Issue #13248: io: Remove obsolete argument "max_buffer_size" of BufferedWriter and BufferedRWPair.

Doc/library/io.rst

@@ -604,8 +604,6 @@ than raw I/O does.
    *raw* stream.  If the *buffer_size* is not given, it defaults to
    :data:`DEFAULT_BUFFER_SIZE`.
 
-   A third argument, *max_buffer_size*, is supported, but unused and deprecated.
-
    :class:`BufferedWriter` provides or overrides these methods in addition to
    those from :class:`BufferedIOBase` and :class:`IOBase`:
 
@@ -631,8 +629,6 @@ than raw I/O does.
    in the first argument.  If the *buffer_size* is omitted it defaults to
    :data:`DEFAULT_BUFFER_SIZE`.
 
-   A third argument, *max_buffer_size*, is supported, but unused and deprecated.
-
    :class:`BufferedRandom` is capable of anything :class:`BufferedReader` or
    :class:`BufferedWriter` can do.
 
@@ -647,9 +643,6 @@ than raw I/O does.
    writeable respectively.  If the *buffer_size* is omitted it defaults to
    :data:`DEFAULT_BUFFER_SIZE`.
 
-   A fourth argument, *max_buffer_size*, is supported, but unused and
-   deprecated.
-
    :class:`BufferedRWPair` implements all of :class:`BufferedIOBase`\'s methods
    except for :meth:`~BufferedIOBase.detach`, which raises
    :exc:`UnsupportedOperation`.

Lib/_pyio.py

@@ -5,7 +5,6 @@ Python implementation of the io module.
 import os
 import abc
 import codecs
-import warnings
 import errno
 # Import _thread instead of threading to reduce startup cost
 try:
@@ -1065,19 +1064,13 @@ class BufferedWriter(_BufferedIOMixin):
     DEFAULT_BUFFER_SIZE.
     """
 
-    _warning_stack_offset = 2
-
-    def __init__(self, raw,
-                 buffer_size=DEFAULT_BUFFER_SIZE, max_buffer_size=None):
+    def __init__(self, raw, buffer_size=DEFAULT_BUFFER_SIZE):
         if not raw.writable():
             raise IOError('"raw" argument must be writable.')
 
         _BufferedIOMixin.__init__(self, raw)
         if buffer_size <= 0:
             raise ValueError("invalid buffer size")
-        if max_buffer_size is not None:
-            warnings.warn("max_buffer_size is deprecated", DeprecationWarning,
-                          self._warning_stack_offset)
         self.buffer_size = buffer_size
         self._write_buf = bytearray()
         self._write_lock = Lock()
@@ -1167,15 +1160,11 @@ class BufferedRWPair(BufferedIOBase):
     # XXX The usefulness of this (compared to having two separate IO
     # objects) is questionable.
 
-    def __init__(self, reader, writer,
-                 buffer_size=DEFAULT_BUFFER_SIZE, max_buffer_size=None):
+    def __init__(self, reader, writer, buffer_size=DEFAULT_BUFFER_SIZE):
         """Constructor.
 
         The arguments are two RawIO instances.
         """
-        if max_buffer_size is not None:
-            warnings.warn("max_buffer_size is deprecated", DeprecationWarning, 2)
-
         if not reader.readable():
             raise IOError('"reader" argument must be readable.')
 
@@ -1232,13 +1221,10 @@ class BufferedRandom(BufferedWriter, BufferedReader):
     defaults to DEFAULT_BUFFER_SIZE.
     """
 
-    _warning_stack_offset = 3
-
-    def __init__(self, raw,
-                 buffer_size=DEFAULT_BUFFER_SIZE, max_buffer_size=None):
+    def __init__(self, raw, buffer_size=DEFAULT_BUFFER_SIZE):
         raw._checkSeekable()
         BufferedReader.__init__(self, raw, buffer_size)
-        BufferedWriter.__init__(self, raw, buffer_size, max_buffer_size)
+        BufferedWriter.__init__(self, raw, buffer_size)
 
     def seek(self, pos, whence=0):
         if whence not in valid_seek_flags:

Lib/test/test_io.py

@@ -1255,9 +1255,8 @@ class BufferedWriterTest(unittest.TestCase, CommonBufferedTests):
         self.assertRaises(IOError, bufio.tell)
         self.assertRaises(IOError, bufio.write, b"abcdef")
 
-    def test_max_buffer_size_deprecation(self):
-        with support.check_warnings(("max_buffer_size is deprecated",
-                                     DeprecationWarning)):
+    def test_max_buffer_size_removal(self):
+        with self.assertRaises(TypeError):
             self.tp(self.MockRawIO(), 8, 12)
 
 
@@ -1313,9 +1312,8 @@ class BufferedRWPairTest(unittest.TestCase):
         pair = self.tp(self.MockRawIO(), self.MockRawIO())
         self.assertRaises(self.UnsupportedOperation, pair.detach)
 
-    def test_constructor_max_buffer_size_deprecation(self):
-        with support.check_warnings(("max_buffer_size is deprecated",
-                                     DeprecationWarning)):
+    def test_constructor_max_buffer_size_removal(self):
+        with self.assertRaises(TypeError):
             self.tp(self.MockRawIO(), self.MockRawIO(), 8, 12)
 
     def test_constructor_with_not_readable(self):

Misc/NEWS

@@ -23,6 +23,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #13248: Remove obsolete argument "max_buffer_size" of BufferedWriter
+  and BufferedRWPair, from the io module.
+
 - Issue #13248: Remove obsolete argument "version" of argparse.ArgumentParser.
 
