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.

hgext/inotify/linux/_inotify.c

@@ -15,6 +15,13 b''
 #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 b' static struct PyGetSetDef event_getsets['
 };
 
 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 b' static void event_dealloc(struct event *'
 
 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 b' static PyObject *event_repr(struct event'
 	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 b' bail:'
 done:
 	Py_XDECREF(pymask);
 	Py_XDECREF(pymasks);
-	Py_XDECREF(join);
+	Py_XDECREF(tuple);
 
 	return ret;
 }
@@ -561,6 +565,17 b' done:'
 	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 b' void init_inotify(void)'
 	if (PyType_Ready(&event_type) == -1)
 		return;
 
+	if (!init_globals())
+		return;
+
 	mod = Py_InitModule3("_inotify", methods, doc);
 
 	dict = PyModule_GetDict(mod);