Merge master

infrastructure/lambda/task_queue_manager/redis/_compat.py

@@ -0,0 +1,188 @@
+"""Internal module for Python 2 backwards compatibility."""
+# flake8: noqa
+import errno
+import socket
+import sys
+
+
+def sendall(sock, *args, **kwargs):
+    return sock.sendall(*args, **kwargs)
+
+
+def shutdown(sock, *args, **kwargs):
+    return sock.shutdown(*args, **kwargs)
+
+
+def ssl_wrap_socket(context, sock, *args, **kwargs):
+    return context.wrap_socket(sock, *args, **kwargs)
+
+
+# For Python older than 3.5, retry EINTR.
+if sys.version_info[0] < 3 or (sys.version_info[0] == 3 and
+                               sys.version_info[1] < 5):
+    # Adapted from https://bugs.python.org/review/23863/patch/14532/54418
+    import time
+
+    # Wrapper for handling interruptable system calls.
+    def _retryable_call(s, func, *args, **kwargs):
+        # Some modules (SSL) use the _fileobject wrapper directly and
+        # implement a smaller portion of the socket interface, thus we
+        # need to let them continue to do so.
+        timeout, deadline = None, 0.0
+        attempted = False
+        try:
+            timeout = s.gettimeout()
+        except AttributeError:
+            pass
+
+        if timeout:
+            deadline = time.time() + timeout
+
+        try:
+            while True:
+                if attempted and timeout:
+                    now = time.time()
+                    if now >= deadline:
+                        raise socket.error(errno.EWOULDBLOCK, "timed out")
+                    else:
+                        # Overwrite the timeout on the socket object
+                        # to take into account elapsed time.
+                        s.settimeout(deadline - now)
+                try:
+                    attempted = True
+                    return func(*args, **kwargs)
+                except socket.error as e:
+                    if e.args[0] == errno.EINTR:
+                        continue
+                    raise
+        finally:
+            # Set the existing timeout back for future
+            # calls.
+            if timeout:
+                s.settimeout(timeout)
+
+    def recv(sock, *args, **kwargs):
+        return _retryable_call(sock, sock.recv, *args, **kwargs)
+
+    def recv_into(sock, *args, **kwargs):
+        return _retryable_call(sock, sock.recv_into, *args, **kwargs)
+
+else:  # Python 3.5 and above automatically retry EINTR
+    def recv(sock, *args, **kwargs):
+        return sock.recv(*args, **kwargs)
+
+    def recv_into(sock, *args, **kwargs):
+        return sock.recv_into(*args, **kwargs)
+
+if sys.version_info[0] < 3:
+    # In Python 3, the ssl module raises socket.timeout whereas it raises
+    # SSLError in Python 2. For compatibility between versions, ensure
+    # socket.timeout is raised for both.
+    import functools
+
+    try:
+        from ssl import SSLError as _SSLError
+    except ImportError:
+        class _SSLError(Exception):
+            """A replacement in case ssl.SSLError is not available."""
+            pass
+
+    _EXPECTED_SSL_TIMEOUT_MESSAGES = (
+        "The handshake operation timed out",
+        "The read operation timed out",
+        "The write operation timed out",
+    )
+
+    def _handle_ssl_timeout(func):
+        @functools.wraps(func)
+        def wrapper(*args, **kwargs):
+            try:
+                return func(*args, **kwargs)
+            except _SSLError as e:
+                message = len(e.args) == 1 and unicode(e.args[0]) or ''
+                if any(x in message for x in _EXPECTED_SSL_TIMEOUT_MESSAGES):
+                    # Raise socket.timeout for compatibility with Python 3.
+                    raise socket.timeout(*e.args)
+                raise
+        return wrapper
+
+    recv = _handle_ssl_timeout(recv)
+    recv_into = _handle_ssl_timeout(recv_into)
+    sendall = _handle_ssl_timeout(sendall)
+    shutdown = _handle_ssl_timeout(shutdown)
+    ssl_wrap_socket = _handle_ssl_timeout(ssl_wrap_socket)
+
+if sys.version_info[0] < 3:
+    from urllib import unquote
+    from urlparse import parse_qs, urlparse
+    from itertools import imap, izip
+    from string import letters as ascii_letters
+    from Queue import Queue
+
+    # special unicode handling for python2 to avoid UnicodeDecodeError
+    def safe_unicode(obj, *args):
+        """ return the unicode representation of obj """
+        try:
+            return unicode(obj, *args)
+        except UnicodeDecodeError:
+            # obj is byte string
+            ascii_text = str(obj).encode('string_escape')
+            return unicode(ascii_text)
+
+    def iteritems(x):
+        return x.iteritems()
+
+    def iterkeys(x):
+        return x.iterkeys()
+
+    def itervalues(x):
+        return x.itervalues()
+
+    def nativestr(x):
+        return x if isinstance(x, str) else x.encode('utf-8', 'replace')
+
+    def next(x):
+        return x.next()
+
+    unichr = unichr
+    xrange = xrange
+    basestring = basestring
+    unicode = unicode
+    long = long
+    BlockingIOError = socket.error
+else:
+    from urllib.parse import parse_qs, unquote, urlparse
+    from string import ascii_letters
+    from queue import Queue
+
+    def iteritems(x):
+        return iter(x.items())
+
+    def iterkeys(x):
+        return iter(x.keys())
+
+    def itervalues(x):
+        return iter(x.values())
+
+    def nativestr(x):
+        return x if isinstance(x, str) else x.decode('utf-8', 'replace')
+
+    def safe_unicode(value):
+        if isinstance(value, bytes):
+            value = value.decode('utf-8', 'replace')
+        return str(value)
+
+    next = next
+    unichr = chr
+    imap = map
+    izip = zip
+    xrange = range
+    basestring = str
+    unicode = str
+    long = int
+    BlockingIOError = BlockingIOError
+
+try:  # Python 3
+    from queue import LifoQueue, Empty, Full
+except ImportError:  # Python 2
+    from Queue import LifoQueue, Empty, Full