def fill_ranges(self, start, end, length):
"""
Fill the request ranges.
"""
if length == 0:
return
if self.buf_size:
# discard bytes
# so we only yield complete EC segments
self.discard_bytes = discard_bytes(self.buf_size, start)
# change headers for efficient recovery
if 'Range' in self.request_headers:
try:
orig_ranges = utils.ranges_from_http_header(
self.request_headers['Range'])
new_ranges = [(start, end)] + orig_ranges[1:]
except ValueError:
new_ranges = [(start, end)]
else:
new_ranges = [(start, end)]
self.request_headers['Range'] = utils.http_header_from_ranges(
new_ranges)
def _convert_range(self, req_start, req_end, length):
try:
ranges = utils.ranges_from_http_header("bytes=%s-%s" % (
req_start if req_start is not None else '',
req_end if req_end is not None else ''))
except ValueError:
return (None, None)
result = utils.convert_ranges(ranges, length)
if not result:
return (None, None)
else:
return (result[0][0], result[0][1])
def recover(self, nb_bytes):
"""
Recover the request.
:params nb_bytes: number of bytes already consumed that we need to
discard if we perform a recovery from another source.
:raises ValueError: if range header is not valid
:raises UnsatisfiableRange
:raises EmptyByteRange
"""
if 'Range' in self.request_headers:
request_range = utils.ranges_from_http_header(
self.request_headers['Range'])
start, end = request_range[0]
if start is None:
# suffix byte range
end -= nb_bytes
else:
start += nb_bytes
if end is not None:
if start == end + 1:
# no more bytes to serve in the requested byte range
raise exc.EmptyByteRange()
if start > end:
# invalid range
raise exc.UnsatisfiableRange()
if end and start:
# full byte range
request_range = [(start, end)] + request_range[1:]
else:
# suffix byte range
request_range = [(None, end)] + request_range[1:]
else:
# prefix byte range
request_range = [(start, None)] + request_range[1:]
self.request_headers['Range'] = utils.http_header_from_ranges(
request_range)
else:
# just add an offset to the request
self.request_headers['Range'] = 'bytes=%d-' % nb_bytes
