perf: Replace BTreeMap with constant vector in MemoryManager

[frankdavid]

Since we can have maximum 255 memories, we can store those cheaply in a Vec and save time during the lookup.

[github-actions]

canbench 🏋 (dir: .)

Significant performance change detected! ⚠️

./canbench_results.yml is up to date ✅

---------------------------------------------------
Benchmark: btreemap_insert_blob_4_1024
total:
instructions: 487.13 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 123 pages (no change)
---------------------------------------------------
Benchmark: btreemap_insert_blob_4_1024_v2
total:
instructions: 578.28 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 92 pages (no change)
---------------------------------------------------
Benchmark: btreemap_insert_blob_8_1024
total:
instructions: 599.37 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 183 pages (no change)
---------------------------------------------------
Benchmark: btreemap_insert_blob_8_1024_v2
total:
instructions: 695.18 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 138 pages (no change)
---------------------------------------------------
Benchmark: btreemap_insert_blob_16_1024
total:
instructions: 684.01 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 215 pages (no change)
---------------------------------------------------
Benchmark: btreemap_insert_blob_16_1024_v2
total:
instructions: 771.24 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 161 pages (no change)
---------------------------------------------------
Benchmark: btreemap_insert_blob_32_1024
total:
instructions: 716.95 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 230 pages (no change)
---------------------------------------------------
Benchmark: btreemap_insert_blob_32_1024_v2
total:
instructions: 807.74 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 173 pages (no change)
---------------------------------------------------
Benchmark: btreemap_insert_blob_64_1024
total:
instructions: 985.59 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 245 pages (no change)
---------------------------------------------------
Benchmark: btreemap_insert_blob_64_1024_v2
total:
instructions: 1.08 B (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 183 pages (no change)
---------------------------------------------------
Benchmark: btreemap_insert_blob_128_1024
total:
instructions: 1.26 B (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 260 pages (no change)
---------------------------------------------------
Benchmark: btreemap_insert_blob_128_1024_v2
total:
instructions: 1.35 B (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 195 pages (no change)
---------------------------------------------------
Benchmark: btreemap_insert_blob_256_1024
total:
instructions: 1.81 B (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 292 pages (no change)
---------------------------------------------------
Benchmark: btreemap_insert_blob_256_1024_v2
total:
instructions: 1.90 B (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 219 pages (no change)
---------------------------------------------------
Benchmark: btreemap_insert_blob_512_1024
total:
instructions: 2.90 B (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 351 pages (no change)
---------------------------------------------------
Benchmark: btreemap_insert_blob_512_1024_v2
total:
instructions: 2.99 B (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 263 pages (no change)
---------------------------------------------------
Benchmark: btreemap_insert_blob_1024_4
total:
instructions: 4.77 B (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 235 pages (no change)
---------------------------------------------------
Benchmark: btreemap_insert_blob_1024_4_v2
total:
instructions: 4.84 B (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 176 pages (no change)
---------------------------------------------------
Benchmark: btreemap_insert_blob_1024_8
total:
instructions: 4.83 B (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 237 pages (no change)
---------------------------------------------------
Benchmark: btreemap_insert_blob_1024_8_v2
total:
instructions: 4.93 B (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 178 pages (no change)
---------------------------------------------------
Benchmark: btreemap_insert_blob_1024_16
total:
instructions: 4.86 B (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 241 pages (no change)
---------------------------------------------------
Benchmark: btreemap_insert_blob_1024_16_v2
total:
instructions: 4.94 B (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 181 pages (no change)
---------------------------------------------------
Benchmark: btreemap_insert_blob_1024_32
total:
instructions: 4.87 B (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 239 pages (no change)
---------------------------------------------------
Benchmark: btreemap_insert_blob_1024_32_v2
total:
instructions: 4.96 B (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 180 pages (no change)
---------------------------------------------------
Benchmark: btreemap_insert_blob_1024_64
total:
instructions: 4.89 B (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 250 pages (no change)
---------------------------------------------------
Benchmark: btreemap_insert_blob_1024_64_v2
total:
instructions: 4.98 B (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 188 pages (no change)
---------------------------------------------------
Benchmark: btreemap_insert_blob_1024_128
total:
instructions: 4.87 B (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 262 pages (no change)
---------------------------------------------------
Benchmark: btreemap_insert_blob_1024_128_v2
total:
instructions: 4.96 B (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 196 pages (no change)
---------------------------------------------------
