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Apply map/zip pre-sizing optimization to a broader class of objects.

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Formerly, the length was only fetched from sequence objects.
Now, any object that reports its length can benefit from pre-sizing.
This commit is contained in:
Raymond Hettinger 2004-01-04 08:54:44 +00:00
parent 7832cd6141
commit 77f3c87113
1 changed files with 7 additions and 11 deletions
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18
Python/bltinmodule.c
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@ -791,17 +791,13 @@ builtin_map(PyObject *self, PyObject *args)
}
/* Update len. */
curlen = -1; /* unknown */
if (PySequence_Check(curseq) &&
curseq->ob_type->tp_as_sequence->sq_length) {
curlen = PySequence_Size(curseq);
if (curlen < 0)
PyErr_Clear();
}
if (curlen < 0)
curlen = PyObject_Size(curseq);
if (curlen < 0) {
PyErr_Clear();
curlen = 8; /* arbitrary */
if (curlen > len)
len = curlen;
}
if (curlen > len)
len = curlen;
}
/* Get space for the result list. */
@ -1968,7 +1964,7 @@ builtin_zip(PyObject *self, PyObject *args)
len = -1; /* unknown */
for (i = 0; i < itemsize; ++i) {
PyObject *item = PyTuple_GET_ITEM(args, i);
int thislen = PySequence_Length(item);
int thislen = PyObject_Size(item);
if (thislen < 0) {
PyErr_Clear();
len = -1;