[mirror_edk2.git] / AppPkg / Applications / Python / Python-2.7.2 / Modules / _io / fileio.c

/* Author: Daniel Stutzbach */\r
\r
#define PY_SSIZE_T_CLEAN\r
#include "Python.h"\r
#ifdef HAVE_SYS_TYPES_H\r
#include <sys/types.h>\r
#endif\r
#ifdef HAVE_SYS_STAT_H\r
#include <sys/stat.h>\r
#endif\r
#ifdef HAVE_FCNTL_H\r
#include <fcntl.h>\r
#endif\r
#include <stddef.h> /* For offsetof */\r
#include "_iomodule.h"\r
\r
/*\r
 * Known likely problems:\r
 *\r
 * - Files larger then 2**32-1\r
 * - Files with unicode filenames\r
 * - Passing numbers greater than 2**32-1 when an integer is expected\r
 * - Making it work on Windows and other oddball platforms\r
 *\r
 * To Do:\r
 *\r
 * - autoconfify header file inclusion\r
 */\r
\r
#ifdef MS_WINDOWS\r
/* can simulate truncate with Win32 API functions; see file_truncate */\r
#define HAVE_FTRUNCATE\r
#define WIN32_LEAN_AND_MEAN\r
#include <windows.h>\r
#endif\r
\r
#if BUFSIZ < (8*1024)\r
#define SMALLCHUNK (8*1024)\r
#elif (BUFSIZ >= (2 << 25))\r
#error "unreasonable BUFSIZ > 64MB defined"\r
#else\r
#define SMALLCHUNK BUFSIZ\r
#endif\r
\r
#if SIZEOF_INT < 4\r
#define BIGCHUNK  (512 * 32)\r
#else\r
#define BIGCHUNK  (512 * 1024)\r
#endif\r
\r
typedef struct {\r
    PyObject_HEAD\r
    int fd;\r
    unsigned int readable : 1;\r
    unsigned int writable : 1;\r
    signed int seekable : 2; /* -1 means unknown */\r
    unsigned int closefd : 1;\r
    PyObject *weakreflist;\r
    PyObject *dict;\r
} fileio;\r
\r
PyTypeObject PyFileIO_Type;\r
\r
#define PyFileIO_Check(op) (PyObject_TypeCheck((op), &PyFileIO_Type))\r
\r
int\r
_PyFileIO_closed(PyObject *self)\r
{\r
    return ((fileio *)self)->fd < 0;\r
}\r
\r
static PyObject *\r
portable_lseek(int fd, PyObject *posobj, int whence);\r
\r
static PyObject *portable_lseek(int fd, PyObject *posobj, int whence);\r
\r
/* Returns 0 on success, -1 with exception set on failure. */\r
static int\r
internal_close(fileio *self)\r
{\r
    int err = 0;\r
    int save_errno = 0;\r
    if (self->fd >= 0) {\r
        int fd = self->fd;\r
        self->fd = -1;\r
        /* fd is accessible and someone else may have closed it */\r
        if (_PyVerify_fd(fd)) {\r
            Py_BEGIN_ALLOW_THREADS\r
            err = close(fd);\r
            if (err < 0)\r
                save_errno = errno;\r
            Py_END_ALLOW_THREADS\r
        } else {\r
            save_errno = errno;\r
            err = -1;\r
        }\r
    }\r
    if (err < 0) {\r
        errno = save_errno;\r
        PyErr_SetFromErrno(PyExc_IOError);\r
        return -1;\r
    }\r
    return 0;\r
}\r
\r
static PyObject *\r
fileio_close(fileio *self)\r
{\r
    if (!self->closefd) {\r
        self->fd = -1;\r
        Py_RETURN_NONE;\r
    }\r
    errno = internal_close(self);\r
    if (errno < 0)\r
        return NULL;\r
\r
    return PyObject_CallMethod((PyObject*)&PyRawIOBase_Type,\r
                               "close", "O", self);\r
}\r
\r
static PyObject *\r
fileio_new(PyTypeObject *type, PyObject *args, PyObject *kwds)\r
{\r
    fileio *self;\r
\r
    assert(type != NULL && type->tp_alloc != NULL);\r
\r
    self = (fileio *) type->tp_alloc(type, 0);\r
    if (self != NULL) {\r
        self->fd = -1;\r
        self->readable = 0;\r
        self->writable = 0;\r
        self->seekable = -1;\r
        self->closefd = 1;\r
        self->weakreflist = NULL;\r
    }\r
\r
    return (PyObject *) self;\r
}\r
\r
/* On Unix, open will succeed for directories.\r
   In Python, there should be no file objects referring to\r
   directories, so we need a check.  */\r
\r
static int\r
dircheck(fileio* self, const char *name)\r
{\r
#if defined(HAVE_FSTAT) && defined(S_IFDIR) && defined(EISDIR)\r
    struct stat buf;\r
    if (self->fd < 0)\r
        return 0;\r
    if (fstat(self->fd, &buf) == 0 && S_ISDIR(buf.st_mode)) {\r
        char *msg = strerror(EISDIR);\r
        PyObject *exc;\r
