cpython/Objects/fileobject.c

858 lines
15 KiB
C

/***********************************************************
Copyright 1991-1995 by Stichting Mathematisch Centrum, Amsterdam,
The Netherlands.
All Rights Reserved
Permission to use, copy, modify, and distribute this software and its
documentation for any purpose and without fee is hereby granted,
provided that the above copyright notice appear in all copies and that
both that copyright notice and this permission notice appear in
supporting documentation, and that the names of Stichting Mathematisch
Centrum or CWI or Corporation for National Research Initiatives or
CNRI not be used in advertising or publicity pertaining to
distribution of the software without specific, written prior
permission.
While CWI is the initial source for this software, a modified version
is made available by the Corporation for National Research Initiatives
(CNRI) at the Internet address ftp://ftp.python.org.
STICHTING MATHEMATISCH CENTRUM AND CNRI DISCLAIM ALL WARRANTIES WITH
REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL STICHTING MATHEMATISCH
CENTRUM OR CNRI BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL
DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
PERFORMANCE OF THIS SOFTWARE.
******************************************************************/
/* File object implementation */
#include "allobjects.h"
#include "modsupport.h"
#include "structmember.h"
#include "ceval.h"
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef THINK_C
#define HAVE_FOPENRF
#endif
#ifdef __MWERKS__
/* Mwerks fopen() doesn't always set errno */
#define NO_FOPEN_ERRNO
#endif
#define BUF(v) GETSTRINGVALUE((stringobject *)v)
#include <errno.h>
typedef struct {
OB_HEAD
FILE *f_fp;
object *f_name;
object *f_mode;
int (*f_close) PROTO((FILE *));
int f_softspace; /* Flag used by 'print' command */
} fileobject;
FILE *
getfilefile(f)
object *f;
{
if (f == NULL || !is_fileobject(f))
return NULL;
else
return ((fileobject *)f)->f_fp;
}
object *
getfilename(f)
object *f;
{
if (f == NULL || !is_fileobject(f))
return NULL;
else
return ((fileobject *)f)->f_name;
}
object *
newopenfileobject(fp, name, mode, close)
FILE *fp;
char *name;
char *mode;
int (*close) FPROTO((FILE *));
{
fileobject *f = NEWOBJ(fileobject, &Filetype);
if (f == NULL)
return NULL;
f->f_fp = NULL;
f->f_name = newstringobject(name);
f->f_mode = newstringobject(mode);
f->f_close = close;
f->f_softspace = 0;
if (f->f_name == NULL || f->f_mode == NULL) {
DECREF(f);
return NULL;
}
f->f_fp = fp;
return (object *) f;
}
object *
newfileobject(name, mode)
char *name, *mode;
{
extern int fclose PROTO((FILE *));
fileobject *f;
f = (fileobject *) newopenfileobject((FILE *)NULL, name, mode, fclose);
if (f == NULL)
return NULL;
#ifdef HAVE_FOPENRF
if (*mode == '*') {
FILE *fopenRF();
f->f_fp = fopenRF(name, mode+1);
}
else
#endif
{
BGN_SAVE
f->f_fp = fopen(name, mode);
END_SAVE
}
if (f->f_fp == NULL) {
#ifdef NO_FOPEN_ERRNO
if ( errno == 0 ) {
err_setstr(IOError, "Cannot open file");
DECREF(f);
return NULL;
}
#endif
err_errno(IOError);
DECREF(f);
return NULL;
}
return (object *)f;
}
void
setfilebufsize(f, bufsize)
object *f;
int bufsize;
{
if (bufsize >= 0) {
#ifdef HAVE_SETVBUF
int type;
switch (bufsize) {
case 0:
type = _IONBF;
break;
case 1:
type = _IOLBF;
bufsize = BUFSIZ;
break;
default:
type = _IOFBF;
}
setvbuf(((fileobject *)f)->f_fp, (char *)NULL, type, bufsize);
#endif /* HAVE_SETVBUF */
}
}
static object *
err_closed()
{
err_setstr(ValueError, "I/O operation on closed file");
return NULL;
}
/* Methods */
static void
file_dealloc(f)
fileobject *f;
