SF bug 433228: repr(list) woes when len(list) big.
Gave Python linear-time repr() implementations for dicts, lists, strings.
This means, e.g., that repr(range(50000)) is no longer 50x slower than
pprint.pprint() in 2.2 <wink>.
I don't consider this a bugfix candidate, as it's a performance boost.
Added _PyString_Join() to the internal string API. If we want that in the
public API, fine, but then it requires runtime error checks instead of
asserts.
diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index 21cc6c6..42bfd40 100644
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -809,42 +809,80 @@
static PyObject *
dict_repr(dictobject *mp)
{
- auto PyObject *v;
- PyObject *sepa, *colon;
- register int i;
- register int any;
+ int i, pos;
+ PyObject *s, *temp, *colon = NULL;
+ PyObject *pieces = NULL, *result = NULL;
+ PyObject *key, *value;
- i = Py_ReprEnter((PyObject*)mp);
+ i = Py_ReprEnter((PyObject *)mp);
if (i != 0) {
- if (i > 0)
- return PyString_FromString("{...}");
- return NULL;
+ return i > 0 ? PyString_FromString("{...}") : NULL;
}
- v = PyString_FromString("{");
- sepa = PyString_FromString(", ");
- colon = PyString_FromString(": ");
- any = 0;
- for (i = 0; i <= mp->ma_mask && v; i++) {
- dictentry *ep = mp->ma_table + i;
- PyObject *pvalue = ep->me_value;
- if (pvalue != NULL) {
- /* Prevent PyObject_Repr from deleting value during
- key format */
- Py_INCREF(pvalue);
- if (any++)
- PyString_Concat(&v, sepa);
- PyString_ConcatAndDel(&v, PyObject_Repr(ep->me_key));
- PyString_Concat(&v, colon);
- PyString_ConcatAndDel(&v, PyObject_Repr(pvalue));
- Py_DECREF(pvalue);
- }
+ if (mp->ma_used == 0) {
+ result = PyString_FromString("{}");
+ goto Done;
}
- PyString_ConcatAndDel(&v, PyString_FromString("}"));
- Py_ReprLeave((PyObject*)mp);
- Py_XDECREF(sepa);
+
+ pieces = PyList_New(0);
+ if (pieces == NULL)
+ goto Done;
+
+ colon = PyString_FromString(": ");
+ if (colon == NULL)
+ goto Done;
+
+ /* Do repr() on each key+value pair, and insert ": " between them.
+ Note that repr may mutate the dict. */
+ pos = 0;
+ while (PyDict_Next((PyObject *)mp, &pos, &key, &value)) {
+ int status;
+ /* Prevent repr from deleting value during key format. */
+ Py_INCREF(value);
+ s = PyObject_Repr(key);
+ PyString_Concat(&s, colon);
+ PyString_ConcatAndDel(&s, PyObject_Repr(value));
+ Py_DECREF(value);
+ if (s == NULL)
+ goto Done;
+ status = PyList_Append(pieces, s);
+ Py_DECREF(s); /* append created a new ref */
+ if (status < 0)
+ goto Done;
+ }
+
+ /* Add "{}" decorations to the first and last items. */
+ assert(PyList_GET_SIZE(pieces) > 0);
+ s = PyString_FromString("{");
+ if (s == NULL)
+ goto Done;
+ temp = PyList_GET_ITEM(pieces, 0);
+ PyString_ConcatAndDel(&s, temp);
+ PyList_SET_ITEM(pieces, 0, s);
+ if (s == NULL)
+ goto Done;
+
+ s = PyString_FromString("}");
+ if (s == NULL)
+ goto Done;
+ temp = PyList_GET_ITEM(pieces, PyList_GET_SIZE(pieces) - 1);
+ PyString_ConcatAndDel(&temp, s);
+ PyList_SET_ITEM(pieces, PyList_GET_SIZE(pieces) - 1, temp);
+ if (temp == NULL)
+ goto Done;
+
+ /* Paste them all together with ", " between. */
+ s = PyString_FromString(", ");
+ if (s == NULL)
+ goto Done;
+ result = _PyString_Join(s, pieces);
+ Py_DECREF(s);
+
+Done:
+ Py_XDECREF(pieces);
Py_XDECREF(colon);
- return v;
+ Py_ReprLeave((PyObject *)mp);
+ return result;
}
static int
diff --git a/Objects/listobject.c b/Objects/listobject.c
index e595c85..6fb3145 100644
--- a/Objects/listobject.c
+++ b/Objects/listobject.c
@@ -246,26 +246,68 @@
static PyObject *
list_repr(PyListObject *v)
{
- PyObject *s, *comma;
int i;
+ PyObject *s, *temp;
+ PyObject *pieces = NULL, *result = NULL;
i = Py_ReprEnter((PyObject*)v);
if (i != 0) {
- if (i > 0)
- return PyString_FromString("[...]");
- return NULL;
+ return i > 0 ? PyString_FromString("[...]") : NULL;
}
+
+ if (v->ob_size == 0) {
+ result = PyString_FromString("[]");
+ goto Done;
