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cpython/Modules/_io/bytesio.c

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#include "Python.h"
#include "pycore_critical_section.h" // Py_BEGIN_CRITICAL_SECTION()
#include "pycore_object.h"
#include "pycore_pyatomic_ft_wrappers.h"
#include "pycore_sysmodule.h" // _PySys_GetSizeOf()
#include "pycore_weakref.h" // FT_CLEAR_WEAKREFS()
#include <stddef.h> // offsetof()
#include "_iomodule.h"
/*[clinic input]
module _io
class _io.BytesIO "bytesio *" "clinic_state()->PyBytesIO_Type"
[clinic start generated code]*/
/*[clinic end generated code: output=da39a3ee5e6b4b0d input=48ede2f330f847c3]*/
typedef struct {
PyObject_HEAD
PyObject *buf;
Py_ssize_t pos;
Py_ssize_t string_size;
PyObject *dict;
PyObject *weakreflist;
Py_ssize_t exports;
} bytesio;
#define bytesio_CAST(op) ((bytesio *)(op))
typedef struct {
PyObject_HEAD
bytesio *source;
} bytesiobuf;
#define bytesiobuf_CAST(op) ((bytesiobuf *)(op))
/* The bytesio object can be in three states:
* Py_REFCNT(buf) == 1, exports == 0.
* Py_REFCNT(buf) > 1. exports == 0,
first modification or export causes the internal buffer copying.
* exports > 0. Py_REFCNT(buf) == 1, any modifications are forbidden.
*/
static int
check_closed(bytesio *self)
{
if (self->buf == NULL) {
PyErr_SetString(PyExc_ValueError, "I/O operation on closed file.");
return 1;
}
return 0;
}
static int
check_exports(bytesio *self)
{
if (FT_ATOMIC_LOAD_SSIZE_RELAXED(self->exports) > 0) {
PyErr_SetString(PyExc_BufferError,
"Existing exports of data: object cannot be re-sized");
return 1;
}
return 0;
}
#define CHECK_CLOSED(self) \
if (check_closed(self)) { \
return NULL; \
}
#define CHECK_EXPORTS(self) \
if (check_exports(self)) { \
return NULL; \
}
#define SHARED_BUF(self) (!_PyObject_IsUniquelyReferenced((self)->buf))
/* Internal routine to get a line from the buffer of a BytesIO
object. Returns the length between the current position to the
next newline character. */
static Py_ssize_t
scan_eol_lock_held(bytesio *self, Py_ssize_t len)
{
_Py_CRITICAL_SECTION_ASSERT_OBJECT_LOCKED(self);
const char *start, *n;
Py_ssize_t maxlen;
assert(self->buf != NULL);
assert(self->pos >= 0);
if (self->pos >= self->string_size)
return 0;
/* Move to the end of the line, up to the end of the string, s. */
maxlen = self->string_size - self->pos;
if (len < 0 || len > maxlen)
len = maxlen;
if (len) {
start = PyBytes_AS_STRING(self->buf) + self->pos;
n = memchr(start, '\n', len);
if (n)
/* Get the length from the current position to the end of
the line. */
len = n - start + 1;
}
assert(len >= 0);
assert(self->pos < PY_SSIZE_T_MAX - len);
return len;
}
/* Internal routine for detaching the shared buffer of BytesIO objects.
The caller should ensure that the 'size' argument is non-negative and
not lesser than self->string_size. Returns 0 on success, -1 otherwise. */
static int
unshare_buffer_lock_held(bytesio *self, size_t size)
{
_Py_CRITICAL_SECTION_ASSERT_OBJECT_LOCKED(self);
PyObject *new_buf;
assert(SHARED_BUF(self));
assert(FT_ATOMIC_LOAD_SSIZE_RELAXED(self->exports) == 0);
assert(size >= (size_t)self->string_size);
new_buf = PyBytes_FromStringAndSize(NULL, size);
if (new_buf == NULL)
return -1;
memcpy(PyBytes_AS_STRING(new_buf), PyBytes_AS_STRING(self->buf),
self->string_size);
Py_SETREF(self->buf, new_buf);
return 0;
}
/* Internal routine for changing the size of the buffer of BytesIO objects.