{
if (f->f_fp != NULL && f->f_close != NULL) {
BGN_SAVE
(*f->f_close)(f->f_fp);
END_SAVE
}
if (f->f_name != NULL)
DECREF(f->f_name);
if (f->f_mode != NULL)
DECREF(f->f_mode);
free((char *)f);
}
static object *
file_repr(f)
fileobject *f;
{
char buf[300];
sprintf(buf, "<%s file '%.256s', mode '%.10s' at %lx>",
f->f_fp == NULL ? "closed" : "open",
getstringvalue(f->f_name),
getstringvalue(f->f_mode),
(long)f);
return newstringobject(buf);
}
static object *
file_close(f, args)
fileobject *f;
object *args;
{
int sts = 0;
if (!getnoarg(args))
return NULL;
if (f->f_fp != NULL) {
if (f->f_close != NULL) {
BGN_SAVE
errno = 0;
sts = (*f->f_close)(f->f_fp);
END_SAVE
}
f->f_fp = NULL;
}
if (sts == EOF)
return err_errno(IOError);
if (sts != 0)
return newintobject((long)sts);
INCREF(None);
return None;
}
static object *
file_seek(f, args)
fileobject *f;
object *args;
{
long offset;
int whence;
int ret;
if (f->f_fp == NULL)
return err_closed();
whence = 0;
if (!getargs(args, "l", &offset)) {
err_clear();
if (!getargs(args, "(li)", &offset, &whence))
return NULL;
}
BGN_SAVE
errno = 0;
ret = fseek(f->f_fp, offset, whence);
END_SAVE
if (ret != 0) {
err_errno(IOError);
clearerr(f->f_fp);
return NULL;
}
INCREF(None);
return None;
}
#ifdef HAVE_FTRUNCATE
static object *
file_truncate(f, args)
fileobject *f;
object *args;
{
long newsize;
int ret;
if (f->f_fp == NULL)
return err_closed();
if (!getargs(args, "l", &newsize)) {
err_clear();
if (!getnoarg(args))
return NULL;
BGN_SAVE
errno = 0;
newsize = ftell(f->f_fp); /* default to current position*/
END_SAVE
if (newsize == -1L) {
err_errno(IOError);
clearerr(f->f_fp);
return NULL;
}
}
BGN_SAVE
errno = 0;
ret = fflush(f->f_fp);
END_SAVE
if (ret == 0) {
BGN_SAVE
errno = 0;
ret = ftruncate(fileno(f->f_fp), newsize);
END_SAVE
}
if (ret != 0) {
err_errno(IOError);
clearerr(f->f_fp);
return NULL;
}
INCREF(None);
return None;
}
#endif /* HAVE_FTRUNCATE */
static object *
file_tell(f, args)
fileobject *f;
object *args;
{
long offset;
if (f->f_fp == NULL)
return err_closed();
if (!getnoarg(args))
return NULL;
BGN_SAVE
errno = 0;
offset = ftell(f->f_fp);
END_SAVE
if (offset == -1L) {
err_errno(IOError);
clearerr(f->f_fp);
return NULL;
}
return newintobject(offset);
}
static object *
file_fileno(f, args)
fileobject *f;
object *args;
{
if (f->f_fp == NULL)
return err_closed();
if (!getnoarg(args))
return NULL;
return newintobject((long) fileno(f->f_fp));
}
static object *
file_flush(f, args)
fileobject *f;
object *args;
{
int res;
if (f->f_fp == NULL)
return err_closed();
if (!getnoarg(args))
return NULL;
BGN_SAVE
errno = 0;
res = fflush(f->f_fp);
END_SAVE
if (res != 0) {
err_errno(IOError);
clearerr(f->f_fp);
return NULL;
}
INCREF(None);
return None;
}
static object *
file_isatty(f, args)
fileobject *f;
object *args;
{
long res;
if (f->f_fp == NULL)
return err_closed();
if (!getnoarg(args))
return NULL;
BGN_SAVE
res = isatty((int)fileno(f->f_fp));
END_SAVE
return newintobject(res);
}
static object *
file_read(f, args)
fileobject *f;
object *args;
{
int n, n1, n2, n3;
object *v;
if (f->f_fp == NULL)
return err_closed();
if (args == NULL)
n = -1;
else {
if (!getargs(args, "i", &n))
return NULL;
}
n2 = n >= 0 ? n : BUFSIZ;
v = newsizedstringobject((char *)NULL, n2);
if (v == NULL)
return NULL;
n1 = 0;
BGN_SAVE
for (;;) {
n3 = fread(BUF(v)+n1, 1, n2-n1, f->f_fp);
/* XXX Error check? */
if (n3 == 0)
break;
n1 += n3;
if (n1 == n)
break;
if (n < 0) {
n2 = n1 + BUFSIZ;
RET_SAVE
if (resizestring(&v, n2) < 0)
return NULL;
RES_SAVE
}
}
END_SAVE
if (n1 != n2)
resizestring(&v, n1);
return v;
}
/* Internal routine to get a line.