        if (internal_close(self))\r
            return -1;\r
\r
        exc = PyObject_CallFunction(PyExc_IOError, "(iss)",\r
                                    EISDIR, msg, name);\r
        PyErr_SetObject(PyExc_IOError, exc);\r
        Py_XDECREF(exc);\r
        return -1;\r
    }\r
#endif\r
    return 0;\r
}\r
\r
static int\r
check_fd(int fd)\r
{\r
#if defined(HAVE_FSTAT)\r
    struct stat buf;\r
    if (!_PyVerify_fd(fd) || (fstat(fd, &buf) < 0 && errno == EBADF)) {\r
        PyObject *exc;\r
        char *msg = strerror(EBADF);\r
        exc = PyObject_CallFunction(PyExc_OSError, "(is)",\r
                                    EBADF, msg);\r
        PyErr_SetObject(PyExc_OSError, exc);\r
        Py_XDECREF(exc);\r
        return -1;\r
    }\r
#endif\r
    return 0;\r
}\r
\r
\r
static int\r
fileio_init(PyObject *oself, PyObject *args, PyObject *kwds)\r
{\r
    fileio *self = (fileio *) oself;\r
    static char *kwlist[] = {"file", "mode", "closefd", NULL};\r
    const char *name = NULL;\r
    PyObject *nameobj, *stringobj = NULL;\r
    char *mode = "r";\r
    char *s;\r
#ifdef MS_WINDOWS\r
    Py_UNICODE *widename = NULL;\r
#endif\r
    int ret = 0;\r
    int rwa = 0, plus = 0, append = 0;\r
    int flags = 0;\r
    int fd = -1;\r
    int closefd = 1;\r
\r
    assert(PyFileIO_Check(oself));\r
    if (self->fd >= 0) {\r
        /* Have to close the existing file first. */\r
        if (internal_close(self) < 0)\r
            return -1;\r
    }\r
\r
    if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|si:fileio",\r
                                     kwlist, &nameobj, &mode, &closefd))\r
        return -1;\r
\r
    if (PyFloat_Check(nameobj)) {\r
        PyErr_SetString(PyExc_TypeError,\r
                        "integer argument expected, got float");\r
        return -1;\r
    }\r
\r
    fd = PyLong_AsLong(nameobj);\r
    if (fd < 0) {\r
        if (!PyErr_Occurred()) {\r
            PyErr_SetString(PyExc_ValueError,\r
                            "Negative filedescriptor");\r
            return -1;\r
        }\r
        PyErr_Clear();\r
    }\r
\r
#ifdef MS_WINDOWS\r
    if (PyUnicode_Check(nameobj))\r
        widename = PyUnicode_AS_UNICODE(nameobj);\r
    if (widename == NULL)\r
#endif\r
    if (fd < 0)\r
    {\r
        if (PyBytes_Check(nameobj) || PyByteArray_Check(nameobj)) {\r
            Py_ssize_t namelen;\r
            if (PyObject_AsCharBuffer(nameobj, &name, &namelen) < 0)\r
                return -1;\r
        }\r
        else {\r
            PyObject *u = PyUnicode_FromObject(nameobj);\r
\r
            if (u == NULL)\r
                return -1;\r
\r
            stringobj = PyUnicode_AsEncodedString(\r
                u, Py_FileSystemDefaultEncoding, NULL);\r
            Py_DECREF(u);\r
            if (stringobj == NULL)\r
                return -1;\r
            if (!PyBytes_Check(stringobj)) {\r
                PyErr_SetString(PyExc_TypeError,\r
                                "encoder failed to return bytes");\r
                goto error;\r
            }\r
            name = PyBytes_AS_STRING(stringobj);\r
        }\r
    }\r
\r
    s = mode;\r
    while (*s) {\r
        switch (*s++) {\r
        case 'r':\r
            if (rwa) {\r
            bad_mode:\r
                PyErr_SetString(PyExc_ValueError,\r
                                "Must have exactly one of read/write/append "\r
                                "mode and at most one plus");\r
                goto error;\r
            }\r
            rwa = 1;\r
            self->readable = 1;\r
            break;\r
        case 'w':\r
            if (rwa)\r
                goto bad_mode;\r
            rwa = 1;\r
            self->writable = 1;\r
            flags |= O_CREAT | O_TRUNC;\r
            break;\r
        case 'a':\r
            if (rwa)\r
                goto bad_mode;\r
            rwa = 1;\r
            self->writable = 1;\r
            flags |= O_CREAT;\r
