Send numeric identifiers instead of strings

Saves bandwidth by using a number instead of sending the full string
to identify the GL command.

Change-Id: I5e8010465729d7a9c320d0375582d3a92d76019d
Reviewed-by: Mårten Nordheim <[email protected]>
Reviewed-by: Edward Welbourne <[email protected]>

Author: jsfdez

src/plugins/platforms/webgl/qwebglcontext.cpp

@@ -48,6 +48,7 @@
 #include <QtWebSockets/qwebsocket.h>
 
 #include <cstring>
+#include <limits>
 
 QT_BEGIN_NAMESPACE
 
@@ -286,7 +287,6 @@ static T queryValue(int id, const T &defaultValue = T())
     return variant.value<T>();
 }
 
-struct GLFunction;
 template<typename T>
 struct ParameterTypeTraits {
     static int typeId() { return qMetaTypeId<T>(); }
@@ -320,6 +320,7 @@ struct GLFunction
     };
 
     static QHash<QString, const GLFunction *> byName;
+    static QStringList remoteFunctionNames;
     using ParameterList = QVector<Parameter>;
 
     GLFunction(const QString &remoteName,
@@ -331,18 +332,23 @@ struct GLFunction
     {
         Q_ASSERT(!byName.contains(localName));
         byName.insert(localName, this);
+        id = remoteFunctionNames.size();
+        Q_ASSERT(remoteFunctionNames.size() <= std::numeric_limits<quint8>::max());
+        remoteFunctionNames.append(remoteName);
+        Q_ASSERT(byName.size() == remoteFunctionNames.size());
     }
 
     GLFunction(const QString &name) : GLFunction(name, name, nullptr)
     {}
-
+    quint8 id;
     const QString remoteName;
     const QString localName;
     const QFunctionPointer functionPointer;
     const ParameterList parameters;
 };
 
 QHash<QString, const GLFunction *> GLFunction::byName;
+QStringList GLFunction::remoteFunctionNames;
 
 template<const GLFunction *Function>
 static QWebGLFunctionCall *createEventImpl(bool wait)
@@ -355,7 +361,7 @@ static QWebGLFunctionCall *createEventImpl(bool wait)
     if (!clientData || !clientData->socket
             || clientData->socket->state() != QAbstractSocket::ConnectedState)
         return nullptr;
-    return new QWebGLFunctionCall(Function->remoteName, handle->currentSurface(), wait);
+    return new QWebGLFunctionCall(Function->localName, handle->currentSurface(), wait);
 }
 
 static void postEventImpl(QWebGLFunctionCall *event)
@@ -667,7 +673,7 @@ QWEBGL_FUNCTION(disableVertexAttribArray, void, glDisableVertexAttribArray,
 QWEBGL_FUNCTION(drawArrays, void, glDrawArrays,
                 (GLenum) mode, (GLint) first, (GLsizei) count)
 {
-    auto event = currentContext()->createEvent(QStringLiteral("drawArrays"));
+    auto event = currentContext()->createEvent(QStringLiteral("glDrawArrays"));
     if (!event)
         return;
     event->addParameters(mode, first, count);
@@ -681,7 +687,7 @@ QWEBGL_FUNCTION(drawArrays, void, glDrawArrays,
 QWEBGL_FUNCTION(drawElements, void, glDrawElements,
                 (GLenum) mode, (GLsizei) count, (GLenum) type, (const void *) indices)
 {
-    auto event = currentContext()->createEvent(QStringLiteral("drawElements"));
+    auto event = currentContext()->createEvent(QStringLiteral("glDrawElements"));
     if (!event)
         return;
     event->addParameters(mode, count, type);
@@ -1177,7 +1183,7 @@ QWEBGL_FUNCTION(shaderSource, void, glShaderSource,
                 (GLuint) shader, (GLsizei) count,
                 (const GLchar *const *) string, (const GLint *) length)
 {
-    auto event = currentContext()->createEvent(QStringLiteral("shaderSource"));
+    auto event = currentContext()->createEvent(QStringLiteral("glShaderSource"));
     if (!event)
         return;
     event->addParameters(shader, count);
@@ -1578,4 +1584,16 @@ QVariant QWebGLContext::queryValue(int id)
     return variant;
 }
 
+QStringList QWebGLContext::supportedFunctions()
+{
+    return GLFunction::remoteFunctionNames;
+}
+
+quint8 QWebGLContext::functionIndex(const QString &functionName)
+{
+    const auto it = GLFunction::byName.find(functionName);
+    Q_ASSERT(it != GLFunction::byName.end());
+    return (*it)->id;
+}
+
 QT_END_NAMESPACE

src/plugins/platforms/webgl/qwebglcontext.h

@@ -60,6 +60,9 @@ class QWebGLContext : public QPlatformOpenGLContext
     static QWebGLFunctionCall *createEvent(const QString &functionName, bool wait = false);
     static QVariant queryValue(int id);
 
+    static QStringList supportedFunctions();
+    static quint8 functionIndex(const QString &functionName);
+
 private:
     Q_DISABLE_COPY(QWebGLContext)
     Q_DECLARE_PRIVATE(QWebGLContext)

src/plugins/platforms/webgl/qwebglwebsocketserver.cpp

@@ -175,7 +175,7 @@ void QWebGLWebSocketServer::sendMessage(QWebSocket *socket,
         QByteArray data;
         {
             QDataStream stream(&data, QIODevice::WriteOnly);
-            stream << functionName;
+            stream << QWebGLContext::functionIndex(functionName);
             if (values.contains("id")) {
                 auto ok = false;
                 stream << quint32(values["id"].toUInt(&ok));
@@ -295,6 +295,8 @@ void QWebGLWebSocketServer::onNewConnection()
 #endif
             },
             { QStringLiteral("loadingScreen"), qgetenv("QT_WEBGL_LOADINGSCREEN") },
+            { QStringLiteral("supportedFunctions"),
+              QVariant::fromValue(QWebGLContext::supportedFunctions()) },
             { "sysinfo",
                 QVariantMap {
                     { QStringLiteral("buildAbi"), QSysInfo::buildAbi() },

src/plugins/platforms/webgl/webqt.jsx

@@ -65,6 +65,7 @@ window.onload = function () {
             }
         };
     }
+    var supportedFunctions;
 
     var sendObject = function (obj) { socket.send(JSON.stringify(obj)); }
 
@@ -967,10 +968,8 @@ window.onload = function () {
 
         var offset = 0;
         var obj = { "parameters" : [] };
-        obj["functionNameSize"] = view.getUint32(offset);
-        offset += 4;
-        obj["function"] = textDecoder.decode(new Uint8Array(buffer, offset, obj.functionNameSize));
-        offset += obj.functionNameSize;
+        obj["function"] = supportedFunctions[view.getUint8(offset)];
+        offset += 1;
         if (obj.function in commandsNeedingResponse) {
             obj["id"] = view.getUint32(offset);
             offset += 4;
@@ -1153,6 +1152,7 @@ window.onload = function () {
         } else if (obj.type === "change_title") {
             document.title = obj.text;
         } else if (obj.type === "connect") {
+            supportedFunctions = obj["supportedFunctions"];
             var sysinfo = obj["sysinfo"];
             if (obj["debug"])
                 DEBUG = 1;