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Restructured get_line() for clarity and speed. 

- The raw_input() functionality is moved to a separate function.

- Drop GNU getline() in favor of getc_unlocked(), which exists on more
  platforms (and is even a tad faster on my system).
This commit is contained in:
Guido van Rossum 2001-01-05 14:43:05 +00:00
parent 742bb6f9fd
commit 1187aa4d33
1 changed files with 59 additions and 66 deletions
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125
Objects/fileobject.c
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@ -639,49 +639,28 @@ file_readinto(PyFileObject *f, PyObject *args)
Size argument interpretation:
> 0: max length;
= 0: read arbitrary line;
< 0: strip trailing '\n', raise EOFError if EOF reached immediately
< 0: illegal (use get_line_raw() instead)
*/
#ifdef HAVE_GETC_UNLOCKED
#define GETC(f) getc_unlocked(f)
#define FLOCKFILE(f) flockfile(f)
#define FUNLOCKFILE(f) funlockfile(f)
#else
#define GETC(f) getc(f)
#define FLOCKFILE(f)
#define FUNLOCKFILE(f)
#endif
static PyObject *
get_line(PyFileObject *f, int n)
{
register FILE *fp = f->f_fp;
register int c;
FILE *fp = f->f_fp;
int c;
char *buf, *end;
size_t n1, n2;
PyObject *v;
#if defined(HAVE_GETLINE) && defined(_GNU_SOURCE)
/* Use GNU libc extension getline() for arbitrary-sized lines */
if (n == 0) {
size_t size = 0;
buf = NULL;
Py_BEGIN_ALLOW_THREADS
n1 = getline(&buf, &size, fp);
Py_END_ALLOW_THREADS
if (n1 == -1) {
if (buf){
free(buf);
}
clearerr(fp);
if (PyErr_CheckSignals()) {
return NULL;
}
if (n < 0 && feof(fp)) {
PyErr_SetString(PyExc_EOFError,
"EOF when reading a line");
return NULL;
}
return PyString_FromStringAndSize(NULL, 0);
}
/* No error */
v = PyString_FromStringAndSize(buf, n1);
free(buf);
return v;
}
#endif
n2 = n > 0 ? n : 100;
v = PyString_FromStringAndSize((char *)NULL, n2);
if (v == NULL)
@ -689,48 +668,40 @@ get_line(PyFileObject *f, int n)
buf = BUF(v);
end = buf + n2;
Py_BEGIN_ALLOW_THREADS
for (;;) {
if ((c = getc(fp)) == EOF) {
Py_BEGIN_ALLOW_THREADS
FLOCKFILE(fp);
while ((c = GETC(fp)) != EOF &&
(*buf++ = c) != '\n' &&
buf != end)
;
FUNLOCKFILE(fp);
Py_END_ALLOW_THREADS
if (c == '\n')
break;
if (c == EOF) {
clearerr(fp);
Py_BLOCK_THREADS
if (PyErr_CheckSignals()) {
Py_DECREF(v);
return NULL;
}
if (n < 0 && buf == BUF(v)) {
Py_DECREF(v);
PyErr_SetString(PyExc_EOFError,
"EOF when reading a line");
return NULL;
}
Py_UNBLOCK_THREADS
break;
}
if ((*buf++ = c) == '\n') {
if (n < 0)
buf--;
/* Must be because buf == end */
if (n > 0)
break;
n1 = n2;
n2 += 1000;
if (n2 > INT_MAX) {
PyErr_SetString(PyExc_OverflowError,
"line is longer than a Python string can hold");
return NULL;
}
if (buf == end) {
if (n > 0)
break;
n1 = n2;
n2 += 1000;
if (n2 > INT_MAX) {
PyErr_SetString(PyExc_OverflowError,
"line is longer than a Python string can hold");
return NULL;
}
Py_BLOCK_THREADS
if (_PyString_Resize(&v, n2) < 0)
return NULL;
Py_UNBLOCK_THREADS
buf = BUF(v) + n1;
end = BUF(v) + n2;
}
if (_PyString_Resize(&v, n2) < 0)
return NULL;
buf = BUF(v) + n1;
end = BUF(v) + n2;
}
Py_END_ALLOW_THREADS
n1 = buf - BUF(v);
if (n1 != n2)
@ -738,6 +709,25 @@ get_line(PyFileObject *f, int n)
return v;
}
/* Internal routine to get a line for raw_input():
strip trailing '\n', raise EOFError if EOF reached immediately
*/
static PyObject *
get_line_raw(PyFileObject *f)
{
PyObject *line;
line = get_line(f, 0);
if (line == NULL || PyString_GET_SIZE(line) > 0)
return line;
else {
Py_DECREF(line);
PyErr_SetString(PyExc_EOFError, "EOF when reading a line");
return NULL;
}
}
/* External C interface */
PyObject *
@ -796,7 +786,10 @@ PyFile_GetLine(PyObject *f, int n)
}
if (((PyFileObject*)f)->f_fp == NULL)
return err_closed();
return get_line((PyFileObject *)f, n);
if (n < 0)
return get_line_raw((PyFileObject *)f);
else
return get_line((PyFileObject *)f, n);
}
/* Python method */