            append = 1;\r
            break;\r
        case 'b':\r
            break;\r
        case '+':\r
            if (plus)\r
                goto bad_mode;\r
            self->readable = self->writable = 1;\r
            plus = 1;\r
            break;\r
        default:\r
            PyErr_Format(PyExc_ValueError,\r
                         "invalid mode: %.200s", mode);\r
            goto error;\r
        }\r
    }\r
\r
    if (!rwa)\r
        goto bad_mode;\r
\r
    if (self->readable && self->writable)\r
        flags |= O_RDWR;\r
    else if (self->readable)\r
        flags |= O_RDONLY;\r
    else\r
        flags |= O_WRONLY;\r
\r
#ifdef O_BINARY\r
    flags |= O_BINARY;\r
#endif\r
\r
#ifdef O_APPEND\r
    if (append)\r
        flags |= O_APPEND;\r
#endif\r
\r
    if (fd >= 0) {\r
        if (check_fd(fd))\r
            goto error;\r
        self->fd = fd;\r
        self->closefd = closefd;\r
    }\r
    else {\r
        self->closefd = 1;\r
        if (!closefd) {\r
            PyErr_SetString(PyExc_ValueError,\r
                "Cannot use closefd=False with file name");\r
            goto error;\r
        }\r
\r
        Py_BEGIN_ALLOW_THREADS\r
        errno = 0;\r
#ifdef MS_WINDOWS\r
        if (widename != NULL)\r
            self->fd = _wopen(widename, flags, 0666);\r
        else\r
#endif\r
            self->fd = open(name, flags, 0666);\r
        Py_END_ALLOW_THREADS\r
        if (self->fd < 0) {\r
#ifdef MS_WINDOWS\r
            if (widename != NULL)\r
                PyErr_SetFromErrnoWithUnicodeFilename(PyExc_IOError, widename);\r
            else\r
#endif\r
                PyErr_SetFromErrnoWithFilename(PyExc_IOError, name);\r
            goto error;\r
        }\r
        if(dircheck(self, name) < 0)\r
            goto error;\r
    }\r
\r
    if (PyObject_SetAttrString((PyObject *)self, "name", nameobj) < 0)\r
        goto error;\r
\r
    if (append) {\r
        /* For consistent behaviour, we explicitly seek to the\r
           end of file (otherwise, it might be done only on the\r
           first write()). */\r
        PyObject *pos = portable_lseek(self->fd, NULL, 2);\r
        if (pos == NULL) {\r
            if (closefd) {\r
                close(self->fd);\r
                self->fd = -1;\r
            }\r
            goto error;\r
        }\r
        Py_DECREF(pos);\r
    }\r
\r
    goto done;\r
\r
 error:\r
    ret = -1;\r
\r
 done:\r
    Py_CLEAR(stringobj);\r
    return ret;\r
}\r
\r
static int\r
fileio_traverse(fileio *self, visitproc visit, void *arg)\r
{\r
    Py_VISIT(self->dict);\r
    return 0;\r
}\r
\r
static int\r
fileio_clear(fileio *self)\r
{\r
    Py_CLEAR(self->dict);\r
    return 0;\r
}\r
\r
static void\r
fileio_dealloc(fileio *self)\r
{\r
    if (_PyIOBase_finalize((PyObject *) self) < 0)\r
        return;\r
    _PyObject_GC_UNTRACK(self);\r
    if (self->weakreflist != NULL)\r
        PyObject_ClearWeakRefs((PyObject *) self);\r
    Py_CLEAR(self->dict);\r
    Py_TYPE(self)->tp_free((PyObject *)self);\r
}\r
\r
static PyObject *\r
err_closed(void)\r
{\r
    PyErr_SetString(PyExc_ValueError, "I/O operation on closed file");\r
    return NULL;\r
}\r
\r
static PyObject *\r
err_mode(char *action)\r
{\r
    PyErr_Format(PyExc_ValueError, "File not open for %s", action);\r
    return NULL;\r
}\r
\r
static PyObject *\r
fileio_fileno(fileio *self)\r
{\r
    if (self->fd < 0)\r
        return err_closed();\r
    return PyInt_FromLong((long) self->fd);\r
}\r
\r
static PyObject *\r
fileio_readable(fileio *self)\r
{\r
    if (self->fd < 0)\r
        return err_closed();\r
    return PyBool_FromLong((long) self->readable);\r
}\r
\r
static PyObject *\r
fileio_writable(fileio *self)\r
{\r
    if (self->fd < 0)\r
        return err_closed();\r
    return PyBool_FromLong((long) self->writable);\r
}\r
\r
static PyObject *\r
fileio_seekable(fileio *self)\r
{\r
    if (self->fd < 0)\r
