stream.pyx•31.9 kB
cdef extern from *:
'''
enum {__PREALLOCED_BUFS = 4};
'''
const bint __PREALLOCED_BUFS
@cython.no_gc_clear
@cython.freelist(DEFAULT_FREELIST_SIZE)
cdef class _StreamWriteContext:
# used to hold additional write request information for uv_write
cdef:
uv.uv_write_t req
list buffers
uv.uv_buf_t uv_bufs_sml[__PREALLOCED_BUFS]
Py_buffer py_bufs_sml[__PREALLOCED_BUFS]
bint py_bufs_sml_inuse
uv.uv_buf_t* uv_bufs
Py_buffer* py_bufs
size_t py_bufs_len
uv.uv_buf_t* uv_bufs_start
size_t uv_bufs_len
UVStream stream
bint closed
cdef free_bufs(self):
cdef size_t i
if self.uv_bufs is not NULL:
PyMem_RawFree(self.uv_bufs)
self.uv_bufs = NULL
if UVLOOP_DEBUG:
if self.py_bufs_sml_inuse:
raise RuntimeError(
'_StreamWriteContext.close: uv_bufs != NULL and '
'py_bufs_sml_inuse is True')
if self.py_bufs is not NULL:
for i from 0 <= i < self.py_bufs_len:
PyBuffer_Release(&self.py_bufs[i])
PyMem_RawFree(self.py_bufs)
self.py_bufs = NULL
if UVLOOP_DEBUG:
if self.py_bufs_sml_inuse:
raise RuntimeError(
'_StreamWriteContext.close: py_bufs != NULL and '
'py_bufs_sml_inuse is True')
if self.py_bufs_sml_inuse:
for i from 0 <= i < self.py_bufs_len:
PyBuffer_Release(&self.py_bufs_sml[i])
self.py_bufs_sml_inuse = 0
self.py_bufs_len = 0
self.buffers = None
cdef close(self):
if self.closed:
return
self.closed = 1
self.free_bufs()
Py_DECREF(self)
cdef advance_uv_buf(self, size_t sent):
# Advance the pointer to first uv_buf and the
# pointer to first byte in that buffer.
#
# We do this after a "uv_try_write" call, which
# sometimes sends only a portion of data.
# We then call "advance_uv_buf" on the write
# context, and reuse it in a "uv_write" call.
cdef:
uv.uv_buf_t* buf
size_t idx
for idx from 0 <= idx < self.uv_bufs_len:
buf = &self.uv_bufs_start[idx]
if buf.len > sent:
buf.len -= sent
buf.base = buf.base + sent
self.uv_bufs_start = buf
self.uv_bufs_len -= idx
return
else:
sent -= self.uv_bufs_start[idx].len
if UVLOOP_DEBUG:
if sent < 0:
raise RuntimeError('fatal: sent < 0 in advance_uv_buf')
raise RuntimeError('fatal: Could not advance _StreamWriteContext')
@staticmethod
cdef _StreamWriteContext new(UVStream stream, list buffers):
cdef:
_StreamWriteContext ctx
int uv_bufs_idx = 0
size_t py_bufs_len = 0
int i
Py_buffer* p_pybufs
uv.uv_buf_t* p_uvbufs
ctx = _StreamWriteContext.__new__(_StreamWriteContext)
ctx.stream = None
ctx.closed = 1
ctx.py_bufs_len = 0
ctx.py_bufs_sml_inuse = 0
ctx.uv_bufs = NULL
ctx.py_bufs = NULL
ctx.buffers = buffers
ctx.stream = stream
if len(buffers) <= __PREALLOCED_BUFS:
# We've got a small number of buffers to write, don't
# need to use malloc.
ctx.py_bufs_sml_inuse = 1
p_pybufs = <Py_buffer*>&ctx.py_bufs_sml
p_uvbufs = <uv.uv_buf_t*>&ctx.uv_bufs_sml
else:
for buf in buffers:
if UVLOOP_DEBUG:
if not isinstance(buf, (bytes, bytearray, memoryview)):
raise RuntimeError(
'invalid data in writebuf: an instance of '
'bytes, bytearray or memoryview was expected, '
'got {}'.format(type(buf)))
if not PyBytes_CheckExact(buf):
py_bufs_len += 1
if py_bufs_len > 0:
ctx.py_bufs = <Py_buffer*>PyMem_RawMalloc(
py_bufs_len * sizeof(Py_buffer))
if ctx.py_bufs is NULL:
raise MemoryError()
ctx.uv_bufs = <uv.uv_buf_t*>PyMem_RawMalloc(
len(buffers) * sizeof(uv.uv_buf_t))
if ctx.uv_bufs is NULL:
raise MemoryError()
p_pybufs = ctx.py_bufs
p_uvbufs = ctx.uv_bufs
py_bufs_len = 0
for buf in buffers:
if PyBytes_CheckExact(buf):
# We can only use this hack for bytes since it's
# immutable. For everything else it is only safe to
# use buffer protocol.
p_uvbufs[uv_bufs_idx].base = PyBytes_AS_STRING(buf)
p_uvbufs[uv_bufs_idx].len = Py_SIZE(buf)
else:
try:
PyObject_GetBuffer(
buf, &p_pybufs[py_bufs_len], PyBUF_SIMPLE)
except Exception:
# This shouldn't ever happen, as `UVStream._buffer_write`
# casts non-bytes objects to `memoryviews`.
ctx.py_bufs_len = py_bufs_len
ctx.free_bufs()
raise
p_uvbufs[uv_bufs_idx].base = <char*>p_pybufs[py_bufs_len].buf
p_uvbufs[uv_bufs_idx].len = p_pybufs[py_bufs_len].len
py_bufs_len += 1
uv_bufs_idx += 1
ctx.uv_bufs_start = p_uvbufs
ctx.uv_bufs_len = uv_bufs_idx
ctx.py_bufs_len = py_bufs_len
ctx.req.data = <void*> ctx
if UVLOOP_DEBUG:
stream._loop._debug_stream_write_ctx_total += 1
stream._loop._debug_stream_write_ctx_cnt += 1
# Do incref after everything else is done.
# Under no circumstances we want `ctx` to be GCed while
# libuv is still working with `ctx.uv_bufs`.
Py_INCREF(ctx)
ctx.closed = 0
return ctx
def __dealloc__(self):
if not self.closed:
# Because we do an INCREF in _StreamWriteContext.new,
# __dealloc__ shouldn't ever happen with `self.closed == 1`
raise RuntimeError(
'open _StreamWriteContext is being deallocated')
if UVLOOP_DEBUG:
if self.stream is not None:
self.stream._loop._debug_stream_write_ctx_cnt -= 1
self.stream = None
@cython.no_gc_clear
cdef class UVStream(UVBaseTransport):
def __cinit__(self):
self.__shutting_down = 0
self.__reading = 0
self.__read_error_close = 0
self.__buffered = 0
self._eof = 0
self._buffer = []
self._buffer_size = 0
self._protocol_get_buffer = None
self._protocol_buffer_updated = None
self._read_pybuf_acquired = False
cdef _set_protocol(self, object protocol):
if protocol is None:
raise TypeError('protocol is required')
UVBaseTransport._set_protocol(self, protocol)
if (hasattr(protocol, 'get_buffer') and
not isinstance(protocol, aio_Protocol)):
try:
self._protocol_get_buffer = protocol.get_buffer
self._protocol_buffer_updated = protocol.buffer_updated
self.__buffered = 1
