Trait IoStatsRecorder 

pub trait IoStatsRecorder:
    Debug
    + Send
    + Sync {
    // Required method
    fn record_request(&self, ranges: &[Range<u64>]);
}

A sink that records I/O requests as they are submitted to storage.

This lives in lance-core so that the encoding layer (lance-encoding) and the I/O layer (lance-io) can both refer to it without depending on one another. It lets a caller attach a lightweight counter to a file reader and measure the exact bytes/IOPS performed for a bounded scope (e.g. a single query); see lance_io::scheduler::IoStats for the concrete implementation.

When to use this

Lance also exposes two process-wide, cumulative I/O accounting facilities: the global scheduler counters (lance_io::scheduler::iops_counter / bytes_read_counter) and the object-store IOTracker wrapper used in tests. Both aggregate every read in the process and cannot attribute I/O to a single bounded scope. Prefer an IoStatsRecorder when you need the exact I/O of one operation (e.g. a single query): attach it to a reader with with_io_stats, then read the snapshot when the scope ends. It re-uses the reader’s cached metadata, so measuring costs no extra file opens and does not disturb the global counters.

Required Methods

fn record_request(&self, ranges: &[Range<u64>])

Record one completed request, given the byte ranges as actually submitted to storage (i.e. after any coalescing/splitting), so the counts reflect physical I/O.

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors