| # -*- coding: utf-8 -*- |
| """ |
| hyper/http20/util |
| ~~~~~~~~~~~~~~~~~ |
| |
| Utility functions for use with hyper. |
| """ |
| from collections import defaultdict |
| |
| |
| def combine_repeated_headers(kvset): |
| """ |
| Given a list of key-value pairs (like for HTTP headers!), combines pairs |
| with the same key together, separating the values with NULL bytes. This |
| function maintains the order of input keys, because it's awesome. |
| """ |
| def set_pop(set, item): |
| set.remove(item) |
| return item |
| |
| headers = defaultdict(list) |
| keys = set() |
| |
| for key, value in kvset: |
| headers[key].append(value) |
| keys.add(key) |
| |
| return [(set_pop(keys, k), b'\x00'.join(headers[k])) for k, v in kvset |
| if k in keys] |
| |
| |
| def split_repeated_headers(kvset): |
| """ |
| Given a set of key-value pairs (like for HTTP headers!), finds values that |
| have NULL bytes in them and splits them into a dictionary whose values are |
| lists. |
| """ |
| headers = defaultdict(list) |
| |
| for key, value in kvset: |
| headers[key] = value.split(b'\x00') |
| |
| return dict(headers) |
| |
| |
| def h2_safe_headers(headers): |
| """ |
| This method takes a set of headers that are provided by the user and |
| transforms them into a form that is safe for emitting over HTTP/2. |
| |
| Currently, this strips the Connection header and any header it refers to. |
| """ |
| stripped = { |
| i.lower().strip() |
| for k, v in headers if k == 'connection' |
| for i in v.split(',') |
| } |
| stripped.add('connection') |
| |
| return [header for header in headers if header[0] not in stripped] |
