inotify: Better implementation of the event string representation.

inotify: Better implementation of the event string representation.

This patch reimplements the event_repr function. It got mostly rewritten to
eliminate the need for conditional compilation of the module when building in
py3k. The trick there (thanks to Antoine Pitrou) is to use the % operator to
let the python interpreter format the string to be returned.

--- a/hgext/inotify/linux/_inotify.c	Fri Jul 02 16:21:42 2010 -0300
+++ b/hgext/inotify/linux/_inotify.c	Fri Jul 02 16:21:46 2010 -0300
@@ -15,6 +15,13 @@
 #include <sys/ioctl.h>
 #include <unistd.h>
 
+/* Variables used in the event string representation */
+static PyObject *join;
+static PyObject *er_wm;
+static PyObject *er_wmc;
+static PyObject *er_wmn;
+static PyObject *er_wmcn;
+
 static PyObject *init(PyObject *self, PyObject *args)
 {
 	PyObject *ret = NULL;
@@ -312,8 +319,8 @@
 };
 
 PyDoc_STRVAR(
-    event_doc,
-    "event: Structure describing an inotify event.");
+	event_doc,
+	"event: Structure describing an inotify event.");
 
 static PyObject *event_new(PyTypeObject *t, PyObject *a, PyObject *k)
 {
@@ -332,15 +339,10 @@
 
 static PyObject *event_repr(struct event *evt)
 {
-	int wd = PyInt_AsLong(evt->wd);
 	int cookie = evt->cookie == Py_None ? -1 : PyInt_AsLong(evt->cookie);
 	PyObject *ret = NULL, *pymasks = NULL, *pymask = NULL;
-	PyObject *join = NULL;
 	char *maskstr;
-
-	join = PyString_FromString("|");
-	if (join == NULL)
-		goto bail;
+	PyObject *tuple = NULL, *formatstr = NULL;
 
 	pymasks = decode_mask(PyInt_AsLong(evt->mask));
 	if (pymasks == NULL)
@@ -350,33 +352,35 @@
 	if (pymask == NULL)
 		goto bail;
 
-	maskstr = PyString_AsString(pymask);
-
 	if (evt->name != Py_None) {
-		PyObject *pyname = PyString_Repr(evt->name, 1);
-		char *name = pyname ? PyString_AsString(pyname) : "???";
-
-		if (cookie == -1)
-			ret = PyString_FromFormat(
-				"event(wd=%d, mask=%s, name=%s)",
-				wd, maskstr, name);
-		else
-			ret = PyString_FromFormat("event(wd=%d, mask=%s, "
-						  "cookie=0x%x, name=%s)",
-						  wd, maskstr, cookie, name);
-
-		Py_XDECREF(pyname);
+		if (cookie == -1) {
+			formatstr = er_wmn;
+			tuple = PyTuple_Pack(3, evt->wd, pymask, evt->name);
+		}
+		else {
+			formatstr = er_wmcn;
+			tuple = PyTuple_Pack(4, evt->wd, pymask,
+					     evt->cookie, evt->name);
+		}
 	} else {
-		if (cookie == -1)
-			ret = PyString_FromFormat("event(wd=%d, mask=%s)",
-						  wd, maskstr);
+		if (cookie == -1) {
+			formatstr = er_wm;
+			tuple = PyTuple_Pack(2, evt->wd, pymask);
+		}
 		else {
-			ret = PyString_FromFormat(
-				"event(wd=%d, mask=%s, cookie=0x%x)",
-				wd, maskstr, cookie);
+			formatstr = er_wmc;
+			tuple = PyTuple_Pack(3, evt->wd, pymask, evt->cookie);
 		}
 	}
 
+	if (tuple == NULL)
+		goto bail;
+
+	ret = PyNumber_Remainder(formatstr, tuple);
+
+	if (ret == NULL)
+		goto bail;
+
 	goto done;
 bail:
 	Py_CLEAR(ret);
@@ -384,7 +388,7 @@
 done:
 	Py_XDECREF(pymask);
 	Py_XDECREF(pymasks);
-	Py_XDECREF(join);
+	Py_XDECREF(tuple);
 
 	return ret;
 }
@@ -561,6 +565,17 @@
 	return ret;
 }
 
+static int init_globals(void)
+{
+	join = PyString_FromString("|");
+	er_wm = PyString_FromString("event(wd=%d, mask=%s)");
+	er_wmn = PyString_FromString("event(wd=%d, mask=%s, name=%s)");
+	er_wmc = PyString_FromString("event(wd=%d, mask=%s, cookie=0x%x)");
+	er_wmcn = PyString_FromString("event(wd=%d, mask=%s, cookie=0x%x, name=%s)");
+
+	return join && er_wm && er_wmn && er_wmc && er_wmcn;
+}
+
 PyDoc_STRVAR(
 	read_doc,
 	"read(fd, bufsize[=65536]) -> list_of_events\n"
@@ -592,6 +607,9 @@
 	if (PyType_Ready(&event_type) == -1)
 		return;
 
+	if (!init_globals())
+		return;
+
 	mod = Py_InitModule3("_inotify", methods, doc);
 
 	dict = PyModule_GetDict(mod);