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SF bug 433228: repr(list) woes when len(list) big.

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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
Download patch file Download diff file Expand all files Collapse all files

4
Include/stringobject.h
View file

@ -77,6 +77,10 @@ extern DL_IMPORT(void) _Py_ReleaseInternedStrings(void);
#define PyString_AS_STRING(op) (((PyStringObject *)(op))->ob_sval) #define PyString_AS_STRING(op) (((PyStringObject *)(op))->ob_sval)
#define PyString_GET_SIZE(op) (((PyStringObject *)(op))->ob_size) #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 ----------------------------------------------------- */ /* --- Generic Codecs ----------------------------------------------------- */
/* Create an object by decoding the encoded string s of the /* Create an object by decoding the encoded string s of the

96
Objects/dictobject.c
View file

@ -809,42 +809,80 @@ dict_print(register dictobject *mp, register FILE *fp, register int flags)
static PyObject * static PyObject *
dict_repr(dictobject *mp) dict_repr(dictobject *mp)
{ {
auto PyObject *v; int i, pos;
PyObject *sepa, *colon; PyObject *s, *temp, *colon = NULL;
register int i; PyObject *pieces = NULL, *result = NULL;
register int any; PyObject *key, *value;
i = Py_ReprEnter((PyObject*)mp); i = Py_ReprEnter((PyObject *)mp);
if (i != 0) { if (i != 0) {
if (i > 0) return i > 0 ? PyString_FromString("{...}") : NULL;
return PyString_FromString("{...}");
return NULL;
} }
v = PyString_FromString("{"); if (mp->ma_used == 0) {
sepa = PyString_FromString(", "); result = PyString_FromString("{}");
goto Done;
}
pieces = PyList_New(0);
if (pieces == NULL)
goto Done;
colon = PyString_FromString(": "); colon = PyString_FromString(": ");
any = 0; if (colon == NULL)
for (i = 0; i <= mp->ma_mask && v; i++) { goto Done;
dictentry *ep = mp->ma_table + i;
PyObject *pvalue = ep->me_value; /* Do repr() on each key+value pair, and insert ": " between them.
if (pvalue != NULL) { Note that repr may mutate the dict. */
/* Prevent PyObject_Repr from deleting value during pos = 0;
key format */ while (PyDict_Next((PyObject *)mp, &pos, &key, &value)) {
Py_INCREF(pvalue); int status;
if (any++) /* Prevent repr from deleting value during key format. */
PyString_Concat(&v, sepa); Py_INCREF(value);
PyString_ConcatAndDel(&v, PyObject_Repr(ep->me_key)); s = PyObject_Repr(key);
PyString_Concat(&v, colon); PyString_Concat(&s, colon);
PyString_ConcatAndDel(&v, PyObject_Repr(pvalue)); PyString_ConcatAndDel(&s, PyObject_Repr(value));
Py_DECREF(pvalue); 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;
} }
}
PyString_ConcatAndDel(&v, PyString_FromString("}")); /* Add "{}" decorations to the first and last items. */
Py_ReprLeave((PyObject*)mp); assert(PyList_GET_SIZE(pieces) > 0);
Py_XDECREF(sepa); 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); Py_XDECREF(colon);
return v; Py_ReprLeave((PyObject *)mp);
return result;
} }
static int static int

68
Objects/listobject.c
View file

@ -246,26 +246,68 @@ list_print(PyListObject *op, FILE *fp, int flags)
static PyObject * static PyObject *
list_repr(PyListObject *v) list_repr(PyListObject *v)
{ {
PyObject *s, *comma;
int i; int i;
PyObject *s, *temp;
PyObject *pieces = NULL, *result = NULL;
i = Py_ReprEnter((PyObject*)v); i = Py_ReprEnter((PyObject*)v);
if (i != 0) { if (i != 0) {
if (i > 0) return i > 0 ? PyString_FromString("[...]") : NULL;
return PyString_FromString("[...]");
return 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("["); s = PyString_FromString("[");
comma = PyString_FromString(", "); if (s == NULL)
for (i = 0; i < v->ob_size && s != NULL; i++) { goto Done;
if (i > 0) temp = PyList_GET_ITEM(pieces, 0);
PyString_Concat(&s, comma); PyString_ConcatAndDel(&s, temp);
PyString_ConcatAndDel(&s, PyObject_Repr(v->ob_item[i])); PyList_SET_ITEM(pieces, 0, s);
} if (s == NULL)
Py_XDECREF(comma); goto Done;
PyString_ConcatAndDel(&s, PyString_FromString("]"));
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); Py_ReprLeave((PyObject *)v);
return s; return result;
} }
static int static int

17
Objects/stringobject.c
View file

@ -1031,6 +1031,23 @@ string_join(PyStringObject *self, PyObject *args)
return res; 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 static long
string_find_internal(PyStringObject *self, PyObject *args, int dir) string_find_internal(PyStringObject *self, PyObject *args, int dir)
{ {

62
Objects/tupleobject.c
View file

@ -184,20 +184,56 @@ tupleprint(PyTupleObject *op, FILE *fp, int flags)
static PyObject * static PyObject *
tuplerepr(PyTupleObject *v) tuplerepr(PyTupleObject *v)
{ {
PyObject *s, *comma; int i, n;
int i; PyObject *s, *temp;
s = PyString_FromString("("); PyObject *pieces, *result = NULL;
comma = PyString_FromString(", ");
for (i = 0; i < v->ob_size && s != NULL; i++) { n = v->ob_size;
if (i > 0) if (n == 0)
PyString_Concat(&s, comma); return PyString_FromString("()");
PyString_ConcatAndDel(&s, PyObject_Repr(v->ob_item[i]));
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) /* Add "()" decorations to the first and last items. */
PyString_ConcatAndDel(&s, PyString_FromString(",")); assert(n > 0);
PyString_ConcatAndDel(&s, PyString_FromString(")")); s = PyString_FromString("(");
return s; 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 static long