpc/qtgrpcglobal.h>
+
+#include <unordered_map>
+
+QT_BEGIN_NAMESPACE
+
+using QGrpcMetadata = std::unordered_multimap<QByteArray, QByteArray>;
+
+QT_END_NAMESPACE
+
+#endif // QGRPCMETADATA_H