Use a clone to allocate BytesStart

[meven]

Was inspired by #41
Using a clone to allocate BytesStart allows to save calling borrowed_name in the loop resulting in some performance improvements:

==>  ./flamegraph/test/perf-iperf-stacks-pidtid-01.txt  <==
Benchmark #1: target/release/inferno-collapse-perf --all ./flamegraph/test/perf-iperf-stacks-pidtid-01.txt
  Time (mean ± σ):      11.3 ms ±   3.1 ms    [User: 9.0 ms, System: 2.4 ms]
  Range (min … max):     4.3 ms …  19.1 ms    189 runs
 
Benchmark #2: target/release/inferno-collapse-perf-origin --all ./flamegraph/test/perf-iperf-stacks-pidtid-01.txt
  Time (mean ± σ):       9.0 ms ±   5.0 ms    [User: 7.1 ms, System: 2.0 ms]
  Range (min … max):     3.5 ms …  19.3 ms    172 runs
 
Summary
  'target/release/inferno-collapse-perf-origin --all ./flamegraph/test/perf-iperf-stacks-pidtid-01.txt' ran
    1.26 ± 0.79 times faster than 'target/release/inferno-collapse-perf --all ./flamegraph/test/perf-iperf-stacks-pidtid-01.txt'


==>  ./flamegraph/test/perf-java-stacks-01.txt  <==
Benchmark #1: target/release/inferno-collapse-perf --all ./flamegraph/test/perf-java-stacks-01.txt
  Time (mean ± σ):       7.9 ms ±   1.5 ms    [User: 5.7 ms, System: 2.2 ms]
  Range (min … max):     2.5 ms …  12.9 ms    877 runs
 
Benchmark #2: target/release/inferno-collapse-perf-origin --all ./flamegraph/test/perf-java-stacks-01.txt
  Time (mean ± σ):       8.5 ms ±   1.3 ms    [User: 6.1 ms, System: 2.3 ms]
  Range (min … max):     7.2 ms …  14.1 ms    238 runs
 
Summary
  'target/release/inferno-collapse-perf --all ./flamegraph/test/perf-java-stacks-01.txt' ran
    1.08 ± 0.26 times faster than 'target/release/inferno-collapse-perf-origin --all ./flamegraph/test/perf-java-stacks-01.txt'


==>  ./flamegraph/test/perf-numa-stacks-01.txt  <==
Benchmark #1: target/release/inferno-collapse-perf --all ./flamegraph/test/perf-numa-stacks-01.txt
  Time (mean ± σ):       8.1 ms ±   1.8 ms    [User: 6.5 ms, System: 1.8 ms]
  Range (min … max):     3.7 ms …  14.3 ms    234 runs
 
Benchmark #2: target/release/inferno-collapse-perf-origin --all ./flamegraph/test/perf-numa-stacks-01.txt
  Time (mean ± σ):       9.6 ms ±   1.3 ms    [User: 7.3 ms, System: 2.4 ms]
  Range (min … max):     4.6 ms …  15.0 ms    288 runs
 
Summary
  'target/release/inferno-collapse-perf --all ./flamegraph/test/perf-numa-stacks-01.txt' ran
    1.18 ± 0.31 times faster than 'target/release/inferno-collapse-perf-origin --all ./flamegraph/test/perf-numa-stacks-01.txt'


==>  ./flamegraph/test/perf-rust-Yamakaky-dcpu.txt  <==
Benchmark #1: target/release/inferno-collapse-perf --all ./flamegraph/test/perf-rust-Yamakaky-dcpu.txt
  Time (mean ± σ):       6.3 ms ±   1.3 ms    [User: 4.7 ms, System: 1.9 ms]
  Range (min … max):     1.6 ms …  10.2 ms    353 runs
 
Benchmark #2: target/release/inferno-collapse-perf-origin --all ./flamegraph/test/perf-rust-Yamakaky-dcpu.txt
  Time (mean ± σ):       6.7 ms ±   1.1 ms    [User: 4.5 ms, System: 2.4 ms]
  Range (min … max):     5.3 ms …  11.6 ms    360 runs
 
Summary
  'target/release/inferno-collapse-perf --all ./flamegraph/test/perf-rust-Yamakaky-dcpu.txt' ran
    1.05 ± 0.27 times faster than 'target/release/inferno-collapse-perf-origin --all ./flamegraph/test/perf-rust-Yamakaky-dcpu.txt'


==>  ./flamegraph/test/perf-vertx-stacks-01.txt  <==
Benchmark #1: target/release/inferno-collapse-perf --all ./flamegraph/test/perf-vertx-stacks-01.txt
  Time (mean ± σ):      33.4 ms ±   6.6 ms    [User: 30.7 ms, System: 2.8 ms]
  Range (min … max):    16.8 ms …  51.0 ms    68 runs
 
Benchmark #2: target/release/inferno-collapse-perf-origin --all ./flamegraph/test/perf-vertx-stacks-01.txt
  Time (mean ± σ):      30.5 ms ±   9.3 ms    [User: 27.7 ms, System: 2.9 ms]
  Range (min … max):    11.2 ms …  47.7 ms    190 runs
 
Summary
  'target/release/inferno-collapse-perf-origin --all ./flamegraph/test/perf-vertx-stacks-01.txt' ran
    1.10 ± 0.40 times faster than 'target/release/inferno-collapse-perf --all ./flamegraph/test/perf-vertx-stacks-01.txt'

[codecov-io]

Codecov Report

Merging #46 into master will increase coverage by 0.02%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master      #46      +/-   ##
==========================================
+ Coverage   82.39%   82.41%   +0.02%     
==========================================
  Files           9        9              
  Lines         869      870       +1     
==========================================
+ Hits          716      717       +1     
  Misses        153      153

Impacted Files	Coverage Δ
src/flamegraph/mod.rs	84.17% <100%> (+0.1%)	⬆️

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[jonhoo]

Hmm, those results don't look like this actually gives a consistent speed-up; isn't it all just lost in the noise? Sadly I think we need tafia/quick-xml#148 for this to actually give a meaningful speed-up :/

[meven]

I agree with you, based on my performance measurement tests, the results are inconsistent and lost in noice.

[jonhoo]

@meven If you want to fix #41 though, maybe you could give writing a PR for tafia/quick-xml#148 a stab though? Should be pretty easy to fix! And then you can properly fix #41 :D