Mercurial > hg
view tests/test-branches.t @ 26623:5a95fe44121d
clonebundles: support for seeding clones from pre-generated bundles
Cloning can be an expensive operation for servers because the server
generates a bundle from existing repository data at request time. For
a large repository like mozilla-central, this consumes 4+ minutes
of CPU time on the server. It also results in significant network
utilization. Multiplied by hundreds or even thousands of clients and
the ensuing load can result in difficulties scaling the Mercurial server.
Despite generation of bundles being deterministic until the next
changeset is added, the generation of bundles to service a clone request
is not cached. Each clone thus performs redundant work. This is
wasteful.
This patch introduces the "clonebundles" extension and related
client-side functionality to help alleviate this deficiency. The
client-side feature is behind an experimental flag and is not enabled by
default.
It works as follows:
1) Server operator generates a bundle and makes it available on a
server (likely HTTP).
2) Server operator defines the URL of a bundle file in a
.hg/clonebundles.manifest file.
3) Client `hg clone`ing sees the server is advertising bundle URLs.
4) Client fetches and applies the advertised bundle.
5) Client performs equivalent of `hg pull` to fetch changes made since
the bundle was created.
Essentially, the server performs the expensive work of generating a
bundle once and all subsequent clones fetch a static file from
somewhere. Scaling static file serving is a much more manageable
problem than scaling a Python application like Mercurial. Assuming your
repository grows less than 1% per day, the end result is 99+% of CPU
and network load from clones is eliminated, allowing Mercurial servers
to scale more easily. Serving static files also means data can be
transferred to clients as fast as they can consume it, rather than as
fast as servers can generate it. This makes clones faster.
Mozilla has implemented similar functionality of this patch on
hg.mozilla.org using a custom extension. We are hosting bundle files in
Amazon S3 and CloudFront (a CDN) and have successfully offloaded
>1 TB/day in data transfer from hg.mozilla.org, freeing up significant
bandwidth and CPU resources. The positive impact has been stellar and
I believe it has proved its value to be included in Mercurial core. I
feel it is important for the client-side support to be enabled in core
by default because it means that clients will get faster, more reliable
clones and will enable server operators to reduce load without
requiring any client-side configuration changes (assuming clients are
up to date, of course).
The scope of this feature is narrowly and specifically tailored to
cloning, despite "serve pulls from pre-generated bundles" being a valid
and useful feature. I would eventually like for Mercurial servers to
support transferring *all* repository data via statically hosted files.
You could imagine a server that siphons all pushed data to bundle files
and instructs clients to apply a stream of bundles to reconstruct all
repository data. This feature, while useful and powerful, is
significantly more work to implement because it requires the server
component have awareness of discovery and a mapping of which changesets
are in which files. Full, clone bundles, by contrast, are much simpler.
The wire protocol command is named "clonebundles" instead of something
more generic like "staticbundles" to leave the door open for a new, more
powerful and more generic server-side component with minimal backwards
compatibility implications. The name "bundleclone" is used by Mozilla's
extension and would cause problems since there are subtle differences
in Mozilla's extension.
Mozilla's experience with this idea has taught us that some form of
"content negotiation" is required. Not all clients will support all
bundle formats or even URLs (advanced TLS requirements, etc). To ensure
the highest uptake possible, a server needs to advertise multiple
versions of bundles and clients need to be able to choose the most
appropriate from that list one. The "attributes" in each
server-advertised entry facilitate this filtering and sorting. Their
use will become apparent in subsequent patches.
