import os
try:
from cStringIO import StringIO
except ImportError:
from StringIO import StringIO
from django.utils.encoding import smart_str,smart_unicode
from django.core.files.utils import FileProxyMixin
class File(FileProxyMixin):
DEFAULT_CHUNK_SIZE = 64 * 2**10
def __init__(self, file, name=None):
self.file = file
if name is None:
name = getattr(file, 'name', None)
self.name = name
self.mode = getattr(file, 'mode', None)
def __str__(self):
return smart_str(self.name or '')
def __unicode__(self):
return smart_unicode(self.name or u'')
def __repr__(self):
return "<%s: %s>" % (self.__class__.__name__, self or "None")
def __nonzero__(self):
return bool(self.name)
def __len__(self):
return self.size
def _get_size(self):
if not hasattr(self, '_size'):
if hasattr(self.file, 'size'):
self._size = self.file.size
elif os.path.exists(self.file.name):
self._size = os.path.getsize(self.file.name)
else:
raise AttributeError("Unable to determine the file's size.")
return self._size
def _set_size(self, size):
self._size = size
size = property(_get_size, _set_size)
def _get_closed(self):
return not self.file or self.file.closed
closed = property(_get_closed)
def chunks(self, chunk_size=None):
"""
Read the file and yield chucks of ``chunk_size`` bytes (defaults to
``UploadedFile.DEFAULT_CHUNK_SIZE``).
"""
if not chunk_size:
chunk_size = self.DEFAULT_CHUNK_SIZE
if hasattr(self, 'seek'):
self.seek(0)
# Assume the pointer is at zero...
counter = self.size
while counter > 0:
yield self.read(chunk_size)
counter -= chunk_size
def multiple_chunks(self, chunk_size=None):
"""
Returns ``True`` if you can expect multiple chunks.
NB: If a particular file representation is in memory, subclasses should
always return ``False`` -- there's no good reason to read from memory in
chunks.
"""
if not chunk_size:
chunk_size = self.DEFAULT_CHUNK_SIZE
return self.size > chunk_size
def __iter__(self):
# Iterate over this file-like object by newlines
buffer_ = None
for chunk in self.chunks():
chunk_buffer = StringIO(chunk)
for line in chunk_buffer:
if buffer_:
line = buffer_ + line
buffer_ = None
# If this is the end of a line, yield
# otherwise, wait for the next round
if line[-1] in ('\n', '\r'):
yield line
else:
buffer_ = line
if buffer_ is not None:
yield buffer_
def open(self, mode=None):
if not self.closed:
self.seek(0)
elif self.name and os.path.exists(self.name):
self.file = open(self.name, mode or self.mode)
else:
raise ValueError("The file cannot be reopened.")
def close(self):
self.file.close()
class ContentFile(File):
"""
A File-like object that takes just raw content, rather than an actual file.
"""
def __init__(self, content):
content = content or ''
super(ContentFile, self).__init__(StringIO(content))
self.size = len(content)
def __str__(self):
return 'Raw content'
def __nonzero__(self):
return True
def open(self, mode=None):
self.seek(0)
def close(self):
pass
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