Passing protobuf message from Javascript to C++ WebAssembly module
Csaba Szigeti
I do receive, and can successfully parse the simpler protobuf messages on the C++ side, however, protobuf is failing to parse the less-simple protobuf messages.
Here is the code that I am using :
```
goog.module('protobufMessageGenerator');
goog.require('proto.my_proto.MyMessage');
function generateMyMessage() {
var msg = new proto.my_proto.MyMessage()
var internal = new proto.my_proto.MyMessageInternal()
internal.setAccentColor("#CC1D24")
internal.setLogo("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")
msg.setInternal(internal)
return msg
}
```
Using the google-closure-compiler, I compile this protobuf message generator to pure Javascript. I use this code to pass the message to the C++ WebAssembly module :
```
function sendMessage() {
Module.self().setMyMessage(module$contents$protobufMessageGenerator_generateMyMessage().serializeBinary())
}
sendMessage()
```
I receive the message on the C++ side using this code :
```
void JavascriptPublicInterface::setMyMessage(const QString &myMessage)
{
if (_myMessage != myMessage)
{
_myMessage = myMessage;
emit myMessageChanged();
}
}
void JavascriptPublicInterface::setMyMessageEMS(const std::string &myMessage)
{
setMyMessage(QString::fromStdString(myMessage));
}
//...
void startListeningToMyMessage(std::function<void(euf_proto::MyMessage myMessage)> listener)
{
const auto changedListener = [listener]() {
const auto newMyMessageString = JavascriptPublicInterface::self()->myMessage();
my_proto::MyMessage myMessagePb;
if (myMessagePb.ParseFromString(newMyMessageString.toStdString()))
{
qDebug() << "C++ : Successfully parsed new MyMessage: " << newMyMessageString;
}
else
{
qDebug() << "C++ : Failed to parse new MyMessage: " << newMyMessageString;
}
qDebug() << "MyMessage received: " << QString::fromStdString(myMessagePb.DebugString());
listener(myMessagePb);
};
if (!QObject::connect(JavascriptPublicInterface::self(), &JavascriptPublicInterface::myMessageChanged, changedListener))
{
throw std::runtime_error("Failed to connect to JavascriptPublicInterface myMessageChanged");
}
}
```
In the Javascript console I see : "C++ : Failed to parse new MyMessage: ..."
I guess that it can be related to the fact that Javascript is using UTF-16 and C++ is using UTF-8 encoding (because the messages that are UTF-8 only can be successfully parsed), so I tried to fix the sending and receiving like this:
```
//For more info see : https://emscripten.org/docs/api_reference/emscripten.h.html?highlight=stringtoutf8
function convertUtf16ToUtf8(input) {
var uint8Arr = input
var jsString = String.fromCharCode.apply(null, uint8Arr)
var lengthBytes = lengthBytesUTF8(jsString)+1
var stringOnWasmHeap = _malloc(lengthBytes)
stringToUTF8(jsString, stringOnWasmHeap, lengthBytes)
return stringOnWasmHeap
}
function sendMessage() {
var myMessage = convertUtf16ToUtf8(module$contents$protobufMessageGenerator_generateMyMessage().serializeBinary())
Module.self().setMyMessage(myMessage)
_free(myMessage)
}
sendMessage()
```
And I modified the parsing on the C++ side like this :
```
void JavascriptPublicInterface::setMyMessageEMS(const int pointer)
{
const char* msg = (char*)pointer;
setMyMessage(QString::fromStdString(msg));
}
```
But I still get this error : "C++ : Failed to parse new MyMessage: ..."
How could I fix this?
(I am using protobuf 3.19.1 (same version on both the Javascript and the C++ side).)
Csaba Szigeti
I would like to pass a protobuf message from Javascript to a C++ WebAssembly module.
I do receive, and can successfully parse the simpler protobuf messages on the C++ side, however, protobuf is failing to parse the less-simple protobuf messages.
