src/node_timer.cc

#include <node.h>
#include <node_timer.h>
#include <assert.h>

using namespace v8;
using namespace node;

Persistent<FunctionTemplate> Timer::constructor_template;

static Persistent<String> timeout_symbol;
static Persistent<String> repeat_symbol;
static Persistent<String> callback_symbol;

void
Timer::Initialize (Handle<Object> target)
{
  HandleScope scope;

  Local<FunctionTemplate> t = FunctionTemplate::New(Timer::New);
  constructor_template = Persistent<FunctionTemplate>::New(t);
  constructor_template->InstanceTemplate()->SetInternalFieldCount(1);
  constructor_template->SetClassName(String::NewSymbol("Timer"));

  timeout_symbol = NODE_PSYMBOL("timeout");
  repeat_symbol = NODE_PSYMBOL("repeat");
  callback_symbol = NODE_PSYMBOL("callback");

  NODE_SET_PROTOTYPE_METHOD(constructor_template, "start", Timer::Start);
  NODE_SET_PROTOTYPE_METHOD(constructor_template, "stop", Timer::Stop);
  NODE_SET_PROTOTYPE_METHOD(constructor_template, "again", Timer::Again);

  constructor_template->InstanceTemplate()->SetAccessor(repeat_symbol,
      RepeatGetter, RepeatSetter);

  target->Set(String::NewSymbol("Timer"), constructor_template->GetFunction());
}

Handle<Value>
Timer::RepeatGetter (Local<String> property, const AccessorInfo& info)
{
  HandleScope scope;
  Timer *timer = ObjectWrap::Unwrap<Timer>(info.This());

  assert(timer);
  assert (property == repeat_symbol);

  Local<Integer> v = Integer::New(timer->watcher_.repeat);

  return scope.Close(v);
}

void
Timer::RepeatSetter (Local<String> property, Local<Value> value, const AccessorInfo& info)
{
  HandleScope scope;
  Timer *timer = ObjectWrap::Unwrap<Timer>(info.This());

  assert(timer);
  assert(property == repeat_symbol);

  timer->watcher_.repeat = NODE_V8_UNIXTIME(value);
}

void
Timer::OnTimeout (EV_P_ ev_timer *watcher, int revents)
{
  Timer *timer = static_cast<Timer*>(watcher->data);

  assert(revents == EV_TIMEOUT);

  HandleScope scope;

  Local<Value> callback_v = timer->handle_->Get(callback_symbol);
  if (!callback_v->IsFunction()) {
    timer->Stop();
    return;
  }

  Local<Function> callback = Local<Function>::Cast(callback_v);

  TryCatch try_catch;

  callback->Call(timer->handle_, 0, NULL);

  if (try_catch.HasCaught()) {
    FatalException(try_catch);
  }

  if (timer->watcher_.repeat == 0) timer->Unref();
}

Timer::~Timer ()
{
  ev_timer_stop(EV_DEFAULT_UC_ &watcher_);
}

Handle<Value>
Timer::New (const Arguments& args)
{
  HandleScope scope;

  Timer *t = new Timer();
  t->Wrap(args.Holder());

  return args.This();
}

Handle<Value>
Timer::Start (const Arguments& args)
{
  HandleScope scope;
  Timer *timer = ObjectWrap::Unwrap<Timer>(args.Holder());

  if (args.Length() != 2)
    return ThrowException(String::New("Bad arguments"));

  bool was_active = ev_is_active(&timer->watcher_);

  ev_tstamp after = NODE_V8_UNIXTIME(args[0]);
  ev_tstamp repeat = NODE_V8_UNIXTIME(args[1]);
  ev_timer_init(&timer->watcher_, Timer::OnTimeout, after, repeat);
  timer->watcher_.data = timer;

  // Update the event loop time. Need to call this because processing JS can
  // take non-negligible amounts of time.
  ev_now_update(EV_DEFAULT_UC);

  ev_timer_start(EV_DEFAULT_UC_ &timer->watcher_);

  if (!was_active) timer->Ref();

  return Undefined();
}


Handle<Value> Timer::Stop(const Arguments& args) {
  HandleScope scope;
  Timer *timer = ObjectWrap::Unwrap<Timer>(args.Holder());
  timer->Stop();
  return Undefined();
}


void Timer::Stop () {
  if (watcher_.active) {
    ev_timer_stop(EV_DEFAULT_UC_ &watcher_);
    Unref();
  }
}


Handle<Value> Timer::Again(const Arguments& args) {
  HandleScope scope;
  Timer *timer = ObjectWrap::Unwrap<Timer>(args.Holder());

  int was_active = ev_is_active(&timer->watcher_);

  if (args.Length() > 0) {
    ev_tstamp repeat = NODE_V8_UNIXTIME(args[0]);
    if (repeat > 0) timer->watcher_.repeat = repeat;
  }

  ev_timer_again(EV_DEFAULT_UC_ &timer->watcher_);

  // ev_timer_again can start or stop the watcher.
  // So we need to check what happened and adjust the ref count
  // appropriately.

  if (ev_is_active(&timer->watcher_)) {
    if (!was_active) timer->Ref();
  } else {
    if (was_active) timer->Unref();
  }

  return Undefined();
}