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# -*- coding: utf-8 -*- |
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import re |
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class RangeParseException(Exception): |
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''' |
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Used for handling errors during range parsing |
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''' |
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pass |
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12
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13
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class Range(object): |
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def __init__(self, start, end, page=1): |
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self.start = start |
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self.end = end |
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self.page = page |
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def get_page_size(self): |
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''' |
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:return: the size of a page |
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''' |
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return self.end - self.start + 1 |
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def content_range(self, length): |
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''' |
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:param length: the total number of results |
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:return: range header string |
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''' |
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end = self.end if self.end <= length else length - 1 |
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return 'items %d-%d/%d' % (self.start, end, length) |
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@classmethod |
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def parse(cls, request, default_start=0, default_end=11, max_end=50): |
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''' |
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Parse the range headers into a range object. When there are no range headers, |
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check for a page 'pagina' parameter, otherwise use the defaults defaults |
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:param request: a request object |
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:param default_start: default start for paging (optional, default is 0) |
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:param default_end: default end for paging (optional, default is 11) |
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:param default_end: maximum end for paging (optional, default is 50, no limits in case of None) |
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:return: :class: 'oe_utils.range_parser.Range' |
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''' |
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if 'Range' in request.headers and request.headers['Range'] is not '': |
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match = re.match('^items=([0-9]+)-([0-9]+)$', request.headers['Range']) |
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if match: |
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start = int(match.group(1)) |
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end = int(match.group(2)) |
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if end < start: |
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end = start |
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if max_end and end > start + max_end: |
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end = start + max_end |
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return cls(start, end) |
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else: |
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raise RangeParseException('range header does not match expected format') |
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elif 'pagina' in request.params: |
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page = int(request.params.get('pagina')) |
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start = default_start + (default_end + 1) * (page - 1) |
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end = default_end * page + page - 1 |
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return cls(start, end, page) |
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else: |
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return cls(default_start, default_end) |
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def set_response_headers(self, response, total_count): |
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''' |
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Set the correct range headers on the response |
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:param response: a response object |
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:param total_count: the total number of results |
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''' |
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response.headerlist.append(('Access-Control-Expose-Headers', 'Content-Range, X-Content-Range')) |
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response.accept_ranges = 'items' |
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if total_count is None: |
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raise RangeParseException('Provided length value is null') |
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if total_count > 0: |
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response.content_range = self.content_range(total_count) |
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OnroerendErfgoed /
oe_utils
