node-pulseaudio-control/main.c

#include <node/node_api.h>
#include <stdio.h>
#include <execinfo.h>
#include <signal.h>
#include <unistd.h>
#include <pulse/pulseaudio.h>

struct PACBData {
  pa_context *context;
  pa_mainloop *mainloop;
};

struct NapiCBData {
	napi_value *cb;
	napi_env *env;
  napi_ref *cbRef;
};

const char *NAME = "miccontrol";

void handleSourceList(struct pa_context *c, const pa_source_info *i, int eol, void *userdata);
void connectToPulseCB(pa_context *context, void *userdata);
napi_value connectToPulse(napi_env env, napi_callback_info info);
napi_value init(napi_env env, napi_value exports);

napi_value connectToPulse(napi_env env, napi_callback_info info) {
  size_t argc = 1;
  napi_value args[1];
  struct PACBData *paCBData;
  napi_status status;
  struct NapiCBData *napiCBData = malloc(sizeof(struct NapiCBData));
  napiCBData->cbRef = malloc(sizeof(napi_ref));
  
  status = napi_get_cb_info(env, info, &argc, args, NULL, (void**)&paCBData);
  assert(argc == 1);
  assert(status == napi_ok);

  printf("finished getting calback info... \n");
  
  napiCBData->env = &env;

  status = napi_create_reference(env, *args, 1, napiCBData->cbRef);
  assert(status == napi_ok);
  
  int ret = 1;
  
  pa_context_set_state_callback(paCBData->context, connectToPulseCB, napiCBData);
  pa_context_connect(paCBData->context, NULL, 0, NULL);
  
  pa_mainloop_run(paCBData->mainloop, &ret);

  pa_context_unref(paCBData->context);
  pa_mainloop_free(paCBData->mainloop);
  //free(napiCBData); 
  return NULL;
}

void connectToPulseCB(pa_context *context, void *userdata) {
  printf("Callback called... \n");
  napi_status status;
  napi_value argv[1];
  struct NapiCBData *napiCBData = (struct NapiCBData*)userdata;
  pa_context_state_t pa_state = pa_context_get_state(context);
  napi_value errorString;

  if(pa_state == PA_CONTEXT_READY) {
    status = napi_get_undefined(*(napiCBData->env), &argv[0]);
  } else if(pa_state == PA_CONTEXT_FAILED) {

    status = napi_create_string_utf8(
        *(napiCBData->env), 
        "Error connecting to Pulse Audio", 
        NAPI_AUTO_LENGTH,
        &errorString);
    assert(status == napi_ok);
    status = napi_create_error(*(napiCBData->env), NULL, errorString, &argv[0]);
    assert(status == napi_ok);
  } else {
    return;
    //eventually need to look into reconnecting on disconnections and handling
    //connection failures.
  }
  napi_value global;
  status = napi_get_global(*(napiCBData->env), &global);
  assert(status == napi_ok);
  napi_value result;
  napi_value cb;

  status = napi_get_reference_value(*(napiCBData->env), *(napiCBData->cbRef), &cb);
  assert(status == napi_ok);
  printf("Calling callback from native... \n");
  status = napi_call_function(*(napiCBData->env), global, cb, 1, argv, &result);
  assert(status == napi_ok);
}

//napi_value getSources() {
//  pa_operation *getSourceOp = NULL;
//  getSourceOp = pa_context_get_source_info_list(context, handleSourceList, NULL);
//  if(!getSourceOp) {
//  } else {
//    pa_operation_state_t state = pa_operation_get_state(getSourceOp);
//    switch(state) {
//      case PA_OPERATION_RUNNING:
//        break;
//      case PA_OPERATION_DONE:
//        break;
//      case PA_OPERATION_CANCELLED:
//    }
//  }
//}
//
//void handleSourceList(pa_context *c, const pa_source_info *i, int eol, void *userdata) {
//  printf("Callback called...\n");
//  printf("eol is %d\n", eol);
//  printf(i->description);
//  printf("\n");
//  
//  return;
//}

void handler(int sig) {
  void *array[10];
  size_t size;

  size = backtrace(array, 10);
  fprintf(stderr, "Error: signal %d:\n", sig);
  backtrace_symbols_fd(array, size, STDERR_FILENO);
  exit(1);
}

napi_value init(napi_env env, napi_value exports) {
    signal(SIGSEGV, handler);
    pa_mainloop *mainloop = pa_mainloop_new();
    pa_mainloop_api *mainloop_api = pa_mainloop_get_api(mainloop);
    pa_context *context = pa_context_new(mainloop_api, NULL);

    struct PACBData *paCBData = malloc(sizeof(*paCBData));

    paCBData->context = context;
    paCBData->mainloop = mainloop;
    
    napi_status status;
    napi_value fn;

    status = napi_create_function(
        env, 
        "connectToPulse", 
        NAPI_AUTO_LENGTH,
        connectToPulse,
        paCBData,
        &fn);
    if(status != napi_ok) {
        return NULL;
    }

    status = napi_set_named_property(env, exports, "connectToPulse", fn);
    if(status != napi_ok) {
        return NULL;
    }

//    status = napi_create_function(env, NULL, NAPI_AUTO_LENGTH, getSources, paCBData, &fn);
//
//    if(status != napi_ok) {
//        return NULL;
//    }
//    
//    status = napi_set_named_property(env, exports, "getSources", fn);
//
//    if(status != napi_ok) {
//        return NULL;
//    }
    

    return exports;
}

NAPI_MODULE(NODE_GYP_MODULE_NAME, init);