The caller should ensure that the 'size' argument is non-negative. Returns
0 on success, -1 otherwise. */
static int
resize_buffer_lock_held(bytesio *self, size_t size)
{
_Py_CRITICAL_SECTION_ASSERT_OBJECT_LOCKED(self);
assert(self->buf != NULL);
assert(FT_ATOMIC_LOAD_SSIZE_RELAXED(self->exports) == 0);
/* Here, unsigned types are used to avoid dealing with signed integer
overflow, which is undefined in C. */
size_t alloc = PyBytes_GET_SIZE(self->buf);
/* 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 (SHARED_BUF(self)) {
if (unshare_buffer_lock_held(self, alloc) < 0)
return -1;
}
else {
if (_PyBytes_Resize(&self->buf, alloc) < 0)
return -1;
}
return 0;
overflow:
PyErr_SetString(PyExc_OverflowError,
"new buffer size too large");
return -1;
}
/* Internal routine for writing a string of bytes to the buffer of a BytesIO
object. Returns the number of bytes written, or -1 on error.
Inlining is disabled because it's significantly decreases performance
of writelines() in PGO build. */
Py_NO_INLINE static Py_ssize_t
write_bytes_lock_held(bytesio *self, PyObject *b)
{
_Py_CRITICAL_SECTION_ASSERT_OBJECT_LOCKED(self);
if (check_closed(self)) {
return -1;
}
if (check_exports(self)) {
return -1;
}
Py_buffer buf;
if (PyObject_GetBuffer(b, &buf, PyBUF_CONTIG_RO) < 0) {
return -1;
}
Py_ssize_t len = buf.len;
if (len == 0) {
goto done;
}
assert(self->pos >= 0);
size_t endpos = (size_t)self->pos + len;
if (endpos > (size_t)PyBytes_GET_SIZE(self->buf)) {
if (resize_buffer_lock_held(self, endpos) < 0) {
len = -1;
goto done;
}
}
else if (SHARED_BUF(self)) {
if (unshare_buffer_lock_held(self, Py_MAX(endpos, (size_t)self->string_size)) < 0) {
len = -1;
goto done;
}
}
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(PyBytes_AS_STRING(self->buf) + self->string_size, '\0',
(self->pos - self->string_size) * sizeof(char));
}
/* Copy the data to the internal buffer, overwriting some of the existing
data if self->pos < self->string_size. */
memcpy(PyBytes_AS_STRING(self->buf) + self->pos, buf.buf, len);
self->pos = endpos;
/* Set the new length of the internal string if it has changed. */
if ((size_t)self->string_size < endpos) {
self->string_size = endpos;
}
done:
PyBuffer_Release(&buf);
return len;
}
static PyObject *
bytesio_get_closed(PyObject *op, void *Py_UNUSED(closure))
{
PyObject *ret;
bytesio *self = bytesio_CAST(op);
Py_BEGIN_CRITICAL_SECTION(self);
if (self->buf == NULL) {
ret = Py_True;
}
else {
ret = Py_False;
}
Py_END_CRITICAL_SECTION();
return ret;
}
/*[clinic input]
@critical_section
_io.BytesIO.readable
Returns True if the IO object can be read.
[clinic start generated code]*/
static PyObject *
_io_BytesIO_readable_impl(bytesio *self)
/*[clinic end generated code: output=4e93822ad5b62263 input=ab7816facef48bfd]*/
{
CHECK_CLOSED(self);
Py_RETURN_TRUE;
}
/*[clinic input]
@critical_section
_io.BytesIO.writable
Returns True if the IO object can be written.
[clinic start generated code]*/
static PyObject *
_io_BytesIO_writable_impl(bytesio *self)
/*[clinic end generated code: output=64ff6a254b1150b8 input=4f35d49d26dab024]*/
{
CHECK_CLOSED(self);
Py_RETURN_TRUE;
}
/*[clinic input]
@critical_section
_io.BytesIO.seekable
Returns True if the IO object can be seeked.
[clinic start generated code]*/
static PyObject *
_io_BytesIO_seekable_impl(bytesio *self)
/*[clinic end generated code: output=6b417f46dcc09b56 input=9cc78d15aa1deaa3]*/
{
CHECK_CLOSED(self);
Py_RETURN_TRUE;
}
/*[clinic input]
@critical_section
_io.BytesIO.flush
Does nothing.
[clinic start generated code]*/
static PyObject *
_io_BytesIO_flush_impl(bytesio *self)
/*[clinic end generated code: output=187e3d781ca134a0 input=c60842743910b381]*/
{
CHECK_CLOSED(self);
Py_RETURN_NONE;
}
/*[clinic input]
@critical_section
_io.BytesIO.getbuffer
cls: defining_class
/
Get a read-write view over the contents of the BytesIO object.