+ }
+
+ pieces = PyList_New(0);
+ if (pieces == NULL)
+ goto Done;
+
+ /* Do repr() on each element. Note that this may mutate the list,
+ so must refetch the list size on each iteration. */
+ for (i = 0; i < v->ob_size; ++i) {
+ int status;
+ s = PyObject_Repr(v->ob_item[i]);
+ if (s == NULL)
+ goto Done;
+ status = PyList_Append(pieces, s);
+ Py_DECREF(s); /* append created a new ref */
+ if (status < 0)
+ goto Done;
+ }
+
+ /* Add "[]" decorations to the first and last items. */
+ assert(PyList_GET_SIZE(pieces) > 0);
s = PyString_FromString("[");
- comma = PyString_FromString(", ");
- for (i = 0; i < v->ob_size && s != NULL; i++) {
- if (i > 0)
- PyString_Concat(&s, comma);
- PyString_ConcatAndDel(&s, PyObject_Repr(v->ob_item[i]));
- }
- Py_XDECREF(comma);
- PyString_ConcatAndDel(&s, PyString_FromString("]"));
+ if (s == NULL)
+ goto Done;
+ temp = PyList_GET_ITEM(pieces, 0);
+ PyString_ConcatAndDel(&s, temp);
+ PyList_SET_ITEM(pieces, 0, s);
+ if (s == NULL)
+ goto Done;
+
+ s = PyString_FromString("]");
+ if (s == NULL)
+ goto Done;
+ temp = PyList_GET_ITEM(pieces, PyList_GET_SIZE(pieces) - 1);
+ PyString_ConcatAndDel(&temp, s);
+ PyList_SET_ITEM(pieces, PyList_GET_SIZE(pieces) - 1, temp);
+ if (temp == NULL)
+ goto Done;
+
+ /* Paste them all together with ", " between. */
+ s = PyString_FromString(", ");
+ if (s == NULL)
+ goto Done;
+ result = _PyString_Join(s, pieces);
+ Py_DECREF(s);
+
+Done:
+ Py_XDECREF(pieces);
Py_ReprLeave((PyObject *)v);
- return s;
+ return result;
}
static int
diff --git a/Objects/stringobject.c b/Objects/stringobject.c
index bcf5147..24443d8 100644
--- a/Objects/stringobject.c
+++ b/Objects/stringobject.c
@@ -1031,6 +1031,23 @@
return res;
}
+PyObject *_PyString_Join(PyObject *sep, PyObject *x)
+{
+ PyObject* args;
+ PyObject* result = NULL;
+
+ assert(sep != NULL && PyString_Check(sep));
+ assert(x != NULL);
+ args = PyTuple_New(1);
+ if (args != NULL) {
+ Py_INCREF(x);
+ PyTuple_SET_ITEM(args, 0, x);
+ result = string_join((PyStringObject *)sep, args);
+ Py_DECREF(args);
+ }
+ return result;
+}
+
static long
string_find_internal(PyStringObject *self, PyObject *args, int dir)
{
diff --git a/Objects/tupleobject.c b/Objects/tupleobject.c
index 17ec1a0..538cc70 100644
--- a/Objects/tupleobject.c
+++ b/Objects/tupleobject.c
@@ -184,20 +184,56 @@
static PyObject *
tuplerepr(PyTupleObject *v)
{
- PyObject *s, *comma;
- int i;
- s = PyString_FromString("(");
- comma = PyString_FromString(", ");
- for (i = 0; i < v->ob_size && s != NULL; i++) {
- if (i > 0)
- PyString_Concat(&s, comma);
- PyString_ConcatAndDel(&s, PyObject_Repr(v->ob_item[i]));
+ int i, n;
+ PyObject *s, *temp;
+ PyObject *pieces, *result = NULL;
+
+ n = v->ob_size;
+ if (n == 0)
+ return PyString_FromString("()");
+
+ pieces = PyTuple_New(n);
+ if (pieces == NULL)
+ return NULL;
+
+ /* Do repr() on each element. */
+ for (i = 0; i < n; ++i) {
+ s = PyObject_Repr(v->ob_item[i]);
+ if (s == NULL)
+ goto Done;
+ PyTuple_SET_ITEM(pieces, i, s);
}
- Py_DECREF(comma);
- if (v->ob_size == 1)
- PyString_ConcatAndDel(&s, PyString_FromString(","));
- PyString_ConcatAndDel(&s, PyString_FromString(")"));
- return s;
+
+ /* Add "()" decorations to the first and last items. */
+ assert(n > 0);
+ s = PyString_FromString("(");
+ if (s == NULL)
+ goto Done;
+ temp = PyTuple_GET_ITEM(pieces, 0);
+ PyString_ConcatAndDel(&s, temp);
+ PyTuple_SET_ITEM(pieces, 0, s);
+ if (s == NULL)
+ goto Done;
+
+ s = PyString_FromString(n == 1 ? ",)" : ")");
+ if (s == NULL)
+ goto Done;
+ temp = PyTuple_GET_ITEM(pieces, n-1);
+ PyString_ConcatAndDel(&temp, s);
+ PyTuple_SET_ITEM(pieces, n-1, temp);
+ if (temp == NULL)
+ goto Done;
+
+ /* Paste them all together with ", " between. */
+ s = PyString_FromString(", ");
+ if (s == NULL)
+ goto Done;
+ result = _PyString_Join(s, pieces);
+ Py_DECREF(s);
+
+Done:
+ Py_DECREF(pieces);
+ return result;
}
static long