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.
This commit is contained in:
Tim Peters 2001-06-16 05:11:17 +00:00
parent 239508cd10
commit a7259597f1
5 changed files with 193 additions and 56 deletions

View File

@ -77,6 +77,10 @@ extern DL_IMPORT(void) _Py_ReleaseInternedStrings(void);
#define PyString_AS_STRING(op) (((PyStringObject *)(op))->ob_sval)
#define PyString_GET_SIZE(op) (((PyStringObject *)(op))->ob_size)
/* _PyString_Join(sep, x) is like sep.join(x). sep must be PyStringObject*,
x must be an iterable object. */
extern DL_IMPORT(PyObject *) _PyString_Join(PyObject *sep, PyObject *x);
/* --- Generic Codecs ----------------------------------------------------- */
/* Create an object by decoding the encoded string s of the

View File

@ -809,42 +809,80 @@ dict_print(register dictobject *mp, register FILE *fp, register int flags)
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

View File

@ -246,26 +246,68 @@ list_print(PyListObject *op, FILE *fp, int flags)
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

View File

@ -1031,6 +1031,23 @@ string_join(PyStringObject *self, PyObject *args)
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)
{

View File

@ -184,20 +184,56 @@ tupleprint(PyTupleObject *op, FILE *fp, int flags)
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