        return err_closed();\r
    if (self->seekable < 0) {\r
        PyObject *pos = portable_lseek(self->fd, NULL, SEEK_CUR);\r
        if (pos == NULL) {\r
            PyErr_Clear();\r
            self->seekable = 0;\r
        } else {\r
            Py_DECREF(pos);\r
            self->seekable = 1;\r
        }\r
    }\r
    return PyBool_FromLong((long) self->seekable);\r
}\r
\r
static PyObject *\r
fileio_readinto(fileio *self, PyObject *args)\r
{\r
    Py_buffer pbuf;\r
    Py_ssize_t n;\r
\r
    if (self->fd < 0)\r
        return err_closed();\r
    if (!self->readable)\r
        return err_mode("reading");\r
\r
    if (!PyArg_ParseTuple(args, "w*", &pbuf))\r
        return NULL;\r
\r
    if (_PyVerify_fd(self->fd)) {\r
        Py_BEGIN_ALLOW_THREADS\r
        errno = 0;\r
        n = read(self->fd, pbuf.buf, pbuf.len);\r
        Py_END_ALLOW_THREADS\r
    } else\r
        n = -1;\r
    PyBuffer_Release(&pbuf);\r
    if (n < 0) {\r
        if (errno == EAGAIN)\r
            Py_RETURN_NONE;\r
        PyErr_SetFromErrno(PyExc_IOError);\r
        return NULL;\r
    }\r
\r
    return PyLong_FromSsize_t(n);\r
}\r
\r
static size_t\r
new_buffersize(fileio *self, size_t currentsize)\r
{\r
#ifdef HAVE_FSTAT\r
    off_t pos, end;\r
    struct stat st;\r
    if (fstat(self->fd, &st) == 0) {\r
        end = st.st_size;\r
        pos = lseek(self->fd, 0L, SEEK_CUR);\r
        /* Files claiming a size smaller than SMALLCHUNK may\r
           actually be streaming pseudo-files. In this case, we\r
           apply the more aggressive algorithm below.\r
        */\r
        if (end >= SMALLCHUNK && end >= pos && pos >= 0) {\r
            /* Add 1 so if the file were to grow we'd notice. */\r
            return currentsize + end - pos + 1;\r
        }\r
    }\r
#endif\r
    if (currentsize > SMALLCHUNK) {\r
        /* Keep doubling until we reach BIGCHUNK;\r
           then keep adding BIGCHUNK. */\r
        if (currentsize <= BIGCHUNK)\r
            return currentsize + currentsize;\r
        else\r
            return currentsize + BIGCHUNK;\r
    }\r
    return currentsize + SMALLCHUNK;\r
}\r
\r
static PyObject *\r
fileio_readall(fileio *self)\r
{\r
    PyObject *result;\r
    Py_ssize_t total = 0;\r
    int n;\r
\r
    if (self->fd < 0)\r
        return err_closed();\r
    if (!_PyVerify_fd(self->fd))\r
        return PyErr_SetFromErrno(PyExc_IOError);\r
\r
    result = PyBytes_FromStringAndSize(NULL, SMALLCHUNK);\r
    if (result == NULL)\r
        return NULL;\r
\r
    while (1) {\r
        size_t newsize = new_buffersize(self, total);\r
        if (newsize > PY_SSIZE_T_MAX || newsize <= 0) {\r
            PyErr_SetString(PyExc_OverflowError,\r
                "unbounded read returned more bytes "\r
                "than a Python string can hold ");\r
            Py_DECREF(result);\r
            return NULL;\r
        }\r
\r
        if (PyBytes_GET_SIZE(result) < (Py_ssize_t)newsize) {\r
            if (_PyBytes_Resize(&result, newsize) < 0) {\r
                if (total == 0) {\r
                    Py_DECREF(result);\r
                    return NULL;\r
                }\r
                PyErr_Clear();\r
                break;\r
            }\r
        }\r
        Py_BEGIN_ALLOW_THREADS\r
        errno = 0;\r
        n = read(self->fd,\r
                 PyBytes_AS_STRING(result) + total,\r
                 newsize - total);\r
        Py_END_ALLOW_THREADS\r
        if (n == 0)\r
            break;\r
        if (n < 0) {\r
            if (total > 0)\r
                break;\r
            if (errno == EAGAIN) {\r
                Py_DECREF(result);\r
                Py_RETURN_NONE;\r
            }\r
            Py_DECREF(result);\r
            PyErr_SetFromErrno(PyExc_IOError);\r
            return NULL;\r
        }\r
        total += n;\r
    }\r
\r
    if (PyBytes_GET_SIZE(result) > total) {\r
