partialdiscovery: avoid `undecided` related computation sooner than necessary
Changeset 1d30be90c move the update of the `undecided` set within the
`partialdiscovery` object in order to clarify the API.
The update to the `undecided` set was unconditional in 1d30be90c and the first
access to the `self.undecided` property triggered the initial computation of
the set of undecided revisions. As a result, the set was computed much
earlier, at a time where less information is available, immediately followed
by an update of this set to remove common revisions.
To fix this regression, we ignore the `undecided` related logic in
`addcommons` when that `undecided` set has not been computed yet. Code that
actually needs to know the `undecided` set will trigger its computation later.
The change has no effects on semantic because the initial computation
`undecided` set takes all knowns `common` into account.
Example performance running `hg debugdiscovery` from a pypy repo missing 10
changesets:
870a89c6909d: 52.3ms (regression parent)
1d30be90c9dc: 72.0ms (regression)
5a5f504a7175: 64.8ms (this fix parent)
this fix: 52.6ms
[package]
name = "hg-cpython"
version = "0.1.0"
authors = ["Georges Racinet <gracinet@anybox.fr>"]
[lib]
name='rusthg'
crate-type = ["cdylib"]
[features]
default = ["python27"]
python27 = ["cpython/python27-sys",
"cpython/extension-module-2-7",
"python27-sys",
]
python3 = ["python3-sys", "cpython/python3-sys", "cpython/extension-module"]
[dependencies]
hg-core = { path = "../hg-core" }
libc = '*'
[dependencies.cpython]
version = "*"
default-features = false
[dependencies.python27-sys]
version = "0.2.1"
optional = true
[dependencies.python3-sys]
version = "0.2.1"
optional = true