cpython/Modules/_io/stringio.c at 3.3 · python/cpython · GitHub

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#define PY_SSIZE_T_CLEAN

#include "Python.h"

#include "structmember.h"

#include "accu.h"

#include "_iomodule.h"

/* Implementation note: the buffer is always at least one character longer

than the enclosed string, for proper functioning of _PyIO_find_line_ending.

#define STATE_REALIZED 1

#define STATE_ACCUMULATING 2

typedef struct {

PyObject_HEAD

Py_UCS4 *buf;

Py_ssize_t pos;

Py_ssize_t string_size;

size_t buf_size;

/* The stringio object can be in two states: accumulating or realized.

In accumulating state, the internal buffer contains nothing and

the contents are given by the embedded _PyAccu structure.

In realized state, the internal buffer is meaningful and the

_PyAccu is destroyed.

int state;

_PyAccu accu;

char ok; /* initialized? */

char closed;

char readuniversal;

char readtranslate;

PyObject *decoder;

PyObject *readnl;

PyObject *writenl;

PyObject *dict;

PyObject *weakreflist;

} stringio;

#define CHECK_INITIALIZED(self) \

if (self->ok <= 0) { \

PyErr_SetString(PyExc_ValueError, \

"I/O operation on uninitialized object"); \

return NULL; \

}

#define CHECK_CLOSED(self) \

if (self->closed) { \

PyErr_SetString(PyExc_ValueError, \

"I/O operation on closed file"); \

return NULL; \

}

#define ENSURE_REALIZED(self) \

if (realize(self) < 0) { \

return NULL; \

}

PyDoc_STRVAR(stringio_doc,

"Text I/O implementation using an in-memory buffer.\n"

"\n"

"The initial_value argument sets the value of object. The newline\n"

"argument is like the one of TextIOWrapper's constructor.");

/* Internal routine for changing the size, in terms of characters, of the

buffer of StringIO objects. The caller should ensure that the 'size'

argument is non-negative. Returns 0 on success, -1 otherwise. */

static int

resize_buffer(stringio *self, size_t size)

{

/* Here, unsigned types are used to avoid dealing with signed integer

overflow, which is undefined in C. */

size_t alloc = self->buf_size;

Py_UCS4 *new_buf = NULL;

assert(self->buf != NULL);

/* Reserve one more char for line ending detection. */

size = size + 1;

/* For simplicity, stay in the range of the signed type. Anyway, Python

doesn't allow strings to be longer than this. */

if (size > PY_SSIZE_T_MAX)

goto overflow;

if (size < alloc / 2) {

/* Major downsize; resize down to exact size. */

alloc = size + 1;

}

else if (size < alloc) {

/* Within allocated size; quick exit */

return 0;

}

else if (size <= alloc * 1.125) {

/* Moderate upsize; overallocate similar to list_resize() */

alloc = size + (size >> 3) + (size < 9 ? 3 : 6);

}

else {

/* Major upsize; resize up to exact size */

alloc = size + 1;

}

if (alloc > PY_SIZE_MAX / sizeof(Py_UCS4))

goto overflow;

new_buf = (Py_UCS4 *)PyMem_Realloc(self->buf, alloc * sizeof(Py_UCS4));

if (new_buf == NULL) {

PyErr_NoMemory();

return -1;

}

self->buf_size = alloc;

self->buf = new_buf;

return 0;

overflow:

PyErr_SetString(PyExc_OverflowError,

"new buffer size too large");

return -1;

}

static PyObject *

make_intermediate(stringio *self)

{

PyObject *intermediate = _PyAccu_Finish(&self->accu);

self->state = STATE_REALIZED;

if (intermediate == NULL)

return NULL;

if (_PyAccu_Init(&self->accu) ||

_PyAccu_Accumulate(&self->accu, intermediate)) {

Py_DECREF(intermediate);

return NULL;

}

self->state = STATE_ACCUMULATING;

return intermediate;

}

static int

realize(stringio *self)

{

Py_ssize_t len;

PyObject *intermediate;

if (self->state == STATE_REALIZED)

return 0;

assert(self->state == STATE_ACCUMULATING);

self->state = STATE_REALIZED;

intermediate = _PyAccu_Finish(&self->accu);

if (intermediate == NULL)

return -1;

/* Append the intermediate string to the internal buffer.