Initial inspiration and credit for the idea of cloning from static files
belongs to Augie Fackler and his "lookaside clone" extension proof of
concept.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Fri, 09 Oct 2015 11:22:01 -0700 |
parents | 701df761aa94 |
children | cfa0037448f4 |
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$ hg init a $ cd a $ echo 'root' >root $ hg add root $ hg commit -d '0 0' -m "Adding root node" $ echo 'a' >a $ hg add a $ hg branch a marked working directory as branch a (branches are permanent and global, did you want a bookmark?) $ hg commit -d '1 0' -m "Adding a branch" $ hg branch q marked working directory as branch q $ echo 'aa' >a $ hg branch -C reset working directory to branch a $ hg commit -d '2 0' -m "Adding to a branch" $ hg update -C 0 0 files updated, 0 files merged, 1 files removed, 0 files unresolved $ echo 'b' >b $ hg add b $ hg branch b marked working directory as branch b $ hg commit -d '2 0' -m "Adding b branch" $ echo 'bh1' >bh1 $ hg add bh1 $ hg commit -d '3 0' -m "Adding b branch head 1" $ hg update -C 2 1 files updated, 0 files merged, 2 files removed, 0 files unresolved $ echo 'bh2' >bh2 $ hg add bh2 $ hg commit -d '4 0' -m "Adding b branch head 2" $ echo 'c' >c $ hg add c $ hg branch c marked working directory as branch c $ hg commit -d '5 0' -m "Adding c branch" reserved names $ hg branch tip abort: the name 'tip' is reserved [255] $ hg branch null abort: the name 'null' is reserved [255] $ hg branch . abort: the name '.' is reserved [255] invalid characters $ hg branch 'foo:bar' abort: ':' cannot be used in a name [255] $ hg branch 'foo > bar' abort: '\n' cannot be used in a name [255] trailing or leading spaces should be stripped before testing duplicates $ hg branch 'b ' abort: a branch of the same name already exists (use 'hg update' to switch to it) [255] $ hg branch ' b' abort: a branch of the same name already exists (use 'hg update' to switch to it) [255] verify update will accept invalid legacy branch names $ hg init test-invalid-branch-name $ cd test-invalid-branch-name $ hg pull -u "$TESTDIR"/bundles/test-invalid-branch-name.hg pulling from *test-invalid-branch-name.hg (glob) requesting all changes adding changesets adding manifests adding file changes added 3 changesets with 3 changes to 2 files 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ hg update '"colon:test"' 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ cd .. $ echo 'd' >d $ hg add d $ hg branch 'a branch name much longer than the default justification used by branches' marked working directory as branch a branch name much longer than the default justification used by branches $ hg commit -d '6 0' -m "Adding d branch" $ hg branches a branch name much longer than the default justification used by branches 7:10ff5895aa57 b 4:aee39cd168d0 c 6:589736a22561 (inactive) a 5:d8cbc61dbaa6 (inactive) default 0:19709c5a4e75 (inactive) ------- $ hg branches -a a branch name much longer than the default justification used by branches 7:10ff5895aa57 b 4:aee39cd168d0 --- Branch a $ hg log -b a changeset: 5:d8cbc61dbaa6 branch: a parent: 2:881fe2b92ad0 user: test date: Thu Jan 01 00:00:04 1970 +0000 summary: Adding b branch head 2 changeset: 2:881fe2b92ad0 branch: a user: test date: Thu Jan 01 00:00:02 1970 +0000 summary: Adding to a branch changeset: 1:dd6b440dd85a branch: a user: test date: Thu Jan 01 00:00:01 1970 +0000 summary: Adding a branch ---- Branch b $ hg log -b b changeset: 4:aee39cd168d0 branch: b user: test date: Thu Jan 01 00:00:03 