fileobject.c

python s60 1.4.5版本的源代码

	end = buf + n2;

	for (;;) {
		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) {
			if (ferror(fp)) {
				PyErr_SetFromErrno(PyExc_IOError);
				clearerr(fp);
				Py_DECREF(v);
				return NULL;
			}
			clearerr(fp);
			if (PyErr_CheckSignals()) {
				Py_DECREF(v);
				return NULL;
			}
			break;
		}
		/* 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");
			Py_DECREF(v);
			return NULL;
		}
		if (_PyString_Resize(&v, n2) < 0)
			return NULL;
		buf = BUF(v) + n1;
		end = BUF(v) + n2;
	}

	n1 = buf - BUF(v);
	if (n1 != n2)
		_PyString_Resize(&v, n1);
	return v;
}

/* External C interface */

DL_EXPORT(PyObject *)
PyFile_GetLine(PyObject *f, int n)
{
	PyObject *result;

	if (f == NULL) {
		PyErr_BadInternalCall();
		return NULL;
	}

	if (PyFile_Check(f)) {
		if (((PyFileObject*)f)->f_fp == NULL)
			return err_closed();
		result = get_line((PyFileObject *)f, n);
	}
	else {
		PyObject *reader;
		PyObject *args;

		reader = PyObject_GetAttrString(f, "readline");
		if (reader == NULL)
			return NULL;
		if (n <= 0)
			args = Py_BuildValue("()");
		else
			args = Py_BuildValue("(i)", n);
		if (args == NULL) {
			Py_DECREF(reader);
			return NULL;
		}
		result = PyEval_CallObject(reader, args);
		Py_DECREF(reader);
		Py_DECREF(args);
		if (result != NULL && !PyString_Check(result)) {
			Py_DECREF(result);
			result = NULL;
			PyErr_SetString(PyExc_TypeError,
				   "object.readline() returned non-string");
		}
	}

	if (n < 0 && result != NULL && PyString_Check(result)) {
		char *s = PyString_AS_STRING(result);
		int len = PyString_GET_SIZE(result);
		if (len == 0) {
			Py_DECREF(result);
			result = NULL;
			PyErr_SetString(PyExc_EOFError,
					"EOF when reading a line");
		}
		else if (s[len-1] == '\n') {
			if (result->ob_refcnt == 1)
				_PyString_Resize(&result, len-1);
			else {
				PyObject *v;
				v = PyString_FromStringAndSize(s, len-1);
				Py_DECREF(result);
				result = v;
			}
		}
	}
	return result;
}

/* Python method */

static PyObject *
file_readline(PyFileObject *f, PyObject *args)
{
	int n = -1;

	if (f->f_fp == NULL)
		return err_closed();
	if (!PyArg_ParseTuple(args, "|i:readline", &n))
		return NULL;
	if (n == 0)
		return PyString_FromString("");
	if (n < 0)
		n = 0;
	return get_line(f, n);
}

static PyObject *
file_xreadlines(PyFileObject *f)
{
#ifndef SYMBIAN
        static PyObject* xreadlines_function = NULL;
#else
        SPy_Python_globals* pyglobals = PYTHON_GLOBALS; // avoid TLS reads
#define xreadlines_function (pyglobals->xreadlines_function)
#endif

	if (!xreadlines_function) {
		PyObject *xreadlines_module =
			PyImport_ImportModule("xreadlines");
		if(!xreadlines_module)
			return NULL;

		xreadlines_function = PyObject_GetAttrString(xreadlines_module,
							     "xreadlines");
		Py_DECREF(xreadlines_module);
		if(!xreadlines_function)
			return NULL;
	}
	return PyObject_CallFunction(xreadlines_function, "(O)", f);
}

static PyObject *
file_readlines(PyFileObject *f, PyObject *args)
{
	long sizehint = 0;
	PyObject *list;
	PyObject *line;
	char small_buffer[SMALLCHUNK];
	char *buffer = small_buffer;
	size_t buffersize = SMALLCHUNK;
	PyObject *big_buffer = NULL;
	size_t nfilled = 0;
	size_t nread;
	size_t totalread = 0;
	char *p, *q, *end;
	int err;
	int shortread = 0;