The length should be equal to the current cursor position.

len = PyUnicode_GET_LENGTH(intermediate);

if (resize_buffer(self, len) < 0) {

Py_DECREF(intermediate);

return -1;

}

if (!PyUnicode_AsUCS4(intermediate, self->buf, len, 0)) {

Py_DECREF(intermediate);

return -1;

}

Py_DECREF(intermediate);

return 0;

}

/* Internal routine for writing a whole PyUnicode object to the buffer of a

StringIO object. Returns 0 on success, or -1 on error. */

static Py_ssize_t

write_str(stringio *self, PyObject *obj)

{

Py_ssize_t len;

PyObject *decoded = NULL;

assert(self->buf != NULL);

assert(self->pos >= 0);

if (self->decoder != NULL) {

decoded = _PyIncrementalNewlineDecoder_decode(

self->decoder, obj, 1 /* always final */);

}

else {

decoded = obj;

Py_INCREF(decoded);

}

if (self->writenl) {

PyObject *translated = PyUnicode_Replace(

decoded, _PyIO_str_nl, self->writenl, -1);

Py_DECREF(decoded);

decoded = translated;

}

if (decoded == NULL)

return -1;

assert(PyUnicode_Check(decoded));

if (PyUnicode_READY(decoded)) {

Py_DECREF(decoded);

return -1;

}

len = PyUnicode_GET_LENGTH(decoded);

assert(len >= 0);

/* This overflow check is not strictly necessary. However, it avoids us to

deal with funky things like comparing an unsigned and a signed

integer. */

if (self->pos > PY_SSIZE_T_MAX - len) {

PyErr_SetString(PyExc_OverflowError,

"new position too large");

goto fail;

}

if (self->state == STATE_ACCUMULATING) {

if (self->string_size == self->pos) {

if (_PyAccu_Accumulate(&self->accu, decoded))

goto fail;

goto success;

}

if (realize(self))

goto fail;

}

if (self->pos + len > self->string_size) {

if (resize_buffer(self, self->pos + len) < 0)

goto fail;

}

if (self->pos > self->string_size) {

/* In case of overseek, pad with null bytes the buffer region between

the end of stream and the current position.

0 lo string_size hi

| |<---used--->|<----------available----------->|

| | <--to pad-->|<---to write---> |

0 buf position

memset(self->buf + self->string_size, '\0',

(self->pos - self->string_size) * sizeof(Py_UCS4));

}

/* Copy the data to the internal buffer, overwriting some of the

existing data if self->pos < self->string_size. */

if (!PyUnicode_AsUCS4(decoded,

self->buf + self->pos,

self->buf_size - self->pos,

0))

goto fail;

success:

/* Set the new length of the internal string if it has changed. */

self->pos += len;

if (self->string_size < self->pos)

self->string_size = self->pos;

Py_DECREF(decoded);

return 0;

fail:

Py_XDECREF(decoded);

return -1;

}

PyDoc_STRVAR(stringio_getvalue_doc,

"Retrieve the entire contents of the object.");

static PyObject *

stringio_getvalue(stringio *self)

{

CHECK_INITIALIZED(self);

CHECK_CLOSED(self);

if (self->state == STATE_ACCUMULATING)

return make_intermediate(self);

return PyUnicode_FromKindAndData(PyUnicode_4BYTE_KIND, self->buf,

self->string_size);

}

PyDoc_STRVAR(stringio_tell_doc,

"Tell the current file position.");

static PyObject *

stringio_tell(stringio *self)

{

CHECK_INITIALIZED(self);

CHECK_CLOSED(self);

return PyLong_FromSsize_t(self->pos);

}

PyDoc_STRVAR(stringio_read_doc,

"Read at most n characters, returned as a string.\n"

"\n"

"If the argument is negative or omitted, read until EOF\n"

"is reached. Return an empty string at EOF.\n");

static PyObject *

stringio_read(stringio *self, PyObject *args)

{

Py_ssize_t size, n;

Py_UCS4 *output;

PyObject *arg = Py_None;

CHECK_INITIALIZED(self);

if (!PyArg_ParseTuple(args, "|O:read", &arg))

return NULL;

