/* Author: Daniel Stutzbach */ #define PY_SSIZE_T_CLEAN #include "Python.h" #include #include #include #include /* For offsetof */ /* * Known likely problems: * * - Files larger then 2**32-1 * - Files with unicode filenames * - Passing numbers greater than 2**32-1 when an integer is expected * - Making it work on Windows and other oddball platforms * * To Do: * * - autoconfify header file inclusion */ #ifdef MS_WINDOWS /* can simulate truncate with Win32 API functions; see file_truncate */ #define HAVE_FTRUNCATE #define WIN32_LEAN_AND_MEAN #include #endif typedef struct { PyObject_HEAD int fd; unsigned readable : 1; unsigned writable : 1; int seekable : 2; /* -1 means unknown */ PyObject *weakreflist; } PyFileIOObject; PyTypeObject PyFileIO_Type; #define PyFileIO_Check(op) (PyObject_TypeCheck((op), &PyFileIO_Type)) /* Returns 0 on success, errno (which is < 0) on failure. */ static int internal_close(PyFileIOObject *self) { int save_errno = 0; if (self->fd >= 0) { int fd = self->fd; self->fd = -1; Py_BEGIN_ALLOW_THREADS if (close(fd) < 0) save_errno = errno; Py_END_ALLOW_THREADS } return save_errno; } static PyObject * fileio_close(PyFileIOObject *self) { errno = internal_close(self); if (errno < 0) { PyErr_SetFromErrno(PyExc_IOError); return NULL; } Py_RETURN_NONE; } static PyObject * fileio_new(PyTypeObject *type, PyObject *args, PyObject *kews) { PyFileIOObject *self; assert(type != NULL && type->tp_alloc != NULL); self = (PyFileIOObject *) type->tp_alloc(type, 0); if (self != NULL) { self->fd = -1; self->weakreflist = NULL; } return (PyObject *) self; } /* On Unix, open will succeed for directories. In Python, there should be no file objects referring to directories, so we need a check. */ static int dircheck(PyFileIOObject* self) { #if defined(HAVE_FSTAT) && defined(S_IFDIR) && defined(EISDIR) struct stat buf; if (self->fd < 0) return 0; if (fstat(self->fd, &buf) == 0 && S_ISDIR(buf.st_mode)) { #ifdef HAVE_STRERROR char *msg = strerror(EISDIR); #else char *msg = "Is a directory"; #endif PyObject *exc; internal_close(self); exc = PyObject_CallFunction(PyExc_IOError, "(is)", EISDIR, msg); PyErr_SetObject(PyExc_IOError, exc); Py_XDECREF(exc); return -1; } #endif return 0; } static int fileio_init(PyObject *oself, PyObject *args, PyObject *kwds) { PyFileIOObject *self = (PyFileIOObject *) oself; static char *kwlist[] = {"file", "mode", NULL}; char *name = NULL; char *mode = "r"; char *s; #ifdef MS_WINDOWS Py_UNICODE *widename = NULL; #endif int ret = 0; int rwa = 0, plus = 0, append = 0; int flags = 0; int fd = -1; assert(PyFileIO_Check(oself)); if (self->fd >= 0) { /* Have to close the existing file first. */ if (internal_close(self) < 0) return -1; } if (PyArg_ParseTupleAndKeywords(args, kwds, "i|s:fileio", kwlist, &fd, &mode)) { if (fd < 0) { PyErr_SetString(PyExc_ValueError, "Negative filedescriptor"); return -1; } } else { PyErr_Clear(); #ifdef Py_WIN_WIDE_FILENAMES if (GetVersion() < 0x80000000) { /* On NT, so wide API available */ PyObject *po; if (PyArg_ParseTupleAndKeywords(args, kwds, "U|s:fileio", kwlist, &po, &mode)) { widename = PyUnicode_AS_UNICODE(po); } else { /* Drop the argument parsing error as narrow strings are also valid. */ PyErr_Clear(); } } if (widename == NULL) #endif { if (!PyArg_ParseTupleAndKeywords(args, kwds, "et|s:fileio", kwlist, Py_FileSystemDefaultEncoding, &name, &mode)) goto error; } } self->readable = self->writable = 0; self->seekable = -1; s = mode; while (*s) { switch (*s++) { case 'r': if (rwa) { bad_mode: PyErr_SetString(PyExc_ValueError, "Must have exactly one of read/write/append mode"); goto error; } rwa = 1; self->readable = 1; break; case 'w': if (rwa) goto bad_mode; rwa = 1; self->writable = 1; flags |= O_CREAT | O_TRUNC; break; case 'a': if (rwa) goto bad_mode; rwa = 1; self->writable = 1; flags |= O_CREAT; append = 1; break; case '+': if (plus) goto bad_mode; self->readable = self->writable = 1; plus = 1; break; default: PyErr_Format(PyExc_ValueError, "invalid mode: %.200s", mode); goto error; } } if (!rwa) goto bad_mode; if (self->readable && self->writable) flags |= O_RDWR; else if (self->readable) flags |= O_RDONLY; else flags |= O_WRONLY; #ifdef O_BINARY flags |= O_BINARY; #endif #ifdef O_APPEND if (append) flags |= O_APPEND; #endif if (fd >= 0) { self->fd = fd; } else { Py_BEGIN_ALLOW_THREADS errno = 0; #ifdef MS_WINDOWS if (widename != NULL) self->fd = _wopen(widename, flags, 0666); else #endif self->fd = open(name, flags, 0666); Py_END_ALLOW_THREADS if (self->fd < 0 || dircheck(self) < 0) { PyErr_SetFromErrnoWithFilename(PyExc_IOError, name); goto error; } } goto done; error: ret = -1; done: PyMem_Free(name); return ret; } static void fileio_dealloc(PyFileIOObject *self) { if (self->weakreflist != NULL) PyObject_ClearWeakRefs((PyObject *) self); if (self->fd >= 0) { errno = internal_close(self); if (errno < 0) { #ifdef HAVE_STRERROR PySys_WriteStderr("close failed: [Errno %d] %s\n", errno, strerror(errno)); #else PySys_WriteStderr("close failed: [Errno %d]\n", errno); #endif } } Py_Type(self)->tp_free((PyObject *)self); } static PyObject * err_closed(void) { PyErr_SetString(PyExc_ValueError, "I/O operation on closed file"); return NULL; } static PyObject * err_mode(char *action) { PyErr_Format(PyExc_ValueError, "File not open for %s", action); return NULL; } static PyObject * fileio_fileno(PyFileIOObject *self) { if (self->fd < 0) return err_closed(); return PyInt_FromLong((long) self->fd); } static PyObject * fileio_readable(PyFileIOObject *self) { if (self->fd < 0) return err_closed(); return PyBool_FromLong((long) self->readable); } static PyObject * fileio_writable(PyFileIOObject *self) { if (self->fd < 0) return err_closed(); return PyBool_FromLong((long) self->writable); } static PyObject * fileio_seekable(PyFileIOObject *self) { if (self->fd < 0) return err_closed(); if (self->seekable < 0) { int ret; Py_BEGIN_ALLOW_THREADS ret = lseek(self->fd, 0, SEEK_CUR); Py_END_ALLOW_THREADS if (ret < 0) self->seekable = 0; else self->seekable = 1; } return PyBool_FromLong((long) self->seekable); } static PyObject * fileio_readinto(PyFileIOObject *self, PyObject *args) { char *ptr; Py_ssize_t n; if (self->fd < 0) return err_closed(); if (!self->readable) return err_mode("reading"); if (!PyArg_ParseTuple(args, "w#", &ptr, &n)) return NULL; Py_BEGIN_ALLOW_THREADS errno = 0; n = read(self->fd, ptr, n); Py_END_ALLOW_THREADS if (n < 0) { if (errno == EAGAIN) Py_RETURN_NONE; PyErr_SetFromErrno(PyExc_IOError); return NULL; } return PyInt_FromSsize_t(n); } #define DEFAULT_BUFFER_SIZE (8*1024) static PyObject * fileio_readall(PyFileIOObject *self) { PyObject *result; Py_ssize_t total = 0; int n; result = PyBytes_FromStringAndSize(NULL, DEFAULT_BUFFER_SIZE); if (result == NULL) return NULL; while (1) { Py_ssize_t newsize = total + DEFAULT_BUFFER_SIZE; if (PyBytes_GET_SIZE(result) < newsize) { if (PyBytes_Resize(result, newsize) < 0) { if (total == 0) { Py_DECREF(result); return NULL; } PyErr_Clear(); break; } } Py_BEGIN_ALLOW_THREADS