add abstract interface

Author: picnixz

Include/internal/pycore_global_objects_fini_generated.h

@@ -298,6 +298,8 @@ struct _Py_global_strings {
         STRUCT_FOR_ID(authorizer_callback)
         STRUCT_FOR_ID(autocommit)
         STRUCT_FOR_ID(b)
+        STRUCT_FOR_ID(backread)
+        STRUCT_FOR_ID(backreadinto)
         STRUCT_FOR_ID(backtick)
         STRUCT_FOR_ID(base)
         STRUCT_FOR_ID(before)

Include/internal/pycore_global_strings.h

@@ -109,6 +109,43 @@ _io__BufferedIOBase_readinto1_impl(PyObject *self, Py_buffer *buffer)
     return _bufferediobase_readinto_generic(self, buffer, 1);
 }
 
+/*[clinic input]
+@critical_section
+_io._BufferedIOBase.backreadinto
+    buffer: Py_buffer(accept={rwbuffer})
+    /
+[clinic start generated code]*/
+
+static PyObject *
+_io__BufferedIOBase_backreadinto_impl(PyObject *self, Py_buffer *buffer)
+/*[clinic end generated code: output=089fdcf2b4b15522 input=8240e5a3d7c8fe26]*/
+{
+    Py_ssize_t len;
+    PyObject *data;
+    PyObject *attr = &_Py_ID(backread);
+    data = _PyObject_CallMethod(self, attr, "n", buffer->len);
+    if (data == NULL) {
+        return NULL;
+    }
+    if (!PyBytes_Check(data)) {
+        Py_DECREF(data);
+        PyErr_SetString(PyExc_TypeError, "backread() should return bytes");
+        return NULL;
+    }
+    len = PyBytes_GET_SIZE(data);
+    if (len > buffer->len) {
+        PyErr_Format(PyExc_ValueError,
+                     "backread() returned too much data: "
+                     "%zd bytes requested, %zd returned",
+                     buffer->len, len);
+        Py_DECREF(data);
+        return NULL;
+    }
+    memcpy(buffer->buf, PyBytes_AS_STRING(data), len);
+    Py_DECREF(data);
+    return PyLong_FromSsize_t(len);
+}
+
 static PyObject *
 bufferediobase_unsupported(_PyIO_State *state, const char *message)
 {
@@ -192,6 +229,40 @@ _io__BufferedIOBase_read1_impl(PyObject *self, PyTypeObject *cls,
     return bufferediobase_unsupported(state, "read1");
 }
 
+/*[clinic input]
+_io._BufferedIOBase.backread
+
+    cls: defining_class
+    size: int(unused=True) = -1
+    /
+
+Read backwards and return up to n bytes.
+
+If the size argument is omitted, None, or negative, read and
+return all data until BOF.
+
+If the size argument is positive, and the underlying raw stream is
+not 'interactive', multiple raw reads may be issued to satisfy
+the byte count (unless BOF is reached first).
+However, for interactive raw streams (as well as sockets and pipes),
+at most one raw read will be issued, and a short result does not
+imply that EOF is imminent.
+
+Return an empty bytes object on BOF.
+
+Return None if the underlying raw stream was open in non-blocking
+mode and no data is available at the moment.
+[clinic start generated code]*/
+
+static PyObject *
+_io__BufferedIOBase_backread_impl(PyObject *self, PyTypeObject *cls,
+                                  int Py_UNUSED(size))
+/*[clinic end generated code: output=e2aa0f9e2adc3edc input=fa5dff8791c1db97]*/
+{
+    _PyIO_State *state = get_io_state_by_cls(cls);
+    return bufferediobase_unsupported(state, "backread");
+}
+
 /*[clinic input]
 _io._BufferedIOBase.write
 
@@ -1074,6 +1145,21 @@ _io__Buffered_read1_impl(buffered *self, Py_ssize_t n)
     return res;
 }
 
+/*[clinic input]
+@critical_section
+_io._Buffered.backread
+    size as n: Py_ssize_t(accept={int, NoneType}) = -1
+    /
+[clinic start generated code]*/
+
+static PyObject *
+_io__Buffered_backread_impl(buffered *self, Py_ssize_t n)
+/*[clinic end generated code: output=1d9419484778ae01 input=e0459b8a28c1bc41]*/
+{
+    _PyIO_State *state = get_io_state_by_cls(Py_TYPE(self));
+    return bufferediobase_unsupported(state, "backread");
+}
+
 static PyObject *
 _buffered_readinto_generic(buffered *self, Py_buffer *buffer, char readinto1)
 {
@@ -1184,6 +1270,20 @@ _io__Buffered_readinto1_impl(buffered *self, Py_buffer *buffer)
     return _buffered_readinto_generic(self, buffer, 1);
 }
 