[clinic start generated code]*/
static PyObject *
_io_BytesIO_getbuffer_impl(bytesio *self, PyTypeObject *cls)
/*[clinic end generated code: output=045091d7ce87fe4e input=8295764061be77fd]*/
{
_PyIO_State *state = get_io_state_by_cls(cls);
PyTypeObject *type = state->PyBytesIOBuffer_Type;
bytesiobuf *buf;
PyObject *view;
CHECK_CLOSED(self);
buf = (bytesiobuf *) type->tp_alloc(type, 0);
if (buf == NULL)
return NULL;
buf->source = (bytesio*)Py_NewRef(self);
view = PyMemoryView_FromObject((PyObject *) buf);
Py_DECREF(buf);
return view;
}
/*[clinic input]
@critical_section
_io.BytesIO.getvalue
Retrieve the entire contents of the BytesIO object.
[clinic start generated code]*/
static PyObject *
_io_BytesIO_getvalue_impl(bytesio *self)
/*[clinic end generated code: output=b3f6a3233c8fd628 input=c91bff398df0c352]*/
{
CHECK_CLOSED(self);
if (self->string_size <= 1 || FT_ATOMIC_LOAD_SSIZE_RELAXED(self->exports) > 0)
return PyBytes_FromStringAndSize(PyBytes_AS_STRING(self->buf),
self->string_size);
if (self->string_size != PyBytes_GET_SIZE(self->buf)) {
if (SHARED_BUF(self)) {
if (unshare_buffer_lock_held(self, self->string_size) < 0)
return NULL;
}
else {
if (_PyBytes_Resize(&self->buf, self->string_size) < 0)
return NULL;
}
}
return Py_NewRef(self->buf);
}
/*[clinic input]
@critical_section
_io.BytesIO.isatty
Always returns False.
BytesIO objects are not connected to a TTY-like device.
[clinic start generated code]*/
static PyObject *
_io_BytesIO_isatty_impl(bytesio *self)
/*[clinic end generated code: output=df67712e669f6c8f input=50487b74dc5ae8a9]*/
{
CHECK_CLOSED(self);
Py_RETURN_FALSE;
}
/*[clinic input]
@critical_section
_io.BytesIO.tell
Current file position, an integer.
[clinic start generated code]*/
static PyObject *
_io_BytesIO_tell_impl(bytesio *self)
/*[clinic end generated code: output=b54b0f93cd0e5e1d input=2c7b0e8f82e05c4d]*/
{
CHECK_CLOSED(self);
return PyLong_FromSsize_t(self->pos);
}
static PyObject *
read_bytes_lock_held(bytesio *self, Py_ssize_t size)
{
_Py_CRITICAL_SECTION_ASSERT_OBJECT_LOCKED(self);
const char *output;
assert(self->buf != NULL);
assert(size <= self->string_size);
if (size > 1 &&
self->pos == 0 && size == PyBytes_GET_SIZE(self->buf) &&
FT_ATOMIC_LOAD_SSIZE_RELAXED(self->exports) == 0) {
self->pos += size;
return Py_NewRef(self->buf);
}
output = PyBytes_AS_STRING(self->buf) + self->pos;
self->pos += size;
return PyBytes_FromStringAndSize(output, size);
}
/*[clinic input]
@critical_section
_io.BytesIO.read
size: Py_ssize_t(accept={int, NoneType}) = -1
/
Read at most size bytes, returned as a bytes object.
If the size argument is negative, read until EOF is reached.
Return an empty bytes object at EOF.
[clinic start generated code]*/
static PyObject *
_io_BytesIO_read_impl(bytesio *self, Py_ssize_t size)
/*[clinic end generated code: output=9cc025f21c75bdd2 input=9e2f7ff3075fdd39]*/
{
Py_ssize_t n;
CHECK_CLOSED(self);
/* adjust invalid sizes */
n = self->string_size - self->pos;
if (size < 0 || size > n) {
size = n;
if (size < 0)
size = 0;
}
return read_bytes_lock_held(self, size);
}
/*[clinic input]
@critical_section
_io.BytesIO.read1
size: Py_ssize_t(accept={int, NoneType}) = -1
/
Read at most size bytes, returned as a bytes object.
If the size argument is negative or omitted, read until EOF is reached.
Return an empty bytes object at EOF.
[clinic start generated code]*/
static PyObject *
_io_BytesIO_read1_impl(bytesio *self, Py_ssize_t size)
/*[clinic end generated code: output=d0f843285aa95f1c input=a08fc9e507ab380c]*/
{
return _io_BytesIO_read_impl(self, size);
}
/*[clinic input]
@critical_section
_io.BytesIO.readline
size: Py_ssize_t(accept={int, NoneType}) = -1
/
Next line from the file, as a bytes object.
Retain newline. A non-negative size argument limits the maximum
number of bytes to return (an incomplete line may be returned then).
Return an empty bytes object at EOF.
[clinic start generated code]*/
static PyObject *
_io_BytesIO_readline_impl(bytesio *self, Py_ssize_t size)
/*[clinic end generated code: output=4bff3c251df8ffcd input=db09d47e23cf2c9e]*/
{
Py_ssize_t n;
CHECK_CLOSED(self);
n = scan_eol_lock_held(self, size);
return read_bytes_lock_held(self, n);
}
/*[clinic input]
@critical_section
_io.BytesIO.readlines
size as arg: object = None
/
List of bytes objects, each a line from the file.
Call readline() repeatedly and return a list of the lines so read.
The optional size argument, if given, is an approximate bound on the
total number of bytes in the lines returned.
[clinic start generated code]*/
static PyObject *
_io_BytesIO_readlines_impl(bytesio *self, PyObject *arg)
/*[clinic end generated code: output=09b8e34c880808ff input=5c57d7d78e409985]*/
{
Py_ssize_t maxsize, size, n;
PyObject *result, *line;
const char *output;
CHECK_CLOSED(self);
if (PyLong_Check(arg)) {
maxsize = PyLong_AsSsize_t(arg);
if (maxsize == -1 && PyErr_Occurred())
return NULL;
}
else if (arg == Py_None) {
/* No size limit, by default. */
maxsize = -1;
}
else {
PyErr_Format(PyExc_TypeError, "integer argument expected, got '%s'",
Py_TYPE(arg)->tp_name);
return NULL;
}
size = 0;
result = PyList_New(0);
if (!result)
return NULL;
output = PyBytes_AS_STRING(self->buf) + self->pos;
while ((n = scan_eol_lock_held(self, -1)) != 0) {
self->pos += n;
line = PyBytes_FromStringAndSize(output, n);
if (!line)
goto on_error;
if (PyList_Append(result, line) == -1) {
Py_DECREF(line);
goto on_error;
}
Py_DECREF(line);
size += n;
if (maxsize > 0 && size >= maxsize)
break;
output += n;
}
return result;
on_error:
Py_DECREF(result);
return NULL;
}
/*[clinic input]
@critical_section
_io.BytesIO.readinto
buffer: Py_buffer(accept={rwbuffer})
/
Read bytes into buffer.
Returns number of bytes read (0 for EOF), or None if the object
is set not to block and has no data to read.
[clinic start generated code]*/
static PyObject *
_io_BytesIO_readinto_impl(bytesio *self, Py_buffer *buffer)
/*[clinic end generated code: output=a5d407217dcf0639 input=093a8d330de3fcd1]*/
{
Py_ssize_t len, n;
CHECK_CLOSED(self);
/* adjust invalid sizes */
len = buffer->len;
n = self->string_size - self->pos;
if (len > n) {
len = n;
if (len < 0)
len = 0;
}
assert(self->pos + len < PY_SSIZE_T_MAX);
assert(len >= 0);
memcpy(buffer->buf, PyBytes_AS_STRING(self->buf) + self->pos, len);
self->pos += len;
return PyLong_FromSsize_t(len);
}
/*[clinic input]
@critical_section
_io.BytesIO.truncate
size: object = None
/
Truncate the file to at most size bytes.
Size defaults to the current file position, as returned by tell().
The current file position is unchanged. Returns the new size.
