Mercurial > hg
view tests/test-stack.t @ 47965:f9e6f2bb721d
rhg: Don’t compare ambiguous files one byte at a time
Even though the use of `BufReader` reduces the number of syscalls to read
the file from disk, `.bytes()` yields a separate `Result` for every byte.
Creating those results and dispatching on them is most likely costly.
Instead, this commit opts for simplicity by reading the entire file into memory
and comparing a single pair of byte strings. Note that memory already needs to
contain the entire previous contents of the file, as read from the filelog.
So with an extremely large file this doubles memory use but does not make it
grow by orders of magnitude.
At first I wrote code that still avoids reading the entire file into memory
and compares one buffer at a time with `BufReader`. Find this code below for
posterity. However its correctness is subtle. I ended up preferring the
simplicity of the obviously-correct single comparison.
```rust
let mut reader = BufReader::new(fobj);
let mut expected = &contents_in_p1[..];
loop {
let buf = reader.fill_buf().when_reading_file(&fs_path)?;
if buf.is_empty() {
// Found EOF
return Ok(expected.is_empty());
} else if let Some(rest) = expected.drop_prefix(buf) {
// What we read so far matches the expected content, continue reading
let buf_len = buf.len();
reader.consume(buf_len);
expected = rest
} else {
// Found different content
return Ok(false);
}
}
```
Differential Revision: https://phab.mercurial-scm.org/D11412
author | Simon Sapin <simon.sapin@octobus.net> |
---|---|
date | Mon, 13 Sep 2021 18:48:48 +0200 |
parents | 68fcc5503ec5 |
children |
line wrap: on
line source
This test test the low-level definition of stack, agnostic from all formatting Initial setup $ cat << EOF >> $HGRCPATH > [ui] > logtemplate = {rev} {branch} {phase} {desc|firstline}\n > [extensions] > rebase= > [experimental] > evolution=createmarkers,exchange,allowunstable > EOF $ hg init main $ cd main $ hg branch other marked working directory as branch other (branches are permanent and global, did you want a bookmark?) $ echo aaa > aaa $ hg add aaa $ hg commit -m c_a $ echo aaa > bbb $ hg add bbb $ hg commit -m c_b $ hg branch foo marked working directory as branch foo $ echo aaa > ccc $ hg add ccc $ hg commit -m c_c $ echo aaa > ddd $ hg add ddd $ hg commit -m c_d $ echo aaa > eee $ hg add eee $ hg commit -m c_e $ echo aaa > fff $ hg add fff $ hg commit -m c_f $ hg log -G @ 5 foo draft c_f | o 4 foo draft c_e | o 3 foo draft c_d | o 2 foo draft c_c | o 1 other draft c_b | o 0 other draft c_a Check that stack doesn't include public changesets -------------------------------------------------- $ hg up other 0 files updated, 0 files merged, 4 files removed, 0 files unresolved $ hg log -G -r "stack()" @ 1 other draft c_b | o 0 other draft c_a $ hg phase --public 'branch("other")' $ hg log -G -r "stack()" $ hg up foo 4 files updated, 0 files merged, 0 files removed, 0 files unresolved Simple test ----------- 'stack()' list all changeset in the branch $ hg branch foo $ hg log -G -r "stack()" @ 5 foo draft c_f | o 4 foo draft c_e | o 3 foo draft c_d | o 2 foo draft c_c | ~ Case with some of the branch unstable ------------------------------------ $ hg up 3 0 files updated, 0 files merged, 2 files removed, 0 files unresolved $ echo bbb > ddd $ hg commit --amend 2 new orphan changesets $ hg log -G @ 6 foo draft c_d | | * 5 foo draft c_f | | | * 4 foo draft c_e | | | x 3 foo draft c_d |/ o 2 foo draft c_c | o 1 other public c_b | o 0 other public c_a $ hg log -G -r "stack()" @ 6 foo draft c_d | ~ $ hg up -r "desc(c_e)" 2 files updated, 0 files merged, 0 files removed, 0 files unresolved $ hg log -G -r "stack()" @ 4 foo draft c_e | x 3 foo draft c_d | ~ $ hg up -r "desc(c_d)" 1 files updated, 0 files merged, 1 files removed, 0 files unresolved $ hg log -G -r "stack()" @ 6 foo draft c_d | ~ Case with multiple topological heads ------------------------------------ Make things linear again $ hg rebase -s 'desc(c_e)' -d 'desc(c_d) - obsolete()' rebasing 4:4f2a69f6d380 "c_e" rebasing 5:913c298d8b0a "c_f" $ hg log -G o 8 foo draft c_f | o 7 foo draft c_e | @ 6 foo draft c_d | o 2 foo draft c_c | o 1 other public c_b | o 0 other public c_a Create the second branch $ hg up 'desc(c_d)' 0 files updated, 0 files merged, 0 files removed, 0 files unresolved $ echo aaa > ggg $ hg add ggg $ hg commit -m c_g created new head $ echo aaa > hhh $ hg add hhh $ hg commit -m c_h $ hg log -G @ 10 foo draft c_h | o 9 foo draft c_g | | o 8 foo draft c_f | | | o 7 foo draft c_e |/ o 6 foo draft c_d | o 2 foo draft c_c | o 1 other public c_b | o 0 other public c_a Test output $ hg log -G -r "stack(10)" @ 10 foo draft c_h | o 9 foo draft c_g | ~ $ hg log -G -r "stack(8)" o 8 foo draft c_f | o 7 foo draft c_e | ~ $ hg log -G -r "stack(head())" @ 10 foo draft c_h | o 9 foo draft c_g | ~ o 8 foo draft c_f | o 7 foo draft c_e | ~ Check the stack order $ hg log -r "first(stack())" 9 foo draft c_g $ hg log -r "first(stack(10))" 9 foo draft c_g $ hg log -r "first(stack(8))" 7 foo draft c_e $ hg log -r "first(stack(head()))" 7 foo draft c_e Case with multiple heads with unstability involved -------------------------------------------------- We amend the message to make sure the display base pick the right changeset $ hg up 'desc(c_d)' 0 files updated, 0 files merged, 2 files removed, 0 files unresolved $ echo ccc > ddd $ hg commit --amend -m 'c_D' 4 new orphan changesets $ hg rebase -d . -s 'desc(c_g)' rebasing 9:2ebb6e48ab8a "c_g" rebasing 10:634f38e27a1d "c_h" $ hg log -G o 13 foo draft c_h | o 12 foo draft c_g | @ 11 foo draft c_D | | * 8 foo draft c_f | | | * 7 foo draft c_e | | | x 6 foo draft c_d |/ o 2 foo draft c_c | o 1 other public c_b | o 0 other public c_a We should improve stack definition to also show 12 and 13 here $ hg log -G -r "stack()" @ 11 foo draft c_D | ~