tests/test-init.t

revlog: use existing file handle when reading during _addrevision

_addrevision() may need to read from revlogs as part of computing
deltas. Previously, we would flush existing file handles and open
a new, short-lived file handle to perform the reading.

If we have an existing file handle, it seems logical to reuse it
for reading instead of opening a new file handle. This patch
makes that the new behavior.

After this patch, revlog files are only reopened when adding
revisions if the revlog is switched from inline to non-inline.

On Linux when unbundling a bundle of the mozilla-central repo, this
patch has the following impact on system call counts:

Call     Before     After       Delta
write    827,639    673,390   -154,249
open     700,103    684,089    -16,014
read      74,489     74,489          0
fstat    493,924    461,896    -32,028
close    249,131    233,117    -16,014
stat     242,001    242,001          0
lstat     18,676     18,676          0
lseek     20,268     20,268          0
ioctl     14,652     13,173     -1,479
TOTAL  3,180,758  2,930,679   -250,079

It's worth noting that many of the open() calls fail due to missing
files. That's why there are many more open() calls than close().

Despite the significant system call reduction, this change does not
seem to have a significant performance impact on Linux.

On Windows 10 (not a VM, on a SSD), this patch appears to reduce
unbundle time for mozilla-central from ~960s to ~920s. This isn't
as significant as I was hoping. But a decrease it is nonetheless.
Still, Windows unbundle performance is still >2x slower than Linux.

Despite the lack of significant gains, fewer system calls is fewer
system calls. If nothing else, this will narrow the focus of potential
areas to optimize in the future.

This test tries to exercise the ssh functionality with a dummy script

  $ checknewrepo()
  > {
  >    name=$1
  >    if [ -d "$name"/.hg/store ]; then
  >    echo store created
  >    fi
  >    if [ -f "$name"/.hg/00changelog.i ]; then
  >    echo 00changelog.i created
  >    fi
  >    cat "$name"/.hg/requires
  > }

creating 'local'

  $ hg init local
  $ checknewrepo local
  store created
  00changelog.i created
  dotencode
  fncache
  revlogv1
  store
  $ echo this > local/foo
  $ hg ci --cwd local -A -m "init"
  adding foo

test custom revlog chunk cache sizes

  $ hg --config format.chunkcachesize=0 log -R local -pv
  abort: revlog chunk cache size 0 is not greater than 0!
  [255]
  $ hg --config format.chunkcachesize=1023 log -R local -pv
  abort: revlog chunk cache size 1023 is not a power of 2!
  [255]
  $ hg --config format.chunkcachesize=1024 log -R local -pv
  changeset:   0:08b9e9f63b32
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       foo
  description:
  init
  
  
  diff -r 000000000000 -r 08b9e9f63b32 foo
  --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
  +++ b/foo	Thu Jan 01 00:00:00 1970 +0000
  @@ -0,0 +1,1 @@
  +this
  

creating repo with format.usestore=false

  $ hg --config format.usestore=false init old
  $ checknewrepo old
  revlogv1

creating repo with format.usefncache=false

  $ hg --config format.usefncache=false init old2
  $ checknewrepo old2
  store created
  00changelog.i created
  revlogv1
  store

creating repo with format.dotencode=false

  $ hg --config format.dotencode=false init old3
  $ checknewrepo old3
  store created
  00changelog.i created
  fncache
  revlogv1
  store

test failure

  $ hg init local
  abort: repository local already exists!
  [255]

init+push to remote2

  $ hg init -e "python \"$TESTDIR/dummyssh\"" ssh://user@dummy/remote2
  $ hg incoming -R remote2 local
  comparing with local
  changeset:   0:08b9e9f63b32
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     init
  

  $ hg push -R local -e "python \"$TESTDIR/dummyssh\"" ssh://user@dummy/remote2
  pushing to ssh://user@dummy/remote2
  searching for changes
  remote: adding changesets
  remote: adding manifests
  remote: adding file changes
  remote: added 1 changesets with 1 changes to 1 files

clone to remote1

  $ hg clone -e "python \"$TESTDIR/dummyssh\"" local ssh://user@dummy/remote1
  searching for changes
  remote: adding changesets
  remote: adding manifests
  remote: adding file changes
  remote: added 1 changesets with 1 changes to 1 files

