i have successfully made

get_snapshot_subset()

much faster:

X> ./build-support/bin/native/cargo bench --manifest-path=src/rust/engine/Cargo.toml --package store -- snapshot_subset
   Compiling store v0.1.0 (/Users/dmcclanahan/tools/p1/src/rust/engine/fs/store)
    Finished bench [optimized] target(s) in 1m 03s
     Running src/rust/engine/target/release/deps/store-19b7787f9cbb94ca

running 0 tests

test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 103 filtered out

     Running src/rust/engine/target/release/deps/store-d540c519942f9006
Gnuplot not found, using plotters backend
Benchmarking snapshot_subset/snapshot_subset: Collecting 10 samples in estimated                                                                                  snapshot_subset/snapshot_subset
                        time:   [317.30 ms 323.56 ms 329.23 ms]
                        change: [-67.082% -66.265% -65.349%] (p = 0.00 < 0.05)
                        Performance has improved.

Incredible!! Thank you! This will have a real impact on every day users

i think that tracing via zipkin possibly could have been used to infer this, but it would have to be in between rust methods. not a priority because profiling found this one relatively easily though!