hghave: make bzr checks stricter
My bzr does not have bzrlib.revisionspec.RevisionSpec,
and thus tests were failing because convert refused to believe in bzr,
but hghave without this change thought it was available.
help: document wire protocol "handshake" protocol
There isn't a formal handshake protocol in the wire protocol. But
clients almost certainly need to perform particular actions before they
can communicate with a server optimally. So document what that is
so people understand what's going on at connection establishment time.
help: document wire protocol capabilities
All capabilities from the history of the project are now documented.
crecord: properly handle files with No newline at eof (
issue5268)
Yes, this bug was a single character with the wrong case...
annotate: pre-calculate the "needed" dictionary (
issue5360)
The "needed" dict is used as a reference counter to free items in the giant
"hist" dict. However, currently it is not very accurate and can lead to
dropping "hist" items unnecessarily, for example, with the following DAG,
-3-
/ \
0--1--2--4--
The current algorithm will visit and calculate rev 1 twice, undesired. And
it tries to be smart by clearing rev 1's parents: "pcache[1] = []" at the
time hist[1] being accessed (note: hist[1] needs to be used twice, by rev 2
and rev 3). It can result in incorrect results if p1 of rev 4 deletes chunks
belonging to rev 0.
However, simply removing "needed" is not okay, because it will consume 10x
memory:
# without any change
% HGRCPATH= lrun ./hg annotate mercurial/commands.py -r d130a38 3>&2 [1]
MEMORY
49074176
CPUTIME 9.213
REALTIME 9.270
# with "needed" removed
MEMORY
637673472
CPUTIME 8.164
REALTIME 8.249
This patch moves "needed" (and "pcache") calculation to a separate DFS to
address the issue. It improves perf and fixes
issue5360 by correctly reusing
hist, while maintaining low memory usage. Some additional attempt has been
made to further reduce memory usage, like changing "pcache[f] = []" to "del
pcache[f]". Therefore the result can be both faster and lower memory usage:
# with this patch applied
MEMORY
47575040
CPUTIME 7.870
REALTIME 7.926
[1]: lrun is a lightweight sandbox built on Linux cgroup and namespace. It's
used to measure CPU and memory usage here. Source code is available at
github.com/quark-zju/lrun.