CHECK_CLOSED(self);

if (PyNumber_Check(arg)) {

size = PyNumber_AsSsize_t(arg, PyExc_OverflowError);

if (size == -1 && PyErr_Occurred())

return NULL;

}

else if (arg == Py_None) {

/* Read until EOF is reached, by default. */

size = -1;

}

else {

PyErr_Format(PyExc_TypeError, "integer argument expected, got '%s'",

Py_TYPE(arg)->tp_name);

return NULL;

}

/* adjust invalid sizes */

n = self->string_size - self->pos;

if (size < 0 || size > n) {

size = n;

if (size < 0)

size = 0;

}

/* Optimization for seek(0); read() */

if (self->state == STATE_ACCUMULATING && self->pos == 0 && size == n) {

PyObject *result = make_intermediate(self);

self->pos = self->string_size;

return result;

}

ENSURE_REALIZED(self);

output = self->buf + self->pos;

self->pos += size;

return PyUnicode_FromKindAndData(PyUnicode_4BYTE_KIND, output, size);

}

/* Internal helper, used by stringio_readline and stringio_iternext */

static PyObject *

_stringio_readline(stringio *self, Py_ssize_t limit)

{

Py_UCS4 *start, *end, old_char;

Py_ssize_t len, consumed;

/* In case of overseek, return the empty string */

if (self->pos >= self->string_size)

return PyUnicode_New(0, 0);

start = self->buf + self->pos;

if (limit < 0 || limit > self->string_size - self->pos)

limit = self->string_size - self->pos;

end = start + limit;

old_char = *end;

*end = '\0';

len = _PyIO_find_line_ending(

self->readtranslate, self->readuniversal, self->readnl,

PyUnicode_4BYTE_KIND, (char*)start, (char*)end, &consumed);

*end = old_char;

/* If we haven't found any line ending, we just return everything

(`consumed` is ignored). */

if (len < 0)

len = limit;

self->pos += len;

return PyUnicode_FromKindAndData(PyUnicode_4BYTE_KIND, start, len);

}

PyDoc_STRVAR(stringio_readline_doc,

"Read until newline or EOF.\n"

"\n"

"Returns an empty string if EOF is hit immediately.\n");

static PyObject *

stringio_readline(stringio *self, PyObject *args)

{

PyObject *arg = Py_None;

Py_ssize_t limit = -1;

CHECK_INITIALIZED(self);

if (!PyArg_ParseTuple(args, "|O:readline", &arg))

return NULL;

CHECK_CLOSED(self);

ENSURE_REALIZED(self);

if (PyNumber_Check(arg)) {

limit = PyNumber_AsSsize_t(arg, PyExc_OverflowError);

if (limit == -1 && PyErr_Occurred())

return NULL;

}

else if (arg != Py_None) {

PyErr_Format(PyExc_TypeError, "integer argument expected, got '%s'",

Py_TYPE(arg)->tp_name);

return NULL;

}

return _stringio_readline(self, limit);

}

static PyObject *

stringio_iternext(stringio *self)

{

PyObject *line;

CHECK_INITIALIZED(self);

CHECK_CLOSED(self);

ENSURE_REALIZED(self);

if (Py_TYPE(self) == &PyStringIO_Type) {

/* Skip method call overhead for speed */

line = _stringio_readline(self, -1);

}

else {

/* XXX is subclassing StringIO really supported? */

line = PyObject_CallMethodObjArgs((PyObject *)self,

_PyIO_str_readline, NULL);

if (line && !PyUnicode_Check(line)) {

PyErr_Format(PyExc_IOError,

"readline() should have returned an str object, "

"not '%.200s'", Py_TYPE(line)->tp_name);

Py_DECREF(line);

return NULL;

}

if (line == NULL)

return NULL;

if (PyUnicode_GET_LENGTH(line) == 0) {

/* Reached EOF */

Py_DECREF(line);

return NULL;

}

return line;

}

PyDoc_STRVAR(stringio_truncate_doc,

"Truncate size to pos.\n"

"\n"

"The pos argument defaults to the current file position, as\n"

"returned by tell(). The current file position is unchanged.\n"

"Returns the new absolute position.\n");

static PyObject *

stringio_truncate(stringio *self, PyObject *args)