Benchmark: btreemap_insert_blob_1024_256
total:
instructions: 4.90 B (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 292 pages (no change)
---------------------------------------------------
Benchmark: btreemap_insert_blob_1024_256_v2
total:
instructions: 4.99 B (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 219 pages (no change)
---------------------------------------------------
Benchmark: btreemap_insert_blob_1024_512
total:
instructions: 4.98 B (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 348 pages (no change)
---------------------------------------------------
Benchmark: btreemap_insert_blob_1024_512_v2
total:
instructions: 5.07 B (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 261 pages (no change)
---------------------------------------------------
Benchmark: btreemap_insert_blob_1024_512_v2_mem_manager
total:
instructions: 6.19 B (-1.66%) (change within noise threshold)
heap_increase: 0 pages (no change)
stable_memory_increase: 256 pages (no change)
---------------------------------------------------
Benchmark: btreemap_insert_u64_u64
total:
instructions: 342.61 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 7 pages (no change)
---------------------------------------------------
Benchmark: btreemap_insert_u64_u64_mem_manager
total:
instructions: 937.85 M (improved by 8.02%)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_insert_u64_u64_v2
total:
instructions: 421.50 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 6 pages (no change)
---------------------------------------------------
Benchmark: btreemap_insert_u64_blob_8
total:
instructions: 336.80 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 7 pages (no change)
---------------------------------------------------
Benchmark: btreemap_insert_u64_blob_8_v2
total:
instructions: 412.64 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 5 pages (no change)
---------------------------------------------------
Benchmark: btreemap_insert_blob_8_u64
total:
instructions: 324.57 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 6 pages (no change)
---------------------------------------------------
Benchmark: btreemap_insert_blob_8_u64_v2
total:
instructions: 429.53 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 4 pages (no change)
---------------------------------------------------
Benchmark: btreemap_insert_10mib_values
total:
instructions: 5.25 B (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 3613 pages (no change)
---------------------------------------------------
Benchmark: btreemap_read_keys_from_range
total:
instructions: 82.93 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_read_every_third_value_from_range
total:
instructions: 82.89 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_iter_small_values
total:
instructions: 13.53 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_iter_rev_small_values
total:
instructions: 13.49 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_iter_10mib_values
total:
instructions: 11.39 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_iter_rev_10mib_values
total:
instructions: 11.38 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_keys_small_values
total:
instructions: 9.50 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_keys_rev_small_values
total:
instructions: 9.65 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_keys_10mib_values
total:
instructions: 465.91 K (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_keys_rev_10mib_values
total:
instructions: 465.79 K (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_values_small_values
total:
instructions: 14.66 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_values_rev_small_values
total:
instructions: 14.65 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_values_10mib_values
total:
instructions: 11.41 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_values_rev_10mib_values
total:
instructions: 11.41 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_iter_count_small_values
total:
instructions: 9.37 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_iter_count_10mib_values
total:
instructions: 475.84 K (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_remove_blob_4_1024
total:
instructions: 473.56 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_remove_blob_4_1024_v2
total:
instructions: 580.94 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_remove_blob_8_1024
total:
instructions: 624.82 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_remove_blob_8_1024_v2
total:
instructions: 748.81 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_remove_blob_16_1024
total:
instructions: 793.42 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_remove_blob_16_1024_v2
total:
instructions: 921.05 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_remove_blob_32_1024
total:
instructions: 854.24 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_remove_blob_32_1024_v2
total:
instructions: 983.72 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_remove_blob_64_1024
total:
instructions: 1.18 B (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_remove_blob_64_1024_v2
total:
instructions: 1.31 B (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_remove_blob_128_1024
total:
instructions: 1.51 B (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_remove_blob_128_1024_v2
total:
instructions: 1.65 B (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_remove_blob_256_1024
total:
instructions: 2.15 B (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_remove_blob_256_1024_v2
total:
instructions: 2.28 B (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_remove_blob_512_1024
total:
instructions: 3.50 B (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_remove_blob_512_1024_v2
total:
instructions: 3.62 B (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_remove_u64_u64
total:
instructions: 491.36 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_remove_u64_u64_v2
total:
instructions: 609.10 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_remove_u64_blob_8
total:
instructions: 478.20 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_remove_u64_blob_8_v2
total:
instructions: 586.70 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_remove_blob_8_u64
total:
instructions: 425.35 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_remove_blob_8_u64_v2
total:
instructions: 566.09 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_get_blob_4_1024
total:
instructions: 180.84 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_get_blob_4_1024_v2
total:
instructions: 263.11 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_get_blob_8_1024
total:
instructions: 213.47 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_get_blob_8_1024_v2
total:
instructions: 293.54 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_get_blob_16_1024
total:
instructions: 294.73 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_get_blob_16_1024_v2
total:
instructions: 367.05 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_get_blob_32_1024
total:
instructions: 322.88 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_get_blob_32_1024_v2
total:
instructions: 398.14 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_get_blob_64_1024
total:
instructions: 572.51 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_get_blob_64_1024_v2
total:
instructions: 649.84 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_get_blob_128_1024
total:
instructions: 821.16 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_get_blob_128_1024_v2
total:
instructions: 899.57 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_get_blob_256_1024
total:
instructions: 1.32 B (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_get_blob_256_1024_v2
total:
instructions: 1.40 B (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_get_blob_512_1024
total:
instructions: 2.33 B (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_get_blob_512_1024_v2
total:
instructions: 2.41 B (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_get_blob_512_1024_v2_mem_manager
total:
instructions: 3.09 B (improved by 2.24%)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_get_u64_u64
total:
instructions: 177.27 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_get_u64_u64_v2
total:
instructions: 255.49 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_get_u64_u64_v2_mem_manager
total:
instructions: 619.04 M (improved by 8.12%)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_get_u64_blob_8
total:
instructions: 176.51 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_get_u64_blob_8_v2
total:
instructions: 248.72 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_get_blob_8_u64
total:
instructions: 196.93 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: btreemap_get_blob_8_u64_v2
total:
instructions: 291.58 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: memory_manager_baseline
total:
instructions: 1.18 B (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 8000 pages (no change)
---------------------------------------------------
Benchmark: memory_manager_overhead
total:
instructions: 1.18 B (-0.01%) (change within noise threshold)
heap_increase: 0 pages (no change)
stable_memory_increase: 8320 pages (no change)
---------------------------------------------------
Benchmark: memory_manager_grow
total:
instructions: 346.63 M (-0.79%) (change within noise threshold)
heap_increase: 2 pages (no change)
stable_memory_increase: 32.00 K pages (no change)
---------------------------------------------------
Benchmark: vec_insert_blob_4
total:
instructions: 3.29 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: vec_insert_blob_8
total:
instructions: 3.32 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 1 pages (no change)
---------------------------------------------------
Benchmark: vec_insert_blob_16
total:
instructions: 3.38 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 2 pages (no change)
---------------------------------------------------
Benchmark: vec_insert_blob_32
total:
instructions: 3.50 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 5 pages (no change)
---------------------------------------------------
Benchmark: vec_insert_blob_64
total:
instructions: 3.74 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 9 pages (no change)
---------------------------------------------------
Benchmark: vec_insert_blob_128
total:
instructions: 4.21 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 19 pages (no change)
---------------------------------------------------
Benchmark: vec_insert_u64
total:
instructions: 5.93 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 1 pages (no change)
---------------------------------------------------
Benchmark: vec_get_blob_4
total:
instructions: 4.87 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: vec_get_blob_4_mem_manager
total:
instructions: 12.86 M (improved by 11.19%)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: vec_get_blob_8
total:
instructions: 5.67 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: vec_get_blob_16
total:
instructions: 8.05 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: vec_get_blob_32
total:
instructions: 8.64 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: vec_get_blob_64
total:
instructions: 12.96 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: vec_get_blob_64_mem_manager
total:
instructions: 22.53 M (improved by 6.71%)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: vec_get_blob_128
total:
instructions: 17.96 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------
Benchmark: vec_get_u64
total:
instructions: 5.39 M (no change)
heap_increase: 0 pages (no change)
stable_memory_increase: 0 pages (no change)
---------------------------------------------------

