Struct TrackDimension 

pub struct TrackDimension {
    pub name_field: Option<NameField>,
    pub value: Option<Value>,
    pub display: Option<Display>,
}

A named, typed key/value which is part of a track’s identity.

Dimensions are the single vocabulary for identifiers which apply to a set of tracks: well-known dimensions are synthesized by trace processor, while producers can declare their own custom dimensions (rank, shard, stage, …) on a TrackDescriptor.

Reserved names: the names of the well-known dimensions are reserved and cannot be used for custom dimensions. They are:

• machine: the machine the track belongs to.
• gpu: the GPU the track belongs to.
• cpu: the CPU the track belongs to.
• process: the process the track belongs to.
• thread: the thread the track belongs to. Their values are derived by trace processor from the typed fields of the TrackDescriptor (e.g. process, thread) and from import context, and mean the same thing across data sources. A custom dimension using a reserved name is ignored and trace processor records the track_descriptor_reserved_dimension_name import error.

A dimension has no scope field: it is declared on the track described by the containing TrackDescriptor and applies to that track and its parent_uuid descendants, whether it is a process, thread or any other track. In particular, a dimension declared on a process track doesn’t apply to the threads of the process unless their tracks are parent_uuid descendants of the process track.

Declaring a different value for a dimension name which is already inherited from an ancestor is invalid: trace processor records an import error and keeps the inherited value.

The dimensions declared on a TrackDescriptor (names and values; the order and display_name don’t matter) are part of the identity of that track:

• they are fixed for the lifetime of the track, so every TrackDescriptor emitted for a given uuid, including the first one, must declare the same dimensions. A TrackDescriptor declaring different dimensions is rejected as a conflicting reservation and the first one is kept.
• sibling tracks are only merged (see TrackDescriptor.sibling_merge_behavior) if they declare the same dimensions.

Fields

name_field: Option<NameField>

The canonical dimension key, e.g. “rank”. Must be non-empty and must not be one of the reserved names listed above.

value: Option<Value>

The typed value of the dimension. This is the value used for SQL queries, track identity and (for well-known dimensions) merging, so it must be stable for the whole trace.

display: Option<Display>

Optional human readable label for this value, e.g. “worker-east” for rank 7. Only affects presentation: the canonical typed value above is what SQL and merging use.

Trait Implementations

impl Clone for TrackDimension

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 TrackDimension

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

Formats the value using the given formatter.

impl Default for TrackDimension

fn default() -> Self

Returns the “default value” for a type.

impl Eq for TrackDimension

impl Hash for TrackDimension

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Message for TrackDimension

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 TrackDimension

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for TrackDimension