util: lower water mark when removing nodes after cost limit reached
See the inline comment for the reasoning here. This is a pretty
common strategy for garbage collectors, other cache-like primtives.
The performance impact is substantial:
$ hg perflrucachedict --size 4 --gets 1000000 --sets 1000000 --mixed 1000000 --costlimit 100
! inserts w/ cost limit
! wall 1.659181 comb 1.650000 user 1.650000 sys 0.000000 (best of 7)
! wall 1.722122 comb 1.720000 user 1.720000 sys 0.000000 (best of 6)
! mixed w/ cost limit
! wall 1.139955 comb 1.140000 user 1.140000 sys 0.000000 (best of 9)
! wall 1.182513 comb 1.180000 user 1.180000 sys 0.000000 (best of 9)
$ hg perflrucachedict --size 1000 --gets 1000000 --sets 1000000 --mixed 1000000 --costlimit 10000
! inserts
! wall 0.679546 comb 0.680000 user 0.680000 sys 0.000000 (best of 15)
! sets
! wall 0.825147 comb 0.830000 user 0.830000 sys 0.000000 (best of 13)
! inserts w/ cost limit
! wall 25.105273 comb 25.080000 user 25.080000 sys 0.000000 (best of 3)
! wall 1.724397 comb 1.720000 user 1.720000 sys 0.000000 (best of 6)
! mixed
! wall 0.807096 comb 0.810000 user 0.810000 sys 0.000000 (best of 13)
! mixed w/ cost limit
! wall 12.104470 comb 12.070000 user 12.070000 sys 0.000000 (best of 3)
! wall 1.190563 comb 1.190000 user 1.190000 sys 0.000000 (best of 9)
$ hg perflrucachedict --size 1000 --gets 1000000 --sets 1000000 --mixed 1000000 --costlimit 10000 --mixedgetfreq 90
! inserts
! wall 0.711177 comb 0.710000 user 0.710000 sys 0.000000 (best of 14)
! sets
! wall 0.846992 comb 0.850000 user 0.850000 sys 0.000000 (best of 12)
! inserts w/ cost limit
! wall 25.963028 comb 25.960000 user 25.960000 sys 0.000000 (best of 3)
! wall 2.184311 comb 2.180000 user 2.180000 sys 0.000000 (best of 5)
! mixed
! wall 0.728256 comb 0.730000 user 0.730000 sys 0.000000 (best of 14)
! mixed w/ cost limit
! wall 3.174256 comb 3.170000 user 3.170000 sys 0.000000 (best of 4)
! wall 0.773186 comb 0.770000 user 0.770000 sys 0.000000 (best of 13)
$ hg perflrucachedict --size 100000 --gets 1000000 --sets 1000000 --mixed 1000000 --mixedgetfreq 90 --costlimit 5000000
! gets
! wall 1.191368 comb 1.190000 user 1.190000 sys 0.000000 (best of 9)
! wall 1.195304 comb 1.190000 user 1.190000 sys 0.000000 (best of 9)
! inserts
! wall 0.950995 comb 0.950000 user 0.950000 sys 0.000000 (best of 11)
! inserts w/ cost limit
! wall 1.589732 comb 1.590000 user 1.590000 sys 0.000000 (best of 7)
! sets
! wall 1.094941 comb 1.100000 user 1.090000 sys 0.010000 (best of 9)
! mixed
! wall 0.936420 comb 0.940000 user 0.930000 sys 0.010000 (best of 10)
! mixed w/ cost limit
! wall 0.882780 comb 0.870000 user 0.870000 sys 0.000000 (best of 11)
This puts us ~2x slower than caches without cost accounting. And for
read-heavy workloads (the prime use cases for caches), performance is
nearly identical.
In the worst case (pure write workloads with cost accounting enabled),
we're looking at ~1.5us per insert on large caches. That seems "fast
enough."
Differential Revision: https://phab.mercurial-scm.org/D4505
#require serve
$ hg init a
$ cd a
$ echo a > a
$ hg ci -Ama -d '1123456789 0'
adding a
$ hg serve --config server.uncompressed=True -p $HGPORT -d --pid-file=hg.pid
$ cat hg.pid >> $DAEMON_PIDS
$ cd ..
$ tinyproxy.py $HGPORT1 localhost 2>proxy.log >/dev/null </dev/null &
$ while [ ! -f proxy.pid ]; do sleep 0; done
$ cat proxy.pid >> $DAEMON_PIDS
url for proxy, stream
$ http_proxy=http://localhost:$HGPORT1/ hg --config http_proxy.always=True clone --stream http://localhost:$HGPORT/ b
streaming all changes
3 files to transfer, 303 bytes of data (reporevlogstore !)