        if (_PyBytes_Resize(&result, total) < 0) {\r
            /* This should never happen, but just in case */\r
            Py_DECREF(result);\r
            return NULL;\r
        }\r
    }\r
    return result;\r
}\r
\r
static PyObject *\r
fileio_read(fileio *self, PyObject *args)\r
{\r
    char *ptr;\r
    Py_ssize_t n;\r
    Py_ssize_t size = -1;\r
    PyObject *bytes;\r
\r
    if (self->fd < 0)\r
        return err_closed();\r
    if (!self->readable)\r
        return err_mode("reading");\r
\r
    if (!PyArg_ParseTuple(args, "|O&", &_PyIO_ConvertSsize_t, &size))\r
        return NULL;\r
\r
    if (size < 0) {\r
        return fileio_readall(self);\r
    }\r
\r
    bytes = PyBytes_FromStringAndSize(NULL, size);\r
    if (bytes == NULL)\r
        return NULL;\r
    ptr = PyBytes_AS_STRING(bytes);\r
\r
    if (_PyVerify_fd(self->fd)) {\r
        Py_BEGIN_ALLOW_THREADS\r
        errno = 0;\r
        n = read(self->fd, ptr, size);\r
        Py_END_ALLOW_THREADS\r
    } else\r
        n = -1;\r
\r
    if (n < 0) {\r
        Py_DECREF(bytes);\r
        if (errno == EAGAIN)\r
            Py_RETURN_NONE;\r
        PyErr_SetFromErrno(PyExc_IOError);\r
        return NULL;\r
    }\r
\r
    if (n != size) {\r
        if (_PyBytes_Resize(&bytes, n) < 0) {\r
            Py_DECREF(bytes);\r
            return NULL;\r
        }\r
    }\r
\r
    return (PyObject *) bytes;\r
}\r
\r
static PyObject *\r
fileio_write(fileio *self, PyObject *args)\r
{\r
    Py_buffer pbuf;\r
    Py_ssize_t n;\r
\r
    if (self->fd < 0)\r
        return err_closed();\r
    if (!self->writable)\r
        return err_mode("writing");\r
\r
    if (!PyArg_ParseTuple(args, "s*", &pbuf))\r
        return NULL;\r
\r
    if (_PyVerify_fd(self->fd)) {\r
        Py_BEGIN_ALLOW_THREADS\r
        errno = 0;\r
        n = write(self->fd, pbuf.buf, pbuf.len);\r
        Py_END_ALLOW_THREADS\r
    } else\r
        n = -1;\r
\r
    PyBuffer_Release(&pbuf);\r
\r
    if (n < 0) {\r
        if (errno == EAGAIN)\r
            Py_RETURN_NONE;\r
        PyErr_SetFromErrno(PyExc_IOError);\r
        return NULL;\r
    }\r
\r
    return PyLong_FromSsize_t(n);\r
}\r
\r
/* XXX Windows support below is likely incomplete */\r
\r
/* Cribbed from posix_lseek() */\r
static PyObject *\r
portable_lseek(int fd, PyObject *posobj, int whence)\r
{\r
    Py_off_t pos, res;\r
\r
#ifdef SEEK_SET\r
    /* Turn 0, 1, 2 into SEEK_{SET,CUR,END} */\r
    switch (whence) {\r
#if SEEK_SET != 0\r
    case 0: whence = SEEK_SET; break;\r
#endif\r
#if SEEK_CUR != 1\r
    case 1: whence = SEEK_CUR; break;\r
#endif\r
#if SEEK_END != 2\r
    case 2: whence = SEEK_END; break;\r
#endif\r
    }\r
#endif /* SEEK_SET */\r
\r
    if (posobj == NULL)\r
        pos = 0;\r
    else {\r
        if(PyFloat_Check(posobj)) {\r
            PyErr_SetString(PyExc_TypeError, "an integer is required");\r
            return NULL;\r
        }\r
#if defined(HAVE_LARGEFILE_SUPPORT)\r
        pos = PyLong_AsLongLong(posobj);\r
#else\r
        pos = PyLong_AsLong(posobj);\r
#endif\r
        if (PyErr_Occurred())\r
            return NULL;\r
    }\r
\r
    if (_PyVerify_fd(fd)) {\r
        Py_BEGIN_ALLOW_THREADS\r
#if defined(MS_WIN64) || defined(MS_WINDOWS)\r
        res = _lseeki64(fd, pos, whence);\r
#else\r
        res = lseek(fd, pos, whence);\r
#endif\r
        Py_END_ALLOW_THREADS\r
    } else\r
        res = -1;\r
    if (res < 0)\r
        return PyErr_SetFromErrno(PyExc_IOError);\r
\r
#if defined(HAVE_LARGEFILE_SUPPORT)\r
    return PyLong_FromLongLong(res);\r
#else\r
    return PyLong_FromLong(res);\r
#endif\r
}\r
\r
static PyObject *\r
fileio_seek(fileio *self, PyObject *args)\r
{\r
    PyObject *posobj;\r
    int whence = 0;\r
\r
    if (self->fd < 0)\r
        return err_closed();\r
\r
    if (!PyArg_ParseTuple(args, "O|i", &posobj, &whence))\r
        return NULL;\r
\r
    return portable_lseek(self->fd, posobj, whence);\r
}\r
\r
static PyObject *\r
