def _populate(self):
"""
Put some revisions of a blob object in our database and on the
filesystem.
"""
from ZODB.utils import u64 as bytes8_to_int64
connection1 = self.database.open()
root = connection1.root()
tids = self.tids = []
times = self.times = []
blob = Blob()
for i in range(self.BLOB_REVISION_COUNT):
transaction.begin()
with blob.open('w') as f:
f.write(b'this is blob data ' + str(i).encode())
if 'blob' not in root:
root['blob'] = blob
transaction.commit()
blob._p_activate()
tid = blob._p_serial
tids.append(tid)
tid_int = bytes8_to_int64(tid)
times.append(tid_int - 1)
blob._p_activate()
self.oid = oid = root['blob']._p_oid
fshelper = self.blob_storage.blobhelper.fshelper
self.fns = [fshelper.getBlobFilename(oid, x) for x in tids]
connection1.close()
class File(Persistent):
title = _BLANK
name = renamer()
def __init__(self, stream=None, mimetype=None, title=_BLANK):
""" The constructor of a File object.
``stream`` should be a filelike object (an object with a ``read``
method that takes a size argument) or ``None``. If stream is
``None``, the blob attached to this file object is created empty.
``title`` must be a string or Unicode object.
``mimetype`` may be any of the following:
- ``None``, meaning set this file object's mimetype to
``application/octet-stream`` (the default).
- A mimetype string (e.g. ``image/gif``)
- The constant :attr:`substanced.file.USE_MAGIC`, which will
derive the mimetype from the stream content (if ``stream`` is also
supplied) using the ``python-magic`` library.
.. warning::
On non-Linux systems, successful use of
:attr:`substanced.file.USE_MAGIC` requires the installation
of additional dependencies. See :ref:`optional_dependencies`.
"""
self.blob = Blob()
self.title = title or _BLANK
# mimetype will be overridden by upload if there's a stream
if mimetype is USE_MAGIC:
self.mimetype = "application/octet-stream"
else:
self.mimetype = mimetype or "application/octet-stream"
if stream is not None:
if mimetype is USE_MAGIC:
hint = USE_MAGIC
else:
hint = None
self.upload(stream, mimetype_hint=hint)
def upload(self, stream, mimetype_hint=None):
""" Replace the current contents of this file's blob with the
contents of ``stream``. ``stream`` must be a filelike object (it
must have a ``read`` method that takes a size argument).
``mimetype_hint`` can be any of the following:
- ``None``, meaning don't reset the current mimetype. This is the
default. If you already know the file's mimetype, and you don't
want it divined from a filename or stream content, use ``None`` as
the ``mimetype_hint`` value, and set the ``mimetype`` attribute of
the file object directly before or after calling this method.
- A string containing a filename that has an extension; the mimetype
will be derived from the extension in the filename using the Python
``mimetypes`` module, and the result will be set as the mimetype
attribute of this object.
- The constant :attr:`pyramid.file.USE_MAGIC`, which will derive
the mimetype using the ``python-magic`` library based on the
stream's actual content. The result will be set as the mimetype
attribute of this object.
.. warning::
On non-Linux systems, successful use of
:attr:`substanced.file.USE_MAGIC` requires the installation
of additional dependencies. See :ref:`optional_dependencies`.
"""
if not stream:
stream = io.StringIO()
fp = self.blob.open("w")
first = True
use_magic = False
if mimetype_hint is USE_MAGIC:
use_magic = True
if magic is None: # pragma: no cover
warnings.warn(
"The python-magic library does not have its requisite "
"dependencies installed properly, therefore the "
'"USE_MAGIC" flag passed to this method has been ignored '
'(it has been converted to "None"). The mimetype of '
"substanced.file.File objects created may be incorrect as "
"a result."
)
use_magic = False
mimetype_hint = None
if not use_magic:
if mimetype_hint is not None:
mimetype, _ = mimetypes.guess_type(mimetype_hint, strict=False)
if mimetype is None:
mimetype = "application/octet-stream"
self.mimetype = mimetype
for chunk in chunks(stream):
if use_magic and first:
first = False
m = magic.Magic(mime=True)
mimetype = m.from_buffer(chunk)
self.mimetype = u(mimetype)
fp.write(chunk)
fp.close()
def get_response(self, **kw):
""" Return a WebOb-compatible response object which uses the blob
content as the stream data and the mimetype of the file as the
content type. The ``**kw`` arguments will be passed to the
``pyramid.response.FileResponse`` constructor as its keyword
arguments."""
if not "content_type" in kw:
kw["content_type"] = str(self.mimetype)
path = self.blob.committed()
response = FileResponse(path, **kw)
return response
def get_size(self):
""" Return the size in bytes of the data in the blob associated with
the file"""
return os.stat(self.blob.committed()).st_size
def get_etag(self):
""" Return a token identifying the "version" of the file.