{

Py_ssize_t size;

PyObject *arg = Py_None;

CHECK_INITIALIZED(self);

if (!PyArg_ParseTuple(args, "|O:truncate", &arg))

return NULL;

CHECK_CLOSED(self);

if (PyNumber_Check(arg)) {

size = PyNumber_AsSsize_t(arg, PyExc_OverflowError);

if (size == -1 && PyErr_Occurred())

return NULL;

}

else if (arg == Py_None) {

/* Truncate to current position if no argument is passed. */

size = self->pos;

}

else {

PyErr_Format(PyExc_TypeError, "integer argument expected, got '%s'",

Py_TYPE(arg)->tp_name);

return NULL;

}

if (size < 0) {

PyErr_Format(PyExc_ValueError,

"Negative size value %zd", size);

return NULL;

}

if (size < self->string_size) {

ENSURE_REALIZED(self);

if (resize_buffer(self, size) < 0)

return NULL;

self->string_size = size;

}

return PyLong_FromSsize_t(size);

}

PyDoc_STRVAR(stringio_seek_doc,

"Change stream position.\n"

"\n"

"Seek to character offset pos relative to position indicated by whence:\n"

" 0 Start of stream (the default). pos should be >= 0;\n"

" 1 Current position - pos must be 0;\n"

" 2 End of stream - pos must be 0.\n"

"Returns the new absolute position.\n");

static PyObject *

stringio_seek(stringio *self, PyObject *args)

{

Py_ssize_t pos;

int mode = 0;

CHECK_INITIALIZED(self);

if (!PyArg_ParseTuple(args, "n|i:seek", &pos, &mode))

return NULL;

CHECK_CLOSED(self);

if (mode != 0 && mode != 1 && mode != 2) {

PyErr_Format(PyExc_ValueError,

"Invalid whence (%i, should be 0, 1 or 2)", mode);

return NULL;

}

else if (pos < 0 && mode == 0) {

PyErr_Format(PyExc_ValueError,

"Negative seek position %zd", pos);

return NULL;

}

else if (mode != 0 && pos != 0) {

PyErr_SetString(PyExc_IOError,

"Can't do nonzero cur-relative seeks");

return NULL;

}

/* mode 0: offset relative to beginning of the string.

mode 1: no change to current position.

mode 2: change position to end of file. */

if (mode == 1) {

pos = self->pos;

}

else if (mode == 2) {

pos = self->string_size;

}

self->pos = pos;

return PyLong_FromSsize_t(self->pos);

}

PyDoc_STRVAR(stringio_write_doc,

"Write string to file.\n"

"\n"

"Returns the number of characters written, which is always equal to\n"

"the length of the string.\n");

static PyObject *

stringio_write(stringio *self, PyObject *obj)

{

Py_ssize_t size;

CHECK_INITIALIZED(self);

if (!PyUnicode_Check(obj)) {

PyErr_Format(PyExc_TypeError, "string argument expected, got '%s'",

Py_TYPE(obj)->tp_name);

return NULL;

}

if (PyUnicode_READY(obj))

return NULL;

CHECK_CLOSED(self);

size = PyUnicode_GET_LENGTH(obj);

if (size > 0 && write_str(self, obj) < 0)

return NULL;

return PyLong_FromSsize_t(size);

}

PyDoc_STRVAR(stringio_close_doc,

"Close the IO object. Attempting any further operation after the\n"

"object is closed will raise a ValueError.\n"

"\n"

"This method has no effect if the file is already closed.\n");

static PyObject *

stringio_close(stringio *self)

{

self->closed = 1;

/* Free up some memory */

if (resize_buffer(self, 0) < 0)

return NULL;

_PyAccu_Destroy(&self->accu);

Py_CLEAR(self->readnl);

Py_CLEAR(self->writenl);

Py_CLEAR(self->decoder);

Py_RETURN_NONE;

}

static int

stringio_traverse(stringio *self, visitproc visit, void *arg)

{

Py_VISIT(self->dict);

return 0;

}

static int

stringio_clear(stringio *self)

{

Py_CLEAR(self->dict);

return 0;

}

static void

stringio_dealloc(stringio *self)