errno = 0; n = read(self->fd, PyBytes_AS_STRING(result) + total, newsize - total); Py_END_ALLOW_THREADS if (n == 0) break; if (n < 0) { if (total > 0) break; if (errno == EAGAIN) { Py_DECREF(result); Py_RETURN_NONE; } Py_DECREF(result); PyErr_SetFromErrno(PyExc_IOError); return NULL; } total += n; } if (PyBytes_GET_SIZE(result) > total) { if (PyBytes_Resize(result, total) < 0) { /* This should never happen, but just in case */ Py_DECREF(result); return NULL; } } return result; } static PyObject * fileio_read(PyFileIOObject *self, PyObject *args) { char *ptr; Py_ssize_t n; Py_ssize_t size = -1; PyObject *bytes; if (self->fd < 0) return err_closed(); if (!self->readable) return err_mode("reading"); if (!PyArg_ParseTuple(args, "|n", &size)) return NULL; if (size < 0) { return fileio_readall(self); } bytes = PyBytes_FromStringAndSize(NULL, size); if (bytes == NULL) return NULL; ptr = PyBytes_AsString(bytes); Py_BEGIN_ALLOW_THREADS errno = 0; n = read(self->fd, ptr, size); Py_END_ALLOW_THREADS if (n < 0) { if (errno == EAGAIN) Py_RETURN_NONE; PyErr_SetFromErrno(PyExc_IOError); return NULL; } if (n != size) { if (PyBytes_Resize(bytes, n) < 0) { Py_DECREF(bytes); return NULL; } } return (PyObject *) bytes; } static PyObject * fileio_write(PyFileIOObject *self, PyObject *args) { Py_ssize_t n; char *ptr; if (self->fd < 0) return err_closed(); if (!self->writable) return err_mode("writing"); if (!PyArg_ParseTuple(args, "s#", &ptr, &n)) return NULL; Py_BEGIN_ALLOW_THREADS errno = 0; n = write(self->fd, ptr, n); Py_END_ALLOW_THREADS if (n < 0) { if (errno == EAGAIN) Py_RETURN_NONE; PyErr_SetFromErrno(PyExc_IOError); return NULL; } return PyInt_FromSsize_t(n); } /* XXX Windows support below is likely incomplete */ #if defined(MS_WIN64) || defined(MS_WINDOWS) typedef PY_LONG_LONG Py_off_t; #else typedef off_t Py_off_t; #endif /* Cribbed from posix_lseek() */ static PyObject * portable_lseek(int fd, PyObject *posobj, int whence) { Py_off_t pos, res; #ifdef SEEK_SET /* Turn 0, 1, 2 into SEEK_{SET,CUR,END} */ switch (whence) { #if SEEK_SET != 0 case 0: whence = SEEK_SET; break; #endif #if SEEK_CUR != 1 case 1: whence = SEEK_CUR; break; #endif #if SEEL_END != 2 case 2: whence = SEEK_END; break; #endif } #endif /* SEEK_SET */ if (posobj == NULL) pos = 0; else { #if !defined(HAVE_LARGEFILE_SUPPORT) pos = PyInt_AsLong(posobj); #else pos = PyLong_Check(posobj) ? PyLong_AsLongLong(posobj) : PyInt_AsLong(posobj); #endif if (PyErr_Occurred()) return NULL; } Py_BEGIN_ALLOW_THREADS #if defined(MS_WIN64) || defined(MS_WINDOWS) res = _lseeki64(fd, pos, whence); #else res = lseek(fd, pos, whence); #endif Py_END_ALLOW_THREADS if (res < 0) return PyErr_SetFromErrno(PyExc_IOError); #if !defined(HAVE_LARGEFILE_SUPPORT) return PyInt_FromLong(res); #else return PyLong_FromLongLong(res); #endif } static PyObject * fileio_seek(PyFileIOObject *self, PyObject *args) { PyObject *posobj; int whence = 0; if (self->fd < 0) return err_closed(); if (!PyArg_ParseTuple(args, "O|i", &posobj, &whence)) return NULL; return portable_lseek(self->fd, posobj, whence); } static PyObject * fileio_tell(PyFileIOObject *self, PyObject *args) { if (self->fd < 0) return err_closed(); return portable_lseek(self->fd, NULL, 1); } #ifdef HAVE_FTRUNCATE static PyObject * fileio_truncate(PyFileIOObject *self, PyObject *args) { PyObject *posobj = NULL; Py_off_t pos; int ret; int fd; fd = self->fd; if (fd < 0) return err_closed(); if (!self->writable) return err_mode("writing"); if (!PyArg_ParseTuple(args, "|O", &posobj)) return NULL; if (posobj == Py_None || posobj == NULL) { posobj = portable_lseek(fd, NULL, 1); if (posobj == NULL) return NULL; } else { Py_INCREF(posobj); } #if !defined(HAVE_LARGEFILE_SUPPORT) pos = PyInt_AsLong(posobj); #else pos = PyLong_Check(posobj) ? PyLong_AsLongLong(posobj) : PyInt_AsLong(posobj); #endif if (PyErr_Occurred()) { Py_DECREF(posobj); return NULL; } #ifdef MS_WINDOWS /* MS _chsize doesn't work if newsize doesn't fit in 32 bits, so don't even try using it. */ { HANDLE hFile; PyObject *pos2, *oldposobj; /* store the current position */ oldposobj = portable_lseek(self->fd, NULL, 1); if (oldposobj == NULL) { Py_DECREF(posobj); return NULL; } /* Have to move current pos to desired endpoint on Windows. */ errno = 0; pos2 = portable_lseek(fd, posobj, SEEK_SET); if (pos2 == NULL) { Py_DECREF(posobj); Py_DECREF(oldposobj); return NULL; } Py_DECREF(pos2); /* Truncate. Note that this may grow the file! */ Py_BEGIN_ALLOW_THREADS errno = 0; hFile = (HANDLE)_get_osfhandle(fd); ret = hFile == (HANDLE)-1; if (ret == 0) { ret = SetEndOfFile(hFile) == 0; if (ret) errno = EACCES; } Py_END_ALLOW_THREADS if (ret == 0) { /* Move to the previous position in the file */ pos2 = portable_lseek(fd, oldposobj, SEEK_SET); if (pos2 == NULL) { Py_DECREF(posobj); Py_DECREF(oldposobj); return NULL; } } Py_DECREF(pos2); Py_DECREF(oldposobj); } #else Py_BEGIN_ALLOW_THREADS errno = 0; ret = ftruncate(fd, pos); Py_END_ALLOW_THREADS #endif /* !MS_WINDOWS */ if (ret != 0) { Py_DECREF(posobj); PyErr_SetFromErrno(PyExc_IOError); return NULL; } return posobj; } #endif static char * mode_string(PyFileIOObject *self) { if (self->readable) { if (self->writable) return "r+"; else return "r"; } else return "w"; } static PyObject * fileio_repr(PyFileIOObject *self) { if (self->fd < 0) return PyUnicode_FromFormat("_fileio._FileIO(-1)"); return PyUnicode_FromFormat("_fileio._FileIO(%d, '%s')", self->fd, mode_string(self)); } static PyObject * fileio_isatty(PyFileIOObject *self) { long res; if (self->fd < 0) return err_closed(); Py_BEGIN_ALLOW_THREADS res = isatty(self->fd); Py_END_ALLOW_THREADS return PyBool_FromLong(res); } PyDoc_STRVAR(fileio_doc, "file(name: str[, mode: str]) -> file IO 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 '+' to the mode to allow simultaneous\n" "reading and writing."); PyDoc_STRVAR(read_doc, "read(size: int) -> bytes. read at most size bytes, returned as bytes.\n" "\n" "Only makes one system call, so less data may be returned than requested\n" "In non-blocking mode, returns None if no data is available.\n" "On end-of-file, returns ''."); PyDoc_STRVAR(readall_doc, "readall() -> bytes. read all data from the file, returned as bytes.\n" "\n" "In non-blocking mode, returns as much as is immediately available,\n" "or None if no data is available. On end-of-file, returns ''."); PyDoc_STRVAR(write_doc, "write(b: bytes) -> int. Write bytes b to file, return number written.\n" "\n" "Only makes one system call, so not all of the data may be written.\n" "The number of bytes actually written is returned."); PyDoc_STRVAR(fileno_doc, "fileno() -> int. \"file descriptor\".\n" "\n" "This is needed for lower-level file interfaces, such the fcntl module."); PyDoc_STRVAR(seek_doc, "seek(offset: int[, whence: int]) -> 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" "Note that not all file objects are seekable."); #ifdef HAVE_FTRUNCATE PyDoc_STRVAR(truncate_doc, "truncate([size: int]) -> None. Truncate the file to at most size bytes.