annotate tests/test-static-http.t @ 30561:7c0c722d568d

bdiff: early pruning of common prefix before doing expensive computations

It seems quite common that files don't change completely. New lines are often
pretty much appended, and modifications will often only change a small section
of the file which on average will be in the middle.

There can thus be a big win by pruning a common prefix before starting the more
expensive search for longest common substrings.

Worst case, it will scan through a long sequence of similar bytes without
encountering a newline. Splitlines will then have to do the same again ...
twice for each side. If similar lines are found, splitlines will save the
double iteration and hashing of the lines ... plus there will be less lines to
find common substrings in.

This change might in some cases make the algorith pick shorter or less optimal
common substrings. We can't have the cake and eat it.

This make hg --time bundle --base null -r 4.0 go from 14.5 to 15 s - a 3%
increase.

On mozilla-unified:
perfbdiff -m 3041e4d59df2
! wall 0.053088 comb 0.060000 user 0.060000 sys 0.000000 (best of 100) to
! wall 0.024618 comb 0.020000 user 0.020000 sys 0.000000 (best of 116)
perfbdiff 0e9928989e9c --alldata --count 10
! wall 0.702075 comb 0.700000 user 0.700000 sys 0.000000 (best of 15) to
! wall 0.579235 comb 0.580000 user 0.580000 sys 0.000000 (best of 18)

#require killdaemons

  $ hg clone http://localhost:$HGPORT/ copy
  abort: * (glob)
  [255]
  $ test -d copy
  [1]

This server doesn't do range requests so it's basically only good for
one pull

  $ python "$TESTDIR/dumbhttp.py" -p $HGPORT --pid dumb.pid
  $ cat dumb.pid >> $DAEMON_PIDS
  $ hg init remote
  $ cd remote
  $ echo foo > bar
  $ echo c2 > '.dotfile with spaces'
  $ hg add
  adding .dotfile with spaces
  adding bar
  $ hg commit -m"test"
  $ hg tip
  changeset:   0:02770d679fb8
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     test
  
  $ cd ..
  $ hg clone static-http://localhost:$HGPORT/remote local
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 2 changes to 2 files
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd local
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  2 files, 1 changesets, 2 total revisions
  $ cat bar
  foo
  $ cd ../remote
  $ echo baz > quux
  $ hg commit -A -mtest2
  adding quux

check for HTTP opener failures when cachefile does not exist

  $ rm .hg/cache/*
  $ cd ../local
  $ cat >> .hg/hgrc <<EOF
  > [hooks]
  > changegroup = sh -c "printenv.py changegroup"
  > EOF
  $ hg pull
  pulling from static-http://localhost:$HGPORT/remote
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  changegroup hook: HG_NODE=4ac2e3648604439c580c69b09ec9d93a88d93432 HG_NODE_LAST=4ac2e3648604439c580c69b09ec9d93a88d93432 HG_SOURCE=pull HG_TXNID=TXN:* HG_URL=http://localhost:$HGPORT/remote (glob)
  (run 'hg update' to get a working copy)

trying to push

  $ hg update
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo more foo >> bar
  $ hg commit -m"test"
  $ hg push
  pushing to static-http://localhost:$HGPORT/remote
  abort: destination does not support push
  [255]

trying clone -r

  $ cd ..
  $ hg clone -r doesnotexist static-http://localhost:$HGPORT/remote local0
  abort: unknown revision 'doesnotexist'!
  [255]
  $ hg clone -r 0 static-http://localhost:$HGPORT/remote local0
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 2 changes to 2 files
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved

test with "/" URI (issue747) and subrepo

  $ hg init
  $ hg init sub
  $ touch sub/test
  $ hg -R sub commit -A -m "test"
  adding test
  $ hg -R sub tag not-empty
  $ echo sub=sub > .hgsub
  $ echo a > a
  $ hg add a .hgsub
  $ hg -q ci -ma
  $ hg clone static-http://localhost:$HGPORT/ local2
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 3 changes to 3 files
  updating to branch default
  cloning subrepo sub from static-http://localhost:$HGPORT/sub
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 2 files
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd local2
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  3 files, 1 changesets, 3 total revisions
  checking subrepo links
  $ cat a
  a
  $ hg paths
  default = static-http://localhost:$HGPORT/

test with empty repo (issue965)

  $ cd ..
  $ hg init remotempty
  $ hg clone static-http://localhost:$HGPORT/remotempty local3
  no changes found
  updating to branch default
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd local3
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  0 files, 0 changesets, 0 total revisions
  $ hg paths
  default = static-http://localhost:$HGPORT/remotempty

test with non-repo

  $ cd ..
  $ mkdir notarepo
  $ hg clone static-http://localhost:$HGPORT/notarepo local3
  abort: 'http://localhost:$HGPORT/notarepo' does not appear to be an hg repository!
  [255]
  $ killdaemons.py