{

_PyObject_GC_UNTRACK(self);

self->ok = 0;

if (self->buf) {

PyMem_Free(self->buf);

self->buf = NULL;

}

_PyAccu_Destroy(&self->accu);

Py_CLEAR(self->readnl);

Py_CLEAR(self->writenl);

Py_CLEAR(self->decoder);

Py_CLEAR(self->dict);

if (self->weakreflist != NULL)

PyObject_ClearWeakRefs((PyObject *) self);

Py_TYPE(self)->tp_free(self);

}

static PyObject *

stringio_new(PyTypeObject *type, PyObject *args, PyObject *kwds)

{

stringio *self;

assert(type != NULL && type->tp_alloc != NULL);

self = (stringio *)type->tp_alloc(type, 0);

if (self == NULL)

return NULL;

/* tp_alloc initializes all the fields to zero. So we don't have to

initialize them here. */

self->buf = (Py_UCS4 *)PyMem_Malloc(0);

if (self->buf == NULL) {

Py_DECREF(self);

return PyErr_NoMemory();

}

return (PyObject *)self;

}

static int

stringio_init(stringio *self, PyObject *args, PyObject *kwds)

{

char *kwlist[] = {"initial_value", "newline", NULL};

PyObject *value = NULL;

PyObject *newline_obj = NULL;

char *newline = "\n";

Py_ssize_t value_len;

if (!PyArg_ParseTupleAndKeywords(args, kwds, "|OO:__init__", kwlist,

&value, &newline_obj))

return -1;

/* Parse the newline argument. This used to be done with the 'z'

specifier, however this allowed any object with the buffer interface to

be converted. Thus we have to parse it manually since we only want to

allow unicode objects or None. */

if (newline_obj == Py_None) {

newline = NULL;

}

else if (newline_obj) {

if (!PyUnicode_Check(newline_obj)) {

PyErr_Format(PyExc_TypeError,

"newline must be str or None, not %.200s",

Py_TYPE(newline_obj)->tp_name);

return -1;

}

newline = _PyUnicode_AsString(newline_obj);

if (newline == NULL)

return -1;

}

if (newline && newline[0] != '\0'

&& !(newline[0] == '\n' && newline[1] == '\0')

&& !(newline[0] == '\r' && newline[1] == '\0')

&& !(newline[0] == '\r' && newline[1] == '\n' && newline[2] == '\0')) {

PyErr_Format(PyExc_ValueError,

"illegal newline value: %R", newline_obj);

return -1;

}

if (value && value != Py_None && !PyUnicode_Check(value)) {

PyErr_Format(PyExc_TypeError,

"initial_value must be str or None, not %.200s",

Py_TYPE(value)->tp_name);

return -1;

}

self->ok = 0;

_PyAccu_Destroy(&self->accu);

Py_CLEAR(self->readnl);

Py_CLEAR(self->writenl);

Py_CLEAR(self->decoder);

assert((newline != NULL && newline_obj != Py_None) ||

(newline == NULL && newline_obj == Py_None));

if (newline) {

self->readnl = PyUnicode_FromString(newline);

if (self->readnl == NULL)

return -1;

}

self->readuniversal = (newline == NULL || newline[0] == '\0');

self->readtranslate = (newline == NULL);

/* If newline == "", we don't translate anything.

If newline == "\n" or newline == None, we translate to "\n", which is

a no-op.

(for newline == None, TextIOWrapper translates to os.sepline, but it

is pointless for StringIO)

if (newline != NULL && newline[0] == '\r') {

self->writenl = self->readnl;

Py_INCREF(self->writenl);

}

if (self->readuniversal) {

self->decoder = PyObject_CallFunction(

(PyObject *)&PyIncrementalNewlineDecoder_Type,

"Oi", Py_None, (int) self->readtranslate);

if (self->decoder == NULL)

return -1;

}

/* Now everything is set up, resize buffer to size of initial value,

and copy it */

self->string_size = 0;

if (value && value != Py_None)

value_len = PyUnicode_GetLength(value);

else

value_len = 0;

if (value_len > 0) {

/* This is a heuristic, for newline translation might change

the string length. */

if (resize_buffer(self, 0) < 0)

return -1;

self->state = STATE_REALIZED;

self->pos = 0;

if (write_str(self, value) < 0)

return -1;

