node_midi.cc

#include <v8.h>
#include <node.h>
#include <node_object_wrap.h>
#include <queue>
#include <uv.h>

#ifdef _WIN32
#define __WINDOWS_MM__
#include "pthread.h"

#else
#define __LINUX_ALSASEQ__
#endif
#include "lib/RtMidi/RtMidi.h"
#include "lib/RtMidi/RtMidi.cpp"
a
namespace node {

#define SAFE_NODE_SET_PROTOTYPE_METHOD(templ, name, callback)             \
do {                                                                      \
  v8::Local<v8::Signature> __callback##_SIG = v8::Signature::New(templ);  \
  v8::Local<v8::FunctionTemplate> __callback##_TEM =                      \
    v8::FunctionTemplate::New(callback, v8::Handle<v8::Value>(),          \
                          __callback##_SIG);                              \
  templ->PrototypeTemplate()->Set(v8::String::NewSymbol(name),            \
                                  __callback##_TEM);                      \
} while (0)

class NodeMidiOutput : ObjectWrap
{
private:
    RtMidiOut* out;
public:
    static v8::Persistent<v8::FunctionTemplate> s_ct;
    static void Init(v8::Handle<v8::Object> target)
    {
        v8::HandleScope scope;
        
        v8::Local<v8::FunctionTemplate> t = v8::FunctionTemplate::New(New);
        
        s_ct = v8::Persistent<v8::FunctionTemplate>::New(t);
        s_ct->InstanceTemplate()->SetInternalFieldCount(1);
        s_ct->SetClassName(v8::String::NewSymbol("NodeMidiOutput"));
        
        SAFE_NODE_SET_PROTOTYPE_METHOD(s_ct, "getPortCount", GetPortCount);
        SAFE_NODE_SET_PROTOTYPE_METHOD(s_ct, "getPortName", GetPortName);
      
        SAFE_NODE_SET_PROTOTYPE_METHOD(s_ct, "openPort", OpenPort);
        SAFE_NODE_SET_PROTOTYPE_METHOD(s_ct, "openVirtualPort", OpenVirtualPort);
        SAFE_NODE_SET_PROTOTYPE_METHOD(s_ct, "closePort", ClosePort);
        
        SAFE_NODE_SET_PROTOTYPE_METHOD(s_ct, "sendMessage", SendMessage);
        
        target->Set(v8::String::NewSymbol("output"),
                    s_ct->GetFunction());
    }

    NodeMidiOutput()
    {
        out = new RtMidiOut();
    }
    
    ~NodeMidiOutput()
    {
        delete out;
    }

    static v8::Handle<v8::Value> New(const v8::Arguments& args)
    {
        v8::HandleScope scope;
        NodeMidiOutput* output = new NodeMidiOutput();
        output->Wrap(args.This());
        return args.This();
    }
    
    static v8::Handle<v8::Value> GetPortCount(const v8::Arguments& args)
    {
        v8::HandleScope scope;
        NodeMidiOutput* output = ObjectWrap::Unwrap<NodeMidiOutput>(args.This());
        v8::Local<v8::Integer> result = v8::Uint32::New(output->out->getPortCount());
        return scope.Close(result);
    }
    
    static v8::Handle<v8::Value> GetPortName(const v8::Arguments& args)
    {
        v8::HandleScope scope;
        NodeMidiOutput* output = ObjectWrap::Unwrap<NodeMidiOutput>(args.This());
        if (args.Length() == 0 || !args[0]->IsUint32()) {
            return ThrowException(v8::Exception::TypeError(
                v8::String::New("First argument must be an integer")));
        }
        unsigned int portNumber = args[0]->Uint32Value();
        v8::Local<v8::String> result = v8::String::New(output->out->getPortName(portNumber).c_str());
        return scope.Close(result);
    }
    
    static v8::Handle<v8::Value> OpenPort(const v8::Arguments& args)
    {
        v8::HandleScope scope;
        NodeMidiOutput* output = ObjectWrap::Unwrap<NodeMidiOutput>(args.This());
        if (args.Length() == 0 || !args[0]->IsUint32()) {
            return ThrowException(v8::Exception::TypeError(
                v8::String::New("First argument must be an integer")));
        }
        unsigned int portNumber = args[0]->Uint32Value();
        output->out->openPort(portNumber);
        return scope.Close(v8::Boolean::New(true));
    }
    
    static v8::Handle<v8::Value> OpenVirtualPort(const v8::Arguments& args)
    {
        v8::HandleScope scope;
        NodeMidiOutput* output = ObjectWrap::Unwrap<NodeMidiOutput>(args.This());
        if (args.Length() == 0 || !args[0]->IsString()) {
            return ThrowException(v8::Exception::TypeError(
                v8::String::New("First argument must be a string")));
        }
        std::string name(*v8::String::AsciiValue(args[0]));
        output->out->openVirtualPort(name);
        return scope.Close(v8::Boolean::New(true));
    }
    