\n" "\n" "Size defaults to the current file position, as returned by tell()."); #endif PyDoc_STRVAR(tell_doc, "tell() -> int. Current file position"); PyDoc_STRVAR(readinto_doc, "readinto() -> Undocumented. Don't use this; it may go away."); PyDoc_STRVAR(close_doc, "close() -> None. Close the file.\n" "\n" "A closed file cannot be used for further I/O operations. close() may be\n" "called more than once without error. Changes the fileno to -1."); PyDoc_STRVAR(isatty_doc, "isatty() -> bool. True if the file is connected to a tty device."); PyDoc_STRVAR(seekable_doc, "seekable() -> bool. True if file supports random-access."); PyDoc_STRVAR(readable_doc, "readable() -> bool. True if file was opened in a read mode."); PyDoc_STRVAR(writable_doc, "writable() -> bool. True if file was opened in a write mode."); static PyMethodDef fileio_methods[] = { {"read", (PyCFunction)fileio_read, METH_VARARGS, read_doc}, {"readall", (PyCFunction)fileio_readall, METH_NOARGS, readall_doc}, {"readinto", (PyCFunction)fileio_readinto, METH_VARARGS, readinto_doc}, {"write", (PyCFunction)fileio_write, METH_VARARGS, write_doc}, {"seek", (PyCFunction)fileio_seek, METH_VARARGS, seek_doc}, {"tell", (PyCFunction)fileio_tell, METH_VARARGS, tell_doc}, #ifdef HAVE_FTRUNCATE {"truncate", (PyCFunction)fileio_truncate, METH_VARARGS, truncate_doc}, #endif {"close", (PyCFunction)fileio_close, METH_NOARGS, close_doc}, {"seekable", (PyCFunction)fileio_seekable, METH_NOARGS, seekable_doc}, {"readable", (PyCFunction)fileio_readable, METH_NOARGS, readable_doc}, {"writable", (PyCFunction)fileio_writable, METH_NOARGS, writable_doc}, {"fileno", (PyCFunction)fileio_fileno, METH_NOARGS, fileno_doc}, {"isatty", (PyCFunction)fileio_isatty, METH_NOARGS, isatty_doc}, {NULL, NULL} /* sentinel */ }; /* 'closed' and 'mode' are attributes for backwards compatibility reasons. */ static PyObject * get_closed(PyFileIOObject *self, void *closure) { return PyBool_FromLong((long)(self->fd < 0)); } static PyObject * get_mode(PyFileIOObject *self, void *closure) { return PyUnicode_FromString(mode_string(self)); } static PyGetSetDef fileio_getsetlist[] = { {"closed", (getter)get_closed, NULL, "True if the file is closed"}, {"mode", (getter)get_mode, NULL, "String giving the file mode"}, {0}, }; PyTypeObject PyFileIO_Type = { PyVarObject_HEAD_INIT(&PyType_Type, 0) "FileIO", sizeof(PyFileIOObject), 0, (destructor)fileio_dealloc, /* tp_dealloc */ 0, /* tp_print */ 0, /* tp_getattr */ 0, /* tp_setattr */ 0, /* tp_compare */ (reprfunc)fileio_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 */ fileio_doc, /* tp_doc */ 0, /* tp_traverse */ 0, /* tp_clear */ 0, /* tp_richcompare */ offsetof(PyFileIOObject, weakreflist), /* tp_weaklistoffset */ 0, /* tp_iter */ 0, /* tp_iternext */ fileio_methods, /* tp_methods */ 0, /* tp_members */ fileio_getsetlist, /* tp_getset */ 0, /* tp_base */ 0, /* tp_dict */ 0, /* tp_descr_get */ 0, /* tp_descr_set */ 0, /* tp_dictoffset */ fileio_init, /* tp_init */ PyType_GenericAlloc, /* tp_alloc */ fileio_new, /* tp_new */ PyObject_Del, /* tp_free */ }; static PyMethodDef module_methods[] = { {NULL, NULL} }; PyMODINIT_FUNC init_fileio(void) { PyObject *m; /* a module object */ m = Py_InitModule3("_fileio", module_methods, "Fast implementation of io.FileIO."); if (m == NULL) return; if (PyType_Ready(&PyFileIO_Type) < 0) return; Py_INCREF(&PyFileIO_Type); PyModule_AddObject(m, "_FileIO", (PyObject *) &PyFileIO_Type); }