The largefiles extension doesn't crash
  $ hg clone -e "python \"$TESTDIR/dummyssh\"" local ssh://user@dummy/remotelf --config extensions.largefiles=
  searching for changes
  remote: adding changesets
  remote: adding manifests
  remote: adding file changes
  remote: added 1 changesets with 1 changes to 1 files

init to existing repo

  $ hg init -e "python \"$TESTDIR/dummyssh\"" ssh://user@dummy/remote1
  abort: repository remote1 already exists!
  abort: could not create remote repo!
  [255]

clone to existing repo

  $ hg clone -e "python \"$TESTDIR/dummyssh\"" local ssh://user@dummy/remote1
  abort: repository remote1 already exists!
  abort: could not create remote repo!
  [255]

output of dummyssh

  $ cat dummylog
  Got arguments 1:user@dummy 2:hg init remote2
  Got arguments 1:user@dummy 2:hg -R remote2 serve --stdio
  Got arguments 1:user@dummy 2:hg -R remote2 serve --stdio
  Got arguments 1:user@dummy 2:hg init remote1
  Got arguments 1:user@dummy 2:hg -R remote1 serve --stdio
  Got arguments 1:user@dummy 2:hg init remotelf
  Got arguments 1:user@dummy 2:hg -R remotelf serve --stdio
  Got arguments 1:user@dummy 2:hg init remote1
  Got arguments 1:user@dummy 2:hg init remote1

comparing repositories

  $ hg tip -q -R local
  0:08b9e9f63b32
  $ hg tip -q -R remote1
  0:08b9e9f63b32
  $ hg tip -q -R remote2
  0:08b9e9f63b32

check names for repositories (clashes with URL schemes, special chars)

  $ for i in bundle file hg http https old-http ssh static-http "with space"; do
  >   printf "hg init \"$i\"... "
  >   hg init "$i"
  >   test -d "$i" -a -d "$i/.hg" && echo "ok" || echo "failed"
  > done
  hg init "bundle"... ok
  hg init "file"... ok
  hg init "hg"... ok
  hg init "http"... ok
  hg init "https"... ok
  hg init "old-http"... ok
  hg init "ssh"... ok
  hg init "static-http"... ok
  hg init "with space"... ok
#if eol-in-paths
/* " " is not a valid name for a directory on Windows */
  $ hg init " "
  $ test -d " "
  $ test -d " /.hg"
#endif

creating 'local/sub/repo'

  $ hg init local/sub/repo
  $ checknewrepo local/sub/repo
  store created
  00changelog.i created
  dotencode
  fncache
  revlogv1
  store

prepare test of init of url configured from paths

  $ echo '[paths]' >> $HGRCPATH
  $ echo "somewhere = `pwd`/url from paths" >> $HGRCPATH
  $ echo "elsewhere = `pwd`/another paths url" >> $HGRCPATH

init should (for consistency with clone) expand the url

  $ hg init somewhere
  $ checknewrepo "url from paths"
  store created
  00changelog.i created
  dotencode
  fncache
  revlogv1
  store

verify that clone also expand urls

  $ hg clone somewhere elsewhere
  updating to branch default
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ checknewrepo "another paths url"
  store created
  00changelog.i created
  dotencode
  fncache
  revlogv1
  store

clone bookmarks

  $ hg -R local bookmark test
  $ hg -R local bookmarks
   * test                      0:08b9e9f63b32
  $ hg clone -e "python \"$TESTDIR/dummyssh\"" local ssh://user@dummy/remote-bookmarks
  searching for changes
  remote: adding changesets
  remote: adding manifests
  remote: adding file changes
  remote: added 1 changesets with 1 changes to 1 files
  exporting bookmark test
  $ hg -R remote-bookmarks bookmarks
     test                      0:08b9e9f63b32