Merge remote-tracking branch 'upstream/master'

Updating this branch with changes made in master

Author: edwarde-astranis

docs/source/reference-io.rst

@@ -403,6 +403,10 @@ Socket objects
          left in an unknown state – possibly open, and possibly
          closed. The only reasonable thing to do is to close it.
 
+   .. method:: is_readable
+
+      Check whether the socket is readable or not.
+
    .. method:: sendfile
 
       `Not implemented yet! <https://github.com/python-trio/trio/issues/45>`__

newsfragments/760.feature.rst

@@ -0,0 +1,2 @@
+Trio sockets have a new method `~trio.socket.SocketType.is_readable` that allows
+you to check whether a socket is readable. This is useful for HTTP/1.1 clients.

test-requirements.txt

@@ -16,20 +16,20 @@ coverage==4.5.3           # via pytest-cov
 cryptography==2.7         # via pyopenssl, trustme
 decorator==4.4.0          # via ipython, traitlets
 entrypoints==0.3          # via flake8
-flake8==3.7.7
+flake8==3.7.8
 idna==2.8
 immutables==0.9
 importlib-metadata==0.18  # via pluggy, pytest
 ipython-genutils==0.2.0   # via traitlets
-ipython==7.6.0
+ipython==7.6.1
 isort==4.3.21             # via pylint
-jedi==0.13.3
+jedi==0.14.1
 lazy-object-proxy==1.4.1  # via astroid
 mccabe==0.6.1             # via flake8, pylint
 more-itertools==7.1.0     # via pytest
 outcome==1.0.0
 packaging==19.0           # via pytest
-parso==0.4.0              # via jedi
+parso==0.5.1              # via jedi
 pexpect==4.7.0            # via ipython
 pickleshare==0.7.5        # via ipython
 pluggy==0.12.0            # via pytest
@@ -44,7 +44,7 @@ pylint==2.3.1
 pyopenssl==19.0.0
 pyparsing==2.4.0          # via packaging
 pytest-cov==2.7.1
-pytest==5.0.0
+pytest==5.0.1
 six==1.12.0               # via astroid, cryptography, packaging, prompt-toolkit, pyopenssl, traitlets
 sniffio==1.1.0
 sortedcontainers==2.1.0
@@ -54,4 +54,4 @@ typed-ast==1.3.1 ; python_version < "3.8" and implementation_name == "cpython"
 wcwidth==0.1.7            # via prompt-toolkit, pytest
 wrapt==1.11.2             # via astroid
 yapf==0.27.0
-zipp==0.5.1               # via importlib-metadata
+zipp==0.5.2               # via importlib-metadata

trio/_socket.py

@@ -1,5 +1,6 @@
 import os as _os
 import sys as _sys
+import select
 import socket as _stdlib_socket
 from functools import wraps as _wraps
 
@@ -289,7 +290,7 @@ def socket(
 
 def _sniff_sockopts_for_fileno(family, type, proto, fileno):
     """Correct SOCKOPTS for given fileno, falling back to provided values.
-    
+
     """
     # Wrap the raw fileno into a Python socket object
     # This object might have the wrong metadata, but it lets us easily call getsockopt
@@ -478,6 +479,15 @@ def shutdown(self, flag):
         if flag in [_stdlib_socket.SHUT_WR, _stdlib_socket.SHUT_RDWR]:
             self._did_shutdown_SHUT_WR = True
 
+    def is_readable(self):
+        # use select.select on Windows, and select.poll everywhere else
+        if _sys.platform == "win32":
+            rready, _, _ = select.select([self._sock], [], [], 0)
+            return bool(rready)
+        p = select.poll()
+        p.register(self._sock, select.POLLIN)
+        return bool(p.poll(0))
+
     async def wait_writable(self):
         await _core.wait_writable(self._sock)
 

trio/tests/test_socket.py

@@ -404,6 +404,17 @@ async def test_SocketType_simple_server(address, socket_type):
             assert await client.recv(1) == b"x"
 
 
+async def test_SocketType_is_readable():
+    a, b = tsocket.socketpair()
+    with a, b:
+        assert not a.is_readable()
+        await b.send(b"x")
+        await _core.wait_readable(a)
+        assert a.is_readable()
+        assert await a.recv(1) == b"x"
+        assert not a.is_readable()
+
+
 # On some macOS systems, getaddrinfo likes to return V4-mapped addresses even
 # when we *don't* pass AI_V4MAPPED.
 # https://github.com/python-trio/trio/issues/580