eventloop: Add convenience functions for adding script file handlers

Add Jim_CreateScriptFileHandler() to create a standard script filehandler
event that evaluates the given script with Jim_EvalObjBackground()
when the event occurs.

Also add Jim_FindFileHandler() to find a registered event handler.

Simplify aio by using these.

Signed-off-by: Steve Bennett <steveb@workware.net.au>

1 files changed, 49 insertions, 0 deletions

diff --git a/jim-eventloop.c b/jim-eventloop.c
index 78aae12..1a97191 100644
--- a/jim-eventloop.c
+++ b/jim-eventloop.c
@@ -148,6 +148,16 @@ int Jim_EvalObjBackground(Jim_Interp *interp, Jim_Obj *scriptObjPtr)
 }
 
 
+/**
+ * Register a file event handler on the given file descriptor with the given mask
+ * (may be 1 or more of JIM_EVENT_xxx)
+ *
+ * When the event occurs, proc is called with clientData and the mask of events that occurred.
+ * When the filehandler is removed, finalizerProc is called.
+ *
+ * Note that no check is made that only one handler is registered for the given
+ * event(s).
+ */
 void Jim_CreateFileHandler(Jim_Interp *interp, int fd, int mask,
     Jim_FileProc * proc, void *clientData, Jim_EventFinalizerProc * finalizerProc)
 {
@@ -164,6 +174,45 @@ void Jim_CreateFileHandler(Jim_Interp *interp, int fd, int mask,
     eventLoop->fileEventHead = fe;
 }
 
+static int JimEventHandlerScript(Jim_Interp *interp, void *clientData, int mask)
+{
+    return Jim_EvalObjBackground(interp, (Jim_Obj *)clientData);
+}
+
+static void JimEventHandlerScriptFinalize(Jim_Interp *interp, void *clientData)
+{
+    Jim_DecrRefCount(interp, (Jim_Obj *)clientData);
+}
+
+/**
+ * A convenience version of Jim_CreateFileHandler() which evaluates
+ * scriptObj with Jim_EvalObjBackground() when the event occurs.
+ */
+void Jim_CreateScriptFileHandler(Jim_Interp *interp, int fd, int mask,
+    Jim_Obj *scriptObj)
+{
+    Jim_IncrRefCount(scriptObj);
+    Jim_CreateFileHandler(interp, fd, mask, JimEventHandlerScript, scriptObj, JimEventHandlerScriptFinalize);
+}
+
+/**
+ * If there is a file handler registered with the given mask, return the clientData
+ * for the (first) handler.
+ * Otherwise return NULL.
+ */
+void *Jim_FindFileHandler(Jim_Interp *interp, int fd, int mask)
+{
+    Jim_FileEvent *fe;
+    Jim_EventLoop *eventLoop = Jim_GetAssocData(interp, "eventloop");
+
+    for (fe = eventLoop->fileEventHead; fe; fe = fe->next) {
+        if (fe->fd == fd && (fe->mask & mask)) {
+            return fe->clientData;
+        }
+    }
+    return NULL;
+}
+
 /**
  * Removes all event handlers for 'handle' that match 'mask'.
  */