1970 +0000 summary: Adding b branch head 1 changeset: 3:ac22033332d1 branch: b parent: 0:19709c5a4e75 user: test date: Thu Jan 01 00:00:02 1970 +0000 summary: Adding b branch ---- going to test branch closing $ hg branches a branch name much longer than the default justification used by branches 7:10ff5895aa57 b 4:aee39cd168d0 c 6:589736a22561 (inactive) a 5:d8cbc61dbaa6 (inactive) default 0:19709c5a4e75 (inactive) $ hg up -C b 2 files updated, 0 files merged, 4 files removed, 0 files unresolved $ echo 'xxx1' >> b $ hg commit -d '7 0' -m 'adding cset to branch b' $ hg up -C aee39cd168d0 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ echo 'xxx2' >> b $ hg commit -d '8 0' -m 'adding head to branch b' created new head $ echo 'xxx3' >> b $ hg commit -d '9 0' -m 'adding another cset to branch b' $ hg branches b 10:bfbe841b666e a branch name much longer than the default justification used by branches 7:10ff5895aa57 c 6:589736a22561 (inactive) a 5:d8cbc61dbaa6 (inactive) default 0:19709c5a4e75 (inactive) $ hg heads --closed changeset: 10:bfbe841b666e branch: b tag: tip user: test date: Thu Jan 01 00:00:09 1970 +0000 summary: adding another cset to branch b changeset: 8:eebb944467c9 branch: b parent: 4:aee39cd168d0 user: test date: Thu Jan 01 00:00:07 1970 +0000 summary: adding cset to branch b changeset: 7:10ff5895aa57 branch: a branch name much longer than the default justification used by branches user: test date: Thu Jan 01 00:00:06 1970 +0000 summary: Adding d branch changeset: 6:589736a22561 branch: c user: test date: Thu Jan 01 00:00:05 1970 +0000 summary: Adding c branch changeset: 5:d8cbc61dbaa6 branch: a parent: 2:881fe2b92ad0 user: test date: Thu Jan 01 00:00:04 1970 +0000 summary: Adding b branch head 2 changeset: 0:19709c5a4e75 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: Adding root node $ hg heads changeset: 10:bfbe841b666e branch: b tag: tip user: test date: Thu Jan 01 00:00:09 1970 +0000 summary: adding another cset to branch b changeset: 8:eebb944467c9 branch: b parent: 4:aee39cd168d0 user: test date: Thu Jan 01 00:00:07 1970 +0000 summary: adding cset to branch b changeset: 7:10ff5895aa57 branch: a branch name much longer than the default justification used by branches user: test date: Thu Jan 01 00:00:06 1970 +0000 summary: Adding d branch changeset: 6:589736a22561 branch: c user: test date: Thu Jan 01 00:00:05 1970 +0000 summary: Adding c branch changeset: 5:d8cbc61dbaa6 branch: a parent: 2:881fe2b92ad0 user: test date: Thu Jan 01 00:00:04 1970 +0000 summary: Adding b branch head 2 changeset: 0:19709c5a4e75 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: Adding root node $ hg commit -d '9 0' --close-branch -m 'prune bad branch' $ hg branches -a b 8:eebb944467c9 a branch name much longer than the default justification used by branches 7:10ff5895aa57 $ hg up -C b 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ hg commit -d '9 0' --close-branch -m 'close this part branch too' $ hg commit -d '9 0' --close-branch -m 're-closing this branch' abort: can only close branch heads [255] $ hg log -r tip --debug changeset: 12:e3d49c0575d8fc2cb1cd6859c747c14f5f6d499f branch: b tag: tip phase: draft parent: 8:eebb944467c9fb9651ed232aeaf31b3c0a7fc6c1 parent: -1:0000000000000000000000000000000000000000 manifest: 8:6f9ed32d2b310e391a4f107d5f0f071df785bfee user: test date: Thu Jan 01 00:00:09 1970 +0000 extra: branch=b extra: close=1 description: close this part branch too --- b branch should be inactive $ hg branches a branch name much longer than the