Here is the code that I am using :
goog.module('protobufMessageGenerator');
goog.require('proto.my_proto.MyMessage');
function generateMyMessage() {
var msg = new proto.my_proto.MyMessage()
var internal = new proto.my_proto.MyMessageInternal()
internal.setAccentColor("#CC1D24")
internal.setLogo("iVBORw0KGgoAAAANSUhEUgAAADAAAAAwCAYAAABXAvmHAAAACXBIWXMAAAsTAAALEwEAmpwYAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAYHSURBVHgB7ZhrbBRVFMf/s7vdR9ul7ba09CXQoqVFqcHwFhMQEh4GDSF+ggQhIT6CCUaN/YCaRsWo6QfAKAkvJVEILzECBSE8CyG0lfAoBQu0ttvndrfbZZ8zu9czd22FD+Lc4cNK3F8yO5mZvXfO/95zzzl3JEbgMcaAx5ykgESTFJBokgISTVJAovk/C2BgoTB8decRbG6GXmJuDzy1xxDp7oYeTNADlU+D586ja/v3QCiEjBdmwTZ+vFAXUBT0/Lib+rmASGsbitdVwTxqFEQRnwEyvmfrDjg3fYOSTz6GOTcXaRPGqxOimZjfj9aqdQjfakHp+mpElQhSS0ugCyZEjLkOHGSNk6azcGsbU1xu1jBpGou0tfNnmlAUdmfte+za3IUs6vMxz+FadnnqLMZCIaYHoRmQO7vRUf0ZshfNh3l0Mbx1ddyFTFmZ9FTS1Ifn2HG49/+MgjVvwJCWhv5DR2DOdgBmM/SgXQC5SNfmLaBRh2PRAm6w9+RpGK1WSCkal1I0it5t38E0KhcZL84GCwZx72I9DKmp0DoA0CuABYLw0GgZcxxIe7qCGxO8fkPE9RG62wpfw2XYp0zmRoc6nVD6+iBJ+oxX0Swg3N5OL+uHJT8fEr2chSOI9Ll4KGUkRguBphswyBHYSsdCHXG5qxdSNIYozYRQFNAjQBnwUPiIwWhP59dMlhFTjSchUYoqDydunNzv5mfTiAzuMUPtot5B+lGgB80CJIsVjKZaNZxfG6gpHYxCoNzv+cd20YEByJ4BLkKyWPi9mByO92Ey8rM84OWDoaJQQnN+/S29R5sgzQIs+XkwWMyQXf18tFRjDPY0soZRFu35618PuoHS04ur8xejq2aDai5sY0bzQYh09/L/mjKz+HXMH0CMZsF7/CSal6+C2eEYFvdvaM7EppEjYZtQzheuarC5oBC2okL4nZ2QnR3wNzRi8Mw5hNvaaVZkmCjB2WdMQ8bk53Cv8TeyN0YJr5yCQA78l69w4dbCAgqfKUBERseXNQjRmirdWANrWZnmoKQ9jBqNyF2xjPu899RZqBnE+uQ4/qizZiPaqtcjeKcV7n0/IUKi7GS4+3AtAtea+GIHtVPjfvb8eQhcuYbQ7bswUfw3ZWdDouwuDwziqc2bqCQpg0hQEkhkDI6FC5A2Yypce/fzUbOOHcOfpE+bgvK9P6Do/bUwkquF2zsQIffJfmkhLDTKjNZAy5p30LxiFXwUiVS6t27ng6LOoopj8SIY0tMhGo0EijkJEmXLkq8+x83lK+H89AsMnDrN7xtsajJLgbm4CBUH98Bz9AS5UhtCLbdhKS6G//cWPFH1LlIKC7lve44eR+sH62BMS4WPZkNFCQSG3yMEEyQWi7F79Y2svrSCddds4OeW19eweC10/xEn4nSyW6vfVBsO9cAP1649rKFsIvuj6kPWUDSOdW7ZxvQgXo2Sg/qvXod95nTkrV5JkSST54e/R2/oiJOSl4cx1R/ddyv+PNjSgpxXlyCLXIeH5+E+xBDeDzAKeb2796CUXAk2Gy/EDOkPqWXIz1Pych+4FSLjXb8cQcWunXxfAIMEoy0VehCegcEzZ2GhEGkrj29g1NxgKSgQ6qN3x0445s2hivYJGGhdMUqI5ryR0IOwgP5DtRjx/HQ+aipKhGqb8jLN7RktVveJU8h+ZbF6RVlZJgGU5ErGQg9iAsK0B25sROqzlXFj6Foml0qvrITW8OdvvknOxpBaXg7V7cJd3TyhWSiC6UFsQ0N7AcXrHY7dQQqTNnpxSkE+tIY/dfFaqb1kjddFvkv1yJwzm0K0BXoQEqD4vFQHMb4w1b2xa98BZM2dA5HUqXh9GBKr7jHcR39FztIl0ItQFDLZ7ZCozumjKKQWc94LF1Hw9lsiXcCUMQLBpmZ4Dh+B9+x5pD8zAbYKwS8a9yOUNWSFNS97jV0qHscaKyfzhCYK1UnUdgqrLyplTS8vZbTPYI+CpP6ICFbre2/dBdgrJyKFrwW1uVj6V0uMwI2byJg1E8bMDDwKwgL+ayQ/7iaapIBEkxSQaJICEk1SQKL5E+3sNu+yTCFZAAAAAElFTkSuQmCC")
msg.setInternal(internal)
return msg
}
```
Using the google-closure-compiler, I compile this protobuf message generator to pure Javascript.
I use this code to pass the message to the C++ WebAssembly module :
function sendMessage() {
Module.self().setMyMessage(module$contents$protobufMessageGenerator_generateMyMessage().serializeBinary())
}
sendMessage()
```
I receive the message on the C++ side using this code :
void JavascriptPublicInterface::setMyMessage(const QString &myMessage)
{
if (_myMessage != myMessage)
{
_myMessage = myMessage;
emit myMessageChanged();
}
}
void JavascriptPublicInterface::setMyMessageEMS(const std::string &myMessage)
{
setMyMessage(QString::fromStdString(myMessage));
}
//...
void startListeningToMyMessage(std::function<void(euf_proto::MyMessage myMessage)> listener)
{
const auto changedListener = [listener]() {
const auto newMyMessageString = JavascriptPublicInterface::self()->myMessage();
my_proto::MyMessage myMessagePb;
if (myMessagePb.ParseFromString(newMyMessageString.toStdString()))
{
qDebug() << "C++ : Successfully parsed new MyMessage: " << newMyMessageString;
}
else
{
qDebug() << "C++ : Failed to parse new MyMessage: " << newMyMessageString;
}
qDebug() << "MyMessage received: " << QString::fromStdString(myMessagePb.DebugString());
listener(myMessagePb);
};
if (!QObject::connect(JavascriptPublicInterface::self(), &JavascriptPublicInterface::myMessageChanged, changedListener))
{
throw std::runtime_error("Failed to connect to JavascriptPublicInterface myMessageChanged");
}
}
```
In the Javascript console I see : "C++ : Failed to parse new MyMessage: ..."
I guess that it can be related to the fact that Javascript is using UTF-16 and C++ is using UTF-8 encoding (because the messages that are UTF-8 only can be successfully parsed), so I tried to fix the sending and receiving like this:
//For more info see : https://emscripten.org/docs/api_reference/emscripten.h.html?highlight=stringtoutf8
function convertUtf16ToUtf8(input) {
var uint8Arr = input
var jsString = String.fromCharCode.apply(null, uint8Arr)
var lengthBytes = lengthBytesUTF8(jsString)+1
var stringOnWasmHeap = _malloc(lengthBytes)
stringToUTF8(jsString, stringOnWasmHeap, lengthBytes)
return stringOnWasmHeap
}
function sendMessage() {
var myMessage = convertUtf16ToUtf8(module$contents$protobufMessageGenerator_generateMyMessage().serializeBinary())
Module.self().setMyMessage(myMessage)
_free(myMessage)
}
sendMessage()
```
And I modified the parsing on the C++ side like this :
void JavascriptPublicInterface::setMyMessageEMS(const int pointer)
{
const char* msg = (char*)pointer;
setMyMessage(QString::fromStdString(msg));
}
```
But I still get this error : "C++ : Failed to parse new MyMessage: ..."
How could I fix this?
(I am using protobuf 3.19.1 (same version on both the Javascript and the C++ side).)
