Enum JsonField 

#[non_exhaustive]
pub enum JsonField<'a> {
    Value(&'a Value),
    Missing(SnapshotError),
}

One value’s view at the leaf of a dotted-path walk over a serde_json::Value. Returned by stats_path / StatsValue::get.

Mirrors the super::SnapshotField shape so test authors who already know the BPF-snapshot accessor surface get the same as_u64 / as_i64 / as_f64 / as_bool / as_str terminals on the scx_stats JSON projection. Errors flow through the same SnapshotError variants — FieldNotFound carries the available object keys, NotAStruct flags a non-object cursor, TypeMismatch reports the actual JSON shape — so failure-path rendering in temporal assertions is identical regardless of which side of the Sample bundle the lookup originated on.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Value(&'a Value)

Resolved JSON value at the leaf of the path walk.

Missing(SnapshotError)

Path could not be resolved.

Implementations

impl<'a> JsonField<'a>

pub fn is_present(&self) -> bool

True when the path resolved.

pub fn raw(&self) -> Option<&'a Value>

Underlying JSON value if present.

pub fn error(&self) -> Option<&SnapshotError>

Error reference when the path could not be resolved.

pub fn get(&self, path: &str) -> JsonField<'a>

Walk further into a sub-field. Composable with the result of stats_path — stats_path(v, "layers").get("batch.util") is the canonical “drill into a periodic-stats object” shape. Mirrors super::SnapshotField::get so a test author moves between the BTF-rendered and JSON-rendered surfaces without re-learning the navigator method name.

pub fn as_u64(&self) -> SnapshotResult<u64>

Read as u64. Accepts JSON integers (positive only), JSON booleans (true → 1, false → 0), JSON strings whose content parses as a u64 (scx_stats sometimes stringifies large counters to avoid 53-bit float collapse), and JSON floats that are integral and non-negative (5.0 → 5; fractional, negative, or non-finite floats error). Returns SnapshotError::TypeMismatch otherwise.

pub fn as_i64(&self) -> SnapshotResult<i64>

Read as i64. Accepts JSON integers (any sign), JSON booleans (true → 1, false → 0), JSON strings whose content parses as an i64, and integral finite JSON floats (9.0 → 9; fractional or non-finite floats error).

pub fn as_f64(&self) -> SnapshotResult<f64>

Read as f64. Accepts JSON numbers (integers and floating-point) and JSON strings whose content parses as f64.

pub fn as_bool(&self) -> SnapshotResult<bool>

Read as bool. Accepts JSON booleans directly; rejects everything else. Distinct from as_u64() != 0 so the call site reads honestly: a bool claim wants a JSON true/ false, not a stringified "1" that happens to parse.

pub fn as_str(&self) -> SnapshotResult<&'a str>

Read as &str. Accepts JSON strings only.

pub fn as_u64_array(&self) -> SnapshotResult<Vec<u64>>

Read as Vec<u64> from a serde_json::Value::Array whose every element coerces via Self::as_u64’s rules. Mirrors super::SnapshotField::as_u64_array so JSON-side stats reads use the same method name as BTF-side BPF reads.

pub fn as_u32_array(&self) -> SnapshotResult<Vec<u32>>

Read as Vec<u32> from a JSON array. Mirrors super::SnapshotField::as_u32_array; out-of-range values error rather than silently truncate.

pub fn as_i64_array(&self) -> SnapshotResult<Vec<i64>>

Read as Vec<i64> from a JSON array. Mirrors super::SnapshotField::as_i64_array.

pub fn as_f64_array(&self) -> SnapshotResult<Vec<f64>>

Read as Vec<f64> from a JSON array. Mirrors super::SnapshotField::as_f64_array.

pub fn as_bool_array(&self) -> SnapshotResult<Vec<bool>>

Read as Vec<bool> from a JSON array of booleans. Mirrors super::SnapshotField::as_bool_array; rejects mixed arrays (no implicit truthiness coercion — JSON-side bool already has a wire shape).

pub fn iter_members(&self) -> impl Iterator<Item = JsonField<'a>> + '_

Iterate the elements of a JSON array as JsonFields so chained navigation composes for arrays-of-objects: field.iter_members().filter_map(|el| el.get("name").as_u64().ok()). Mirrors super::SnapshotField::iter_members.

Yields nothing for non-array values or missing fields — the empty iterator is the natural “no elements” shape when the chain just wants to fold over what’s there. Callers needing to distinguish “absent” from “empty” check Self::is_present or Self::error explicitly.

Trait Implementations

impl<'a> Clone for JsonField<'a>

fn clone(&self) -> JsonField<'a>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<'a> Debug for JsonField<'a>

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

Formats the value using the given formatter.