default justification used by branches 7:10ff5895aa57 c 6:589736a22561 (inactive) a 5:d8cbc61dbaa6 (inactive) default 0:19709c5a4e75 (inactive) $ hg branches -c a branch name much longer than the default justification used by branches 7:10ff5895aa57 b 12:e3d49c0575d8 (closed) c 6:589736a22561 (inactive) a 5:d8cbc61dbaa6 (inactive) default 0:19709c5a4e75 (inactive) $ hg branches -a a branch name much longer than the default justification used by branches 7:10ff5895aa57 $ hg branches -q a branch name much longer than the default justification used by branches c a default $ hg heads b no open branch heads found on branches b [1] $ hg heads --closed b changeset: 12:e3d49c0575d8 branch: b tag: tip parent: 8:eebb944467c9 user: test date: Thu Jan 01 00:00:09 1970 +0000 summary: close this part branch too changeset: 11:d3f163457ebf branch: b user: test date: Thu Jan 01 00:00:09 1970 +0000 summary: prune bad branch $ echo 'xxx4' >> b $ hg commit -d '9 0' -m 'reopen branch with a change' reopening closed branch head 12 --- branch b is back in action $ hg branches -a b 13:e23b5505d1ad a branch name much longer than the default justification used by branches 7:10ff5895aa57 ---- test heads listings $ hg heads changeset: 13:e23b5505d1ad branch: b tag: tip user: test date: Thu Jan 01 00:00:09 1970 +0000 summary: reopen branch with a change changeset: 7:10ff5895aa57 branch: a branch name much longer than the default justification used by branches user: test date: Thu Jan 01 00:00:06 1970 +0000 summary: Adding d branch changeset: 6:589736a22561 branch: c user: test date: Thu Jan 01 00:00:05 1970 +0000 summary: Adding c branch changeset: 5:d8cbc61dbaa6 branch: a parent: 2:881fe2b92ad0 user: test date: Thu Jan 01 00:00:04 1970 +0000 summary: Adding b branch head 2 changeset: 0:19709c5a4e75 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: Adding root node branch default $ hg heads default changeset: 0:19709c5a4e75 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: Adding root node branch a $ hg heads a changeset: 5:d8cbc61dbaa6 branch: a parent: 2:881fe2b92ad0 user: test date: Thu Jan 01 00:00:04 1970 +0000 summary: Adding b branch head 2 $ hg heads --active a no open branch heads found on branches a [1] branch b $ hg heads b changeset: 13:e23b5505d1ad branch: b tag: tip user: test date: Thu Jan 01 00:00:09 1970 +0000 summary: reopen branch with a change $ hg heads --closed b changeset: 13:e23b5505d1ad branch: b tag: tip user: test date: Thu Jan 01 00:00:09 1970 +0000 summary: reopen branch with a change changeset: 11:d3f163457ebf branch: b user: test date: Thu Jan 01 00:00:09 1970 +0000 summary: prune bad branch default branch colors: $ cat <<EOF >> $HGRCPATH > [extensions] > color = > [color] > mode = ansi > EOF $ hg up -C c 3 files updated, 0 files merged, 2 files removed, 0 files unresolved $ hg commit -d '9 0' --close-branch -m 'reclosing this branch' $ hg up -C b 2 files updated, 0 files merged, 3 files removed, 0 files unresolved $ hg branches --color=always \x1b[0;32mb\x1b[0m\x1b[0;33m 13:e23b5505d1ad\x1b[0m (esc) \x1b[0;0ma branch name much longer than the default justification used by branches\x1b[0m\x1b[0;33m 7:10ff5895aa57\x1b[0m (esc) \x1b[0;0ma\x1b[0m\x1b[0;33m 5:d8cbc61dbaa6\x1b[0m (inactive) (esc) \x1b[0;0mdefault\x1b[0m\x1b[0;33m 0:19709c5a4e75\x1b[0m (inactive) (esc) default closed branch color: $ hg branches --color=always --closed \x1b[0;32mb\x1b[0m\x1b[0;33m 13:e23b5505d1ad\x1b[0m (esc) \x1b[0;0ma branch name much longer than the default justification used by