Size argument interpretation:
> 0: max length;
= 0: read arbitrary line;
< 0: strip trailing '\n', raise EOFError if EOF reached immediately
*/
static object *
getline(f, n)
fileobject *f;
int n;
{
register FILE *fp;
register int c;
register char *buf, *end;
int n1, n2;
object *v;
fp = f->f_fp;
n2 = n > 0 ? n : 100;
v = newsizedstringobject((char *)NULL, n2);
if (v == NULL)
return NULL;
buf = BUF(v);
end = buf + n2;
BGN_SAVE
for (;;) {
if ((c = getc(fp)) == EOF) {
clearerr(fp);
if (sigcheck()) {
RET_SAVE
DECREF(v);
return NULL;
}
if (n < 0 && buf == BUF(v)) {
RET_SAVE
DECREF(v);
err_setstr(EOFError,
"EOF when reading a line");
return NULL;
}
break;
}
if ((*buf++ = c) == '\n') {
if (n < 0)
buf--;
break;
}
if (buf == end) {
if (n > 0)
break;
n1 = n2;
n2 += 1000;
RET_SAVE
if (resizestring(&v, n2) < 0)
return NULL;
RES_SAVE
buf = BUF(v) + n1;
end = BUF(v) + n2;
}
}
END_SAVE
n1 = buf - BUF(v);
if (n1 != n2)
resizestring(&v, n1);
return v;
}
/* External C interface */
object *
filegetline(f, n)
object *f;
int n;
{
if (f == NULL) {
err_badcall();
return NULL;
}
if (!is_fileobject(f)) {
object *reader;
object *args;
object *result;
reader = getattr(f, "readline");
if (reader == NULL)
return NULL;
if (n <= 0)
args = mkvalue("()");
else
args = mkvalue("(i)", n);
if (args == NULL) {
DECREF(reader);
return NULL;
}
result = call_object(reader, args);
DECREF(reader);
DECREF(args);
if (result != NULL && !is_stringobject(result)) {
DECREF(result);
result = NULL;
err_setstr(TypeError,
"object.readline() returned non-string");
}
if (n < 0 && result != NULL) {
char *s = getstringvalue(result);
int len = getstringsize(result);
if (len == 0) {
DECREF(result);
result = NULL;
err_setstr(EOFError,
"EOF when reading a line");
}
else if (s[len-1] == '\n') {
if (result->ob_refcnt == 1)
resizestring(&result, len-1);
else {
object *v;
v = newsizedstringobject(s, len-1);
DECREF(result);
result = v;
}
}
}
return result;
}
if (((fileobject*)f)->f_fp == NULL)
return err_closed();
return getline((fileobject *)f, n);
}
/* Python method */
static object *
file_readline(f, args)
fileobject *f;
object *args;
{
int n;
if (f->f_fp == NULL)
return err_closed();
if (args == NULL)
n = 0; /* Unlimited */
else {
if (!getintarg(args, &n))
return NULL;
if (n == 0)
return newstringobject("");
if (n < 0)
n = 0;
}
return getline(f, n);
}
static object *
file_readlines(f, args)
fileobject *f;
object *args;
{
object *list;
object *line;
if (f->f_fp == NULL)
return err_closed();
if (!getnoarg(args))
return NULL;
if ((list = newlistobject(0)) == NULL)
return NULL;
for (;;) {
line = getline(f, 0);
if (line != NULL && getstringsize(line) == 0) {
DECREF(line);
break;
}
if (line == NULL || addlistitem(list, line) != 0) {
DECREF(list);
XDECREF(line);
return NULL;
}
DECREF(line);
}
return list;
}
static object *
file_write(f, args)
fileobject *f;
object *args;
{
char *s;
int n, n2;
if (f->f_fp == NULL)
return err_closed();
if (!getargs(args, "s#", &s, &n))
return NULL;
f->f_softspace = 0;
BGN_SAVE
errno = 0;
n2 = fwrite(s, 1, n, f->f_fp);
END_SAVE
if (n2 != n) {
err_errno(IOError);
clearerr(f->f_fp);
return NULL;
}
INCREF(None);
return None;
}
static object *
file_writelines(f, args)
fileobject *f;
object *args;
{
int i, n;
if (f->f_fp == NULL)
return err_closed();
if (args == NULL || !is_listobject(args)) {
err_setstr(TypeError,
"writelines() requires list of strings");
return NULL;
}
n = getlistsize(args);
f->f_softspace = 0;
BGN_SAVE
errno = 0;
for (i = 0; i < n; i++) {
object *line = getlistitem(args, i);
int len;
int nwritten;
if (!is_stringobject(line)) {
RET_SAVE
err_setstr(TypeError,