"""
self._p_activate()
mine = self._p_serial
blob = self.blob._p_serial
if blob == z64:
self.blob._p_activate()
blob = self.blob._p_serial
return oid_repr(max(mine, blob))
class File(Persistent):
title = _BLANK
name = renamer()
def __init__(self, stream=None, mimetype=None, title=_BLANK):
""" The constructor of a File object.
``stream`` should be a filelike object (an object with a ``read``
method that takes a size argument) or ``None``. If stream is
``None``, the blob attached to this file object is created empty.
``title`` must be a string or Unicode object.
``mimetype`` may be any of the following:
- ``None``, meaning set this file object's mimetype to
``application/octet-stream`` (the default).
- A mimetype string (e.g. ``image/gif``)
- The constant :attr:`substanced.file.USE_MAGIC`, which will
derive the mimetype from the stream content (if ``stream`` is also
supplied) using the ``python-magic`` library.
.. warning::
On non-Linux systems, successful use of
:attr:`substanced.file.USE_MAGIC` requires the installation
of additional dependencies. See :ref:`installing_python_magic`.
"""
self.blob = Blob()
self.title = title or _BLANK
# mimetype will be overridden by upload if there's a stream
if mimetype is USE_MAGIC:
self.mimetype = 'application/octet-stream'
else:
self.mimetype = mimetype or 'application/octet-stream'
if stream is not None:
if mimetype is USE_MAGIC:
hint = USE_MAGIC
else:
hint = None
self.upload(stream, mimetype_hint=hint)
def upload(self, stream, mimetype_hint=None):
""" Replace the current contents of this file's blob with the
contents of ``stream``. ``stream`` must be a filelike object (it
must have a ``read`` method that takes a size argument).
``mimetype_hint`` can be any of the following:
- ``None``, meaning don't reset the current mimetype. This is the
default. If you already know the file's mimetype, and you don't
want it divined from a filename or stream content, use ``None`` as
the ``mimetype_hint`` value, and set the ``mimetype`` attribute of
the file object directly before or after calling this method.
- A string containing a filename that has an extension; the mimetype
will be derived from the extension in the filename using the Python
``mimetypes`` module, and the result will be set as the mimetype
attribute of this object.
- The constant :attr:`substanced.file.USE_MAGIC`, which will derive
the mimetype using the ``python-magic`` library based on the
stream's actual content. The result will be set as the mimetype
attribute of this object.
.. warning::
On non-Linux systems, successful use of
:attr:`substanced.file.USE_MAGIC` requires the installation
of additional dependencies. See :ref:`installing_python_magic`.
"""
if not stream:
stream = io.StringIO()
fp = self.blob.open('w')
first = True
use_magic = False
if mimetype_hint is USE_MAGIC:
use_magic = True
if magic is None: # pragma: no cover
warnings.warn(
'The python-magic library does not have its requisite '
'dependencies installed properly, therefore the '
'"USE_MAGIC" flag passed to this method has been ignored '
'(it has been converted to "None"). The mimetype of '
'substanced.file.File objects created may be incorrect as '
'a result.')
use_magic = False
mimetype_hint = None
if not use_magic:
if mimetype_hint is not None:
mimetype, _ = mimetypes.guess_type(mimetype_hint, strict=False)
if mimetype is None:
mimetype = 'application/octet-stream'
self.mimetype = mimetype
for chunk in chunks(stream):
if use_magic and first:
first = False
m = magic.Magic(mime=True)
mimetype = m.from_buffer(chunk)
self.mimetype = u(mimetype)
fp.write(chunk)
fp.close()
def get_response(self, **kw):
""" Return a WebOb-compatible response object which uses the blob
content as the stream data and the mimetype of the file as the
content type. The ``**kw`` arguments will be passed to the
:class:`pyramid.response.FileResponse` constructor as its keyword
arguments."""
if not 'content_type' in kw:
kw['content_type'] = str(self.mimetype)
path = self.blob.committed()
response = FileResponse(path, **kw)
return response
def get_size(self):
""" Return the size in bytes of the data in the blob associated with
the file"""
return os.stat(self.blob.committed()).st_size
def get_etag(self):
""" Return a token identifying the "version" of the file.
"""
self._p_activate()
mine = self._p_serial
blob = self.blob._p_serial
if blob == z64:
self.blob._p_activate()
blob = self.blob._p_serial
return oid_repr(max(mine, blob))
