view tests/test-extdata.t @ 42406:f385ba70e4af

changelog: optionally store added and removed files in changeset extras

As mentioned in an earlier patch, copies._chain() is used a lot in the
changeset-centric version of pathcopies(). It is expensive because it
needs to look at the manifest in order to filter out copies whose
target file has since been removed. I want to store the sets of added
and removed files in the changeset in order to speed that up. This
patch does the writing part of that. It could easily be a separate
config, but it's currently tied to experimental.copies.write-to since
that's the only real use case (it will also make the {file_*} template
keywords faster, but I doubt that anyone cares enough about those to
write extra metadata for them).

The new information is stored in the changeset extras. Since they're
always subsets of the changeset's "files" list, they're stored as
indexes into that list. I've stored the indexes as stringified ints
separated by NUL bytes. The size of 00changelog.d for the hg repo
increased in size by 0.28% percent (compared to the size with only
copy information in the changesets, which in turn is 0.17% larger than
without copy information). We could store only the delta between the
indexes and we could store them in binary, but the chosen format is
more readable.

We could also have implemented this as a cache outside the
changelog. One advantage of doing it that way is that we would get the
speedups from the {file_*} template keywords also on old
repos. Another advantage is that it we can rewrite the cache if we
find a bug in how we calculate the set of files. A disadvantage is
that it would be more complex. Another is that it would surely use
more space. We already write the copy information to the changeset
extras, so it seems like a small step to also write these file sets.

Differential Revision: https://phab.mercurial-scm.org/D6416

  $ hg init repo
  $ cd repo
  $ for n in 0 1 2 3 4 5 6 7 8 9 10 11; do
  >   echo $n > $n
  >   hg ci -qAm $n
  > done

test revset support

  $ cat <<'EOF' >> .hg/hgrc
  > [extdata]
  > filedata = file:extdata.txt
  > notes = notes.txt
  > shelldata = shell:cat extdata.txt | grep 2
  > emptygrep = shell:cat extdata.txt | grep empty
  > EOF
  $ cat <<'EOF' > extdata.txt
  > 2 another comment on 2
  > 3
  > EOF
  $ cat <<'EOF' > notes.txt
  > f6ed this change is great!
  > e834 this is buggy :(
  > 0625 first post
  > bogusnode gives no error
  > a ambiguous node gives no error
  > EOF

  $ hg log -qr "extdata(filedata)"
  2:f6ed99a58333
  3:9de260b1e88e
  $ hg log -qr "extdata(shelldata)"
  2:f6ed99a58333

test weight of extdata() revset

  $ hg debugrevspec -p optimized "extdata(filedata) & 3"
  * optimized:
  (andsmally
    (func
      (symbol 'extdata')
      (symbol 'filedata'))
    (symbol '3'))
  3

test non-zero exit of shell command

  $ hg log -qr "extdata(emptygrep)"
  abort: extdata command 'cat extdata.txt | grep empty' failed: exited with status 1
  [255]

test bad extdata() revset source

  $ hg log -qr "extdata()"
  hg: parse error: extdata takes at least 1 string argument
  [255]
  $ hg log -qr "extdata(unknown)"
  abort: unknown extdata source 'unknown'
  [255]

test template support:

  $ hg log -r:3 -T "{node|short}{if(extdata('notes'), ' # {extdata('notes')}')}\n"
  06254b906311 # first post
  e8342c9a2ed1 # this is buggy :(
  f6ed99a58333 # this change is great!
  9de260b1e88e

test template cache:

  $ hg log -r:3 -T '{rev} "{extdata("notes")}" "{extdata("shelldata")}"\n'
  0 "first post" ""
  1 "this is buggy :(" ""
  2 "this change is great!" "another comment on 2"
  3 "" ""

test bad extdata() template source

  $ hg log -T "{extdata()}\n"
  hg: parse error: extdata expects one argument
  [255]
  $ hg log -T "{extdata('unknown')}\n"
  abort: unknown extdata source 'unknown'
  [255]
  $ hg log -T "{extdata(unknown)}\n"
  hg: parse error: empty data source specified
  (did you mean extdata('unknown')?)
  [255]
  $ hg log -T "{extdata('{unknown}')}\n"
  hg: parse error: empty data source specified
  [255]

we don't fix up relative file URLs, but we do run shell commands in repo root

  $ mkdir sub
  $ cd sub
  $ hg log -qr "extdata(filedata)"
  abort: error: $ENOENT$
  [255]
  $ hg log -qr "extdata(shelldata)"
  2:f6ed99a58333

  $ cd ..