 - Issue #14814: implement more consistent ordering and sorting behaviour

Modules/_io/bufferedio.c

@@ -1759,15 +1759,6 @@ PyTypeObject PyBufferedReader_Type = {
 
 
 
-static int
-complain_about_max_buffer_size(void)
-{
-    if (PyErr_WarnEx(PyExc_DeprecationWarning,
-                     "max_buffer_size is deprecated", 1) < 0)
-        return 0;
-    return 1;
-}
-
 /*
  * class BufferedWriter
  */
@@ -1776,7 +1767,7 @@ PyDoc_STRVAR(bufferedwriter_doc,
     "\n"
     "The constructor creates a BufferedWriter for the given writeable raw\n"
     "stream. If the buffer_size is not given, it defaults to\n"
-    "DEFAULT_BUFFER_SIZE. max_buffer_size isn't used anymore.\n"
+    "DEFAULT_BUFFER_SIZE.\n"
     );
 
 static void
@@ -1789,23 +1780,18 @@ _bufferedwriter_reset_buf(buffered *self)
 static int
 bufferedwriter_init(buffered *self, PyObject *args, PyObject *kwds)
 {
-    /* TODO: properly deprecate max_buffer_size */
-    char *kwlist[] = {"raw", "buffer_size", "max_buffer_size", NULL};
+    char *kwlist[] = {"raw", "buffer_size", NULL};
     Py_ssize_t buffer_size = DEFAULT_BUFFER_SIZE;
-    Py_ssize_t max_buffer_size = -234;
     PyObject *raw;
 
     self->ok = 0;
     self->detached = 0;
 
-    if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|nn:BufferedReader", kwlist,
-                                     &raw, &buffer_size, &max_buffer_size)) {
+    if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|n:BufferedReader", kwlist,
+                                     &raw, &buffer_size)) {
         return -1;
     }
 
-    if (max_buffer_size != -234 && !complain_about_max_buffer_size())
-        return -1;
-
     if (_PyIOBase_check_writable(raw, Py_True) == NULL)
         return -1;
 
@@ -2186,16 +2172,12 @@ bufferedrwpair_init(rwpair *self, PyObject *args, PyObject *kwds)
 {
     PyObject *reader, *writer;
     Py_ssize_t buffer_size = DEFAULT_BUFFER_SIZE;
-    Py_ssize_t max_buffer_size = -234;
 
-    if (!PyArg_ParseTuple(args, "OO|nn:BufferedRWPair", &reader, &writer,
-                          &buffer_size, &max_buffer_size)) {
+    if (!PyArg_ParseTuple(args, "OO|n:BufferedRWPair", &reader, &writer,
+                          &buffer_size)) {
         return -1;
     }
 
-    if (max_buffer_size != -234 && !complain_about_max_buffer_size())
-        return -1;
-
     if (_PyIOBase_check_readable(reader, Py_True) == NULL)
         return -1;
     if (_PyIOBase_check_writable(writer, Py_True) == NULL)
@@ -2420,28 +2402,24 @@ PyDoc_STRVAR(bufferedrandom_doc,
     "\n"
     "The constructor creates a reader and writer for a seekable stream,\n"
     "raw, given in the first argument. If the buffer_size is omitted it\n"
-    "defaults to DEFAULT_BUFFER_SIZE. max_buffer_size isn't used anymore.\n"
+    "defaults to DEFAULT_BUFFER_SIZE.\n"
     );
 
 static int
 bufferedrandom_init(buffered *self, PyObject *args, PyObject *kwds)
 {
-    char *kwlist[] = {"raw", "buffer_size", "max_buffer_size", NULL};
+    char *kwlist[] = {"raw", "buffer_size", NULL};
     Py_ssize_t buffer_size = DEFAULT_BUFFER_SIZE;
-    Py_ssize_t max_buffer_size = -234;
     PyObject *raw;
 
     self->ok = 0;
     self->detached = 0;
 
-    if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|nn:BufferedReader", kwlist,
-                                     &raw, &buffer_size, &max_buffer_size)) {
+    if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|n:BufferedReader", kwlist,
+                                     &raw, &buffer_size)) {
         return -1;
     }
 
-    if (max_buffer_size != -234 && !complain_about_max_buffer_size())
-        return -1;
-
     if (_PyIOBase_check_seekable(raw, Py_True) == NULL)
         return -1;
     if (_PyIOBase_check_readable(raw, Py_True) == NULL)