changegroup: compute seen files as changesets are added (
issue4750)
Before this patch, addchangegroup() would walk the changelog and compute
the set of seen files between applying changesets and applying
manifests. When cloning large repositories such as mozilla-central,
this consumed a non-trivial amount of time. On my MBP, this walk takes
~10s. On a dainty EC2 instance, this was measured to take ~125s! On the
latter machine, this delay was enough for the Mercurial server to
disconnect the client, thinking it had timed out, thus causing a clone
to abort.
This patch enables the changelog to compute the set of changed files as
new revisions are added. By doing so, we:
* avoid a potentially heavy computation between changelog and manifest
processing by spreading the computation across all changelog additions
* avoid extra reads from the changelog by operating on the data as it is
added
The downside of this is that the add revision callback does result in
extra I/O. Before, we would perform a flush (and subsequent read to
construct the full revision) when new delta chains were created. For
changelogs, this is typically every 2-4 revisions. Using the callback
guarantees there will be a flush after every added revision *and* an
open + read of the changelog to obtain the full revision in order to
read the added files. So, this increases the frequency of these
operations by the average chain length. In the future, the revlog
should be smart enough to know how to read revisions that haven't been
flushed yet, thus eliminating this extra I/O.
On my MBP, the total CPU times for an `hg unbundle` with a local
mozilla-central gzip bundle containing 251,934 changesets and 211,065
files did not have a statistically significant change with this patch,
holding steady around 360s. So, the increased revlog flushing did not
have an effect.
With this patch, there is no longer a visible pause between applying
changeset and manifest data. Before, it sure felt like Mercurial was
lethargic making this transition. Now, the transition is nearly
instantaneous, giving the impression that Mercurial is faster. Of course,
eliminating this pause means that the potential for network disconnect due
to channel inactivity during the changelog walk is eliminated as well.
And that is the impetus behind this change.
Test for
b5605d88dc27: Make ui.prompt repeat on "unrecognized response" again
(issue897)
840e2b315c1f: Fix misleading error and prompts during update/merge
(issue556)
$ status() {
> echo "--- status ---"
> hg st -A file1 file2
> for file in file1 file2; do
> if [ -f $file ]; then
> echo "--- $file ---"
> cat $file
> else
> echo "*** $file does not exist"
> fi
> done
> }
$ hg init
$ echo 1 > file1
$ echo 2 > file2
$ hg ci -Am 'added file1 and file2'
adding file1
adding file2
$ hg rm file1
$ echo changed >> file2
$ hg ci -m 'removed file1, changed file2'
$ hg co 0
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo changed >> file1
$ hg rm file2
$ hg ci -m 'changed file1, removed file2'
created new head
Non-interactive merge:
$ hg merge -y
local changed file1 which remote deleted
use (c)hanged version or (d)elete? c
remote changed file2 which local deleted
use (c)hanged version or leave (d)eleted? c
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ status
--- status ---
M file2
C file1
--- file1 ---
1
changed
--- file2 ---
2
changed
Interactive merge:
$ hg co -C
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ hg merge --config ui.interactive=true <<EOF
> c
> d
> EOF
local changed file1 which remote deleted
use (c)hanged version or (d)elete? c
remote changed file2 which local deleted
use (c)hanged version or leave (d)eleted? d
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ status
--- status ---
file2: * (glob)
C file1
--- file1 ---
1
changed
*** file2 does not exist
Interactive merge with bad input:
$ hg co -C
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg merge --config ui.interactive=true <<EOF
> foo
> bar
> d
> baz
> c
> EOF
local changed file1 which remote deleted
use (c)hanged version or (d)elete? foo
unrecognized response
local changed file1 which remote deleted
use (c)hanged version or (d)elete? bar
unrecognized response
local changed file1 which remote deleted
use (c)hanged version or (d)elete? d
remote changed file2 which local deleted
use (c)hanged version or leave (d)eleted? baz
unrecognized response
remote changed file2 which local deleted
use (c)hanged version or leave (d)eleted? c
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ status
--- status ---
M file2
R file1
*** file1 does not exist
--- file2 ---
2
changed
Interactive merge with not enough input:
$ hg co -C
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ hg merge --config ui.interactive=true <<EOF
> d
> EOF
local changed file1 which remote deleted
use (c)hanged version or (d)elete? d
remote changed file2 which local deleted
use (c)hanged version or leave (d)eleted? abort: response expected
[255]
$ status
--- status ---
file2: * (glob)
C file1
--- file1 ---
1
changed
*** file2 does not exist