except AttributeError:
pass
else:
self.__buffered = 0
cdef _clear_protocol(self):
UVBaseTransport._clear_protocol(self)
self._protocol_get_buffer = None
self._protocol_buffer_updated = None
self.__buffered = 0
cdef inline _shutdown(self):
cdef int err
if self.__shutting_down:
return
self.__shutting_down = 1
self._ensure_alive()
self._shutdown_req.data = <void*> self
err = uv.uv_shutdown(&self._shutdown_req,
<uv.uv_stream_t*> self._handle,
__uv_stream_on_shutdown)
if err < 0:
exc = convert_error(err)
self._fatal_error(exc, True)
return
cdef inline _accept(self, UVStream server):
cdef int err
self._ensure_alive()
err = uv.uv_accept(<uv.uv_stream_t*>server._handle,
<uv.uv_stream_t*>self._handle)
if err < 0:
exc = convert_error(err)
self._fatal_error(exc, True)
return
self._on_accept()
cdef inline _close_on_read_error(self):
self.__read_error_close = 1
cdef bint _is_reading(self):
return self.__reading
cdef _start_reading(self):
cdef int err
if self._closing:
return
self._ensure_alive()
if self.__reading:
return
if self.__buffered:
err = uv.uv_read_start(<uv.uv_stream_t*>self._handle,
__uv_stream_buffered_alloc,
__uv_stream_buffered_on_read)
else:
err = uv.uv_read_start(<uv.uv_stream_t*>self._handle,
__loop_alloc_buffer,
__uv_stream_on_read)
if err < 0:
exc = convert_error(err)
self._fatal_error(exc, True)
return
else:
# UVStream must live until the read callback is called
self.__reading_started()
cdef inline __reading_started(self):
if self.__reading:
return
self.__reading = 1
Py_INCREF(self)
cdef inline __reading_stopped(self):
if not self.__reading:
return
self.__reading = 0
Py_DECREF(self)
cdef _stop_reading(self):
cdef int err
if not self.__reading:
return
self._ensure_alive()
# From libuv docs:
# This function is idempotent and may be safely
# called on a stopped stream.
err = uv.uv_read_stop(<uv.uv_stream_t*>self._handle)
if err < 0:
exc = convert_error(err)
self._fatal_error(exc, True)
return
else:
self.__reading_stopped()
cdef inline _try_write(self, object data):
cdef:
ssize_t written
bint used_buf = 0
Py_buffer py_buf
void* buf
size_t blen
int saved_errno
int fd
if (<uv.uv_stream_t*>self._handle).write_queue_size != 0:
raise RuntimeError(
'UVStream._try_write called with data in uv buffers')
if PyBytes_CheckExact(data):
# We can only use this hack for bytes since it's
# immutable. For everything else it is only safe to
# use buffer protocol.
buf = <void*>PyBytes_AS_STRING(data)
blen = Py_SIZE(data)
else:
PyObject_GetBuffer(data, &py_buf, PyBUF_SIMPLE)
used_buf = 1
buf = py_buf.buf
blen = py_buf.len
if blen == 0:
# Empty data, do nothing.
return 0
fd = self._fileno()
# Use `unistd.h/write` directly, it's faster than
# uv_try_write -- less layers of code. The error
# checking logic is copied from libuv.
written = system.write(fd, buf, blen)
while written == -1 and (
errno.errno == errno.EINTR or
(system.PLATFORM_IS_APPLE and
errno.errno == errno.EPROTOTYPE)):