[dsarlis]

I am not entirely sure about this change. It works well maybe now that we can only allocate new memories but what if we finally merge the change which allows to free a memory? Wouldn't that nullify the benefits of using a vector?

EDIT: I'm talking about the open PR on freeing a memory where I'm expecting a memory_buckets.remove(&id) to appear somewhere. How would that look like using a vec?

[frankdavid]

Wouldn't that nullify the benefits of using a vector?

If you think we'd need to delete elements from the middle of the vector, that's not the case. We'll never delete elements from the outer Vec in Vec<Vec<BucketId>>. The outer Vec always has 255 elements (it could also be a fixed-size array, I'm using a Vec to keep the struct's size relatively low, thus cheap to move). When a memory is empty, the corresponding inner Vec will be empty. For example if memory with id 32 is empty, memories[32].is_empty() returns true.

We can remove a memory by simply taking its contents, eg:
std::mem::take(memories[32]) which returns the Vec of BucketIds that were in the memory and leaves an empty Vec behind. Or we can call memories[32].clear() to simply clear all buckets from it.

If this is confusing to read, I could wrap the whole thing into a struct which would have a similar API like stdlib BTreeMap but with the performance benefits of a linear Vec. I think the performance benefits are worth it - in multiple benchmarks it's 4-7% improvement and it's a fairly trivial change.

[dsarlis]

Wouldn't that nullify the benefits of using a vector?

If you think we'd need to delete elements from the middle of the vector, that's not the case. We'll never delete elements from the outer Vec in Vec<Vec<BucketId>>. The outer Vec always has 255 elements (it could also be a fixed-size array, I'm using a Vec to keep the struct's size relatively low, thus cheap to move). When a memory is empty, the corresponding inner Vec will be empty. For example if memory with id 32 is empty, memories[32].is_empty() returns true.

We can remove a memory by simply taking its contents, eg: std::mem::take(memories[32]) which returns the Vec of BucketIds that were in the memory and leaves an empty Vec behind. Or we can call memories[32].clear() to simply clear all buckets from it.

If this is confusing to read, I could wrap the whole thing into a struct which would have a similar API like stdlib BTreeMap but with the performance benefits of a linear Vec. I think the performance benefits are worth it - in multiple benchmarks it's 4-7% improvement and it's a fairly trivial change.

I see, yeah I was thinking we might need to remove in the middle of the vector but I get your point. In this case, I agree the change is beneficial.

[dragoljub-djuric]

@frankdavid nice change, thank you. I approve this change, but can we please wait for the memory freeing to first be merged, we have a couple of stacked PRs, and I hope that can be done next week. And after that, I will put a stamp here. Does that sound fine?

[frankdavid]

Sure, no problem.

[dragoljub-djuric]

Hey @frankdavid just an update, I believe the work on the memory manager will take more time than initially assumed, so please go forward and merge this PR if you think it is ready.

[frankdavid]

After merging recent changes from master, I no longer see significant performance improvements from this change, so I won't move forward with this PR for now.

[frankdavid]

After studying our code more, I realized that we didn't have any benchmarks that properly exercised the MemoryManager, that's why we didn't see any improvements. A few new benchmarks were added in #253 and now the effect of this PR is visible (see benchmarks with _mem_manager suffix)