[clinic start generated code]*/
static PyObject *
_io_BytesIO_truncate_impl(bytesio *self, PyObject *size)
/*[clinic end generated code: output=ab42491b4824f384 input=b4acb5f80481c053]*/
{
CHECK_CLOSED(self);
CHECK_EXPORTS(self);
Py_ssize_t new_size;
if (size == Py_None) {
new_size = self->pos;
}
else {
new_size = PyLong_AsLong(size);
if (new_size == -1 && PyErr_Occurred()) {
return NULL;
}
if (new_size < 0) {
PyErr_Format(PyExc_ValueError,
"negative size value %zd", new_size);
return NULL;
}
}
if (new_size < self->string_size) {
self->string_size = new_size;
if (resize_buffer_lock_held(self, new_size) < 0)
return NULL;
}
return PyLong_FromSsize_t(new_size);
}
static PyObject *
bytesio_iternext_lock_held(PyObject *op)
{
_Py_CRITICAL_SECTION_ASSERT_OBJECT_LOCKED(op);
Py_ssize_t n;
bytesio *self = bytesio_CAST(op);
CHECK_CLOSED(self);
n = scan_eol_lock_held(self, -1);
if (n == 0)
return NULL;
return read_bytes_lock_held(self, n);
}
static PyObject *
bytesio_iternext(PyObject *op)
{
PyObject *ret;
Py_BEGIN_CRITICAL_SECTION(op);
ret = bytesio_iternext_lock_held(op);
Py_END_CRITICAL_SECTION();
return ret;
}
/*[clinic input]
@critical_section
_io.BytesIO.seek
pos: Py_ssize_t
whence: int = 0
/
Change stream position.
Seek to byte offset pos relative to position indicated by whence:
0 Start of stream (the default). pos should be >= 0;
1 Current position - pos may be negative;
2 End of stream - pos usually negative.
Returns the new absolute position.
[clinic start generated code]*/
static PyObject *
_io_BytesIO_seek_impl(bytesio *self, Py_ssize_t pos, int whence)
/*[clinic end generated code: output=c26204a68e9190e4 input=20f05ddf659255df]*/
{
CHECK_CLOSED(self);
if (pos < 0 && whence == 0) {
PyErr_Format(PyExc_ValueError,
"negative seek value %zd", pos);
return NULL;
}
/* whence = 0: offset relative to beginning of the string.
whence = 1: offset relative to current position.
whence = 2: offset relative the end of the string. */
if (whence == 1) {
if (pos > PY_SSIZE_T_MAX - self->pos) {
PyErr_SetString(PyExc_OverflowError,
"new position too large");
return NULL;
}
pos += self->pos;
}
else if (whence == 2) {
if (pos > PY_SSIZE_T_MAX - self->string_size) {
PyErr_SetString(PyExc_OverflowError,
"new position too large");
return NULL;
}
pos += self->string_size;
}
else if (whence != 0) {
PyErr_Format(PyExc_ValueError,
"invalid whence (%i, should be 0, 1 or 2)", whence);
return NULL;
}
if (pos < 0)
pos = 0;
self->pos = pos;
return PyLong_FromSsize_t(self->pos);
}
/*[clinic input]
@critical_section
_io.BytesIO.write
b: object
/
Write bytes to file.
Return the number of bytes written.
[clinic start generated code]*/
static PyObject *
_io_BytesIO_write_impl(bytesio *self, PyObject *b)
/*[clinic end generated code: output=d3e46bcec8d9e21c input=46c0c17eac7474a4]*/
{
Py_ssize_t n = write_bytes_lock_held(self, b);
return n >= 0 ? PyLong_FromSsize_t(n) : NULL;
}
/*[clinic input]
@critical_section
_io.BytesIO.writelines
lines: object
/
Write lines to the file.
Note that newlines are not added. lines can be any iterable object
producing bytes-like objects. This is equivalent to calling write() for
each element.
[clinic start generated code]*/
static PyObject *
_io_BytesIO_writelines_impl(bytesio *self, PyObject *lines)
/*[clinic end generated code: output=03a43a75773bc397 input=5d6a616ae39dc9ca]*/
{
PyObject *it, *item;
CHECK_CLOSED(self);
it = PyObject_GetIter(lines);
if (it == NULL)
return NULL;
while ((item = PyIter_Next(it)) != NULL) {
Py_ssize_t ret = write_bytes_lock_held(self, item);
Py_DECREF(item);
if (ret < 0) {
Py_DECREF(it);
return NULL;
}
}
Py_DECREF(it);
/* See if PyIter_Next failed */
if (PyErr_Occurred())
return NULL;
Py_RETURN_NONE;
}
/*[clinic input]
@critical_section
_io.BytesIO.close
Disable all I/O operations.
[clinic start generated code]*/
static PyObject *
_io_BytesIO_close_impl(bytesio *self)
/*[clinic end generated code: output=1471bb9411af84a0 input=34ce76d8bd17a23b]*/
{
CHECK_EXPORTS(self);
Py_CLEAR(self->buf);
Py_RETURN_NONE;
}
/* Pickling support.