fileio_tell(fileio *self, PyObject *args)\r
{\r
    if (self->fd < 0)\r
        return err_closed();\r
\r
    return portable_lseek(self->fd, NULL, 1);\r
}\r
\r
#ifdef HAVE_FTRUNCATE\r
static PyObject *\r
fileio_truncate(fileio *self, PyObject *args)\r
{\r
    PyObject *posobj = NULL; /* the new size wanted by the user */\r
#ifndef MS_WINDOWS\r
    Py_off_t pos;\r
#endif\r
    int ret;\r
    int fd;\r
\r
    fd = self->fd;\r
    if (fd < 0)\r
        return err_closed();\r
    if (!self->writable)\r
        return err_mode("writing");\r
\r
    if (!PyArg_ParseTuple(args, "|O", &posobj))\r
        return NULL;\r
\r
    if (posobj == Py_None || posobj == NULL) {\r
        /* Get the current position. */\r
        posobj = portable_lseek(fd, NULL, 1);\r
        if (posobj == NULL)\r
            return NULL;\r
    }\r
    else {\r
        Py_INCREF(posobj);\r
    }\r
\r
#ifdef MS_WINDOWS\r
    /* MS _chsize doesn't work if newsize doesn't fit in 32 bits,\r
       so don't even try using it. */\r
    {\r
        PyObject *oldposobj, *tempposobj;\r
        HANDLE hFile;\r
\r
        /* we save the file pointer position */\r
        oldposobj = portable_lseek(fd, NULL, 1);\r
        if (oldposobj == NULL) {\r
            Py_DECREF(posobj);\r
            return NULL;\r
        }\r
\r
        /* we then move to the truncation position */\r
        tempposobj = portable_lseek(fd, posobj, 0);\r
        if (tempposobj == NULL) {\r
            Py_DECREF(oldposobj);\r
            Py_DECREF(posobj);\r
            return NULL;\r
        }\r
        Py_DECREF(tempposobj);\r
\r
        /* Truncate.  Note that this may grow the file! */\r
        Py_BEGIN_ALLOW_THREADS\r
        errno = 0;\r
        hFile = (HANDLE)_get_osfhandle(fd);\r
        ret = hFile == (HANDLE)-1; /* testing for INVALID_HANDLE value */\r
        if (ret == 0) {\r
            ret = SetEndOfFile(hFile) == 0;\r
            if (ret)\r
                errno = EACCES;\r
        }\r
        Py_END_ALLOW_THREADS\r
\r
        /* we restore the file pointer position in any case */\r
        tempposobj = portable_lseek(fd, oldposobj, 0);\r
        Py_DECREF(oldposobj);\r
        if (tempposobj == NULL) {\r
            Py_DECREF(posobj);\r
            return NULL;\r
        }\r
        Py_DECREF(tempposobj);\r
    }\r
#else\r
\r
#if defined(HAVE_LARGEFILE_SUPPORT)\r
    pos = PyLong_AsLongLong(posobj);\r
#else\r
    pos = PyLong_AsLong(posobj);\r
#endif\r
    if (PyErr_Occurred()){\r
        Py_DECREF(posobj);\r
        return NULL;\r
    }\r
\r
    Py_BEGIN_ALLOW_THREADS\r
    errno = 0;\r
    ret = ftruncate(fd, pos);\r
    Py_END_ALLOW_THREADS\r
\r
#endif /* !MS_WINDOWS */\r
\r
    if (ret != 0) {\r
        Py_DECREF(posobj);\r
        PyErr_SetFromErrno(PyExc_IOError);\r
        return NULL;\r
    }\r
\r
    return posobj;\r
}\r
#endif /* HAVE_FTRUNCATE */\r
\r
static char *\r
mode_string(fileio *self)\r
{\r
    if (self->readable) {\r
        if (self->writable)\r
            return "rb+";\r
        else\r
            return "rb";\r
    }\r
    else\r
        return "wb";\r
}\r
\r
static PyObject *\r
fileio_repr(fileio *self)\r
{\r
    PyObject *nameobj, *res;\r
\r
    if (self->fd < 0)\r
        return PyString_FromFormat("<_io.FileIO [closed]>");\r
\r
    nameobj = PyObject_GetAttrString((PyObject *) self, "name");\r
    if (nameobj == NULL) {\r
        if (PyErr_ExceptionMatches(PyExc_AttributeError))\r
            PyErr_Clear();\r
        else\r
            return NULL;\r
        res = PyString_FromFormat("<_io.FileIO fd=%d mode='%s'>",\r
                                   self->fd, mode_string(self));\r
    }\r
    else {\r
        PyObject *repr = PyObject_Repr(nameobj);\r
        Py_DECREF(nameobj);\r
        if (repr == NULL)\r
            return NULL;\r
        res = PyString_FromFormat("<_io.FileIO name=%s mode='%s'>",\r
                                   PyString_AS_STRING(repr),\r
