fileobject.c

python s60 1.4.5版本的源代码

"This is needed for lower-level file interfaces, such os.read().";
#endif

const static char seek_doc[] =
#ifdef SYMBIAN
"";
#else
"seek(offset[, whence]) -> None.  Move to new file position.\n"
"\n"
"Argument offset is a byte count.  Optional argument whence defaults to\n"
"0 (offset from start of file, offset should be >= 0); other values are 1\n"
"(move relative to current position, positive or negative), and 2 (move\n"
"relative to end of file, usually negative, although many platforms allow\n"
"seeking beyond the end of a file).\n"
"\n"
"Note that not all file objects are seekable.";
#endif

#ifdef HAVE_FTRUNCATE
const static char truncate_doc[] =
#ifdef SYMBIAN
"";
#else
"truncate([size]) -> None.  Truncate the file to at most size bytes.\n"
"\n"
"Size defaults to the current file position, as returned by tell().";
#endif
#endif

const static char tell_doc[] =
#ifdef SYMBIAN
"";
#else
"tell() -> current file position, an integer (may be a long integer).";
#endif

const static char readinto_doc[] =
#ifdef SYMBIAN
"";
#else
"readinto() -> Undocumented.  Don't use this; it may go away.";
#endif

const static char readlines_doc[] =
#ifdef SYMBIAN
"";
#else
"readlines([size]) -> list of strings, each a line from the file.\n"
"\n"
"Call readline() repeatedly and return a list of the lines so read.\n"
"The optional size argument, if given, is an approximate bound on the\n"
"total number of bytes in the lines returned.";
#endif

const static char xreadlines_doc[] =
#ifdef SYMBIAN
"";
#else
"xreadlines() -> next line from the file, as a string.\n"
"\n"
"Equivalent to xreadlines.xreadlines(file).  This is like readlines(), but\n"
"often quicker, due to reading ahead internally.";
#endif

const static char writelines_doc[] =
#ifdef SYMBIAN
"";
#else
"writelines(sequence_of_strings) -> None.  Write the strings to the file.\n"
"\n"
"Note that newlines are not added.  The sequence can be any iterable object\n"
"producing strings. This is equivalent to calling write() for each string.";
#endif

const static char flush_doc[] =
#ifdef SYMBIAN
"";
#else
"flush() -> None.  Flush the internal I/O buffer.";
#endif

const static char close_doc[] =
#ifdef SYMBIAN
"";
#else
"close() -> None or (perhaps) an integer.  Close the file.\n"
"\n"
"Sets data attribute .closed to true.  A closed file cannot be used for\n"
"further I/O operations.  close() may be called more than once without\n"
"error.  Some kinds of file objects (for example, opened by popen())\n"
"may return an exit status upon closing.";
#endif

const static char isatty_doc[] =
#ifdef SYMBIAN
"";
#else
"isatty() -> true or false.  True if the file is connected to a tty device.";
#endif

const static PyMethodDef file_methods[] = {
	{"readline",	(PyCFunction)file_readline,   METH_VARARGS, readline_doc},
	{"read",	(PyCFunction)file_read,       METH_VARARGS, read_doc},
	{"write",	(PyCFunction)file_write,      METH_VARARGS, write_doc},
	{"fileno",	(PyCFunction)file_fileno,     METH_NOARGS,  fileno_doc},
	{"seek",	(PyCFunction)file_seek,       METH_VARARGS, seek_doc},
#ifdef HAVE_FTRUNCATE
	{"truncate",	(PyCFunction)file_truncate,   METH_VARARGS, truncate_doc},
#endif
	{"tell",	(PyCFunction)file_tell,       METH_NOARGS,  tell_doc},
	{"readinto",	(PyCFunction)file_readinto,   METH_OLDARGS, readinto_doc},
	{"readlines",	(PyCFunction)file_readlines,  METH_VARARGS, readlines_doc},
	{"xreadlines",	(PyCFunction)file_xreadlines, METH_NOARGS,  xreadlines_doc},
	{"writelines",	(PyCFunction)file_writelines, METH_O,	    writelines_doc},
	{"flush",	(PyCFunction)file_flush,      METH_NOARGS,  flush_doc},
	{"close",	(PyCFunction)file_close,      METH_NOARGS,  close_doc},
	{"isatty",	(PyCFunction)file_isatty,     METH_NOARGS,  isatty_doc},
	{NULL,		NULL}		/* sentinel */
};