Note that only pickle protocol 2 and onward are supported since we use
extended __reduce__ API of PEP 307 to make BytesIO instances picklable.
Providing support for protocol < 2 would require the __reduce_ex__ method
which is notably long-winded when defined properly.
For BytesIO, the implementation would similar to one coded for
object.__reduce_ex__, but slightly less general. To be more specific, we
could call bytesio_getstate directly and avoid checking for the presence of
a fallback __reduce__ method. However, we would still need a __newobj__
function to use the efficient instance representation of PEP 307.
*/
static PyObject *
bytesio_getstate_lock_held(PyObject *op)
{
_Py_CRITICAL_SECTION_ASSERT_OBJECT_LOCKED(op);
bytesio *self = bytesio_CAST(op);
PyObject *initvalue = _io_BytesIO_getvalue_impl(self);
PyObject *dict;
PyObject *state;
if (initvalue == NULL)
return NULL;
if (self->dict == NULL) {
dict = Py_NewRef(Py_None);
}
else {
dict = PyDict_Copy(self->dict);
if (dict == NULL) {
Py_DECREF(initvalue);
return NULL;
}
}
state = Py_BuildValue("(OnN)", initvalue, self->pos, dict);
Py_DECREF(initvalue);
return state;
}
static PyObject *
bytesio_getstate(PyObject *op, PyObject *Py_UNUSED(dummy))
{
PyObject *ret;
Py_BEGIN_CRITICAL_SECTION(op);
ret = bytesio_getstate_lock_held(op);
Py_END_CRITICAL_SECTION();
return ret;
}
static PyObject *
bytesio_setstate_lock_held(PyObject *op, PyObject *state)
{
_Py_CRITICAL_SECTION_ASSERT_OBJECT_LOCKED(op);
PyObject *result;
PyObject *position_obj;
PyObject *dict;
Py_ssize_t pos;
bytesio *self = bytesio_CAST(op);
assert(state != NULL);
/* We allow the state tuple to be longer than 3, because we may need
someday to extend the object's state without breaking
backward-compatibility. */
if (!PyTuple_Check(state) || PyTuple_GET_SIZE(state) < 3) {
PyErr_Format(PyExc_TypeError,
"%.200s.__setstate__ argument should be 3-tuple, got %.200s",
Py_TYPE(self)->tp_name, Py_TYPE(state)->tp_name);
return NULL;
}
CHECK_EXPORTS(self);
/* Reset the object to its default state. This is only needed to handle
the case of repeated calls to __setstate__. */
self->string_size = 0;
self->pos = 0;
/* Set the value of the internal buffer. If state[0] does not support the
buffer protocol, bytesio_write will raise the appropriate TypeError. */
result = _io_BytesIO_write_impl(self, PyTuple_GET_ITEM(state, 0));
if (result == NULL)
return NULL;
Py_DECREF(result);
/* 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 erroneous (or malicious) inputs. */
position_obj = PyTuple_GET_ITEM(state, 1);
if (!PyLong_Check(position_obj)) {
PyErr_Format(PyExc_TypeError,
"second item of state must be an integer, not %.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, 2);
if (dict != Py_None) {
if (!PyDict_Check(dict)) {
PyErr_Format(PyExc_TypeError,
"third 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 {
self->dict = Py_NewRef(dict);
}
}
Py_RETURN_NONE;
}
static PyObject *
bytesio_setstate(PyObject *op, PyObject *state)
{
PyObject *ret;
Py_BEGIN_CRITICAL_SECTION(op);
ret = bytesio_setstate_lock_held(op, state);
Py_END_CRITICAL_SECTION();
return ret;
}
static void
bytesio_dealloc(PyObject *op)
{
bytesio *self = bytesio_CAST(op);
PyTypeObject *tp = Py_TYPE(self);
_PyObject_GC_UNTRACK(self);
if (FT_ATOMIC_LOAD_SSIZE_RELAXED(self->exports) > 0) {
PyErr_SetString(PyExc_SystemError,
"deallocated BytesIO object has exported buffers");
PyErr_Print();
}
Py_CLEAR(self->buf);
Py_CLEAR(self->dict);
FT_CLEAR_WEAKREFS(op, self->weakreflist);
tp->tp_free(self);
Py_DECREF(tp);
}
static PyObject *
bytesio_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
{
bytesio *self;
assert(type != NULL && type->tp_alloc != NULL);
self = (bytesio *)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 = PyBytes_FromStringAndSize(NULL, 0);
if (self->buf == NULL) {
Py_DECREF(self);
return PyErr_NoMemory();
}
return (PyObject *)self;
}
/*[clinic input]
@critical_section
_io.BytesIO.__init__
initial_bytes as initvalue: object(c_default="NULL") = b''
Buffered I/O implementation using an in-memory bytes buffer.