                                   mode_string(self));\r
        Py_DECREF(repr);\r
    }\r
    return res;\r
}\r
\r
static PyObject *\r
fileio_isatty(fileio *self)\r
{\r
    long res;\r
\r
    if (self->fd < 0)\r
        return err_closed();\r
    Py_BEGIN_ALLOW_THREADS\r
    res = isatty(self->fd);\r
    Py_END_ALLOW_THREADS\r
    return PyBool_FromLong(res);\r
}\r
\r
\r
PyDoc_STRVAR(fileio_doc,\r
"file(name: str[, mode: str]) -> file IO object\n"\r
"\n"\r
"Open a file.  The mode can be 'r', 'w' or 'a' for reading (default),\n"\r
"writing or appending.  The file will be created if it doesn't exist\n"\r
"when opened for writing or appending; it will be truncated when\n"\r
"opened for writing.  Add a '+' to the mode to allow simultaneous\n"\r
"reading and writing.");\r
\r
PyDoc_STRVAR(read_doc,\r
"read(size: int) -> bytes.  read at most size bytes, returned as bytes.\n"\r
"\n"\r
"Only makes one system call, so less data may be returned than requested\n"\r
"In non-blocking mode, returns None if no data is available.\n"\r
"On end-of-file, returns ''.");\r
\r
PyDoc_STRVAR(readall_doc,\r
"readall() -> bytes.  read all data from the file, returned as bytes.\n"\r
"\n"\r
"In non-blocking mode, returns as much as is immediately available,\n"\r
"or None if no data is available.  On end-of-file, returns ''.");\r
\r
PyDoc_STRVAR(write_doc,\r
"write(b: bytes) -> int.  Write bytes b to file, return number written.\n"\r
"\n"\r
"Only makes one system call, so not all of the data may be written.\n"\r
"The number of bytes actually written is returned.");\r
\r
PyDoc_STRVAR(fileno_doc,\r
"fileno() -> int. \"file descriptor\".\n"\r
"\n"\r
"This is needed for lower-level file interfaces, such the fcntl module.");\r
\r
PyDoc_STRVAR(seek_doc,\r
"seek(offset: int[, whence: int]) -> None.  Move to new file position.\n"\r
"\n"\r
"Argument offset is a byte count.  Optional argument whence defaults to\n"\r
"0 (offset from start of file, offset should be >= 0); other values are 1\n"\r
"(move relative to current position, positive or negative), and 2 (move\n"\r
"relative to end of file, usually negative, although many platforms allow\n"\r
"seeking beyond the end of a file)."\r
"\n"\r
"Note that not all file objects are seekable.");\r
\r
#ifdef HAVE_FTRUNCATE\r
PyDoc_STRVAR(truncate_doc,\r
"truncate([size: int]) -> None.  Truncate the file to at most size bytes.\n"\r
"\n"\r
"Size defaults to the current file position, as returned by tell()."\r
"The current file position is changed to the value of size.");\r
#endif\r
\r
PyDoc_STRVAR(tell_doc,\r
"tell() -> int.  Current file position");\r
\r
PyDoc_STRVAR(readinto_doc,\r
"readinto() -> Same as RawIOBase.readinto().");\r
\r
PyDoc_STRVAR(close_doc,\r
"close() -> None.  Close the file.\n"\r
"\n"\r
"A closed file cannot be used for further I/O operations.  close() may be\n"\r
"called more than once without error.  Changes the fileno to -1.");\r
\r
PyDoc_STRVAR(isatty_doc,\r
"isatty() -> bool.  True if the file is connected to a tty device.");\r
\r
PyDoc_STRVAR(seekable_doc,\r
"seekable() -> bool.  True if file supports random-access.");\r
\r
PyDoc_STRVAR(readable_doc,\r
"readable() -> bool.  True if file was opened in a read mode.");\r
\r
PyDoc_STRVAR(writable_doc,\r
"writable() -> bool.  True if file was opened in a write mode.");\r
\r
static PyMethodDef fileio_methods[] = {\r
    {"read",     (PyCFunction)fileio_read,         METH_VARARGS, read_doc},\r
    {"readall",  (PyCFunction)fileio_readall,  METH_NOARGS,  readall_doc},\r
    {"readinto", (PyCFunction)fileio_readinto, METH_VARARGS, readinto_doc},\r
    {"write",    (PyCFunction)fileio_write,        METH_VARARGS, write_doc},\r
    {"seek",     (PyCFunction)fileio_seek,         METH_VARARGS, seek_doc},\r
    {"tell",     (PyCFunction)fileio_tell,         METH_VARARGS, tell_doc},\r
#ifdef HAVE_FTRUNCATE\r
