mirrors/cpython
0
0
Fork 0
mirror of https://github.com/python/cpython.git synced 2024-11-27 03:45:08 +08:00
Code Issues Packages Projects Releases Wiki Activity

bpo-47005: Improve performance of bytearray_repeat and bytearray_irepeat (GH-31856)

Browse Source
This commit is contained in:
Pieter Eendebak 2022-03-18 00:10:36 +01:00 committed by GitHub
parent 903f0a02c1
commit ac8308d3ea
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 23 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
Misc/NEWS.d/next/Core and Builtins/2022-03-13-21-04-20.bpo-47005.OHBfCc.rst Normal file
View File

@ -0,0 +1 @@
Improve performance of ``bytearray_repeat`` and ``bytearray_irepeat`` by reducing the number of invocations of ``memcpy``.

28
Objects/bytearrayobject.c
View File

@ -335,9 +335,19 @@ bytearray_repeat(PyByteArrayObject *self, Py_ssize_t count)
if (mysize == 1)
memset(result->ob_bytes, buf[0], size);
else {
Py_ssize_t i;
for (i = 0; i < count; i++)
memcpy(result->ob_bytes + i*mysize, buf, mysize);
Py_ssize_t i, j;
i = 0;
if (i < size) {
memcpy(result->ob_bytes, buf, mysize);
i = mysize;
}
// repeatedly double the number of bytes copied
while (i < size) {
j = Py_MIN(i, size - i);
memcpy(result->ob_bytes + i, result->ob_bytes, j);
i += j;
}
}
}
return (PyObject *)result;
@ -363,9 +373,15 @@ bytearray_irepeat(PyByteArrayObject *self, Py_ssize_t count)
if (mysize == 1)
memset(buf, buf[0], size);
else {
Py_ssize_t i;
for (i = 1; i < count; i++)
memcpy(buf + i*mysize, buf, mysize);
Py_ssize_t i, j;
i = mysize;
// repeatedly double the number of bytes copied
while (i < size) {
j = Py_MIN(i, size - i);
memcpy(buf + i, buf, j);
i += j;
}
}
Py_INCREF(self);