revset: stop serializing node when using "%ln" Turning hundred of thousand of node from node to hex and back can be slow… what about we stop doing it? In many case were we are using node id we should be using revision id. However this is not a good reason to have a stupidly slow implementation of "%ln". This caught my attention again because the phase discovery during push make an extensive use of "%ln" or huge set. In absolute, that phase discovery probably should use "%ld" and need to improves its algorithmic complexity, but improving "%ln" seems simple and long overdue. This greatly speeds up `hg push` on repository with many drafts. Here are some relevant poulpe benchmarks: ### data-env-vars.name = mozilla-try-2023-03-22-zstd-sparse-revlog # benchmark.name = hg.command.push # bin-env-vars.hg.flavor = default # bin-env-vars.hg.py-re2-module = default # benchmark.variants.explicit-rev = all-out-heads # benchmark.variants.issue6528 = disabled # benchmark.variants.protocol = ssh # benchmark.variants.reuse-external-delta-parent = default ## benchmark.variants.revs = any-1-extra-rev before: 44.235070 after: 20.416329 (-53.85%, -23.82) ## benchmark.variants.revs = any-100-extra-rev before: 49.234697 after: 26.519829 (-46.14%, -22.71) ### benchmark.name = hg.command.bundle # bin-env-vars.hg.flavor = default # bin-env-vars.hg.py-re2-module = default # benchmark.variants.revs = all # benchmark.variants.type = none-streamv2 ## data-env-vars.name = heptapod-public-2024-03-25-zstd-sparse-revlog before: 10.138396 after: 7.750458 (-23.55%, -2.39) ## data-env-vars.name = mercurial-public-2024-03-22-zstd-sparse-revlog before: 1.263859 after: 0.700229 (-44.60%, -0.56) ## data-env-vars.name = mozilla-try-2023-03-22-zstd-sparse-revlog before: 399.484481 after: 346.5089 (-13.26%, -52.98) ## data-env-vars.name = pypy-2024-03-22-zstd-sparse-revlog before: 4.540080 after: 3.401700 (-25.07%, -1.14) ## data-env-vars.name = tryton-public-2024-03-22-zstd-sparse-revlog before: 2.975765 after: 1.870798 (-37.13%, -1.10)

This test cover a bug that no longer exist.

Define helpers.

  $ hg_log () { hg log -G -T "{rev}:{node|short}"; }
  $ commit () { echo "foo - ${2:-$1}" > $1; hg commit -Aqm "Edited $1"; }
  $ strip() { hg --config extensions.strip= strip -q -r "$1" ; }

Setup hg repo.

  $ hg init repo
  $ cd repo
  $ touch x; hg add x; hg commit -m "initial"
  $ hg clone -q . ../clone
  $ commit a

  $ cd ../clone

  $ commit b

  $ hg pull -q ../repo

  $ ls -1 .hg/cache/branch?*
  .hg/cache/branch2-base
  .hg/cache/branch2-served
  $ cat .hg/cache/branch?-served
  222ae9789a75703f9836e44de7db179cbfd420ee 2
  a3498d6e39376d2456425dd8c692367bdbf00fa2 o default
  222ae9789a75703f9836e44de7db179cbfd420ee o default

  $ hg_log
  o  2:222ae9789a75
  |
  | @  1:a3498d6e3937
  |/
  o  0:7ab0a3bd758a
  

  $ strip '1:'

After the strip the "served" cache is now identical to the "base" one, and the
older one have been actively deleted.

  $ ls -1 .hg/cache/branch?*
  .hg/cache/branch2-base
  $ cat .hg/cache/branch?-base
  7ab0a3bd758a58b9f79557ce708533e627776cce 0
  7ab0a3bd758a58b9f79557ce708533e627776cce o default

We do a new commit and we get a new valid branchmap for the served version

  $ commit c
  $ ls -1 .hg/cache/branch?*
  .hg/cache/branch2-base
  .hg/cache/branch2-served
  $ cat .hg/cache/branch?-served
  a1602b357cfca067600406eb19060c7128804d72 1
  a1602b357cfca067600406eb19060c7128804d72 o default


On pull we end up with the same tip, and so wrongly reuse the invalid cache and crash.

  $ hg pull ../repo --quiet
  $ hg heads -T '{rev} {node} {branch}\n'
  2 222ae9789a75703f9836e44de7db179cbfd420ee default
  1 a1602b357cfca067600406eb19060c7128804d72 default
  $ ls -1 .hg/cache/branch?*
  .hg/cache/branch2-base
  .hg/cache/branch2-served
  $ cat .hg/cache/branch?-served
  222ae9789a75703f9836e44de7db179cbfd420ee 2
  a1602b357cfca067600406eb19060c7128804d72 o default
  222ae9789a75703f9836e44de7db179cbfd420ee o default