Adam Cozzette
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Csaba Szigeti
In case if I modify my code, so it is passing a simple string as logo, then I can successfully parse the protobuf message on the C++ side :
```javascript...
internal.setLogo("logo")
...
```
So I guess that the issue is with this field. The original string is a base64 encoded image. What should I do with this string to fix the parsing?
Csaba Szigeti
The issue is not fixed yet, but I got much-much closer to fixing it.
Using this code, from the Javascript console, I printed my protobuf message as hex :
```javascript
function buf2hex(buffer) { // buffer is an ArrayBuffer
return [...new Uint8Array(buffer)]
.map(x => x.toString(16).padStart(2, '0'))
.join('');
}
buf2hex(module$contents$protobufMessageGenerator_generatePubDetailsMessage().serializeBinary())
```
I copy pasted it into a.txt, and converted it :
```bash
cat a.txt | tr ',' '\n' | xargs printf '\\\\x%02x'
```
and I copy pasted this output as well, and generated a.bin like this :
```bash
echo -n -e \\x2a\\xd2\\x02\\x1a\\x93\\x01\\x0a\\x0c\\x45\\x6d\\x69\\x74\\x74\\x65\\x72\\x20\\x4e\\x61\\x6d\\x65\\x12\\x0d\\x45\\x6d\\x69\\x74\\x74\\x65\\x72\\x20\\x54\\x69\\x74\\x6c\\x65\\x1a\\x74\\x69\\x56\\x42\\x4f\\x52\\x77\\x30\\x4b\\x47\\x67\\x6f\\x41\\x41\\x41\\x41\\x4e\\x53\\x55\\x68\\x45\\x55\\x67\\x41\\x41\\x41\\x41\\x55\\x41\\x41\\x41\\x41\\x46\\x43\\x41\\x59\\x41\\x41\\x41\\x43\\x4e\\x62\\x79\\x62\\x6c\\x41\\x41\\x41\\x41\\x48\\x45\\x6c\\x45\\x51\\x56\\x51\\x49\\x31\\x32\\x50\\x34\\x2f\\x2f\\x38\\x2f\\x77\\x33\\x38\\x47\\x49\\x41\\x58\\x44\\x49\\x42\\x4b\\x45\\x30\\x44\\x48\\x78\\x67\\x6c\\x6a\\x4e\\x42\\x41\\x41\\x4f\\x39\\x54\\x58\\x4c\\x30\\x59\\x34\\x4f\\x48\\x77\\x41\\x41\\x41\\x41\\x42\\x4a\\x52\\x55\\x35\\x45\\x72\\x6b\\x4a\\x67\\x67\\x67\\x3d\\x3d\\x22\\x0a\\x54\\x68\\x61\\x6e\\x6b\\x20\\x79\\x6f\\x75\\x21\\x3a\\x9a\\x01\\x1a\\x08\\x47\\x72\\x65\\x65\\x74\\x69\\x6e\\x67\\x22\\x06\\x48\\x65\\x61\\x64\\x65\\x72\\x2a\\x04\\x42\\x6f\\x64\\x79\\x32\\x06\\x46\\x6f\\x6f\\x74\\x65\\x72\\x3a\\x0c\\x53\\x69\\x6e\\x67\\x6c\\x65\\x41\\x6e\\x73\\x77\\x65\\x72\\x4a\\x12\\x1a\\x07\\x4f\\x70\\x74\\x69\\x6f\\x6e\\x31\\x22\\x07\\x4f\\x70\\x74\\x69\\x6f\\x6e\\x31\\x4a\\x14\\x08\\x02\\x1a\\x07\\x4f\\x70\\x74\\x69\\x6f\\x6e\\x32\\x22\\x07\\x4f\\x70\\x74\\x69\\x6f\\x6e\\x32\\x4a\\x14\\x08\\x04\\x1a\\x07\\x4f\\x70\\x74\\x69\\x6f\\x6e\\x33\\x22\\x07\\x4f\\x70\\x74\\x69\\x6f\\x6e\\x33\\x4a\\x14\\x08\\x06\\x1a\\x07\\x4f\\x70\\x74\\x69\\x6f\\x6e\\x34\\x22\\x07\\x4f\\x70\\x74\\x69\\x6f\\x6e\\x34\\x4a\\x14\\x08\\x08\\x1a\\x07\\x4f\\x70\\x74\\x69\\x6f\\x6e\\x35\\x22\\x07\\x4f\\x70\\x74\\x69\\x6f\\x6e\\x35\\x4a\\x06\\x75\\x72\\x67\\x65\\x6e\\x74\\x52\\x09\\x6c\\x69\\x67\\x68\\x74\\x6e\\x69\\x6e\\x67\\x32\\x06\\x12\\x04\\x6e\\x6f\\x6e\\x65 > a.bin
```
When I add this file as a resource to my C++ WebAssembly app, and load it, everything works fine :
```cpp
