python-webdav Code

import os

class FileWrapper(file):
    def __init__(self, *args, **kwargs):
        """ :param force_size: Sets a size to force the file to be read
                               in this sized blocks. httplib will send files
                               in 8192 chunks if force_size is not set.
            :type force_size: int

            :param callback: function to call when a percentage step is reached
            :type callback: function

            :param callback_size: Step (in percentage) at which callback should
                                  be called. This must be larger than 0.
            :type callback_size: int

            TODO: finish implementing callback ability (not tested)
        """
        file.__init__(self, *args, **kwargs)

        # Get options
        self.force_size = getattr(self, 'force_size', False)
        self.callback = getattr(self, 'callback', None)
        self.callback_percent = getattr(self, 'callback_size', 100)

        # Avoid Zero division errors
        if self.callback_percent == 0:
            self.callback_percent = 1

        # This next line may be redundant
        self.initial_read_pos = self.tell()
        self.file_size = os.path.getsize(self.name)

    def read(self, size=-1):
        """ Just like a file objects read method but will "rewind" after the
            file has reached EOF.
        """
        if self.force_size:
            size = self.force_size
        data = file.read(self, size)

        if not data or size < 0 or size >= self.file_size:
            self.seek(self.initial_read_pos)

        try:
            percent = int((float(size) / self.file_size) * 100)
        except ZeroDivisionError, err:
            percent = 0

        if self.callback and percent % self.callback_percent == 0:
            self.callback()

        return data