+/*[clinic input]
+@critical_section
+_io._Buffered.backreadinto
+    buffer: Py_buffer(accept={rwbuffer})
+    /
+[clinic start generated code]*/
+
+static PyObject *
+_io__Buffered_backreadinto_impl(buffered *self, Py_buffer *buffer)
+/*[clinic end generated code: output=740fec02a2357570 input=d596047fa0898560]*/
+{
+    _PyIO_State *state = get_io_state_by_cls(Py_TYPE(self));
+    return bufferediobase_unsupported(state, "backreadinto");
+}
 
 static PyObject *
 _buffered_readline(buffered *self, Py_ssize_t limit)
@@ -1308,6 +1408,20 @@ _io__Buffered_readline_impl(buffered *self, Py_ssize_t size)
     return _buffered_readline(self, size);
 }
 
+/*[clinic input]
+@critical_section
+_io._Buffered.backreadline
+    size: Py_ssize_t(accept={int, NoneType}) = -1
+    /
+[clinic start generated code]*/
+
+static PyObject *
+_io__Buffered_backreadline_impl(buffered *self, Py_ssize_t size)
+/*[clinic end generated code: output=dab0e1127f375a53 input=bfaa97db6dc41727]*/
+{
+    _PyIO_State *state = get_io_state_by_cls(Py_TYPE(self));
+    return bufferediobase_unsupported(state, "backreadline");
+}
 
 /*[clinic input]
 @critical_section
@@ -2334,6 +2448,12 @@ bufferedrwpair_read(rwpair *self, PyObject *args)
     return _forward_call(self->reader, &_Py_ID(read), args);
 }
 
+static PyObject *
+bufferedrwpair_backread(rwpair *self, PyObject *args)
+{
+    return _forward_call(self->reader, &_Py_ID(backread), args);
+}
+
 static PyObject *
 bufferedrwpair_peek(rwpair *self, PyObject *args)
 {
@@ -2352,6 +2472,12 @@ bufferedrwpair_readinto(rwpair *self, PyObject *args)
     return _forward_call(self->reader, &_Py_ID(readinto), args);
 }
 
+static PyObject *
+bufferedrwpair_backreadinto(rwpair *self, PyObject *args)
+{
+    return _forward_call(self->reader, &_Py_ID(backreadinto), args);
+}
+
 static PyObject *
 bufferedrwpair_readinto1(rwpair *self, PyObject *args)
 {
@@ -2486,6 +2612,8 @@ _io_BufferedRandom___init___impl(buffered *self, PyObject *raw,
 #undef clinic_state
 
 static PyMethodDef bufferediobase_methods[] = {
+    _IO__BUFFEREDIOBASE_BACKREAD_METHODDEF
+    _IO__BUFFEREDIOBASE_BACKREADINTO_METHODDEF
     _IO__BUFFEREDIOBASE_DETACH_METHODDEF
     _IO__BUFFEREDIOBASE_READ_METHODDEF
     _IO__BUFFEREDIOBASE_READ1_METHODDEF
@@ -2523,9 +2651,12 @@ static PyMethodDef bufferedreader_methods[] = {
     _IO__BUFFERED_READ_METHODDEF
     _IO__BUFFERED_PEEK_METHODDEF
     _IO__BUFFERED_READ1_METHODDEF
+    _IO__BUFFERED_BACKREAD_METHODDEF
     _IO__BUFFERED_READINTO_METHODDEF
     _IO__BUFFERED_READINTO1_METHODDEF
+    _IO__BUFFERED_BACKREADINTO_METHODDEF
     _IO__BUFFERED_READLINE_METHODDEF
+    _IO__BUFFERED_BACKREADLINE_METHODDEF
     _IO__BUFFERED_SEEK_METHODDEF
     _IO__BUFFERED_TELL_METHODDEF
     _IO__BUFFERED_TRUNCATE_METHODDEF
@@ -2637,7 +2768,9 @@ static PyMethodDef bufferedrwpair_methods[] = {
     {"read", (PyCFunction)bufferedrwpair_read, METH_VARARGS},
     {"peek", (PyCFunction)bufferedrwpair_peek, METH_VARARGS},
     {"read1", (PyCFunction)bufferedrwpair_read1, METH_VARARGS},
+    {"backread", (PyCFunction)bufferedrwpair_backread, METH_VARARGS},
     {"readinto", (PyCFunction)bufferedrwpair_readinto, METH_VARARGS},
+    {"backreadinto", (PyCFunction)bufferedrwpair_backreadinto, METH_VARARGS},
     {"readinto1", (PyCFunction)bufferedrwpair_readinto1, METH_VARARGS},
 
