Allow looking up "crate paths" in map without allocating a vector

[yotamofek]

I just wanna see if this shows up on perf. If it doesn't then it's not worth the extra complexity.

(and I'm pretty skeptical it will show up on perf, but I've already spent some time on this so worth a shot...)

[yotamofek]

@bors try @rust-timer queue

[rust-bors]

☀️ Try build successful (CI)
Build commit: bbf33d6 (bbf33d6f8043e8958ec9015a15bfba5f852969b9, parent: c90bcb9571b7aab0d8beaa2ce8a998ffaf079d38)

[rust-timer]

Finished benchmarking commit (bbf33d6): comparison URL.

Overall result: ✅ improvements - no action needed

Benchmarking this pull request means it may be perf-sensitive – we'll automatically label it not fit for rolling up. You can override this, but we strongly advise not to, due to possible changes in compiler perf.

@bors rollup=never
@rustbot label: -S-waiting-on-perf -perf-regression

Instruction count

Our most reliable metric. Used to determine the overall result above. However, even this metric can be noisy.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.2%	[-0.2%, -0.1%]	3
Improvements ✅ (secondary)	-0.2%	[-0.2%, -0.2%]	1
All ❌✅ (primary)	-0.2%	[-0.2%, -0.1%]	3

Max RSS (memory usage)

Results (primary 0.8%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	0.8%	[0.8%, 0.8%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.8%	[0.8%, 0.8%]	1

Cycles

Results (secondary 2.8%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	2.8%	[2.8%, 2.8%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 475.185s -> 476.216s (0.22%)
Artifact size: 390.81 MiB -> 390.78 MiB (-0.01%)

[rustbot]

r? @GuillaumeGomez

rustbot has assigned @GuillaumeGomez.
They will have a look at your PR within the next two weeks and either review your PR or reassign to another reviewer.

Use r? to explicitly pick a reviewer

[yotamofek]

Perf was a happy surprise :)
I think it's worth the small added complexity.