Remove sendfile support

pysendfile[1] was added as an optional dependency but the library
hasn't been maintained and has got no release since 2014.

What is worse, the sendfile implementation is not actually working
since The SendFileIterator class was removed[2]. (Follow-up[3] removed
the remaining reference to the class). The broken implementation has
not been detected because the client is not currently used to upload
contents.

Remove the incomplete implementation to get rid of the dependency on
the unmaintained library.

[1] https://pypi.org/project/pysendfile/
[2] 76c3620c7e
[3] 0c151d7d7e

Closes-Bug: #2062573
Change-Id: Ia4784f59d16660e8d40c0e409f092ac4e46870b4

doc/source/admin/requirements.rst

@@ -23,9 +23,8 @@ External Requirements Affecting Glance
 
 Like other OpenStack projects, Glance uses some external libraries for a subset
 of its features. Some examples include the ``qemu-img`` utility used by the
-tasks feature, ``sendfile`` to utilize the "zero-copy" way of copying data
+tasks feature, ``pydev`` to debug using popular IDEs, ``python-xattr`` for
-faster, ``pydev`` to debug using popular IDEs, ``python-xattr`` for Image Cache
+Image Cache using "xattr" driver.
-using "xattr" driver.
 
 On the other hand, if ``dnspython`` is installed in the environment, Glance
 provides a workaround to make it work with IPV6.

glance/common/client.py

@@ -19,7 +19,6 @@
 
 import collections.abc
 import copy
-import errno
 import functools
 import http.client
 import os
@@ -35,12 +34,6 @@ except ImportError:
 
 import osprofiler.web
 
-try:
-    import sendfile  # noqa
-    SENDFILE_SUPPORTED = True
-except ImportError:
-    SENDFILE_SUPPORTED = False
-
 from oslo_log import log as logging
 from oslo_utils import encodeutils
 from oslo_utils import netutils
@@ -446,12 +439,6 @@ class BaseClient(object):
             def _filelike(body):
                 return hasattr(body, 'read')
 
-            def _sendbody(connection, iter):
-                connection.endheaders()
-                for sent in iter:
-                    # iterator has done the heavy lifting
-                    pass
-
             def _chunkbody(connection, iter):
                 connection.putheader('Transfer-Encoding', 'chunked')
                 connection.endheaders()
@@ -469,22 +456,15 @@ class BaseClient(object):
             elif _filelike(body) or self._iterable(body):
                 c.putrequest(method, path)
 
-                use_sendfile = self._sendable(body)
-
                 # According to HTTP/1.1, Content-Length and Transfer-Encoding
                 # conflict.
                 for header, value in headers.items():
-                    if use_sendfile or header.lower() != 'content-length':
+                    if header.lower() != 'content-length':
                         c.putheader(header, str(value))
 
                 iter = utils.chunkreadable(body)
 
-                if use_sendfile:
+                _chunkbody(c, iter)
-                    # send actual file without copying into userspace
-                    _sendbody(c, iter)
-                else:
-                    # otherwise iterate and chunk
-                    _chunkbody(c, iter)
             else:
                 raise TypeError('Unsupported image type: %s' % body.__class__)
 
@@ -528,22 +508,6 @@ class BaseClient(object):
         except (socket.error, IOError) as e:
             raise exception.ClientConnectionError(e)
 
-    def _seekable(self, body):
-        # pipes are not seekable, avoids sendfile() failure on e.g.
-        #   cat /path/to/image | glance add ...
-        # or where add command is launched via popen
-        try:
-            os.lseek(body.fileno(), 0, os.SEEK_CUR)
-            return True
-        except OSError as e:
-            return (e.errno != errno.ESPIPE)
-
-    def _sendable(self, body):
-        return (SENDFILE_SUPPORTED and
-                hasattr(body, 'fileno') and
-                self._seekable(body) and
-                not self.use_ssl)
-
     def _iterable(self, body):
         return isinstance(body, collections.abc.Iterable)
 

glance/tests/stubs.py

@@ -15,23 +15,11 @@
 
 """Stubouts, mocks and fixtures for the test suite"""
 
-import os
-
-try:
-    import sendfile
-    SENDFILE_SUPPORTED = True
-except ImportError:
-    SENDFILE_SUPPORTED = False
-
 import routes
 import webob
 
 from glance.api.middleware import context
 from glance.api.v2 import router
-import glance.common.client
-
-
-DEBUG = False
 
 
 def stub_out_store_server(stubs, base_dir, **kwargs):
@@ -49,23 +37,10 @@ def stub_out_store_server(stubs, base_dir, **kwargs):
         def fileno(self):
             return 42
 
-    class FakeSendFile(object):
-
-        def __init__(self, req):
-            self.req = req
-
-        def sendfile(self, o, i, offset, nbytes):
-            os.lseek(i, offset, os.SEEK_SET)
-            prev_len = len(self.req.body)
-            self.req.body += os.read(i, nbytes)
-            return len(self.req.body) - prev_len
-
     class FakeGlanceConnection(object):
 
         def __init__(self, *args, **kwargs):
             self.sock = FakeSocket()
-            self.stub_force_sendfile = kwargs.get('stub_force_sendfile',
-                                                  SENDFILE_SUPPORTED)
 
         def connect(self):
             return True
@@ -75,9 +50,6 @@ def stub_out_store_server(stubs, base_dir, **kwargs):
 
         def putrequest(self, method, url):
             self.req = webob.Request.blank(url)
-            if self.stub_force_sendfile:
-                fake_sendfile = FakeSendFile(self.req)
-                stubs.Set(sendfile, 'sendfile', fake_sendfile.sendfile)
             self.req.method = method
 
         def putheader(self, key, value):
@@ -118,15 +90,3 @@ def stub_out_store_server(stubs, base_dir, **kwargs):
     def fake_image_iter(self):
         for i in self.source.app_iter:
             yield i
-
-    def fake_sendable(self, body):
-        force = getattr(self, 'stub_force_sendfile', None)
-        if force is None:
-            return self._stub_orig_sendable(body)
-        else:
-            if force:
-                assert glance.common.client.SENDFILE_SUPPORTED
-            return force
-
-    setattr(glance.common.client.BaseClient, '_stub_orig_sendable',
-            glance.common.client.BaseClient._sendable)

test-requirements.txt

@@ -20,7 +20,6 @@ boto3>=1.9.199 # Apache-2.0
 # Optional packages that should be installed when testing
 PyMySQL>=0.7.6 # MIT License
 psycopg2>=2.8.4 # LGPL/ZPL
-pysendfile>=2.0.0;sys_platform!='win32' # MIT
 xattr>=0.9.2;sys_platform!='win32' # MIT
 python-swiftclient>=3.2.0 # Apache-2.0
 python-cinderclient>=4.1.0 # Apache-2.0