revert: extract actual revert in its own function
With this small refactoring, the computation of the action to perform and the
actual change to the disk happen in different function. This allows extension to
wrap the later in case of need. The initial motivation is the `remotefilelog`
extension that need to prefetch all the file content to be checked out.
from mercurial import util
def printifpresent(d, xs):
for x in xs:
present = x in d
print "'%s' in d: %s" % (x, present)
if present:
print "d['%s']: %s" % (x, d[x])
def test_lrucachedict():
d = util.lrucachedict(4)
d['a'] = 'va'
d['b'] = 'vb'
d['c'] = 'vc'
d['d'] = 'vd'
# all of these should be present
printifpresent(d, ['a', 'b', 'c', 'd'])
# 'a' should be dropped because it was least recently used
d['e'] = 've'
printifpresent(d, ['a', 'b', 'c', 'd', 'e'])
# touch entries in some order (get or set).
d['e']
d['c'] = 'vc2'
d['d']
d['b'] = 'vb2'
# 'e' should be dropped now
d['f'] = 'vf'
printifpresent(d, ['b', 'c', 'd', 'e', 'f'])
d.clear()
printifpresent(d, ['b', 'c', 'd', 'e', 'f'])
if __name__ == '__main__':
test_lrucachedict()