Struct StackSample 

pub struct StackSample {
    pub primary_weight: Option<u64>,
    pub follower_descriptors: Vec<CounterDescriptor>,
    pub follower_descriptor_iids: Vec<u64>,
    pub follower_weights: Vec<u64>,
    pub task_context_field: Option<TaskContextField>,
    pub execution_context_field: Option<ExecutionContextField>,
    pub callstack_field: Option<CallstackField>,
    pub unwind_error_field: Option<UnwindErrorField>,
    pub primary_descriptor_field: Option<PrimaryDescriptorField>,
}

A single stack sample: a callstack captured for a task, measured against a counter timebase. This is transport-neutral and timebase-neutral. The timebase can be CPU cycles, wall-clock nanoseconds, allocated bytes, page faults, etc.; the primary CounterDescriptor says which. It is not specific to CPU profiling.

Each context/callstack/descriptor can be given inline or as an iid referencing an InternedData entry. Producers that reuse a context across samples should intern it so the per-sample cost is a single varint.

Fields

primary_weight: Option<u64>

The value attributed to this sample for the primary counter (e.g. the number of cycles or nanoseconds this sample represents).

follower_descriptors: Vec<CounterDescriptor>

Additional counters read at the same sample (e.g. instructions, cache misses read alongside a cycles timebase). follower_weights is positional with whichever of follower_descriptors / follower_descriptor_iids is set.

follower_descriptor_iids: Vec<u64>

follower_weights: Vec<u64>

task_context_field: Option<TaskContextField>

The task (thread / process / async context) this sample is attributed to. Give it inline via task_context or reference an interned TaskContext via task_context_iid.

execution_context_field: Option<ExecutionContextField>

The execution state (cpu, privilege mode) at sample time. Absent for samplers that observe off-CPU tasks. Give it inline via execution_context or reference an interned ExecutionContext via execution_context_iid.

callstack_field: Option<CallstackField>

The captured callstack, bottom frame first. Give it fully inline via callstack or reference an interned Callstack via callstack_iid.

unwind_error_field: Option<UnwindErrorField>

Set if stack unwinding was incomplete; describes the data, not producer internal state. Give it inline via unwind_error or reference an interned string via unwind_error_iid.

TODO(lalitm): not yet parsed by trace_processor. Defined now to lock the wire layout; a table column will surface it later.

primary_descriptor_field: Option<PrimaryDescriptorField>

The sampling timebase: the counter this sample’s weight is measured against. Set one of the two; may be omitted entirely if declared in StackSampleDefaults.primary_descriptor.

Implementations

impl StackSample

pub fn primary_weight(&self) -> u64

Returns the value of primary_weight, or the default value if primary_weight is unset.

Trait Implementations

impl Clone for StackSample

fn clone(&self) -> StackSample

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for StackSample

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

Formats the value using the given formatter.

impl Default for StackSample

fn default() -> Self

Returns the “default value” for a type.

impl Message for StackSample

fn encoded_len(&self) -> usize

Returns the encoded length of the message without a length delimiter.

fn clear(&mut self)

Clears the message, resetting all fields to their default.

fn encode(&self, buf: &mut impl BufMut) -> Result<(), EncodeError>

where Self: Sized,

Encodes the message to a buffer.

fn encode_to_vec(&self) -> Vec<u8>

where Self: Sized,

Encodes the message to a newly allocated buffer.

fn encode_length_delimited( &self, buf: &mut impl BufMut, ) -> Result<(), EncodeError>

where Self: Sized,

Encodes the message with a length-delimiter to a buffer.

fn encode_length_delimited_to_vec(&self) -> Vec<u8>

where Self: Sized,

Encodes the message with a length-delimiter to a newly allocated buffer.

fn decode(buf: impl Buf) -> Result<Self, DecodeError>

where Self: Default,

Decodes an instance of the message from a buffer.

fn decode_length_delimited(buf: impl Buf) -> Result<Self, DecodeError>

where Self: Default,

Decodes a length-delimited instance of the message from the buffer.

fn merge(&mut self, buf: impl Buf) -> Result<(), DecodeError>

where Self: Sized,

Decodes an instance of the message from a buffer, and merges it into self.

fn merge_length_delimited(&mut self, buf: impl Buf) -> Result<(), DecodeError>

where Self: Sized,

Decodes a length-delimited instance of the message from buffer, and merges it into self.

impl PartialEq for StackSample

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for StackSample