"writelines() requires list of strings");
return NULL;
}
len = getstringsize(line);
nwritten = fwrite(getstringvalue(line), 1, len, f->f_fp);
if (nwritten != len) {
RET_SAVE
err_errno(IOError);
clearerr(f->f_fp);
return NULL;
}
}
END_SAVE
INCREF(None);
return None;
}
static struct methodlist file_methods[] = {
{"close", (method)file_close, 0},
{"flush", (method)file_flush, 0},
{"fileno", (method)file_fileno, 0},
{"isatty", (method)file_isatty, 0},
{"read", (method)file_read, 0},
{"readline", (method)file_readline, 0},
{"readlines", (method)file_readlines, 0},
{"seek", (method)file_seek, 0},
#ifdef HAVE_FTRUNCATE
{"truncate", (method)file_truncate, 0},
#endif
{"tell", (method)file_tell, 0},
{"write", (method)file_write, 0},
{"writelines", (method)file_writelines, 0},
{NULL, NULL} /* sentinel */
};
#define OFF(x) offsetof(fileobject, x)
static struct memberlist file_memberlist[] = {
{"softspace", T_INT, OFF(f_softspace)},
{"mode", T_OBJECT, OFF(f_mode), RO},
{"name", T_OBJECT, OFF(f_name), RO},
/* getattr(f, "closed") is implemented without this table */
{"closed", T_INT, 0, RO},
{NULL} /* Sentinel */
};
static object *
file_getattr(f, name)
fileobject *f;
char *name;
{
object *res;
res = findmethod(file_methods, (object *)f, name);
if (res != NULL)
return res;
err_clear();
if (strcmp(name, "closed") == 0)
return newintobject((long)(f->f_fp == 0));
return getmember((char *)f, file_memberlist, name);
}
static int
file_setattr(f, name, v)
fileobject *f;
char *name;
object *v;
{
if (v == NULL) {
err_setstr(AttributeError, "can't delete file attributes");
return -1;
}
return setmember((char *)f, file_memberlist, name, v);
}
typeobject Filetype = {
OB_HEAD_INIT(&Typetype)
0,
"file",
sizeof(fileobject),
0,
(destructor)file_dealloc, /*tp_dealloc*/
0, /*tp_print*/
(getattrfunc)file_getattr, /*tp_getattr*/
(setattrfunc)file_setattr, /*tp_setattr*/
0, /*tp_compare*/
(reprfunc)file_repr, /*tp_repr*/
};
/* Interface for the 'soft space' between print items. */
int
softspace(f, newflag)
object *f;
int newflag;
{
int oldflag = 0;
if (f == NULL) {
/* Do nothing */
}
else if (is_fileobject(f)) {
oldflag = ((fileobject *)f)->f_softspace;
((fileobject *)f)->f_softspace = newflag;
}
else {
object *v;
v = getattr(f, "softspace");
if (v == NULL)
err_clear();
else {
if (is_intobject(v))
oldflag = getintvalue(v);
DECREF(v);
}
v = newintobject((long)newflag);
if (v == NULL)
err_clear();
else {
if (setattr(f, "softspace", v) != 0)
err_clear();
DECREF(v);
}
}
return oldflag;
}
/* Interfaces to write objects/strings to file-like objects */
int
writeobject(v, f, flags)
object *v;
object *f;
int flags;
{
object *writer, *value, *args, *result;
if (f == NULL) {
err_setstr(TypeError, "writeobject with NULL file");
return -1;
}
else if (is_fileobject(f)) {
FILE *fp = getfilefile(f);
if (fp == NULL) {
err_closed();
return -1;
}
return printobject(v, fp, flags);
}
writer = getattr(f, "write");
if (writer == NULL)
return -1;
if (flags & PRINT_RAW)
value = strobject(v);
else
value = reprobject(v);
if (value == NULL) {
DECREF(writer);
return -1;
}
args = mkvalue("(O)", value);
if (value == NULL) {
DECREF(value);
DECREF(writer);
return -1;
}
result = call_object(writer, args);
DECREF(args);
DECREF(value);
DECREF(writer);
if (result == NULL)
return -1;
DECREF(result);
return 0;
}
void
writestring(s, f)
char *s;
object *f;
{
if (f == NULL) {
/* Do nothing */
}
else if (is_fileobject(f)) {
FILE *fp = getfilefile(f);
if (fp != NULL)
fputs(s, fp);
}
else if (!err_occurred()) {
object *v = newstringobject(s);
if (v == NULL) {
err_clear();
}
else {
if (writeobject(v, f, PRINT_RAW) != 0)
err_clear();
DECREF(v);
}
}
}