feature | weaselab | fdb |
|-|-|-|
|based on|node-copying treap|node-copying treap|
|bytes per node (worst-case)|64 + kv len + 1\*|96 + kv len|
|cheaper iteration*|❌|✅|
|efficient bulk queries|✅|❌|
|entries per set (worst-case)|1|3|
|memory-usage (rough)|%40|%100|
|node gc|mark-and-sweep|reference-counting|
|pointer size|32-bit|64-bit|
|purge strategy|scan|search|
|read from foreign thread|✅ |❌ |
|recursion-free|✅ |❌|
|returns node memory to OS|✅ |❌|
|searches per point clear|1|5|
|searches per range clear|2|5|
|searches per set (worst-case)|1|4|

\* Part of a set of tradeoffs that enable 1 entry per set worst-case

# benchmarks

## weaselab

|               ns/op |                op/s |    err% |     total | benchmark
|--------------------:|--------------------:|--------:|----------:|:----------
|            1,537.31 |          650,485.22 |    2.0% |      0.21 | `monotonically increasing`
|                1.25 |      798,963,102.97 |    0.1% |      0.01 | `*iter`
|               38.71 |       25,831,420.46 |    3.2% |      0.01 | `++iter`
|               37.31 |       26,801,664.98 |    0.3% |      0.01 | `--iter`
|              133.17 |        7,508,978.37 |    2.8% |      0.02 | `begin`
|              129.51 |        7,721,547.35 |    0.4% |      0.02 | `begin (firstGeq)`
|               54.40 |       18,381,173.00 |    1.2% |      0.01 | `end`
|              245.34 |        4,075,961.09 |    1.1% |      0.01 | `bulkFirstGeq`

## fdb

|               ns/op |                op/s |    err% |     total | benchmark
|--------------------:|--------------------:|--------:|----------:|:----------
|            2,244.65 |          445,503.99 |    1.3% |      0.29 | `monotonically increasing`
|                2.06 |      486,311,738.92 |    0.3% |      0.01 | `*iter`
|               12.53 |       79,826,977.13 |    0.4% |      0.01 | `++iter`
|                8.86 |      112,927,293.80 |    1.3% |      0.01 | `--iter`
|               89.27 |       11,201,505.02 |    0.7% |      0.01 | `begin`
|              144.38 |        6,926,060.07 |    2.9% |      0.02 | `begin (firstGeq)`
|               71.84 |       13,920,283.88 |    0.4% |      0.01 | `end`
|              412.10 |        2,426,597.75 |    0.2% |      0.01 | `bulkFirstGeq`