}

else {

/* Empty stringio object, we can start by accumulating */

if (resize_buffer(self, 0) < 0)

return -1;

if (_PyAccu_Init(&self->accu))

return -1;

self->state = STATE_ACCUMULATING;

}

self->pos = 0;

self->closed = 0;

self->ok = 1;

return 0;

}

/* Properties and pseudo-properties */

PyDoc_STRVAR(stringio_readable_doc,

"readable() -> bool. Returns True if the IO object can be read.");

PyDoc_STRVAR(stringio_writable_doc,

"writable() -> bool. Returns True if the IO object can be written.");

PyDoc_STRVAR(stringio_seekable_doc,

"seekable() -> bool. Returns True if the IO object can be seeked.");

static PyObject *

stringio_seekable(stringio *self, PyObject *args)

{

CHECK_INITIALIZED(self);

CHECK_CLOSED(self);

Py_RETURN_TRUE;

}

static PyObject *

stringio_readable(stringio *self, PyObject *args)

{

CHECK_INITIALIZED(self);

CHECK_CLOSED(self);

Py_RETURN_TRUE;

}

static PyObject *

stringio_writable(stringio *self, PyObject *args)

{

CHECK_INITIALIZED(self);

CHECK_CLOSED(self);

Py_RETURN_TRUE;

}

/* Pickling support.

The implementation of __getstate__ is similar to the one for BytesIO,

except that we also save the newline parameter. For __setstate__ and unlike

BytesIO, we call __init__ to restore the object's state. Doing so allows us

to avoid decoding the complex newline state while keeping the object

representation compact.

See comment in bytesio.c regarding why only pickle protocols and onward are

supported.

static PyObject *

stringio_getstate(stringio *self)

{

PyObject *initvalue = stringio_getvalue(self);

PyObject *dict;

PyObject *state;

if (initvalue == NULL)

return NULL;

if (self->dict == NULL) {

Py_INCREF(Py_None);

dict = Py_None;

}

else {

dict = PyDict_Copy(self->dict);

if (dict == NULL)

return NULL;

}

state = Py_BuildValue("(OOnN)", initvalue,

self->readnl ? self->readnl : Py_None,

self->pos, dict);

Py_DECREF(initvalue);

return state;

}

static PyObject *

stringio_setstate(stringio *self, PyObject *state)

{

PyObject *initarg;

PyObject *position_obj;

PyObject *dict;

Py_ssize_t pos;

assert(state != NULL);

CHECK_CLOSED(self);

/* We allow the state tuple to be longer than 4, because we may need

someday to extend the object's state without breaking

backward-compatibility. */

if (!PyTuple_Check(state) || Py_SIZE(state) < 4) {

PyErr_Format(PyExc_TypeError,

"%.200s.__setstate__ argument should be 4-tuple, got %.200s",

Py_TYPE(self)->tp_name, Py_TYPE(state)->tp_name);

return NULL;

}

/* Initialize the object's state. */

initarg = PyTuple_GetSlice(state, 0, 2);

if (initarg == NULL)

return NULL;

if (stringio_init(self, initarg, NULL) < 0) {

Py_DECREF(initarg);

return NULL;

}

Py_DECREF(initarg);

/* Restore the buffer state. Even if __init__ did initialize the buffer,

we have to initialize it again since __init__ may translates the

newlines in the inital_value string. We clearly do not want that

because the string value in the state tuple has already been translated

once by __init__. So we do not take any chance and replace object's

buffer completely. */

{

PyObject *item;

Py_UCS4 *buf;

Py_ssize_t bufsize;

item = PyTuple_GET_ITEM(state, 0);

buf = PyUnicode_AsUCS4Copy(item);

if (buf == NULL)

return NULL;

bufsize = PyUnicode_GET_LENGTH(item);

if (resize_buffer(self, bufsize) < 0) {

PyMem_Free(buf);

return NULL;

}

memcpy(self->buf, buf, bufsize * sizeof(Py_UCS4));

PyMem_Free(buf);

self->string_size = bufsize;