    static v8::Handle<v8::Value> ClosePort(const v8::Arguments& args)
    {
        v8::HandleScope scope;
        NodeMidiOutput* output = ObjectWrap::Unwrap<NodeMidiOutput>(args.This());
        output->out->closePort();
        return scope.Close(v8::Boolean::New(true));
    }
    
    static v8::Handle<v8::Value> SendMessage(const v8::Arguments& args)
    {
        v8::HandleScope scope;
        NodeMidiOutput* output = ObjectWrap::Unwrap<NodeMidiOutput>(args.This());
        if (args.Length() == 0 || !args[0]->IsArray()) {
            return ThrowException(v8::Exception::TypeError(
                v8::String::New("First argument must be an array")));
        }
        v8::Local<v8::Object> message = args[0]->ToObject();
        size_t messageLength = message->Get(v8::String::New("length"))->Int32Value();
        std::vector<unsigned char> messageOutput;
        for (size_t i = 0; i != messageLength; ++i) {
            messageOutput.push_back(message->Get(v8::Integer::New(i))->Int32Value());
        }
        output->out->sendMessage(&messageOutput);
        return scope.Close(v8::Boolean::New(true));
    }
};

static v8::Persistent<v8::String> emit_symbol;

class NodeMidiInput : public ObjectWrap
{
private:
    RtMidiIn* in;

public:
    uv_async_t message_async;
    pthread_mutex_t message_mutex;
    
    struct MidiMessage
    {
        double deltaTime;
        std::vector<unsigned char> message;
    };
    std::queue<MidiMessage*> message_queue;
    
    static v8::Persistent<v8::FunctionTemplate> s_ct;
    static void Init(v8::Handle<v8::Object> target)
    {
        v8::HandleScope scope;
        
        v8::Local<v8::FunctionTemplate> t = v8::FunctionTemplate::New(New);
        
        s_ct = v8::Persistent<v8::FunctionTemplate>::New(t);
        s_ct->InstanceTemplate()->SetInternalFieldCount(1);
        
        emit_symbol = NODE_PSYMBOL("emit");
        
        s_ct->SetClassName(v8::String::NewSymbol("NodeMidiInput"));
        
        SAFE_NODE_SET_PROTOTYPE_METHOD(s_ct, "getPortCount", GetPortCount);
        SAFE_NODE_SET_PROTOTYPE_METHOD(s_ct, "getPortName", GetPortName);
        
        SAFE_NODE_SET_PROTOTYPE_METHOD(s_ct, "openPort", OpenPort);
        SAFE_NODE_SET_PROTOTYPE_METHOD(s_ct, "openVirtualPort", OpenVirtualPort);
        SAFE_NODE_SET_PROTOTYPE_METHOD(s_ct, "closePort", ClosePort);
        
        SAFE_NODE_SET_PROTOTYPE_METHOD(s_ct, "ignoreTypes", IgnoreTypes);

        target->Set(v8::String::NewSymbol("input"),
                    s_ct->GetFunction());
    }
    
    NodeMidiInput()
    {
        in = new RtMidiIn();
        pthread_mutex_init(&message_mutex, NULL);
    }
    
    ~NodeMidiInput()
    {
        in->closePort();
//        uv_async_stop( message_async);
        delete &message_async;
        delete in;
        pthread_mutex_destroy(&message_mutex);
    }
    
    static void EmitMessage(uv_async_t *w, int status)
    {
    	assert(status == 0);
        v8::HandleScope scope;
        NodeMidiInput *input = static_cast<NodeMidiInput*>(w->data);
        pthread_mutex_lock(&input->message_mutex);
        while (!input->message_queue.empty())
        {
            MidiMessage* message = input->message_queue.front();
            v8::Local<v8::Value> args[3];
            args[0]= v8::String::New("message");
            args[1] = v8::Local<v8::Value>::New(v8::Number::New(message->deltaTime));
            size_t count = message->message.size();
            v8::Local<v8::Array> data = v8::Array::New(count);
            for (size_t i = 0; i < count; ++i) { 
                data->Set(v8::Number::New(i), v8::Integer::New(message->message[i])); 
            }
            args[2] = v8::Local<v8::Value>::New(data);
            v8::Local<v8::Value> emit_v = input->handle_->Get(emit_symbol);
            if (emit_v->IsFunction()) {
                v8::Local<v8::Function> emit=v8::Local<v8::Function>::Cast(emit_v);
                v8::TryCatch tc;
                emit->Call(input->handle_,3,args);
                if (tc.HasCaught()){
			node::FatalException(tc);
               }
            }
            input->message_queue.pop();
            delete message;
        }
        pthread_mutex_unlock(&input->message_mutex);
    }
    
    static void Callback(double deltaTime, std::vector<unsigned char> *message, void *userData)
    {
        NodeMidiInput *input = static_cast<NodeMidiInput*>(userData);
        MidiMessage* data = new MidiMessage();
        data->deltaTime = deltaTime;
        data->message = *message;
        pthread_mutex_lock(&input->message_mutex);
        input->message_queue.push(data);
        pthread_mutex_unlock(&input->message_mutex);
        uv_async_send(&input->message_async);
    }
    