    {"truncate", (PyCFunction)fileio_truncate, METH_VARARGS, truncate_doc},\r
#endif\r
    {"close",    (PyCFunction)fileio_close,        METH_NOARGS,  close_doc},\r
    {"seekable", (PyCFunction)fileio_seekable, METH_NOARGS,      seekable_doc},\r
    {"readable", (PyCFunction)fileio_readable, METH_NOARGS,      readable_doc},\r
    {"writable", (PyCFunction)fileio_writable, METH_NOARGS,      writable_doc},\r
    {"fileno",   (PyCFunction)fileio_fileno,   METH_NOARGS,      fileno_doc},\r
    {"isatty",   (PyCFunction)fileio_isatty,   METH_NOARGS,      isatty_doc},\r
    {NULL,           NULL}             /* sentinel */\r
};\r
\r
/* 'closed' and 'mode' are attributes for backwards compatibility reasons. */\r
\r
static PyObject *\r
get_closed(fileio *self, void *closure)\r
{\r
    return PyBool_FromLong((long)(self->fd < 0));\r
}\r
\r
static PyObject *\r
get_closefd(fileio *self, void *closure)\r
{\r
    return PyBool_FromLong((long)(self->closefd));\r
}\r
\r
static PyObject *\r
get_mode(fileio *self, void *closure)\r
{\r
    return PyUnicode_FromString(mode_string(self));\r
}\r
\r
static PyGetSetDef fileio_getsetlist[] = {\r
    {"closed", (getter)get_closed, NULL, "True if the file is closed"},\r
    {"closefd", (getter)get_closefd, NULL,\r
        "True if the file descriptor will be closed"},\r
    {"mode", (getter)get_mode, NULL, "String giving the file mode"},\r
    {NULL},\r
};\r
\r
PyTypeObject PyFileIO_Type = {\r
    PyVarObject_HEAD_INIT(NULL, 0)\r
    "_io.FileIO",\r
    sizeof(fileio),\r
    0,\r
    (destructor)fileio_dealloc,                 /* tp_dealloc */\r
    0,                                          /* tp_print */\r
    0,                                          /* tp_getattr */\r
    0,                                          /* tp_setattr */\r
    0,                                          /* tp_reserved */\r
    (reprfunc)fileio_repr,                      /* tp_repr */\r
    0,                                          /* tp_as_number */\r
    0,                                          /* tp_as_sequence */\r
    0,                                          /* tp_as_mapping */\r
    0,                                          /* tp_hash */\r
    0,                                          /* tp_call */\r
    0,                                          /* tp_str */\r
    PyObject_GenericGetAttr,                    /* tp_getattro */\r
    0,                                          /* tp_setattro */\r
    0,                                          /* tp_as_buffer */\r
    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE\r
                    | Py_TPFLAGS_HAVE_GC,       /* tp_flags */\r
    fileio_doc,                                 /* tp_doc */\r
    (traverseproc)fileio_traverse,              /* tp_traverse */\r
    (inquiry)fileio_clear,                      /* tp_clear */\r
    0,                                          /* tp_richcompare */\r
    offsetof(fileio, weakreflist),      /* tp_weaklistoffset */\r
    0,                                          /* tp_iter */\r
    0,                                          /* tp_iternext */\r
    fileio_methods,                             /* tp_methods */\r
    0,                                          /* tp_members */\r
    fileio_getsetlist,                          /* tp_getset */\r
    0,                                          /* tp_base */\r
    0,                                          /* tp_dict */\r
    0,                                          /* tp_descr_get */\r
    0,                                          /* tp_descr_set */\r
    offsetof(fileio, dict),         /* tp_dictoffset */\r
    fileio_init,                                /* tp_init */\r
    PyType_GenericAlloc,                        /* tp_alloc */\r
    fileio_new,                                 /* tp_new */\r
    PyObject_GC_Del,                            /* tp_free */\r
};\r