Mercurial > public > mercurial-scm > hg
comparison mercurial/util.py @ 39565:2dcc68c7d25b
util: ability to change capacity when copying lrucachedict
This will allow us to easily replace an lrucachedict with one
with a higher or lower capacity as consumers deem necessary.
IMO it is easier to just create a new cache instance than to
muck with the capacity of an existing cache. Mutating an existing
cache's capacity feels more prone to bugs.
Differential Revision: https://phab.mercurial-scm.org/D4500
| author | Gregory Szorc <gregory.szorc@gmail.com> |
|---|---|
| date | Thu, 06 Sep 2018 11:40:20 -0700 |
| parents | 5d75a3c16193 |
| children | bd9d3a89f07b |
comparison
equal
deleted
inserted
replaced
| 39564:5d75a3c16193 | 39565:2dcc68c7d25b |
|---|---|
| 1309 n.markempty() | 1309 n.markempty() |
| 1310 n = n.next | 1310 n = n.next |
| 1311 | 1311 |
| 1312 self._cache.clear() | 1312 self._cache.clear() |
| 1313 | 1313 |
| 1314 def copy(self): | 1314 def copy(self, capacity=None): |
| 1315 result = lrucachedict(self.capacity) | 1315 """Create a new cache as a copy of the current one. |
| 1316 | |
| 1317 By default, the new cache has the same capacity as the existing one. | |
| 1318 But, the cache capacity can be changed as part of performing the | |
| 1319 copy. | |
| 1320 | |
| 1321 Items in the copy have an insertion/access order matching this | |
| 1322 instance. | |
| 1323 """ | |
| 1324 | |
| 1325 capacity = capacity or self.capacity | |
| 1326 result = lrucachedict(capacity) | |
| 1316 | 1327 |
| 1317 # We copy entries by iterating in oldest-to-newest order so the copy | 1328 # We copy entries by iterating in oldest-to-newest order so the copy |
| 1318 # has the correct ordering. | 1329 # has the correct ordering. |
| 1319 | 1330 |
| 1320 # Find the first non-empty entry. | 1331 # Find the first non-empty entry. |
| 1321 n = self._head.prev | 1332 n = self._head.prev |
| 1322 while n.key is _notset and n is not self._head: | 1333 while n.key is _notset and n is not self._head: |
| 1323 n = n.prev | 1334 n = n.prev |
| 1324 | 1335 |
| 1336 # We could potentially skip the first N items when decreasing capacity. | |
| 1337 # But let's keep it simple unless it is a performance problem. | |
| 1325 for i in range(len(self._cache)): | 1338 for i in range(len(self._cache)): |
| 1326 result[n.key] = n.value | 1339 result[n.key] = n.value |
| 1327 n = n.prev | 1340 n = n.prev |
| 1328 | 1341 |
| 1329 return result | 1342 return result |