	if (f->f_fp == NULL)
		return err_closed();
	if (!PyArg_ParseTuple(args, "|l:readlines", &sizehint))
		return NULL;
	if ((list = PyList_New(0)) == NULL)
		return NULL;
	for (;;) {
		if (shortread)
			nread = 0;
		else {
			Py_BEGIN_ALLOW_THREADS
			errno = 0;
			nread = fread(buffer+nfilled, 1,
				      buffersize-nfilled, f->f_fp);
			Py_END_ALLOW_THREADS
			shortread = (nread < buffersize-nfilled);
		}
		if (nread == 0) {
			sizehint = 0;
			if (!ferror(f->f_fp))
				break;
			PyErr_SetFromErrno(PyExc_IOError);
			clearerr(f->f_fp);
		  error:
			Py_DECREF(list);
			list = NULL;
			goto cleanup;
		}
		totalread += nread;
		p = memchr(buffer+nfilled, '\n', nread);
		if (p == NULL) {
			/* Need a larger buffer to fit this line */
			nfilled += nread;
			buffersize *= 2;
			if (buffersize > INT_MAX) {
				PyErr_SetString(PyExc_OverflowError,
			    "line is longer than a Python string can hold");
				goto error;
			}
			if (big_buffer == NULL) {
				/* Create the big buffer */
				big_buffer = PyString_FromStringAndSize(
					NULL, buffersize);
				if (big_buffer == NULL)
					goto error;
				buffer = PyString_AS_STRING(big_buffer);
				memcpy(buffer, small_buffer, nfilled);
			}
			else {
				/* Grow the big buffer */
				_PyString_Resize(&big_buffer, buffersize);
				buffer = PyString_AS_STRING(big_buffer);
			}
			continue;
		}
		end = buffer+nfilled+nread;
		q = buffer;
		do {
			/* Process complete lines */
			p++;
			line = PyString_FromStringAndSize(q, p-q);
			if (line == NULL)
				goto error;
			err = PyList_Append(list, line);
			Py_DECREF(line);
			if (err != 0)
				goto error;
			q = p;
			p = memchr(q, '\n', end-q);
		} while (p != NULL);
		/* Move the remaining incomplete line to the start */
		nfilled = end-q;
		memmove(buffer, q, nfilled);
		if (sizehint > 0)
			if (totalread >= (size_t)sizehint)
				break;
	}
	if (nfilled != 0) {
		/* Partial last line */
		line = PyString_FromStringAndSize(buffer, nfilled);
		if (line == NULL)
			goto error;
		if (sizehint > 0) {
			/* Need to complete the last line */
			PyObject *rest = get_line(f, 0);
			if (rest == NULL) {
				Py_DECREF(line);
				goto error;
			}
			PyString_Concat(&line, rest);
			Py_DECREF(rest);
			if (line == NULL)
				goto error;
		}
		err = PyList_Append(list, line);
		Py_DECREF(line);
		if (err != 0)
			goto error;
	}
  cleanup:
	Py_XDECREF(big_buffer);
	return list;
}

static PyObject *
file_write(PyFileObject *f, PyObject *args)
{
	char *s;
	int n, n2;
	if (f->f_fp == NULL)
		return err_closed();
	if (!PyArg_ParseTuple(args, f->f_binary ? "s#" : "t#", &s, &n))
		return NULL;
	f->f_softspace = 0;
	Py_BEGIN_ALLOW_THREADS
	errno = 0;
	n2 = fwrite(s, 1, n, f->f_fp);
	Py_END_ALLOW_THREADS
	if (n2 != n) {
		PyErr_SetFromErrno(PyExc_IOError);
		clearerr(f->f_fp);
		return NULL;
	}
	Py_INCREF(Py_None);
	return Py_None;
}

static PyObject *
file_writelines(PyFileObject *f, PyObject *seq)
{
#define CHUNKSIZE 1000
	PyObject *list, *line;
	PyObject *it;	/* iter(seq) */
	PyObject *result;
	int i, j, index, len, nwritten, islist;

	assert(seq != NULL);
	if (f->f_fp == NULL)
		return err_closed();

	result = NULL;
	list = NULL;
	islist = PyList_Check(seq);
	if  (islist)
		it = NULL;
	else {
		it = PyObject_GetIter(seq);
		if (it == NULL) {
			PyErr_SetString(PyExc_TypeError,
				"writelines() requires an iterable argument");
			return NULL;
		}
		/* From here on, fail by going to error, to reclaim "it". */
		list = PyList_New(CHUNKSIZE);
		if (list == NULL)
			goto error;
	}