4 files to transfer, 330 bytes of data (reposimplestore !)
transferred * bytes in * seconds (*/sec) (glob)
searching for changes
no changes found
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd b
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 1 changesets with 1 changes to 1 files
$ cd ..
url for proxy, pull
$ http_proxy=http://localhost:$HGPORT1/ hg --config http_proxy.always=True clone http://localhost:$HGPORT/ b-pull
requesting all changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
new changesets 83180e7845de
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd b-pull
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 1 changesets with 1 changes to 1 files
$ cd ..
host:port for proxy
$ http_proxy=localhost:$HGPORT1 hg clone --config http_proxy.always=True http://localhost:$HGPORT/ c
requesting all changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
new changesets 83180e7845de
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
proxy url with user name and password
$ http_proxy=http://user:passwd@localhost:$HGPORT1 hg clone --config http_proxy.always=True http://localhost:$HGPORT/ d
requesting all changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
new changesets 83180e7845de
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
url with user name and password
$ http_proxy=http://user:passwd@localhost:$HGPORT1 hg clone --config http_proxy.always=True http://user:passwd@localhost:$HGPORT/ e
requesting all changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
new changesets 83180e7845de
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
bad host:port for proxy ("Protocol not supported" can happen on
misconfigured hosts)
$ http_proxy=localhost:$HGPORT2 hg clone --config http_proxy.always=True http://localhost:$HGPORT/ f
abort: error: (Connection refused|Protocol not supported|.* actively refused it|Cannot assign requested address) (re)
[255]
do not use the proxy if it is in the no list
$ http_proxy=localhost:$HGPORT1 hg clone --config http_proxy.no=localhost http://localhost:$HGPORT/ g
requesting all changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
new changesets 83180e7845de
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cat proxy.log
* - - [*] "GET http://localhost:$HGPORT/?cmd=capabilities HTTP/1.1" - - (glob)
$LOCALIP - - [$LOGDATE$] "GET http://localhost:$HGPORT/?cmd=branchmap HTTP/1.1" - - x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull (glob)
$LOCALIP - - [$LOGDATE$] "GET http://localhost:$HGPORT/?cmd=stream_out HTTP/1.1" - - x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull (glob)
$LOCALIP - - [$LOGDATE$] "GET http://localhost:$HGPORT/?cmd=batch HTTP/1.1" - - x-hgarg-1:cmds=heads+%3Bknown+nodes%3D83180e7845de420a1bb46896fd5fe05294f8d629 x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull (glob)
$LOCALIP - - [$LOGDATE$] "GET http://localhost:$HGPORT/?cmd=getbundle HTTP/1.1" - - x-hgarg-1:bookmarks=1&$USUAL_BUNDLE_CAPS$&cg=0&common=83180e7845de420a1bb46896fd5fe05294f8d629&heads=83180e7845de420a1bb46896fd5fe05294f8d629&listkeys=bookmarks&phases=1 x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull (glob)
* - - [*] "GET http://localhost:$HGPORT/?cmd=capabilities HTTP/1.1" - - (glob)
$LOCALIP - - [$LOGDATE$] "GET http://localhost:$HGPORT/?cmd=batch HTTP/1.1" - - x-hgarg-1:cmds=heads+%3Bknown+nodes%3D x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull (glob)
$LOCALIP - - [$LOGDATE$] "GET http://localhost:$HGPORT/?cmd=getbundle HTTP/1.1" - - x-hgarg-1:bookmarks=1&$USUAL_BUNDLE_CAPS$&cg=1&common=0000000000000000000000000000000000000000&heads=83180e7845de420a1bb46896fd5fe05294f8d629&listkeys=bookmarks&phases=1 x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull (glob)
* - - [*] "GET http://localhost:$HGPORT/?cmd=capabilities HTTP/1.1" - - (glob)
$LOCALIP - - [$LOGDATE$] "GET http://localhost:$HGPORT/?cmd=batch HTTP/1.1" - - x-hgarg-1:cmds=heads+%3Bknown+nodes%3D x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull (glob)
$LOCALIP - - [$LOGDATE$] "GET http://localhost:$HGPORT/?cmd=getbundle HTTP/1.1" - - x-hgarg-1:bookmarks=1&$USUAL_BUNDLE_CAPS$&cg=1&common=0000000000000000000000000000000000000000&heads=83180e7845de420a1bb46896fd5fe05294f8d629&listkeys=bookmarks&phases=1 x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull (glob)
* - - [*] "GET http://localhost:$HGPORT/?cmd=capabilities HTTP/1.1" - - (glob)
$LOCALIP - - [$LOGDATE$] "GET http://localhost:$HGPORT/?cmd=batch HTTP/1.1" - - x-hgarg-1:cmds=heads+%3Bknown+nodes%3D x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull (glob)
$LOCALIP - - [$LOGDATE$] "GET http://localhost:$HGPORT/?cmd=getbundle HTTP/1.1" - - x-hgarg-1:bookmarks=1&$USUAL_BUNDLE_CAPS$&cg=1&common=0000000000000000000000000000000000000000&heads=83180e7845de420a1bb46896fd5fe05294f8d629&listkeys=bookmarks&phases=1 x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull (glob)
* - - [*] "GET http://localhost:$HGPORT/?cmd=capabilities HTTP/1.1" - - (glob)
$LOCALIP - - [$LOGDATE$] "GET http://localhost:$HGPORT/?cmd=batch HTTP/1.1" - - x-hgarg-1:cmds=heads+%3Bknown+nodes%3D x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull (glob)
$LOCALIP - - [$LOGDATE$] "GET http://localhost:$HGPORT/?cmd=getbundle HTTP/1.1" - - x-hgarg-1:bookmarks=1&$USUAL_BUNDLE_CAPS$&cg=1&common=0000000000000000000000000000000000000000&heads=83180e7845de420a1bb46896fd5fe05294f8d629&listkeys=bookmarks&phases=1 x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull (glob)