     {"write", (PyCFunction)bufferedrwpair_write, METH_VARARGS},
@@ -2702,9 +2835,12 @@ static PyMethodDef bufferedrandom_methods[] = {
     _IO__BUFFERED_TRUNCATE_METHODDEF
     _IO__BUFFERED_READ_METHODDEF
     _IO__BUFFERED_READ1_METHODDEF
+    _IO__BUFFERED_BACKREAD_METHODDEF
     _IO__BUFFERED_READINTO_METHODDEF
     _IO__BUFFERED_READINTO1_METHODDEF
+    _IO__BUFFERED_BACKREADINTO_METHODDEF
     _IO__BUFFERED_READLINE_METHODDEF
+    _IO__BUFFERED_BACKREADLINE_METHODDEF
     _IO__BUFFERED_PEEK_METHODDEF
     _IO_BUFFEREDWRITER_WRITE_METHODDEF
     _IO__BUFFERED___SIZEOF___METHODDEF

Include/internal/pycore_runtime_init_generated.h

@@ -460,6 +460,25 @@ _io_BytesIO_read1_impl(bytesio *self, Py_ssize_t size)
     return _io_BytesIO_read_impl(self, size);
 }
 
+/*[clinic input]
+_io.BytesIO.backread
+    size: Py_ssize_t(accept={int, NoneType}) = -1
+    /
+
+Read backwards 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_backread_impl(bytesio *self, Py_ssize_t size)
+/*[clinic end generated code: output=d3bccd201010ec0a input=3277833a962d0635]*/
+{
+    PyErr_Format(PyExc_NotImplementedError, "TODO");
+    return NULL;
+}
+
 /*[clinic input]
 _io.BytesIO.readline
     size: Py_ssize_t(accept={int, NoneType}) = -1
@@ -485,6 +504,26 @@ _io_BytesIO_readline_impl(bytesio *self, Py_ssize_t size)
     return read_bytes(self, n);
 }
 
+/*[clinic input]
+_io.BytesIO.backreadline
+    size: Py_ssize_t(accept={int, NoneType}) = -1
+    /
+
+Next line from the end of 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 BOF.
+[clinic start generated code]*/
+
+static PyObject *
+_io_BytesIO_backreadline_impl(bytesio *self, Py_ssize_t size)
+/*[clinic end generated code: output=cf53cd21c22e0a4d input=c11ce93b188a03d9]*/
+{
+    PyErr_Format(PyExc_NotImplementedError, "TODO");
+    return NULL;
+}
+
 /*[clinic input]
 _io.BytesIO.readlines
     size as arg: object = None
@@ -586,6 +625,25 @@ _io_BytesIO_readinto_impl(bytesio *self, Py_buffer *buffer)
     return PyLong_FromSsize_t(len);
 }
 
+/*[clinic input]
+_io.BytesIO.backreadinto
+    buffer: Py_buffer(accept={rwbuffer})
+    /
+
+Read backwards bytes into buffer.
+
+Returns number of bytes read (0 for BOF), or None if the object
+is set not to block and has no data to read.
+[clinic start generated code]*/
+
+static PyObject *
+_io_BytesIO_backreadinto_impl(bytesio *self, Py_buffer *buffer)
+/*[clinic end generated code: output=42f2ca676ab55937 input=6ac72ceee21684f3]*/
+{
+    PyErr_Format(PyExc_NotImplementedError, "TODO");
+    return NULL;
+}
+
 /*[clinic input]
 _io.BytesIO.truncate
     size: Py_ssize_t(accept={int, NoneType}, c_default="self->pos") = None
@@ -1016,9 +1074,12 @@ static struct PyMethodDef bytesio_methods[] = {
     _IO_BYTESIO_WRITELINES_METHODDEF
     _IO_BYTESIO_READ1_METHODDEF
     _IO_BYTESIO_READINTO_METHODDEF
+    _IO_BYTESIO_BACKREADINTO_METHODDEF
     _IO_BYTESIO_READLINE_METHODDEF
+    _IO_BYTESIO_BACKREADLINE_METHODDEF
     _IO_BYTESIO_READLINES_METHODDEF
     _IO_BYTESIO_READ_METHODDEF
+    _IO_BYTESIO_BACKREAD_METHODDEF
     _IO_BYTESIO_GETBUFFER_METHODDEF
     _IO_BYTESIO_GETVALUE_METHODDEF
     _IO_BYTESIO_SEEK_METHODDEF