	/* Strategy: slurp CHUNKSIZE lines into a private list,
	   checking that they are all strings, then write that list
	   without holding the interpreter lock, then come back for more. */
	for (index = 0; ; index += CHUNKSIZE) {
		if (islist) {
			Py_XDECREF(list);
			list = PyList_GetSlice(seq, index, index+CHUNKSIZE);
			if (list == NULL)
				goto error;
			j = PyList_GET_SIZE(list);
		}
		else {
			for (j = 0; j < CHUNKSIZE; j++) {
				line = PyIter_Next(it);
				if (line == NULL) {
					if (PyErr_Occurred())
						goto error;
					break;
				}
				PyList_SetItem(list, j, line);
			}
		}
		if (j == 0)
			break;

		/* Check that all entries are indeed strings. If not,
		   apply the same rules as for file.write() and
		   convert the results to strings. This is slow, but
		   seems to be the only way since all conversion APIs
		   could potentially execute Python code. */
		for (i = 0; i < j; i++) {
			PyObject *v = PyList_GET_ITEM(list, i);
			if (!PyString_Check(v)) {
			    	const char *buffer;
			    	int len;
				if (((f->f_binary &&
				      PyObject_AsReadBuffer(v,
					      (const void**)&buffer,
							    &len)) ||
				     PyObject_AsCharBuffer(v,
							   &buffer,
							   &len))) {
					PyErr_SetString(PyExc_TypeError,
				"writelines() argument must be a sequence of strings");
					goto error;
				}
				line = PyString_FromStringAndSize(buffer,
								  len);
				if (line == NULL)
					goto error;
				Py_DECREF(v);
				PyList_SET_ITEM(list, i, line);
			}
		}

		/* Since we are releasing the global lock, the
		   following code may *not* execute Python code. */
		Py_BEGIN_ALLOW_THREADS
		f->f_softspace = 0;
		errno = 0;
		for (i = 0; i < j; i++) {
		    	line = PyList_GET_ITEM(list, i);
			len = PyString_GET_SIZE(line);
			nwritten = fwrite(PyString_AS_STRING(line),
					  1, len, f->f_fp);
			if (nwritten != len) {
				Py_BLOCK_THREADS
				PyErr_SetFromErrno(PyExc_IOError);
				clearerr(f->f_fp);
				goto error;
			}
		}
		Py_END_ALLOW_THREADS

		if (j < CHUNKSIZE)
			break;
	}

	Py_INCREF(Py_None);
	result = Py_None;
  error:
	Py_XDECREF(list);
  	Py_XDECREF(it);
	return result;
#undef CHUNKSIZE
}

const static char readline_doc[] =
#ifdef SYMBIAN
"";
#else
"readline([size]) -> next line from the file, as a string.\n"
"\n"
"Retain newline.  A non-negative size argument limits the maximum\n"
"number of bytes to return (an incomplete line may be returned then).\n"
"Return an empty string at EOF.";
#endif

const static char read_doc[] =
#ifdef SYMBIAN
"";
#else
"read([size]) -> read at most size bytes, returned as a string.\n"
"\n"
"If the size argument is negative or omitted, read until EOF is reached.";
#endif

const static char write_doc[] =
#ifdef SYMBIAN
"";
#else
"write(str) -> None.  Write string str to file.\n"
"\n"
"Note that due to buffering, flush() or close() may be needed before\n"
"the file on disk reflects the data written.";
#endif

const static char fileno_doc[] =
#ifdef SYMBIAN
"";
#else
"fileno() -> integer \"file descriptor\".\n"
"\n"