[clinic start generated code]*/
static int
_io_BytesIO___init___impl(bytesio *self, PyObject *initvalue)
/*[clinic end generated code: output=65c0c51e24c5b621 input=3da5a74ee4c4f1ac]*/
{
/* In case, __init__ is called multiple times. */
self->string_size = 0;
self->pos = 0;
if (FT_ATOMIC_LOAD_SSIZE_RELAXED(self->exports) > 0) {
PyErr_SetString(PyExc_BufferError,
"Existing exports of data: object cannot be re-sized");
return -1;
}
if (initvalue && initvalue != Py_None) {
if (PyBytes_CheckExact(initvalue)) {
Py_XSETREF(self->buf, Py_NewRef(initvalue));
self->string_size = PyBytes_GET_SIZE(initvalue);
}
else {
PyObject *res;
res = _io_BytesIO_write_impl(self, initvalue);
if (res == NULL)
return -1;
Py_DECREF(res);
self->pos = 0;
}
}
return 0;
}
static PyObject *
bytesio_sizeof_lock_held(PyObject *op)
{
_Py_CRITICAL_SECTION_ASSERT_OBJECT_LOCKED(op);
bytesio *self = bytesio_CAST(op);
size_t res = _PyObject_SIZE(Py_TYPE(self));
if (self->buf && !SHARED_BUF(self)) {
size_t s = _PySys_GetSizeOf(self->buf);
if (s == (size_t)-1) {
return NULL;
}
res += s;
}
return PyLong_FromSize_t(res);
}
static PyObject *
bytesio_sizeof(PyObject *op, PyObject *Py_UNUSED(dummy))
{
PyObject *ret;
Py_BEGIN_CRITICAL_SECTION(op);
ret = bytesio_sizeof_lock_held(op);
Py_END_CRITICAL_SECTION();
return ret;
}
static int
bytesio_traverse(PyObject *op, visitproc visit, void *arg)
{
bytesio *self = bytesio_CAST(op);
Py_VISIT(Py_TYPE(self));
Py_VISIT(self->dict);
Py_VISIT(self->buf);
return 0;
}
static int
bytesio_clear(PyObject *op)
{
bytesio *self = bytesio_CAST(op);
Py_CLEAR(self->dict);
if (FT_ATOMIC_LOAD_SSIZE_RELAXED(self->exports) == 0) {
Py_CLEAR(self->buf);
}
return 0;
}
#define clinic_state() (find_io_state_by_def(Py_TYPE(self)))
#include "clinic/bytesio.c.h"
#undef clinic_state
static PyGetSetDef bytesio_getsetlist[] = {
{"closed", bytesio_get_closed, NULL,
"True if the file is closed."},
{NULL}, /* sentinel */
};
static struct PyMethodDef bytesio_methods[] = {
_IO_BYTESIO_READABLE_METHODDEF
_IO_BYTESIO_SEEKABLE_METHODDEF
_IO_BYTESIO_WRITABLE_METHODDEF
_IO_BYTESIO_CLOSE_METHODDEF
_IO_BYTESIO_FLUSH_METHODDEF
_IO_BYTESIO_ISATTY_METHODDEF
_IO_BYTESIO_TELL_METHODDEF
_IO_BYTESIO_WRITE_METHODDEF
_IO_BYTESIO_WRITELINES_METHODDEF
_IO_BYTESIO_READ1_METHODDEF
_IO_BYTESIO_READINTO_METHODDEF
_IO_BYTESIO_READLINE_METHODDEF
_IO_BYTESIO_READLINES_METHODDEF
_IO_BYTESIO_READ_METHODDEF
_IO_BYTESIO_GETBUFFER_METHODDEF
_IO_BYTESIO_GETVALUE_METHODDEF
_IO_BYTESIO_SEEK_METHODDEF
_IO_BYTESIO_TRUNCATE_METHODDEF
{"__getstate__", bytesio_getstate, METH_NOARGS, NULL},
{"__setstate__", bytesio_setstate, METH_O, NULL},
{"__sizeof__", bytesio_sizeof, METH_NOARGS, NULL},
{NULL, NULL} /* sentinel */
};
static PyMemberDef bytesio_members[] = {
{"__weaklistoffset__", Py_T_PYSSIZET, offsetof(bytesio, weakreflist), Py_READONLY},
{"__dictoffset__", Py_T_PYSSIZET, offsetof(bytesio, dict), Py_READONLY},
{NULL}
};