branches\x1b[0m\x1b[0;33m 7:10ff5895aa57\x1b[0m (esc) \x1b[0;30;1mc\x1b[0m\x1b[0;33m 14:f894c25619d3\x1b[0m (closed) (esc) \x1b[0;0ma\x1b[0m\x1b[0;33m 5:d8cbc61dbaa6\x1b[0m (inactive) (esc) \x1b[0;0mdefault\x1b[0m\x1b[0;33m 0:19709c5a4e75\x1b[0m (inactive) (esc) $ cat <<EOF >> $HGRCPATH > [extensions] > color = > [color] > branches.active = green > branches.closed = blue > branches.current = red > branches.inactive = magenta > log.changeset = cyan > EOF custom branch colors: $ hg branches --color=always \x1b[0;31mb\x1b[0m\x1b[0;36m 13:e23b5505d1ad\x1b[0m (esc) \x1b[0;32ma branch name much longer than the default justification used by branches\x1b[0m\x1b[0;36m 7:10ff5895aa57\x1b[0m (esc) \x1b[0;35ma\x1b[0m\x1b[0;36m 5:d8cbc61dbaa6\x1b[0m (inactive) (esc) \x1b[0;35mdefault\x1b[0m\x1b[0;36m 0:19709c5a4e75\x1b[0m (inactive) (esc) custom closed branch color: $ hg branches --color=always --closed \x1b[0;31mb\x1b[0m\x1b[0;36m 13:e23b5505d1ad\x1b[0m (esc) \x1b[0;32ma branch name much longer than the default justification used by branches\x1b[0m\x1b[0;36m 7:10ff5895aa57\x1b[0m (esc) \x1b[0;34mc\x1b[0m\x1b[0;36m 14:f894c25619d3\x1b[0m (closed) (esc) \x1b[0;35ma\x1b[0m\x1b[0;36m 5:d8cbc61dbaa6\x1b[0m (inactive) (esc) \x1b[0;35mdefault\x1b[0m\x1b[0;36m 0:19709c5a4e75\x1b[0m (inactive) (esc) template output: $ hg branches -Tjson --closed [ { "active": true, "branch": "b", "closed": false, "current": true, "node": "e23b5505d1ad24aab6f84fd8c7cb8cd8e5e93be0", "rev": 13 }, { "active": true, "branch": "a branch name much longer than the default justification used by branches", "closed": false, "current": false, "node": "10ff5895aa5793bd378da574af8cec8ea408d831", "rev": 7 }, { "active": false, "branch": "c", "closed": true, "current": false, "node": "f894c25619d3f1484639d81be950e0a07bc6f1f6", "rev": 14 }, { "active": false, "branch": "a", "closed": false, "current": false, "node": "d8cbc61dbaa6dc817175d1e301eecb863f280832", "rev": 5 }, { "active": false, "branch": "default", "closed": false, "current": false, "node": "19709c5a4e75bf938f8e349aff97438539bb729e", "rev": 0 } ] Tests of revision branch name caching We rev branch cache is updated automatically. In these tests we use a trick to trigger rebuilds. We remove the branch head cache and run 'hg head' to cause a rebuild that also will populate the rev branch cache. revision branch cache is created when building the branch head cache $ rm -rf .hg/cache; hg head a -T '{rev}\n' 5 $ f --hexdump --size .hg/cache/rbc-* .hg/cache/rbc-names-v1: size=87 0000: 64 65 66 61 75 6c 74 00 61 00 62 00 63 00 61 20 |default.a.b.c.a | 0010: 62 72 61 6e 63 68 20 6e 61 6d 65 20 6d 75 63 68 |branch name much| 0020: 20 6c 6f 6e 67 65 72 20 74 68 61 6e 20 74 68 65 | longer than the| 0030: 20 64 65 66 61 75 6c 74 20 6a 75 73 74 69 66 69 | default justifi| 0040: 63 61 74 69 6f 6e 20 75 73 65 64 20 62 79 20 62 |cation used by b| 0050: 72 61 6e 63 68 65 73 |ranches| .hg/cache/rbc-revs-v1: size=120 0000: 19 70 9c 5a 00 00 00 00 dd 6b 44 0d 00 00 00 01 |.p.Z.....kD.....| 0010: 88 1f e2 b9 00 00 00 01 ac 22 03 33 00 00 00 02 |.........".3....| 0020: ae e3 9c d1 00 00 00 02 d8 cb c6 1d 00 00 00 01 |................| 0030: 58 97 36 a2 00 00 00 03 10 ff 58 95 00 00 00 04 |X.6.......X.....| 0040: ee bb 94 44 00 00 00 02 5f 40 61 bb 00 00 00 02 |...D...._@a.....| 0050: bf be 84 1b 00 00 00 02 d3 f1 63 45 80 00 00 02 |..........cE....| 0060: e3 d4 9c 05 80 00 00 02 e2 3b 55 05 00 00 00 02 |.........;U.....| 0070: f8 94 c2 56 80 00 00 03 |...V....