Mercurial > p > roundup > code
comparison roundup/hyperdb.py @ 5869:16e1255b16cf
Implement limit and offset for filter
These map to the corresponding SQL parameters for the SQL backends.
| author | Ralf Schlatterbeck <rsc@runtux.com> |
|---|---|
| date | Mon, 26 Aug 2019 20:23:53 +0200 |
| parents | ee2e8f8d6648 |
| children | acc4a128ab9b |
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| 5868:d2fac1069028 | 5869:16e1255b16cf |
|---|---|
| 1397 if 'id' not in seen : | 1397 if 'id' not in seen : |
| 1398 sortattr.append(('+', 'id')) | 1398 sortattr.append(('+', 'id')) |
| 1399 return sortattr | 1399 return sortattr |
| 1400 | 1400 |
| 1401 def filter(self, search_matches, filterspec, sort=[], group=[], | 1401 def filter(self, search_matches, filterspec, sort=[], group=[], |
| 1402 retired=False, exact_match_spec={}): | 1402 retired=False, exact_match_spec={}, limit=None, offset=None): |
| 1403 """Return a list of the ids of the active nodes in this class that | 1403 """Return a list of the ids of the active nodes in this class that |
| 1404 match the 'filter' spec, sorted by the group spec and then the | 1404 match the 'filter' spec, sorted by the group spec and then the |
| 1405 sort spec. | 1405 sort spec. |
| 1406 | 1406 |
| 1407 "search_matches" is a container type which by default is None | 1407 "search_matches" is a container type which by default is None |
| 1424 (un-retired) results. When setting it to True, only retired | 1424 (un-retired) results. When setting it to True, only retired |
| 1425 items are returned. If None, both retired and unretired items | 1425 items are returned. If None, both retired and unretired items |
| 1426 are returned. The default is False, i.e. only live items are | 1426 are returned. The default is False, i.e. only live items are |
| 1427 returned by default. | 1427 returned by default. |
| 1428 | 1428 |
| 1429 The "limit" and "offset" parameters define a limit on the number | |
| 1430 of results returned and an offset before returning any results, | |
| 1431 respectively. These can be used when displaying a number of | |
| 1432 items in a pagination application or similar. A common use-case | |
| 1433 is returning the first item of a sorted search by specifying | |
| 1434 limit=1 (i.e. the maximum or minimum depending on sort order). | |
| 1435 | |
| 1429 The filter must match all properties specificed. If the property | 1436 The filter must match all properties specificed. If the property |
| 1430 value to match is a list: | 1437 value to match is a list: |
| 1431 | 1438 |
| 1432 1. String properties must match all elements in the list, and | 1439 1. String properties must match all elements in the list, and |
| 1433 2. Other properties must match any of the elements in the list. | 1440 2. Other properties must match any of the elements in the list. |
| 1451 override the filter method instead of implementing _filter. | 1458 override the filter method instead of implementing _filter. |
| 1452 """ | 1459 """ |
| 1453 sortattr = self._sortattr(sort = sort, group = group) | 1460 sortattr = self._sortattr(sort = sort, group = group) |
| 1454 proptree = self._proptree(exact_match_spec, filterspec, sortattr) | 1461 proptree = self._proptree(exact_match_spec, filterspec, sortattr) |
| 1455 proptree.search(search_matches, retired=retired) | 1462 proptree.search(search_matches, retired=retired) |
| 1463 if offset is not None or limit is not None: | |
| 1464 items = proptree.sort() | |
| 1465 if limit and offset: | |
| 1466 return items[offset:offset+limit] | |
| 1467 elif offset is not None: | |
| 1468 return items[offset:] | |
| 1469 else: | |
| 1470 return items[:limit] | |
| 1456 return proptree.sort() | 1471 return proptree.sort() |
| 1472 | |
| 1457 | 1473 |
| 1458 # non-optimized filter_iter, a backend may chose to implement a | 1474 # non-optimized filter_iter, a backend may chose to implement a |
| 1459 # better version that provides a real iterator that pre-fills the | 1475 # better version that provides a real iterator that pre-fills the |
| 1460 # cache for each id returned. Note that the filter_iter doesn't | 1476 # cache for each id returned. Note that the filter_iter doesn't |
| 1461 # promise to correctly sort by multilink (which isn't sane to do | 1477 # promise to correctly sort by multilink (which isn't sane to do |