Struct TraceOptions 

#[non_exhaustive]
pub struct TraceOptions {
    pub timings: bool,
    pub changes: bool,
    pub redact: Vec<Path>,
    pub max_bytes: Option<usize>,
}

What a run’s trace records. A run is traced when RunOptions::trace is given these.

use dataflow_rs::observe::TraceOptions;

let opts = TraceOptions::default()
    .timings(true)
    .redact(vec!["data.card".parse().unwrap()])
    .max_bytes(1 << 20);
assert!(opts.changes && opts.timings);

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

timings: bool

Time each call, into its step’s elapsed. false by default: no clock is read for a trace without it.

changes: bool

Record each step’s changes. true by default. A trace records its own changes whatever RunOptions::capture_changes says, which governs only the audit trail, so turning that off cannot empty a debugger’s replay. With false the steps carry statuses and timings, for profiling, and cannot be replayed.

redact: Vec<Path>

Prefixes whose values read null in initial and in every change, applied as each is captured; the message keeps the real values. A change at or below one is recorded as a write of null at it, a removal’s included, so no key below it reaches the trace and a replay reads null there from the first write on. A path that resolves nothing in initial creates nothing there. Empty by default.

It masks values at those paths and nothing else: a step’s errors, like a value derived from a redacted one and written elsewhere, are carried as the message keeps them, so a record whose message quotes a redacted value quotes it in the trace too.

max_bytes: Option<usize>

A ceiling on what the trace holds, on v3’s scale: one machine word per node, plus each string’s and each key’s length, counting initial and every change. The step that would cross it, and every later one, keeps everything but its changes, and Trace::truncated is set. None, the default, is unbounded.

Implementations

impl TraceOptions

pub fn timings(self, on: bool) -> Self

Times each call, or not.

pub fn changes(self, on: bool) -> Self

Records each step’s changes, or not.

pub fn redact(self, paths: Vec<Path>) -> Self

Redacts paths, as the redact field says.

pub fn max_bytes(self, max: usize) -> Self

Bounds the trace at max bytes, as the max_bytes field says.

Trait Implementations

impl Clone for TraceOptions

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for TraceOptions

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for TraceOptions

fn default() -> Self

Returns the “default value” for a type.