    static v8::Handle<v8::Value> New(const v8::Arguments& args)
    {
        v8::HandleScope scope;
        NodeMidiInput* input = new NodeMidiInput();
        input->message_async.data = input;
        uv_async_init(uv_default_loop(),&input->message_async, NodeMidiInput::EmitMessage);
        uv_unref(uv_default_loop());
        input->Wrap(args.This());
        return args.This();
    }
    
    static v8::Handle<v8::Value> GetPortCount(const v8::Arguments& args)
    {
        v8::HandleScope scope;
        NodeMidiInput* input = ObjectWrap::Unwrap<NodeMidiInput>(args.This());
        v8::Local<v8::Integer> result = v8::Uint32::New(input->in->getPortCount());
        return scope.Close(result);
    }
    
    static v8::Handle<v8::Value> GetPortName(const v8::Arguments& args)
    {
        v8::HandleScope scope;
        NodeMidiInput* input = ObjectWrap::Unwrap<NodeMidiInput>(args.This());
        if (args.Length() == 0 || !args[0]->IsUint32()) {
            return ThrowException(v8::Exception::TypeError(
                v8::String::New("First argument must be an integer")));
        }
        unsigned int portNumber = args[0]->Uint32Value();
        v8::Local<v8::String> result = v8::String::New(input->in->getPortName(portNumber).c_str());
        return scope.Close(result);
    }
    
    static v8::Handle<v8::Value> OpenPort(const v8::Arguments& args)
    {
        v8::HandleScope scope;
        NodeMidiInput* input = ObjectWrap::Unwrap<NodeMidiInput>(args.This());
        if (args.Length() == 0 || !args[0]->IsUint32()) {
            return ThrowException(v8::Exception::TypeError(
                v8::String::New("First argument must be an integer")));
        }
        unsigned int portNumber = args[0]->Uint32Value();
        input->Ref();
        input->in->setCallback(&NodeMidiInput::Callback, ObjectWrap::Unwrap<NodeMidiInput>(args.This()));
        input->in->openPort(portNumber);
        return scope.Close(v8::Boolean::New(true));
    }
    
    static v8::Handle<v8::Value> OpenVirtualPort(const v8::Arguments& args)
    {
        v8::HandleScope scope;
        NodeMidiInput* input = ObjectWrap::Unwrap<NodeMidiInput>(args.This());
        if (args.Length() == 0 || !args[0]->IsString()) {
            return ThrowException(v8::Exception::TypeError(
                v8::String::New("First argument must be a string")));
        }
        std::string name(*v8::String::AsciiValue(args[0]));
        input->Ref();
        input->in->setCallback(&NodeMidiInput::Callback, ObjectWrap::Unwrap<NodeMidiInput>(args.This()));
        input->in->openVirtualPort(name);
        return scope.Close(v8::Boolean::New(true));
    }
    
    static v8::Handle<v8::Value> ClosePort(const v8::Arguments& args)
    {
        v8::HandleScope scope;
        NodeMidiInput* input = ObjectWrap::Unwrap<NodeMidiInput>(args.This());
        input->Unref();
        input->in->closePort();
        return scope.Close(v8::Boolean::New(true));
    }

    static v8::Handle<v8::Value> IgnoreTypes(const v8::Arguments& args)
    {
        v8::HandleScope scope;
        NodeMidiInput* input = ObjectWrap::Unwrap<NodeMidiInput>(args.This());
        if (args.Length() != 3 || !args[0]->IsBoolean() || !args[1]->IsBoolean() || !args[2]->IsBoolean()) {
            return ThrowException(v8::Exception::TypeError(
                v8::String::New("Arguments must be boolean")));
        }
        int filter_sysex = args[0]->BooleanValue();
        int filter_timing = args[1]->BooleanValue();
        int filter_sensing = args[2]->BooleanValue();
        input->in->ignoreTypes(filter_sysex,filter_timing,filter_sensing);
        return scope.Close(v8::Undefined());
    }
};

v8::Persistent<v8::FunctionTemplate> NodeMidiOutput::s_ct;
v8::Persistent<v8::FunctionTemplate> NodeMidiInput::s_ct;

void InitMidi (v8::Handle<v8::Object> target)
{
    NodeMidiOutput::Init(target);
    NodeMidiInput::Init(target);
}
    
}; // namespace node

NODE_MODULE(node_midi, node::InitMidi);

midi.js:

var EventEmitter=require('events').EventEmitter;
var midi=process.binding('midi');
midi.input.prototype.proto=EventEmitter.prototype;
module.exports=midi;

• you have to link with -lasound on linux
• macos x case is not handled yet (should define MACOSX_CORE instead of LINUX_ALSASEQ before rtmidi includes)