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SpanTokenUsage

lc_callbacks::tracing::span

Struct SpanTokenUsage

pub struct SpanTokenUsage {
    pub prompt_tokens: usize,
    pub completion_tokens: usize,
    pub total_tokens: usize,
    pub cache_read_input_tokens: Option<usize>,
    pub cache_write_input_tokens: Option<usize>,
    pub reasoning_output_tokens: Option<usize>,
}

Expand description

Token usage recorded in a span.

Fields§

§prompt_tokens: usize

Number of tokens in the prompt.

§completion_tokens: usize

Number of tokens in the completion.

§total_tokens: usize

Total number of tokens.

§cache_read_input_tokens: Option<usize>

gen_ai.usage.cache_read.input_tokens (Development extension).

§cache_write_input_tokens: Option<usize>

gen_ai.usage.cache_write.input_tokens (Development extension; 2026 rename of cache_creation).

§reasoning_output_tokens: Option<usize>

gen_ai.usage.reasoning.output_tokens (Development extension).

Trait Implementations§

impl Clone for SpanTokenUsage

fn clone(&self) -> SpanTokenUsage

Returns a duplicate of the value. Read more

1.0.0 (const: unstable) · Source§

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

Performs copy-assignment from source. Read more

impl Debug for SpanTokenUsage

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

Formats the value using the given formatter. Read more

impl Default for SpanTokenUsage

fn default() -> SpanTokenUsage

Returns the “default value” for a type. Read more

impl<'de> Deserialize<'de> for SpanTokenUsage

fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer. Read more

impl PartialEq for SpanTokenUsage

fn eq(&self, other: &SpanTokenUsage) -> bool

Equality operator ==. Read more

1.0.0 (const: unstable) · Source§

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=. Read more

impl Serialize for SpanTokenUsage

fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where S: Serializer,

Serialize this value into the given Serde serializer. Read more

impl StructuralPartialEq for SpanTokenUsage

Auto Trait Implementations§

impl Freeze for SpanTokenUsage

impl RefUnwindSafe for SpanTokenUsage

impl Send for SpanTokenUsage

impl Sync for SpanTokenUsage

impl Unpin for SpanTokenUsage

impl UnsafeUnpin for SpanTokenUsage

impl UnwindSafe for SpanTokenUsage

Blanket Implementations§

impl<T> Any for T
where T: 'static + ?Sized,

fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more

impl<T> Borrow<T> for T
where T: ?Sized,

fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more

impl<T> BorrowMut<T> for T
where T: ?Sized,

fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more

impl<T> CloneToUninit for T
where T: Clone,

unsafe fn clone_to_uninit(&self, dest: *mut u8)

🔬This is a nightly-only experimental API. (clone_to_uninit)

Performs copy-assignment from self to dest. Read more

impl<T> DeserializeOwned for T
where T: for<'de> Deserialize<'de>,

impl<T> From<T> for T

fn from(t: T) -> T

Returns the argument unchanged.

impl<T> Instrument for T

fn instrument(self, span: Span) -> Instrumented<Self> ⓘ

Instruments this type with the provided Span, returning an Instrumented wrapper. Read more

fn in_current_span(self) -> Instrumented<Self> ⓘ

Instruments this type with the current Span, returning an Instrumented wrapper. Read more

impl<T, U> Into<U> for T
where U: From<T>,

fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

impl<T> PolicyExt for T
where T: ?Sized,

fn and<P, B, E>(self, other: P) -> And<T, P>
where T: Sized + Policy<B, E>, P: Policy<B, E>,

Create a new Policy that returns Action::Follow only if self and other return Action::Follow. Read more

fn or<P, B, E>(self, other: P) -> Or<T, P>
where T: Sized + Policy<B, E>, P: Policy<B, E>,

Create a new Policy that returns Action::Follow if either self or other returns Action::Follow. Read more

impl<T> ToOwned for T
where T: Clone,

type Owned = T

The resulting type after obtaining ownership.

fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more

fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more

impl<T, U> TryFrom<U> for T
where U: Into<T>,

type Error = !

The type returned in the event of a conversion error.

fn try_from(value: U) -> Result<T, !>

Performs the conversion.

impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.

fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.

impl<T> WithSubscriber for T

fn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self> ⓘ
where S: Into<Dispatch>,

Attaches the provided Subscriber to this type, returning a WithDispatch wrapper. Read more

fn with_current_subscriber(self) -> WithDispatch<Self> ⓘ

Attaches the current default Subscriber to this type, returning a WithDispatch wrapper. Read more