$ cat >> $HGRCPATH << EOF

  > [ui]

  > [extensions]

  > fastannotate=

  > [fastannotate]

  > mainbranch=@

  > EOF

setup the server repo

  $ hg init repo-server

  $ cd repo-server

  $ cat >> .hg/hgrc << EOF

  > [fastannotate]

  > server=1

  > EOF

  $ for i in 1 2 3 4; do

  >   echo $i >> a

  >   hg commit -A -m $i a

  > done

  $ [ -d .hg/fastannotate ]

  [1]

  $ hg bookmark @

  $ cd ..

setup the local repo

  $ hg clone 'ssh://user@dummy/repo-server' repo-local -q

  $ cd repo-local

  $ cat >> .hg/hgrc << EOF

  > [fastannotate]

  > client=1

  > clientfetchthreshold=0

  > EOF

  $ [ -d .hg/fastannotate ]

  [1]

  $ hg fastannotate a --debug

  running * (glob)

  sending hello command

  sending between command

  remote: * (glob) (?)

  remote: capabilities: * (glob)

  remote: * (glob) (?)

  sending protocaps command

  fastannotate: requesting 1 files

  sending getannotate command

  fastannotate: writing 112 bytes to fastannotate/default/a.l

  fastannotate: writing 94 bytes to fastannotate/default/a.m

  fastannotate: a: using fast path (resolved fctx: True)

  0: 1

  1: 2

  2: 3

  3: 4

the cache could be reused and no download is necessary

  $ hg fastannotate a --debug

  fastannotate: a: using fast path (resolved fctx: True)

  0: 1

  1: 2

  2: 3

  3: 4

if the client agrees where the head of the master branch is, no re-download

happens even if the client has more commits

  $ echo 5 >> a

  $ hg commit -m 5

  $ hg bookmark -r 3 @ -f

  $ hg fastannotate a --debug

  0: 1

  1: 2

  2: 3

  3: 4

  4: 5

if the client has a different "@" (head of the master branch) and "@" is ahead

of the server, the server can detect things are unchanged and does not return

full contents (not that there is no "writing ... to fastannotate"), but the

client can also build things up on its own (causing diverge)

  $ hg bookmark -r 4 @ -f

  $ hg fastannotate a --debug

  running * (glob)

  sending hello command

  sending between command

  remote: * (glob) (?)

  remote: capabilities: * (glob)

  remote: * (glob) (?)

  sending protocaps command

  fastannotate: requesting 1 files

  sending getannotate command

  fastannotate: a: 1 new changesets in the main branch

  0: 1

  1: 2

  2: 3

  3: 4

  4: 5

if the client has a different "@" which is behind the server. no download is

necessary

  $ hg fastannotate a --debug --config fastannotate.mainbranch=2

  fastannotate: a: using fast path (resolved fctx: True)

  0: 1

  1: 2

  2: 3

  3: 4

  4: 5

define fastannotate on-disk paths

  $ p1=.hg/fastannotate/default

  $ p2=../repo-server/.hg/fastannotate/default

revert bookmark change so the client is behind the server

  $ hg bookmark -r 2 @ -f

in the "fctx" mode with the "annotate" command, the client also downloads the

cache. but not in the (default) "fastannotate" mode.

  $ rm $p1/a.l $p1/a.m

  $ hg annotate a --debug | grep 'fastannotate: writing'

  [1]

  $ hg annotate a --config fastannotate.modes=fctx --debug | grep 'fastannotate: writing' | sort

  fastannotate: writing 112 bytes to fastannotate/default/a.l

  fastannotate: writing 94 bytes to fastannotate/default/a.m

the fastannotate cache (built server-side, downloaded client-side) in two repos

have the same content (because the client downloads from the server)

  $ diff $p1/a.l $p2/a.l

  $ diff $p1/a.m $p2/a.m

in the "fctx" mode, the client could also build the cache locally

  $ hg annotate a --config fastannotate.modes=fctx --debug --config fastannotate.mainbranch=4 | grep fastannotate

  fastannotate: requesting 1 files

  fastannotate: a: 1 new changesets in the main branch

the server would rebuild broken cache automatically

  $ cp $p2/a.m $p2/a.m.bak

  $ echo BROKEN1 > $p1/a.m

  $ echo BROKEN2 > $p2/a.m

  $ hg fastannotate a --debug | grep 'fastannotate: writing' | sort

  fastannotate: writing 112 bytes to fastannotate/default/a.l

  fastannotate: writing 94 bytes to fastannotate/default/a.m

  $ diff $p1/a.m $p2/a.m

  $ diff $p2/a.m $p2/a.m.bak

use the "debugbuildannotatecache" command to build annotate cache

  $ rm -rf $p1 $p2

  $ hg --cwd ../repo-server debugbuildannotatecache a --debug

  fastannotate: a: 4 new changesets in the main branch

  $ hg --cwd ../repo-local debugbuildannotatecache a --debug

  running * (glob)

  sending hello command

  sending between command

  remote: * (glob) (?)

  remote: capabilities: * (glob)

  remote: * (glob) (?)

  sending protocaps command

  fastannotate: requesting 1 files

  sending getannotate command

  fastannotate: writing * (glob)

  fastannotate: writing * (glob)

  $ diff $p1/a.l $p2/a.l

  $ diff $p1/a.m $p2/a.m

with the clientfetchthreshold config option, the client can build up the cache

without downloading from the server

  $ rm -rf $p1

  $ hg fastannotate a --debug --config fastannotate.clientfetchthreshold=10

  fastannotate: a: 3 new changesets in the main branch

  0: 1

  1: 2

  2: 3

  3: 4

  4: 5

if the fastannotate directory is not writable, the fctx mode still works

  $ rm -rf $p1

  $ touch $p1

  $ hg annotate a --debug --traceback --config fastannotate.modes=fctx

  fastannotate: a: cache broken and deleted

  fastannotate: prefetch failed: * (glob)

  fastannotate: a: cache broken and deleted

  fastannotate: falling back to the vanilla annotate: * (glob)

  0: 1

  1: 2

  2: 3

  3: 4

  4: 5

with serverbuildondemand=False, the server will not build anything

  $ cat >> ../repo-server/.hg/hgrc <<EOF

  > [fastannotate]

  > serverbuildondemand=False

  > EOF

  $ rm -rf $p1 $p2

  $ hg fastannotate a --debug | grep 'fastannotate: writing'

  [1]