static PyType_Slot bytesio_slots[] = {
{Py_tp_dealloc, bytesio_dealloc},
{Py_tp_doc, (void *)_io_BytesIO___init____doc__},
{Py_tp_traverse, bytesio_traverse},
{Py_tp_clear, bytesio_clear},
{Py_tp_iter, PyObject_SelfIter},
{Py_tp_iternext, bytesio_iternext},
{Py_tp_methods, bytesio_methods},
{Py_tp_members, bytesio_members},
{Py_tp_getset, bytesio_getsetlist},
{Py_tp_init, _io_BytesIO___init__},
{Py_tp_new, bytesio_new},
{0, NULL},
};
PyType_Spec bytesio_spec = {
.name = "_io.BytesIO",
.basicsize = sizeof(bytesio),
.flags = (Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HAVE_GC |
Py_TPFLAGS_IMMUTABLETYPE),
.slots = bytesio_slots,
};
/*
* Implementation of the small intermediate object used by getbuffer().
* getbuffer() returns a memoryview over this object, which should make it
* invisible from Python code.
*/
static int
bytesiobuf_getbuffer_lock_held(PyObject *op, Py_buffer *view, int flags)
{
bytesiobuf *obj = bytesiobuf_CAST(op);
bytesio *b = bytesio_CAST(obj->source);
_Py_CRITICAL_SECTION_ASSERT_OBJECT_LOCKED(b);
if (FT_ATOMIC_LOAD_SSIZE_RELAXED(b->exports) == 0 && SHARED_BUF(b)) {
if (unshare_buffer_lock_held(b, b->string_size) < 0)
return -1;
}
/* cannot fail if view != NULL and readonly == 0 */
(void)PyBuffer_FillInfo(view, op,
PyBytes_AS_STRING(b->buf), b->string_size,
0, flags);
FT_ATOMIC_ADD_SSIZE(b->exports, 1);
return 0;
}
static int
bytesiobuf_getbuffer(PyObject *op, Py_buffer *view, int flags)
{
if (view == NULL) {
PyErr_SetString(PyExc_BufferError,
"bytesiobuf_getbuffer: view==NULL argument is obsolete");
return -1;
}
int ret;
Py_BEGIN_CRITICAL_SECTION(bytesiobuf_CAST(op)->source);
ret = bytesiobuf_getbuffer_lock_held(op, view, flags);
Py_END_CRITICAL_SECTION();
return ret;
}
static void
bytesiobuf_releasebuffer(PyObject *op, Py_buffer *Py_UNUSED(view))
{
bytesiobuf *obj = bytesiobuf_CAST(op);
bytesio *b = bytesio_CAST(obj->source);
FT_ATOMIC_ADD_SSIZE(b->exports, -1);
}
static int
bytesiobuf_traverse(PyObject *op, visitproc visit, void *arg)
{
bytesiobuf *self = bytesiobuf_CAST(op);
Py_VISIT(Py_TYPE(self));
Py_VISIT(self->source);
return 0;
}
static void
bytesiobuf_dealloc(PyObject *op)
{
bytesiobuf *self = bytesiobuf_CAST(op);
PyTypeObject *tp = Py_TYPE(self);
/* bpo-31095: UnTrack is needed before calling any callbacks */
PyObject_GC_UnTrack(op);
Py_CLEAR(self->source);
tp->tp_free(self);
Py_DECREF(tp);
}
static PyType_Slot bytesiobuf_slots[] = {
{Py_tp_dealloc, bytesiobuf_dealloc},
{Py_tp_traverse, bytesiobuf_traverse},
// Buffer protocol
{Py_bf_getbuffer, bytesiobuf_getbuffer},
{Py_bf_releasebuffer, bytesiobuf_releasebuffer},
{0, NULL},
};
PyType_Spec bytesiobuf_spec = {
.name = "_io._BytesIOBuffer",
.basicsize = sizeof(bytesiobuf),
.flags = (Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
Py_TPFLAGS_IMMUTABLETYPE | Py_TPFLAGS_DISALLOW_INSTANTIATION),
.slots = bytesiobuf_slots,
};
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