Counter: Add 'carry' attribute to counter objects

2 files changed, 12 insertions, 2 deletions

diff --git a/src/_counter.c b/src/_counter.c
index 7dc0f89..6964947 100644
--- a/src/_counter.c
+++ b/src/_counter.c
@@ -104,6 +104,9 @@ CounterObject_init(PCT_CounterObject *self, PyObject *args, PyObject *kwargs)
     /* Set shortcut_disabled */
     self->shortcut_disabled = disable_shortcut;
 
+    /* Clear the carry flag */
+    self->carry = 0;
+
     return 0;
 }
 
@@ -213,6 +216,7 @@ CounterLEObject_increment(PCT_CounterObject *self)
         carry = tmp >> 8;   /* This will only ever be 0 or 1 */
         *p = tmp & 0xff;
     }
+    self->carry = carry;
 }
 
 static void
@@ -230,6 +234,7 @@ CounterBEObject_increment(PCT_CounterObject *self)
         carry = tmp >> 8;   /* This will only ever be 0 or 1 */
         *p = tmp & 0xff;
     }
+    self->carry = carry;
 }
 
 static PyObject *
@@ -264,7 +269,9 @@ static PyObject *
 CounterLEObject_getattr(PyObject *s, char *name)
 {
     PCT_CounterObject *self = (PCT_CounterObject *)s;
-    if (!self->shortcut_disabled && strcmp(name, "__PCT_CTR_SHORTCUT__") == 0) {
+    if (strcmp(name, "carry") == 0) {
+        return PyInt_FromLong((long)self->carry);
+    } else if (!self->shortcut_disabled && strcmp(name, "__PCT_CTR_SHORTCUT__") == 0) {
         /* Shortcut hack - See block_template.c */
         Py_INCREF(Py_True);
         return Py_True;
@@ -276,7 +283,9 @@ static PyObject *
 CounterBEObject_getattr(PyObject *s, char *name)
 {
     PCT_CounterObject *self = (PCT_CounterObject *)s;
-    if (!self->shortcut_disabled && strcmp(name, "__PCT_CTR_SHORTCUT__") == 0) {
+    if (strcmp(name, "carry") == 0) {
+        return PyInt_FromLong((long)self->carry);
+    } else if (!self->shortcut_disabled && strcmp(name, "__PCT_CTR_SHORTCUT__") == 0) {
         /* Shortcut hack - See block_template.c */
         Py_INCREF(Py_True);
         return Py_True;
diff --git a/src/_counter.h b/src/_counter.h
index e7a5137..9735aab 100644
--- a/src/_counter.h
+++ b/src/_counter.h
@@ -37,6 +37,7 @@ typedef struct {
     uint16_t nbytes;    /* The number of bytes that from .p that are part of the counter */
     void (*inc_func)(void *);   /* Pointer to the counter increment function */
     int shortcut_disabled;  /* This gets set to a non-zero value when the shortcut mechanism is disabled */
+    int carry;         /* This gets set by Counter*Object_increment when the counter wraps around */
 } PCT_CounterObject;
 
 #endif /* PCT__COUNTER_H */