Hopefully, graphs will never get wider than 32768 characters. (They would get
kind of hard to navigate if they did...)
This reduces the size of the Pipe struct from 48 to 32 bytes, which makes a
significant difference when there are many millions of instances.
This saves some memory at the cost of a slight performance increase (I suppose
reallocting the slice when adding new Pipes is slightly more expensive now).
Performance of the BenchmarkRenderCommitGraph benchmark is 130μs before, 175μs
after. I'm guessing this is still acceptable.
This in itself is not an improvement, because hashes are unique (they are shared
between real commits and rebase todos, but there are so few of those that it
doesn't matter). However, it becomes an improvement once we also store parent
hashes in the same pool; but the real motivation for this change is to also
reuse the hash pointers in Pipe objects later in the branch. This will be a big
win because in a merge-heavy git repo there are many more Pipe instances than
commits.
The "// merge commit" comment was plain wrong, this is any commit that has a
parent, merge or not. The "else if" condition was unnecessary, a plain "else"
would have been enough. But the code in the two blocks was almost identical, so
extract the one thing that was different and unify it.
And while we're at it, use IsFirstCommit() instead of counting parents.
In go 1.22, loop variables are redeclared with each iteration of the
loop, rather than simple updated on each iteration. This means that we
no longer need to manually redeclare variables when they're closed over
by a function.
We upgraded our minimum Go version to 1.21 in commit
57ac9c2189458a7f0e63c2e9cac8334694a3d545. We can now replace our
`utils.Min` and `utils.Max` functions with the built-in `min` and `max`.
Reference: https://go.dev/ref/spec#Min_and_max
Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>
Changing globals in the init() function of a test file is a bad idea, as it
affects all other tests that run after it. Do it explicitly in each test
function that needs it, and take care of restoring the previous value
afterwards.
We've been sometimes using lo and sometimes using my slices package, and we need to pick one
for consistency. Lo is more extensive and better maintained so we're going with that.
My slices package was a superset of go's own slices package so in some places I've just used
the official one (the methods were just wrappers anyway).
I've also moved the remaining methods into the utils package.
The root commit is special in that it has no parents. So we need to add a pipe that's headed for a commit
that doesn't actually exist i.e. the mythical empty tree commit. We're using the actual hash of that
pseudo-commit, but it's not being read anywhere.