# From libuv code (unix/stream.c):
# Due to a possible kernel bug at least in OS X 10.10 "Yosemite",
# EPROTOTYPE can be returned while trying to write to a socket
# that is shutting down. If we retry the write, we should get
# the expected EPIPE instead.
written = system.write(fd, buf, blen)
saved_errno = errno.errno
if used_buf:
PyBuffer_Release(&py_buf)
if written < 0:
if saved_errno == errno.EAGAIN or \
saved_errno == system.EWOULDBLOCK:
return -1
else:
exc = convert_error(-saved_errno)
self._fatal_error(exc, True)
return
if UVLOOP_DEBUG:
self._loop._debug_stream_write_tries += 1
if <size_t>written == blen:
return 0
return written
cdef inline _buffer_write(self, object data):
cdef int dlen
if not PyBytes_CheckExact(data):
data = memoryview(data).cast('b')
dlen = len(data)
if not dlen:
return
self._buffer_size += dlen
self._buffer.append(data)
cdef inline _initiate_write(self):
if (not self._protocol_paused and
(<uv.uv_stream_t*>self._handle).write_queue_size == 0 and
self._buffer_size > self._high_water):
# Fast-path. If:
# - the protocol isn't yet paused,
# - there is no data in libuv buffers for this stream,
# - the protocol will be paused if we continue to buffer data
#
# Then:
# - Try to write all buffered data right now.
all_sent = self._exec_write()
if UVLOOP_DEBUG:
if self._buffer_size != 0 or self._buffer != []:
raise RuntimeError(
'_buffer_size is not 0 after a successful _exec_write')
# There is no need to call `_queue_write` anymore,
# as `uv_write` should be called already.
if not all_sent:
# If not all of the data was sent successfully,
# we might need to pause the protocol.
self._maybe_pause_protocol()
elif self._buffer_size > 0:
self._maybe_pause_protocol()
self._loop._queue_write(self)
cdef inline _exec_write(self):
cdef:
int err
int buf_len
_StreamWriteContext ctx = None
if self._closed:
# If the handle is closed, just return, it's too
# late to do anything.
return
buf_len = len(self._buffer)
if not buf_len:
return
if (<uv.uv_stream_t*>self._handle).write_queue_size == 0:
# libuv internal write buffers for this stream are empty.
if buf_len == 1:
# If we only have one piece of data to send, let's
# use our fast implementation of try_write.
data = self._buffer[0]
sent = self._try_write(data)
if sent is None:
# A `self._fatal_error` was called.
# It might not raise an exception under some
# conditions.
self._buffer_size = 0
self._buffer.clear()
if not self._closing:
# This should never happen.
raise RuntimeError(
'stream is open after UVStream._try_write '
'returned None')
return
if sent == 0:
# All data was successfully written.
self._buffer_size = 0
self._buffer.clear()
# on_write will call "maybe_resume_protocol".
self._on_write()
return True
if sent > 0:
if UVLOOP_DEBUG:
if sent == len(data):
raise RuntimeError(
'_try_write sent all data and returned '
'non-zero')
if PyBytes_CheckExact(data):
# Cast bytes to memoryview to avoid copying
# data that wasn't sent.
data = memoryview(data)
data = data[sent:]
self._buffer_size -= sent
self._buffer[0] = data
# At this point it's either data was sent partially,
# or an EAGAIN has happened.
else:
ctx = _StreamWriteContext.new(self, self._buffer)
err = uv.uv_try_write(<uv.uv_stream_t*>self._handle,
ctx.uv_bufs_start,
ctx.uv_bufs_len)
if err > 0:
# Some data was successfully sent.
if <size_t>err == self._buffer_size:
# Everything was sent.
ctx.close()
self._buffer.clear()
self._buffer_size = 0
# on_write will call "maybe_resume_protocol".
self._on_write()
return True
try:
# Advance pointers to uv_bufs in `ctx`,
# we will reuse it soon for a uv_write
# call.
ctx.advance_uv_buf(<ssize_t>err)
except Exception as ex: # This should never happen.