| #if unix-permissions no-root no errors when revbranchcache is not writable $ echo >> .hg/cache/rbc-revs-v1 $ chmod a-w .hg/cache/rbc-revs-v1 $ rm -f .hg/cache/branch* && hg head a -T '{rev}\n' 5 $ chmod a+w .hg/cache/rbc-revs-v1 #endif recovery from invalid cache revs file with trailing data $ echo >> .hg/cache/rbc-revs-v1 $ rm -f .hg/cache/branch* && hg head a -T '{rev}\n' --debug 5 truncating cache/rbc-revs-v1 to 120 $ f --size .hg/cache/rbc-revs* .hg/cache/rbc-revs-v1: size=120 recovery from invalid cache file with partial last record $ mv .hg/cache/rbc-revs-v1 . $ f -qDB 119 rbc-revs-v1 > .hg/cache/rbc-revs-v1 $ f --size .hg/cache/rbc-revs* .hg/cache/rbc-revs-v1: size=119 $ rm -f .hg/cache/branch* && hg head a -T '{rev}\n' --debug 5 truncating cache/rbc-revs-v1 to 112 $ f --size .hg/cache/rbc-revs* .hg/cache/rbc-revs-v1: size=120 recovery from invalid cache file with missing record - no truncation $ mv .hg/cache/rbc-revs-v1 . $ f -qDB 112 rbc-revs-v1 > .hg/cache/rbc-revs-v1 $ rm -f .hg/cache/branch* && hg head a -T '{rev}\n' --debug 5 $ f --size .hg/cache/rbc-revs* .hg/cache/rbc-revs-v1: size=120 recovery from invalid cache file with some bad records $ mv .hg/cache/rbc-revs-v1 . $ f -qDB 8 rbc-revs-v1 > .hg/cache/rbc-revs-v1 $ f --size .hg/cache/rbc-revs* .hg/cache/rbc-revs-v1: size=8 $ f -qDB 112 rbc-revs-v1 >> .hg/cache/rbc-revs-v1 $ f --size .hg/cache/rbc-revs* .hg/cache/rbc-revs-v1: size=120 $ hg log -r 'branch(.)' -T '{rev} ' --debug 3 4 8 9 10 11 12 13 truncating cache/rbc-revs-v1 to 8 $ rm -f .hg/cache/branch* && hg head a -T '{rev}\n' --debug 5 truncating cache/rbc-revs-v1 to 104 $ f --size --hexdump --bytes=16 .hg/cache/rbc-revs* .hg/cache/rbc-revs-v1: size=120 0000: 19 70 9c 5a 00 00 00 00 dd 6b 44 0d 00 00 00 01 |.p.Z.....kD.....| cache is updated when committing $ hg branch i-will-regret-this marked working directory as branch i-will-regret-this $ hg ci -m regrets $ f --size .hg/cache/rbc-* .hg/cache/rbc-names-v1: size=106 .hg/cache/rbc-revs-v1: size=128 update after rollback - the cache will be correct but rbc-names will will still contain the branch name even though it no longer is used $ hg up -qr '.^' $ hg rollback -qf $ f --size --hexdump .hg/cache/rbc-* .hg/cache/rbc-names-v1: size=106 0000: 64 65 66 61 75 6c 74 00 61 00 62 00 63 00 61 20 |default.a.b.c.a | 0010: 62 72 61 6e 63 68 20 6e 61 6d 65 20 6d 75 63 68 |branch name much| 0020: 20 6c 6f 6e 67 65 72 20 74 68 61 6e 20 74 68 65 | longer than the| 0030: 20 64 65 66 61 75 6c 74 20 6a 75 73 74 69 66 69 | default justifi| 0040: 63 61 74 69 6f 6e 20 75 73 65 64 20 62 79 20 62 |cation used by b| 0050: 72 61 6e 63 68 65 73 00 69 2d 77 69 6c 6c 2d 72 |ranches.i-will-r| 0060: 65 67 72 65 74 2d 74 68 69 73 |egret-this| .hg/cache/rbc-revs-v1: size=120 0000: 19 70 9c 5a 00 00 00 00 dd 6b 44 0d 00 00 00 01 |.p.Z.....kD.....| 0010: 88 1f e2 b9 00 00 00 01 ac 22 03 33 00 00 00 02 |.........".3....| 0020: ae e3 9c d1 00 00 00 02 d8 cb c6 1d 00 00 00 01 |................| 0030: 58 97 36 a2 00 00 00 03 10 ff 58 95 00 00 00 04 |X.6.......X.....| 0040: ee bb 94 44 00 00 00 02 5f 40 61 bb 00 00 00 02 |...D...._@a.....| 0050: bf be 84 1b 00 00 00 02 d3 f1 63 45 80 00 00 02 |..........cE....| 0060: e3 d4 9c 05 80 00 00 02 e2 3b 55 05 00 00 00 02 |.........;U.....| 0070: f8 94 c2 56 80 00 00 03 |...V....| cache is updated/truncated when stripping - it is thus very hard to get in a situation where the cache is out of sync and the hash check detects it $ hg --config extensions.strip= strip -r tip --nob $ f --size .hg/cache/rbc-revs* .hg/cache/rbc-revs-v1: size=112 $ cd ..