+
−"""
+
−Base file upload handler classes, and the built-in concrete subclasses
+
−"""
+
−
+
−try:
+
−    from cStringIO import StringIO
+
−except ImportError:
+
−    from StringIO import StringIO
+
−
+
−from django.conf import settings
+
−from django.core.exceptions import ImproperlyConfigured
+
−from django.core.files.uploadedfile import TemporaryUploadedFile, InMemoryUploadedFile
+
−
+
−__all__ = ['UploadFileException','StopUpload', 'SkipFile', 'FileUploadHandler',
+
−           'TemporaryFileUploadHandler', 'MemoryFileUploadHandler',
+
−           'load_handler']
+
−
+
−class UploadFileException(Exception):
+
−    """
+
−    Any error having to do with uploading files.
+
−    """
+
−    pass
+
−
+
−class StopUpload(UploadFileException):
+
−    """
+
−    This exception is raised when an upload must abort.
+
−    """
+
−    def __init__(self, connection_reset=False):
+
−        """
+
−        If ``connection_reset`` is ``True``, Django knows will halt the upload
+
−        without consuming the rest of the upload. This will cause the browser to
+
−        show a "connection reset" error.
+
−        """
+
−        self.connection_reset = connection_reset
+
−
+
−    def __unicode__(self):
+
−        if self.connection_reset:
+
−            return u'StopUpload: Halt current upload.'
+
−        else:
+
−            return u'StopUpload: Consume request data, then halt.'
+
−
+
−class SkipFile(UploadFileException):
+
−    """
+
−    This exception is raised by an upload handler that wants to skip a given file.
+
−    """
+
−    pass
+
−    
+
−class StopFutureHandlers(UploadFileException):
+
−    """
+
−    Upload handers that have handled a file and do not want future handlers to
+
−    run should raise this exception instead of returning None.
+
−    """
+
−    pass
+
−
+
−class FileUploadHandler(object):
+
−    """
+
−    Base class for streaming upload handlers.
+
−    """
+
−    chunk_size = 64 * 2 ** 10 #: The default chunk size is 64 KB.
+
−
+
−    def __init__(self, request=None):
+
−        self.file_name = None
+
−        self.content_type = None
+
−        self.content_length = None
+
−        self.charset = None
+
−        self.request = request
+
−
+
−    def handle_raw_input(self, input_data, META, content_length, boundary, encoding=None):
+
−        """
+
−        Handle the raw input from the client.
+
−
+
−        Parameters:
+
−
+
−            :input_data:
+
−                An object that supports reading via .read().
+
−            :META:
+
−                ``request.META``.
+
−            :content_length:
+
−                The (integer) value of the Content-Length header from the
+
−                client.
+
−            :boundary: The boundary from the Content-Type header. Be sure to
+
−                prepend two '--'.
+
−        """
+
−        pass
+
−
+
−    def new_file(self, field_name, file_name, content_type, content_length, charset=None):
+
−        """
+
−        Signal that a new file has been started.
+
−
+
−        Warning: As with any data from the client, you should not trust
+
−        content_length (and sometimes won't even get it).
+
−        """
+
−        self.field_name = field_name
+
−        self.file_name = file_name
+
−        self.content_type = content_type
+
−        self.content_length = content_length
+
−        self.charset = charset
+
−
+
−    def receive_data_chunk(self, raw_data, start):
+
−        """
+
−        Receive data from the streamed upload parser. ``start`` is the position
+
−        in the file of the chunk.
+
−        """
+
−        raise NotImplementedError()
+
−
+
−    def file_complete(self, file_size):
+
−        """
+
−        Signal that a file has completed. File size corresponds to the actual
+
−        size accumulated by all the chunks.
+
−
+
−        Subclasses must should return a valid ``UploadedFile`` object.
+
−        """
+
−        raise NotImplementedError()
+
−
+
−    def upload_complete(self):
+
−        """
+
−        Signal that the upload is complete. Subclasses should perform cleanup
+
−        that is necessary for this handler.
+
−        """
+
−        pass
+
−
+
−class TemporaryFileUploadHandler(FileUploadHandler):
+
−    """
+
−    Upload handler that streams data into a temporary file.
+
−    """
+
−    def __init__(self, *args, **kwargs):
+
−        super(TemporaryFileUploadHandler, self).__init__(*args, **kwargs)
+
−
+
−    def new_file(self, file_name, *args, **kwargs):
+
−        """
+
−        Create the file object to append to as data is coming in.
+
−        """
+
−        super(TemporaryFileUploadHandler, self).new_file(file_name, *args, **kwargs)
+
−        self.file = TemporaryUploadedFile(self.file_name, self.content_type, 0, self.charset)
+
−
+
−    def receive_data_chunk(self, raw_data, start):
+
−        self.file.write(raw_data)
+
−
+
−    def file_complete(self, file_size):
+
−        self.file.seek(0)
+
−        self.file.size = file_size
+
−        return self.file
+
−
+
−class MemoryFileUploadHandler(FileUploadHandler):
+
−    """
+
−    File upload handler to stream uploads into memory (used for small files).
+
−    """
+
−
+
−    def handle_raw_input(self, input_data, META, content_length, boundary, encoding=None):
+
−        """
+
−        Use the content_length to signal whether or not this handler should be in use.
+
−        """
+
−        # Check the content-length header to see if we should
+
−        # If the the post is too large, we cannot use the Memory handler.
+
−        if content_length > settings.FILE_UPLOAD_MAX_MEMORY_SIZE:
+
−            self.activated = False
+
−        else:
+
−            self.activated = True
+
−
+
−    def new_file(self, *args, **kwargs):
+
−        super(MemoryFileUploadHandler, self).new_file(*args, **kwargs)
+
−        if self.activated:
+
−            self.file = StringIO()
+
−            raise StopFutureHandlers()
+
−
+
−    def receive_data_chunk(self, raw_data, start):
+
−        """
+
−        Add the data to the StringIO file.
+
−        """
+
−        if self.activated:
+
−            self.file.write(raw_data)
+
−        else:
+
−            return raw_data
+
−
+
−    def file_complete(self, file_size):
+
−        """
+
−        Return a file object if we're activated.
+
−        """
+
−        if not self.activated:
+
−            return
+
−
+
−        return InMemoryUploadedFile(
+
−            file = self.file,
+
−            field_name = self.field_name,
+
−            name = self.file_name,
+
−            content_type = self.content_type,
+
−            size = file_size,
+
−            charset = self.charset
+
−        )
+
−
+
−
+
−def load_handler(path, *args, **kwargs):
+
−    """
+
−    Given a path to a handler, return an instance of that handler.
+
−
+
−    E.g.::
+
−        >>> load_handler('django.core.files.uploadhandler.TemporaryFileUploadHandler', request)
+
−        <TemporaryFileUploadHandler object at 0x...>
+
−
+
−    """
+
−    i = path.rfind('.')
+
−    module, attr = path[:i], path[i+1:]
+
−    try:
+
−        mod = __import__(module, {}, {}, [attr])
+
−    except ImportError, e:
+
−        raise ImproperlyConfigured('Error importing upload handler module %s: "%s"' % (module, e))
+
−    except ValueError, e:
+
−        raise ImproperlyConfigured('Error importing upload handler module. Is FILE_UPLOAD_HANDLERS a correctly defined list or tuple?')
+
−    try:
+
−        cls = getattr(mod, attr)
+
−    except AttributeError:
+
−        raise ImproperlyConfigured('Module "%s" does not define a "%s" upload handler backend' % (module, attr))
+
−    return cls(*args, **kwargs)