# Let's try to close the `ctx` anyways.
ctx.close()
self._fatal_error(ex, True)
self._buffer.clear()
self._buffer_size = 0
return
elif err != uv.UV_EAGAIN:
ctx.close()
exc = convert_error(err)
self._fatal_error(exc, True)
self._buffer.clear()
self._buffer_size = 0
return
# fall through
if ctx is None:
ctx = _StreamWriteContext.new(self, self._buffer)
err = uv.uv_write(&ctx.req,
<uv.uv_stream_t*>self._handle,
ctx.uv_bufs_start,
ctx.uv_bufs_len,
__uv_stream_on_write)
self._buffer_size = 0
# Can't use `_buffer.clear()` here: `ctx` holds a reference to
# the `_buffer`.
self._buffer = []
if err < 0:
# close write context
ctx.close()
exc = convert_error(err)
self._fatal_error(exc, True)
return
self._maybe_resume_protocol()
cdef size_t _get_write_buffer_size(self):
if self._handle is NULL:
return 0
return ((<uv.uv_stream_t*>self._handle).write_queue_size +
self._buffer_size)
cdef _close(self):
try:
if self._read_pybuf_acquired:
# Should never happen. libuv always calls uv_alloc/uv_read
# in pairs.
self._loop.call_exception_handler({
'transport': self,
'message': 'XXX: an allocated buffer in transport._close()'
})
self._read_pybuf_acquired = 0
PyBuffer_Release(&self._read_pybuf)
self._stop_reading()
finally:
UVSocketHandle._close(<UVHandle>self)
cdef inline _on_accept(self):
# Ultimately called by __uv_stream_on_listen.
self._init_protocol()
cdef inline _on_eof(self):
# Any exception raised here will be caught in
# __uv_stream_on_read.
try:
meth = self._protocol.eof_received
except AttributeError:
keep_open = False
else:
keep_open = run_in_context(self.context, meth)
if keep_open:
# We're keeping the connection open so the
# protocol can write more, but we still can't
# receive more, so remove the reader callback.
self._stop_reading()
else:
self.close()
cdef inline _on_write(self):
self._maybe_resume_protocol()
if not self._get_write_buffer_size():
if self._closing:
self._schedule_call_connection_lost(None)
elif self._eof:
self._shutdown()
cdef inline _init(self, Loop loop, object protocol, Server server,
object waiter, object context):
self.context = context
self._set_protocol(protocol)
self._start_init(loop)
if server is not None:
self._set_server(server)
if waiter is not None:
self._set_waiter(waiter)
cdef inline _on_connect(self, object exc):
# Called from __tcp_connect_callback (tcp.pyx) and
# __pipe_connect_callback (pipe.pyx).
if exc is None:
self._init_protocol()
else:
if self._waiter is None:
self._fatal_error(exc, False, "connect failed")
elif self._waiter.cancelled():
# Connect call was cancelled; just close the transport
# silently.
self._close()
elif self._waiter.done():
self._fatal_error(exc, False, "connect failed")
else:
self._waiter.set_exception(exc)
self._close()
# === Public API ===
def __repr__(self):
return '<{} closed={} reading={} {:#x}>'.format(
self.__class__.__name__,
self._closed,
self.__reading,
id(self))
def write(self, object buf):
self._ensure_alive()
if self._eof:
raise RuntimeError('Cannot call write() after write_eof()')
if not buf:
return
if self._conn_lost:
self._conn_lost += 1
return
self._buffer_write(buf)
self._initiate_write()
def writelines(self, bufs):
self._ensure_alive()
if self._eof:
raise RuntimeError('Cannot call writelines() after write_eof()')
if self._conn_lost:
self._conn_lost += 1
return
for buf in bufs:
self._buffer_write(buf)
self._initiate_write()
def write_eof(self):
self._ensure_alive()
if self._eof:
return
self._eof = 1
if not self._get_write_buffer_size():
self._shutdown()
def can_write_eof(self):
return True
def is_reading(self):
return self._is_reading()
def pause_reading(self):
if self._closing or not self._is_reading():
return
self._stop_reading()
def resume_reading(self):
if self._is_reading() or self._closing:
return
self._start_reading()
cdef void __uv_stream_on_shutdown(uv.uv_shutdown_t* req,
int status) noexcept with gil:
# callback for uv_shutdown
if req.data is NULL:
aio_logger.error(
'UVStream.shutdown callback called with NULL req.data, status=%r',
status)
return
cdef UVStream stream = <UVStream> req.data
if status < 0 and status != uv.UV_ECANCELED:
# From libuv source code:
# The ECANCELED error code is a lie, the shutdown(2) syscall is a
# fait accompli at this point. Maybe we should revisit this in
# v0.11. A possible reason for leaving it unchanged is that it
# informs the callee that the handle has been destroyed.
if UVLOOP_DEBUG:
stream._loop._debug_stream_shutdown_errors_total += 1
exc = convert_error(status)
stream._fatal_error(
exc, False, "error status in uv_stream_t.shutdown callback")
return
cdef inline bint __uv_stream_on_read_common(
UVStream sc,
Loop loop,
ssize_t nread,
):
if sc._closed:
# The stream was closed, there is no reason to
# do any work now.
sc.__reading_stopped() # Just in case.
return True
if nread == uv.UV_EOF:
# From libuv docs:
# The callee is responsible for stopping closing the stream
# when an error happens by calling uv_read_stop() or uv_close().
# Trying to read from the stream again is undefined.
try:
if UVLOOP_DEBUG:
loop._debug_stream_read_eof_total += 1
sc._stop_reading()
sc._on_eof()
except BaseException as ex:
if UVLOOP_DEBUG:
loop._debug_stream_read_eof_cb_errors_total += 1
sc._fatal_error(ex, False)
finally:
return True
if nread == 0:
# From libuv docs:
# nread might be 0, which does not indicate an error or EOF.
# This is equivalent to EAGAIN or EWOULDBLOCK under read(2).
return True
if nread < 0:
# From libuv docs:
# The callee is responsible for stopping closing the stream
# when an error happens by calling uv_read_stop() or uv_close().
# Trying to read from the stream again is undefined.
#
# Therefore, we're closing the stream. Since "UVHandle._close()"
# doesn't raise exceptions unless uvloop is built with DEBUG=1,
# we don't need try...finally here.
if UVLOOP_DEBUG:
loop._debug_stream_read_errors_total += 1
if sc.__read_error_close:
# Used for getting notified when a pipe is closed.
# See WriteUnixTransport for the explanation.
sc._on_eof()
return True
exc = convert_error(nread)
sc._fatal_error(
exc, False, "error status in uv_stream_t.read callback")
return True
return False
cdef inline void __uv_stream_on_read_impl(
uv.uv_stream_t* stream,
ssize_t nread,
const uv.uv_buf_t* buf,
):
cdef:
UVStream sc = <UVStream>stream.data
Loop loop = sc._loop
# It's OK to free the buffer early, since nothing will
# be able to touch it until this method is done.
__loop_free_buffer(loop)
if __uv_stream_on_read_common(sc, loop, nread):
return
try:
if UVLOOP_DEBUG:
loop._debug_stream_read_cb_total += 1
run_in_context1(
sc.context,
sc._protocol_data_received,
loop._recv_buffer[:nread],
)
except BaseException as exc:
if UVLOOP_DEBUG:
loop._debug_stream_read_cb_errors_total += 1
sc._fatal_error(exc, False)
cdef inline void __uv_stream_on_write_impl(
uv.uv_write_t* req,
int status,
):
cdef:
_StreamWriteContext ctx = <_StreamWriteContext> req.data
UVStream stream = <UVStream>ctx.stream
ctx.close()
if stream._closed:
# The stream was closed, there is nothing to do.
# Even if there is an error, like EPIPE, there
# is no reason to report it.
return
if status < 0:
if UVLOOP_DEBUG:
stream._loop._debug_stream_write_errors_total += 1
exc = convert_error(status)
stream._fatal_error(
exc, False, "error status in uv_stream_t.write callback")
return
try:
stream._on_write()
except BaseException as exc:
if UVLOOP_DEBUG:
stream._loop._debug_stream_write_cb_errors_total += 1
stream._fatal_error(exc, False)
cdef void __uv_stream_on_read(
uv.uv_stream_t* stream,
ssize_t nread,
const uv.uv_buf_t* buf,
) noexcept with gil:
if __ensure_handle_data(<uv.uv_handle_t*>stream,
"UVStream read callback") == 0:
return
# Don't need try-finally, __uv_stream_on_read_impl is void
__uv_stream_on_read_impl(stream, nread, buf)
cdef void __uv_stream_on_write(
uv.uv_write_t* req,
int status,
) noexcept with gil:
if UVLOOP_DEBUG:
if req.data is NULL:
aio_logger.error(
'UVStream.write callback called with NULL req.data, status=%r',
status)
return
# Don't need try-finally, __uv_stream_on_write_impl is void
__uv_stream_on_write_impl(req, status)
cdef void __uv_stream_buffered_alloc(
uv.uv_handle_t* stream,
size_t suggested_size,
uv.uv_buf_t* uvbuf,
) noexcept with gil:
if __ensure_handle_data(<uv.uv_handle_t*>stream,
"UVStream alloc buffer callback") == 0:
return
cdef:
UVStream sc = <UVStream>stream.data
Loop loop = sc._loop
Py_buffer* pybuf = &sc._read_pybuf
int got_buf = 0
if sc._read_pybuf_acquired:
uvbuf.len = 0
uvbuf.base = NULL
return
sc._read_pybuf_acquired = 0
try:
buf = run_in_context1(
sc.context,
sc._protocol_get_buffer,
suggested_size,
)
PyObject_GetBuffer(buf, pybuf, PyBUF_WRITABLE)
got_buf = 1
except BaseException as exc:
# Can't call 'sc._fatal_error' or 'sc._close', libuv will SF.
# We'll do it later in __uv_stream_buffered_on_read when we
# receive UV_ENOBUFS.
uvbuf.len = 0
uvbuf.base = NULL
return
if not pybuf.len:
uvbuf.len = 0
uvbuf.base = NULL
if got_buf:
PyBuffer_Release(pybuf)
return
sc._read_pybuf_acquired = 1
uvbuf.base = <char*>pybuf.buf
uvbuf.len = pybuf.len
cdef void __uv_stream_buffered_on_read(
uv.uv_stream_t* stream,
ssize_t nread,
const uv.uv_buf_t* buf,
) noexcept with gil:
if __ensure_handle_data(<uv.uv_handle_t*>stream,
"UVStream buffered read callback") == 0:
return
cdef:
UVStream sc = <UVStream>stream.data
Loop loop = sc._loop
Py_buffer* pybuf = &sc._read_pybuf
if nread == uv.UV_ENOBUFS:
sc._fatal_error(
RuntimeError(
'unhandled error (or an empty buffer) in get_buffer()'),
False)
return
try:
if nread > 0 and not sc._read_pybuf_acquired:
# From libuv docs:
# nread is > 0 if there is data available or < 0 on error. When
# we’ve reached EOF, nread will be set to UV_EOF. When
# nread < 0, the buf parameter might not point to a valid
# buffer; in that case buf.len and buf.base are both set to 0.
raise RuntimeError(
f'no python buffer is allocated in on_read; nread={nread}')
if nread == 0:
# From libuv docs:
# nread might be 0, which does not indicate an error or EOF.
# This is equivalent to EAGAIN or EWOULDBLOCK under read(2).
return
if __uv_stream_on_read_common(sc, loop, nread):
return
if UVLOOP_DEBUG:
loop._debug_stream_read_cb_total += 1
run_in_context1(sc.context, sc._protocol_buffer_updated, nread)
except BaseException as exc:
if UVLOOP_DEBUG:
loop._debug_stream_read_cb_errors_total += 1
sc._fatal_error(exc, False)
finally:
sc._read_pybuf_acquired = 0
PyBuffer_Release(pybuf)