use btreemap for type_map and release

[chenyan-dfinity]

Looking from the encoding flamegraph, with a large type table, the encoder spends a lot of time in hashbrown::raw::RawTable::reserve_rehash. Changing the data structure from HashMap to BTreeMap significantly improves the performance. Another reason for the improvement is that comparing the type AST is usually cheaper than hashing the type AST.

This PR also disables the memoization to unroll types. Type table can now be slightly larger, but saves a lot of time in encoding.

For list_proposal benchmark, encoding cost comes down from 19M to 10M. Further down to 6M after disabling type unrolling.

[github-actions]

Name	Max Mem (Kb)	Encode	Decode
blob	4_224	20_458_812 ($\textcolor{green}{-0.03\%}$)	12_083_520 ($\textcolor{green}{-0.01\%}$)
btreemap	75_456	4_814_024_296 ($\textcolor{green}{-0.00\%}$)	15_380_030_660 ($\textcolor{green}{-0.00\%}$)
nns	192	2_172_806 ($\textcolor{green}{-4.57\%}$)	12_210_232 ($\textcolor{green}{-14.86\%}$)
nns_list_proposal	1_920 ($\textcolor{red}{11.11\%}$)	6_636_110 ($\textcolor{green}{-65.58\%}$)	182_353_563 ($\textcolor{red}{0.13\%}$)
option_list	576	7_436_043 ($\textcolor{red}{1.71\%}$)	31_705_099 ($\textcolor{green}{-6.34\%}$)
text	6_336	28_844_735 ($\textcolor{green}{-0.01\%}$)	17_839_178 ($\textcolor{green}{-0.00\%}$)
variant_list	128	7_431_973 ($\textcolor{green}{-1.15\%}$)	23_873_932 ($\textcolor{green}{-6.32\%}$)
vec_int16	16_704	168_581_831 ($\textcolor{green}{-0.01\%}$)	1_031_829_277 ($\textcolor{green}{-0.00\%}$)

• Parser cost: 18_351_038
• Extra args: 3_348_203 ($\textcolor{green}{-0.54\%}$)

Click to see raw report

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Benchmark: blob
  total:
    instructions: 32.54 M (-0.02%) (change within noise threshold)
    heap_increase: 66 pages (no change)
    stable_memory_increase: 0 pages (no change)

  1. Encoding (scope):
    instructions: 20.46 M (-0.03%) (change within noise threshold)
    heap_increase: 66 pages (no change)
    stable_memory_increase: 0 pages (no change)

  2. Decoding (scope):
    instructions: 12.08 M (-0.01%) (change within noise threshold)
    heap_increase: 0 pages (no change)
    stable_memory_increase: 0 pages (no change)

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Benchmark: text
  total:
    instructions: 46.69 M (-0.01%) (change within noise threshold)
    heap_increase: 99 pages (no change)
    stable_memory_increase: 0 pages (no change)

  1. Encoding (scope):
    instructions: 28.84 M (-0.01%) (change within noise threshold)
    heap_increase: 99 pages (no change)
    stable_memory_increase: 0 pages (no change)

  2. Decoding (scope):
    instructions: 17.84 M (-0.00%) (change within noise threshold)
    heap_increase: 0 pages (no change)
    stable_memory_increase: 0 pages (no change)

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Benchmark: vec_int16
  total:
    instructions: 1.20 B (-0.00%) (change within noise threshold)
    heap_increase: 261 pages (no change)
    stable_memory_increase: 0 pages (no change)

  1. Encoding (scope):
    instructions: 168.58 M (-0.01%) (change within noise threshold)
    heap_increase: 261 pages (no change)
    stable_memory_increase: 0 pages (no change)

  2. Decoding (scope):
    instructions: 1.03 B (-0.00%) (change within noise threshold)
    heap_increase: 0 pages (no change)
    stable_memory_increase: 0 pages (no change)

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Benchmark: btreemap
  total:
    instructions: 20.19 B (-0.00%) (change within noise threshold)
    heap_increase: 1179 pages (no change)
    stable_memory_increase: 0 pages (no change)

  1. Encoding (scope):
    instructions: 4.81 B (-0.00%) (change within noise threshold)
    heap_increase: 257 pages (no change)
    stable_memory_increase: 0 pages (no change)

  2. Decoding (scope):
    instructions: 15.38 B (-0.00%) (change within noise threshold)
    heap_increase: 922 pages (no change)
    stable_memory_increase: 0 pages (no change)

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Benchmark: option_list
  total:
    instructions: 39.14 M (improved by 4.91%)
    heap_increase: 9 pages (no change)
    stable_memory_increase: 0 pages (no change)

  1. Encoding (scope):
    instructions: 7.44 M (1.71%) (change within noise threshold)
    heap_increase: 0 pages (no change)
    stable_memory_increase: 0 pages (no change)

  2. Decoding (scope):
    instructions: 31.71 M (improved by 6.34%)
    heap_increase: 9 pages (no change)
    stable_memory_increase: 0 pages (no change)

---------------------------------------------------

Benchmark: variant_list
  total:
    instructions: 31.31 M (improved by 5.14%)
    heap_increase: 2 pages (no change)
    stable_memory_increase: 0 pages (no change)

  1. Encoding (scope):
    instructions: 7.43 M (-1.15%) (change within noise threshold)
    heap_increase: 0 pages (no change)
    stable_memory_increase: 0 pages (no change)

  2. Decoding (scope):
    instructions: 23.87 M (improved by 6.32%)
    heap_increase: 2 pages (no change)
    stable_memory_increase: 0 pages (no change)

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Benchmark: nns
  total:
    instructions: 33.48 M (improved by 6.27%)
    heap_increase: 3 pages (no change)
    stable_memory_increase: 0 pages (no change)

  0. Parsing (scope):
    instructions: 18.35 M (no change)
    heap_increase: 3 pages (no change)
    stable_memory_increase: 0 pages (no change)

  1. Encoding (scope):
    instructions: 2.17 M (improved by 4.57%)
    heap_increase: 0 pages (no change)
    stable_memory_increase: 0 pages (no change)

  2. Decoding (scope):
    instructions: 12.21 M (improved by 14.86%)
    heap_increase: 0 pages (no change)
    stable_memory_increase: 0 pages (no change)

---------------------------------------------------

Benchmark: nns_list_proposal
  total:
    instructions: 188.99 M (improved by 6.16%)
    heap_increase: 30 pages (regressed by 11.11%)
    stable_memory_increase: 0 pages (no change)

  1. Encoding (scope):
    instructions: 6.64 M (improved by 65.58%)
    heap_increase: 5 pages (improved by 16.67%)
    stable_memory_increase: 0 pages (no change)

  2. Decoding (scope):
    instructions: 182.35 M (0.13%) (change within noise threshold)
    heap_increase: 25 pages (regressed by 19.05%)
    stable_memory_increase: 0 pages (no change)

---------------------------------------------------

Benchmark: extra_args
  total:
    instructions: 3.35 M (-0.54%) (change within noise threshold)
    heap_increase: 0 pages (no change)
    stable_memory_increase: 0 pages (no change)

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Successfully persisted results to canbench_results.yml