#define OFF(x) offsetof(PyFileObject, x)

const static PyMemberDef file_memberlist[] = {
	{"softspace",	T_INT,		OFF(f_softspace), 0,
	 "flag indicating that a space needs to be printed; used by print"},
	{"mode",	T_OBJECT,	OFF(f_mode),	RO,
	 "file mode ('r', 'w', 'a', possibly with 'b' or '+' added)"},
	{"name",	T_OBJECT,	OFF(f_name),	RO,
	 "file name"},
	/* getattr(f, "closed") is implemented without this table */
	{NULL}	/* Sentinel */
};

static PyObject *
get_closed(PyFileObject *f, void *closure)
{
	return PyInt_FromLong((long)(f->f_fp == 0));
}

const static PyGetSetDef file_getsetlist[] = {
	{"closed", (getter)get_closed, NULL, "flag set if the file is closed"},
	{0},
};

static PyObject *
file_getiter(PyObject *f)
{
	return PyObject_CallMethod(f, "xreadlines", "");
}

static PyObject *
file_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
{
	PyObject *self;
#ifndef SYMBIAN
	static PyObject *not_yet_string;
#else
	SPy_Python_globals* pyglobals = PYTHON_GLOBALS; // avoid TLS reads
#define not_yet_string (pyglobals->not_yet_string)
#endif
	assert(type != NULL && type->tp_alloc != NULL);

	if (not_yet_string == NULL) {
		not_yet_string = PyString_FromString("<uninitialized file>");
		if (not_yet_string == NULL)
			return NULL;
	}

	self = type->tp_alloc(type, 0);
	if (self != NULL) {
		/* Always fill in the name and mode, so that nobody else
		   needs to special-case NULLs there. */
		Py_INCREF(not_yet_string);
		((PyFileObject *)self)->f_name = not_yet_string;
		Py_INCREF(not_yet_string);
		((PyFileObject *)self)->f_mode = not_yet_string;
	}
	return self;
}

static int
file_init(PyObject *self, PyObject *args, PyObject *kwds)
{
	PyFileObject *foself = (PyFileObject *)self;
	int ret = 0;
	static const char *const kwlist[] = {"name", "mode", "buffering", 0};
	char *name = NULL;
	char *mode = "r";
	int bufsize = -1;

	assert(PyFile_Check(self));
	if (foself->f_fp != NULL) {
		/* Have to close the existing file first. */
		PyObject *closeresult = file_close(foself);
		if (closeresult == NULL)
			return -1;
		Py_DECREF(closeresult);
	}

	if (!PyArg_ParseTupleAndKeywords(args, kwds, "et|si:file", kwlist,
					 Py_FileSystemDefaultEncoding, &name,
					 &mode, &bufsize))
		return -1;
	if (fill_file_fields(foself, NULL, name, mode, fclose) == NULL)
		goto Error;
	if (open_the_file(foself, name, mode) == NULL)
		goto Error;
	PyFile_SetBufSize(self, bufsize);
	goto Done;

Error:
	ret = -1;
	/* fall through */
Done:
	PyMem_Free(name); /* free the encoded string */
	return ret;
}

const static char file_doc[] =
#ifdef SYMBIAN
"";
#else
"file(name[, mode[, buffering]]) -> file object\n"
"\n"
"Open a file.  The mode can be 'r', 'w' or 'a' for reading (default),\n"
"writing or appending.  The file will be created if it doesn't exist\n"
"when opened for writing or appending; it will be truncated when\n"
"opened for writing.  Add a 'b' to the mode for binary files.\n"
"Add a '+' to the mode to allow simultaneous reading and writing.\n"
"If the buffering argument is given, 0 means unbuffered, 1 means line\n"
"buffered, and larger numbers specify the buffer size.\n"
"Note:  open() is an alias for file().\n";
#endif

#ifndef SYMBIAN
PyTypeObject PyFile_Type = {
	PyObject_HEAD_INIT(&PyType_Type)
#else
const PyTypeObject c_PyFile_Type = {
	PyObject_HEAD_INIT(NULL)
#endif
	0,
	"file",
	sizeof(PyFileObject),
	0,
	(destructor)file_dealloc,		/* tp_dealloc */
	0,					/* tp_print */
	0,			 		/* tp_getattr */
	0,			 		/* tp_setattr */
	0,					/* tp_compare */
	(reprfunc)file_repr, 			/* tp_repr */
	0,					/* tp_as_number */
	0,					/* tp_as_sequence */
	0,					/* tp_as_mapping */
	0,					/* tp_hash */
	0,					/* tp_call */
	0,					/* tp_str */
	PyObject_GenericGetAttr,		/* tp_getattro */
	0,					/* tp_setattro */
	0,					/* tp_as_buffer */
	Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /* tp_flags */
	file_doc,				/* tp_doc */
	0,					/* tp_traverse */
	0,					/* tp_clear */
	0,					/* tp_richcompare */
	0,					/* tp_weaklistoffset */
	file_getiter,				/* tp_iter */
	0,					/* tp_iternext */
	file_methods,				/* tp_methods */
	file_memberlist,			/* tp_members */
	file_getsetlist,			/* tp_getset */
	0,					/* tp_base */
	0,					/* tp_dict */
	0,					/* tp_descr_get */
	0,					/* tp_descr_set */
	0,					/* tp_dictoffset */
	(initproc)file_init,			/* tp_init */
	PyType_GenericAlloc,			/* tp_alloc */
	file_new,				/* tp_new */
	_PyObject_Del,				/* tp_free */
};

