view tests/test-remotefilelog-clone-tree.t @ 49000:dd6b67d5c256 stable

rust: fix unsound `OwningDirstateMap` As per the previous patch, `OwningDirstateMap` is unsound. Self-referential structs are difficult to implement correctly in Rust since the compiler is free to move structs around as much as it wants to. They are also very rarely needed in practice, so the state-of-the-art on how they should be done within the Rust rules is still a bit new. The crate `ouroboros` is an attempt at providing a safe way (in the Rust sense) of declaring self-referential structs. It is getting a lot attention and was improved very quickly when soundness issues were found in the past: rather than relying on our own (limited) review circle, we might as well use the de-facto common crate to fix this problem. This will give us a much better chance of finding issues should any new ones be discovered as well as the benefit of fewer `unsafe` APIs of our own. I was starting to think about how I would present a safe API to the old struct but soon realized that the callback-based approach was already done in `ouroboros`, along with a lot more care towards refusing incorrect structs. In short: we don't return a mutable reference to the `DirstateMap` anymore, we expect users of its API to pass a `FnOnce` that takes the map as an argument. This allows our `OwningDirstateMap` to control the input and output lifetimes of the code that modifies it to prevent such issues. Changing to `ouroboros` meant changing every API with it, but it is relatively low churn in the end. It correctly identified the example buggy modification of `copy_map_insert` outlined in the previous patch as violating the borrow rules. Differential Revision: https://phab.mercurial-scm.org/D12429
author Raphaël Gomès <rgomes@octobus.net>
date Tue, 05 Apr 2022 10:55:28 +0200
parents 7ee07e1a25c0
children dcaa2df1f688
line wrap: on
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#require no-windows

  $ . "$TESTDIR/remotefilelog-library.sh"

  $ hg init master
  $ cd master
  $ echo treemanifest >> .hg/requires
  $ cat >> .hg/hgrc <<EOF
  > [remotefilelog]
  > server=True
  > EOF
# uppercase directory name to test encoding
  $ mkdir -p A/B
  $ echo x > A/B/x
  $ hg commit -qAm x

  $ cd ..

# shallow clone from full

  $ hgcloneshallow ssh://user@dummy/master shallow --noupdate
  streaming all changes
  4 files to transfer, 449 bytes of data
  transferred 449 bytes in * seconds (*/sec) (glob)
  searching for changes
  no changes found
  $ cd shallow
  $ hg debugrequires
  dotencode
  dirstate-v2 (dirstate-v2 !)
  exp-remotefilelog-repo-req-1
  fncache
  generaldelta
  persistent-nodemap (rust !)
  revlog-compression-zstd (zstd !)
  revlogv1
  share-safe
  sparserevlog
  store
  treemanifest
  $ find .hg/store/meta | sort
  .hg/store/meta
  .hg/store/meta/_a
  .hg/store/meta/_a/00manifest.i
  .hg/store/meta/_a/_b
  .hg/store/meta/_a/_b/00manifest.i

  $ hg update
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over *s (glob)

  $ cat A/B/x
  x

  $ ls .hg/store/data
  $ echo foo > A/B/F
  $ hg add A/B/F
  $ hg ci -m 'local content'
  $ ls .hg/store/data
  ca31988f085bfb945cb8115b78fabdee40f741aa

  $ cd ..

# shallow clone from shallow

  $ hgcloneshallow ssh://user@dummy/shallow shallow2  --noupdate
  streaming all changes
  5 files to transfer, 1008 bytes of data
  transferred 1008 bytes in * seconds (*/sec) (glob)
  searching for changes
  no changes found
  $ cd shallow2
  $ hg debugrequires
  dotencode
  dirstate-v2 (dirstate-v2 !)
  exp-remotefilelog-repo-req-1
  fncache
  generaldelta
  persistent-nodemap (rust !)
  revlog-compression-zstd (zstd !)
  revlogv1
  share-safe
  sparserevlog
  store
  treemanifest
  $ ls .hg/store/data
  ca31988f085bfb945cb8115b78fabdee40f741aa

  $ hg update
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ cat A/B/x
  x

  $ cd ..

# full clone from shallow
# - send stderr to /dev/null because the order of stdout/err causes
#   flakiness here
  $ hg clone --noupdate ssh://user@dummy/shallow full 2>/dev/null
  streaming all changes
  [100]

# getbundle full clone

  $ printf '[server]\npreferuncompressed=False\n' >> master/.hg/hgrc
  $ hgcloneshallow ssh://user@dummy/master shallow3
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 0 changes to 0 files
  new changesets 18d955ee7ba0
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ ls shallow3/.hg/store/data
  $ hg debugrequires -R shallow3/
  dotencode
  dirstate-v2 (dirstate-v2 !)
  exp-remotefilelog-repo-req-1
  fncache
  generaldelta
  persistent-nodemap (rust !)
  revlog-compression-zstd (zstd !)
  revlogv1
  share-safe
  sparserevlog
  store
  treemanifest