nodejs: Add isr support to node.js

This commit adds isr support to node.js mraa module, it also forces
SWIGJAVASCRIPT to be set at compile time by cmake (SWIG uses SWIGJAVASCRIPT and
not SWIGNODE in it's preprocessor). This uses libuv uv_queue_work to call v8isr
and is all done at a C++ level unlike the python isr, so this reuses the
mraa_gpio_isr call. This closes #110

Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>

api/mraa/gpio.hpp

@@ -118,6 +118,31 @@ class Gpio {
         mraa_result_t isr(Edge mode, PyObject *pyfunc, PyObject* args) {
             return mraa_gpio_isr(m_gpio, (gpio_edge_t) mode, (void (*) (void *)) pyfunc, (void *) args);
         }
+#elif defined(SWIGJAVASCRIPT)
+        static void v8isr(uv_work_t* req, int status) {
+            mraa::Gpio *This = (mraa::Gpio *)req->data;
+            int argc = 1;
+            v8::Local<v8::Value> argv[] = { v8::Integer::New(-1) };
+            This->m_v8isr->Call(v8::Context::GetCurrent()->Global(), argc, argv);
+            delete req;
+        }
+
+        static void nop(uv_work_t* req)
+        {
+            // Do nothing.
+        }
+
+        static void uvwork(void *ctx) {
+            uv_work_t* req = new uv_work_t;
+            req->data = ctx;
+            uv_queue_work(uv_default_loop(), req, nop, v8isr);
+        }
+
+        mraa_result_t isr(Edge mode, v8::Handle<v8::Function> func) {
+            m_v8isr = v8::Persistent<v8::Function>::New(func);
+            mraa_gpio_isr(m_gpio, (gpio_edge_t) mode, &uvwork, this);
+            return MRAA_SUCCESS;
+        }
 #else
         /**
          * Sets a callback to be called when pin value changes
@@ -139,6 +164,9 @@ class Gpio {
          * @return Result of operation
          */
         mraa_result_t isrExit() {
+#if defined(SWIGJAVASCRIPT)
+            m_v8isr.Dispose();
+#endif
             return mraa_gpio_isr_exit(m_gpio);
         }
         /**
@@ -200,6 +228,9 @@ class Gpio {
         }
     private:
         mraa_gpio_context m_gpio;
+#if defined(SWIGJAVASCRIPT)
+        v8::Persistent<v8::Function> m_v8isr;
+#endif
 };
 
 }

src/javascript/CMakeLists.txt

@@ -27,7 +27,7 @@ if (DOXYGEN_FOUND)
 endif ()
 
 set_target_properties (mraajs PROPERTIES
-  COMPILE_FLAGS "${CMAKE_CXX_FLAGS} -DBUILDING_NODE_EXTENSION"
+  COMPILE_FLAGS "${CMAKE_CXX_FLAGS} -DBUILDING_NODE_EXTENSION -DSWIGJAVASCRIPT=${SWIG_FOUND}"
   PREFIX ""
   OUTPUT_NAME mraa
   SUFFIX ".node"

src/javascript/binding.gyp.cmake

@@ -12,7 +12,7 @@
       'cflags_cc!': [ '-fno-rtti', '-fno-exceptions' ],
       'cflags!': [ '-fno-exceptions' ],
       'defines' : [ 'SWIG',
-                    'SWIGNODE',
+                    'SWIGJAVASCRIPT',
 		    'BUILDING_NODE_EXTENSION=1' ],
       'conditions' : [
           [ 'target_arch=="x64"',

src/javascript/mraajs.i

@@ -3,6 +3,7 @@
 %feature("autodoc", "3");
 
 %include carrays.i
+%include cpointer.i
 %array_class(uint8_t, uint8Array);
 
 %inline %{
@@ -19,6 +20,10 @@
   $2 = node::Buffer::Length($input);
 }
 
+%typemap(in) (v8::Handle<v8::Function> func) {
+  $1 = v8::Local<v8::Function>::Cast($input);
+}
+
 namespace mraa {
 class Spi;
 %typemap(out) uint8_t*

src/mraa.i

@@ -43,6 +43,11 @@
 
 %include "types.h"
 
+%ignore Gpio::nop(uv_work_t* req);
+%ignore Gpio::v8isr(uv_work_t* req);
+%ignore Gpio::v8isr(uv_work_t* req, int status);
+%ignore Gpio::uvwork(void *ctx);
+
 %include "gpio.hpp"
 
 %include "i2c.hpp"