}

/* Set carefully the position value. Alternatively, we could use the seek

method instead of modifying self->pos directly to better protect the

object internal state against errneous (or malicious) inputs. */

position_obj = PyTuple_GET_ITEM(state, 2);

if (!PyLong_Check(position_obj)) {

PyErr_Format(PyExc_TypeError,

"third item of state must be an integer, got %.200s",

Py_TYPE(position_obj)->tp_name);

return NULL;

}

pos = PyLong_AsSsize_t(position_obj);

if (pos == -1 && PyErr_Occurred())

return NULL;

if (pos < 0) {

PyErr_SetString(PyExc_ValueError,

"position value cannot be negative");

return NULL;

}

self->pos = pos;

/* Set the dictionary of the instance variables. */

dict = PyTuple_GET_ITEM(state, 3);

if (dict != Py_None) {

if (!PyDict_Check(dict)) {

PyErr_Format(PyExc_TypeError,

"fourth item of state should be a dict, got a %.200s",

Py_TYPE(dict)->tp_name);

return NULL;

}

if (self->dict) {

/* Alternatively, we could replace the internal dictionary

completely. However, it seems more practical to just update it. */

if (PyDict_Update(self->dict, dict) < 0)

return NULL;

}

else {

Py_INCREF(dict);

self->dict = dict;

}

Py_RETURN_NONE;

}

static PyObject *

stringio_closed(stringio *self, void *context)

{

CHECK_INITIALIZED(self);

return PyBool_FromLong(self->closed);

}

static PyObject *

stringio_line_buffering(stringio *self, void *context)

{

CHECK_INITIALIZED(self);

CHECK_CLOSED(self);

Py_RETURN_FALSE;

}

static PyObject *

stringio_newlines(stringio *self, void *context)

{

CHECK_INITIALIZED(self);

CHECK_CLOSED(self);

if (self->decoder == NULL)

Py_RETURN_NONE;

return PyObject_GetAttr(self->decoder, _PyIO_str_newlines);

}

static struct PyMethodDef stringio_methods[] = {

{"close", (PyCFunction)stringio_close, METH_NOARGS, stringio_close_doc},

{"getvalue", (PyCFunction)stringio_getvalue, METH_NOARGS, stringio_getvalue_doc},

{"read", (PyCFunction)stringio_read, METH_VARARGS, stringio_read_doc},

{"readline", (PyCFunction)stringio_readline, METH_VARARGS, stringio_readline_doc},

{"tell", (PyCFunction)stringio_tell, METH_NOARGS, stringio_tell_doc},

{"truncate", (PyCFunction)stringio_truncate, METH_VARARGS, stringio_truncate_doc},

{"seek", (PyCFunction)stringio_seek, METH_VARARGS, stringio_seek_doc},

{"write", (PyCFunction)stringio_write, METH_O, stringio_write_doc},

{"seekable", (PyCFunction)stringio_seekable, METH_NOARGS, stringio_seekable_doc},

{"readable", (PyCFunction)stringio_readable, METH_NOARGS, stringio_readable_doc},

{"writable", (PyCFunction)stringio_writable, METH_NOARGS, stringio_writable_doc},

{"__getstate__", (PyCFunction)stringio_getstate, METH_NOARGS},

{"__setstate__", (PyCFunction)stringio_setstate, METH_O},

{NULL, NULL} /* sentinel */

};

static PyGetSetDef stringio_getset[] = {

{"closed", (getter)stringio_closed, NULL, NULL},

{"newlines", (getter)stringio_newlines, NULL, NULL},

/* (following comments straight off of the original Python wrapper:)

XXX Cruft to support the TextIOWrapper API. This would only

be meaningful if StringIO supported the buffer attribute.

Hopefully, a better solution, than adding these pseudo-attributes,

will be found.

{"line_buffering", (getter)stringio_line_buffering, NULL, NULL},

{NULL}

};

PyTypeObject PyStringIO_Type = {

PyVarObject_HEAD_INIT(NULL, 0)

"_io.StringIO", /*tp_name*/

sizeof(stringio), /*tp_basicsize*/

0, /*tp_itemsize*/

(destructor)stringio_dealloc, /*tp_dealloc*/

0, /*tp_print*/

View remainder of file in raw view

cpython/Modules/_io/stringio.c at 3.3 · python/cpython · GitHub

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