euf_proto::PubDetails pubDetails;
QByteArray data;
{
QString fileName(":/a.bin");
QFile file(fileName);
if(!file.open(QIODevice::ReadOnly)) {
qDebug() << "file not opened";
}
else
{
qDebug() << "file opened";
data = file.readAll();
}
}
if (pubDetails.ParseFromArray(data.data(), data.size()))
{
qDebug() << "C++ : Successfully parsed new pubDetails: " << data;
}
else
{
qDebug() << "C++ : Failed to parse new pubDetails: " << data;
}
=>
file opened
qtloader.js:382 C++ : Successfully parsed new pubDetails: "*\xD2\x02\x1A\x93\x01\n\fEmitter Name\x12\rEmitter Title\x1AtiVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAYAAACNbyblAAAAHElEQVQI12P4//8/w38GIAXDIBKE0DHxgljNBAAO9TXL0Y4OHwAAAABJRU5ErkJggg==\"\nThank you!:\x9A\x01\x1A\bGreeting\"\x06Header*\x04""Body2\x06""Footer:\fSingleAnswerJ\x12\x1A\x07Option1\"\x07Option1J\x14\b\x02\x1A\x07Option2\"\x07Option2J\x14\b\x04\x1A\x07Option3\"\x07Option3J\x14\b\x06\x1A\x07Option4\"\x07Option4J\x14\b\b\x1A\x07Option5\"\x07Option5J\x06urgentR\tlightning2\x06\x12\x04none"
So the issue is with passing this to C++ somehow.
I tried to encode it as hex on the Javascript side, and decode it on the C++ side, but it didn't help.
Csaba Szigeti
This stackoverflow post described a really similar issue, and it helped me to fix my parsing as well :
https://stackoverflow.com/questions/68750875/protobuf-serialize-deserialize-c-to-js
Here is my updated code, which works well :
I had to update the Javascript side :
```javascript
function sendMessage() {
Module.self().setMyMessage(module$contents$protobufMessageGenerator_generateMyMessage().serializeBinary().toString())
}
sendMessage()
```
and the C++ side :
```cpp
namespace
{
QByteArray decryptProtobufMessage(const std::string &str)
{
QStringList strList = QString::fromStdString(str).split(',');
QByteArray bytedata;
foreach (const QString &str, strList)
{
bytedata += (str.toUInt());
}
return bytedata;
}
} // namespace
void JavascriptPublicInterface::setMyMessage(const QByteArray &myMessage)
{
if (_myMessage != myMessage)
{
_myMessage = myMessage;
emit myMessageChanged();
}
}
void JavascriptPublicInterface::setMyMessageEMS(const std::string &myMessage)
{
}
//...
void startListeningToMyMessage(std::function<void(euf_proto::MyMessage myMessage)> listener)
{
const auto changedListener = [listener]() {
my_proto::MyMessage myMessagePb;
if (myMessagePb.ParseFromArray(newMyMessageByteArray.data(), newMyMessageByteArray.size()))
{
qDebug() << "C++ : Successfully parsed new MyMessage: " << newMyMessageByteArray;
}
else
{
qDebug() << "C++ : Failed to parse new MyMessage: " << newMyMessageByteArray;
}
qDebug() << "MyMessage received: " << QString::fromStdString(myMessagePb.DebugString());
listener(myMessagePb);
};
if (!QObject::connect(JavascriptPublicInterface::self(), &JavascriptPublicInterface::myMessageChanged, changedListener))
{
throw std::runtime_error("Failed to connect to JavascriptPublicInterface myMessageChanged");
}
}
```