/* Interface for the 'soft space' between print items. */

DL_EXPORT(int)
PyFile_SoftSpace(PyObject *f, int newflag)
{
	int oldflag = 0;
	if (f == NULL) {
		/* Do nothing */
	}
	else if (PyFile_Check(f)) {
		oldflag = ((PyFileObject *)f)->f_softspace;
		((PyFileObject *)f)->f_softspace = newflag;
	}
	else {
		PyObject *v;
		v = PyObject_GetAttrString(f, "softspace");
		if (v == NULL)
			PyErr_Clear();
		else {
			if (PyInt_Check(v))
				oldflag = PyInt_AsLong(v);
			Py_DECREF(v);
		}
		v = PyInt_FromLong((long)newflag);
		if (v == NULL)
			PyErr_Clear();
		else {
			if (PyObject_SetAttrString(f, "softspace", v) != 0)
				PyErr_Clear();
			Py_DECREF(v);
		}
	}
	return oldflag;
}

/* Interfaces to write objects/strings to file-like objects */

DL_EXPORT(int)
PyFile_WriteObject(PyObject *v, PyObject *f, int flags)
{
	PyObject *writer, *value, *args, *result;
	if (f == NULL) {
		PyErr_SetString(PyExc_TypeError, "writeobject with NULL file");
		return -1;
	}
	else if (PyFile_Check(f)) {
		FILE *fp = PyFile_AsFile(f);
		if (fp == NULL) {
			err_closed();
			return -1;
		}
		return PyObject_Print(v, fp, flags);
	}
	writer = PyObject_GetAttrString(f, "write");
	if (writer == NULL)
		return -1;
	if (flags & Py_PRINT_RAW) {
                if (PyUnicode_Check(v)) {
                        value = v;
                        Py_INCREF(value);
                } else
                        value = PyObject_Str(v);
	}
        else
		value = PyObject_Repr(v);
	if (value == NULL) {
		Py_DECREF(writer);
		return -1;
	}
	args = Py_BuildValue("(O)", value);
	if (args == NULL) {
		Py_DECREF(value);
		Py_DECREF(writer);
		return -1;
	}
	result = PyEval_CallObject(writer, args);
	Py_DECREF(args);
	Py_DECREF(value);
	Py_DECREF(writer);
	if (result == NULL)
		return -1;
	Py_DECREF(result);
	return 0;
}

DL_EXPORT(int)
PyFile_WriteString(const char *s, PyObject *f)
{
	if (f == NULL) {
		/* Should be caused by a pre-existing error */
		if (!PyErr_Occurred())
			PyErr_SetString(PyExc_SystemError,
					"null file for PyFile_WriteString");
		return -1;
	}
	else if (PyFile_Check(f)) {
		FILE *fp = PyFile_AsFile(f);
		if (fp == NULL) {
			err_closed();
			return -1;
		}
		fputs(s, fp);
		return 0;
	}
	else if (!PyErr_Occurred()) {
		PyObject *v = PyString_FromString(s);
		int err;
		if (v == NULL)
			return -1;
		err = PyFile_WriteObject(v, f, Py_PRINT_RAW);
		Py_DECREF(v);
		return err;
	}
	else
		return -1;
}

/* Try to get a file-descriptor from a Python object.  If the object
   is an integer or long integer, its value is returned.  If not, the
   object's fileno() method is called if it exists; the method must return
   an integer or long integer, which is returned as the file descriptor value.
   -1 is returned on failure.
*/

DL_EXPORT(int)
PyObject_AsFileDescriptor(PyObject *o)
{
	int fd;
	PyObject *meth;

	if (PyInt_Check(o)) {
		fd = PyInt_AsLong(o);
	}
	else if (PyLong_Check(o)) {
		fd = PyLong_AsLong(o);
	}
	else if ((meth = PyObject_GetAttrString(o, "fileno")) != NULL)
	{
		PyObject *fno = PyEval_CallObject(meth, NULL);
		Py_DECREF(meth);
		if (fno == NULL)
			return -1;

		if (PyInt_Check(fno)) {
			fd = PyInt_AsLong(fno);
			Py_DECREF(fno);
		}
		else if (PyLong_Check(fno)) {
			fd = PyLong_AsLong(fno);
			Py_DECREF(fno);
		}
		else {
			PyErr_SetString(PyExc_TypeError,
					"fileno() returned a non-integer");
			Py_DECREF(fno);
			return -1;
		}
	}
	else {
		PyErr_SetString(PyExc_TypeError,
				"argument must be an int, or have a fileno() method.");
		return -1;
	}

	if (fd < 0) {
		PyErr_Format(PyExc_ValueError,
			     "file descriptor cannot be a negative integer (%i)",
			     fd);
		return -1;
	}
	return fd;
}