Struct Metadata 

pub struct Metadata {
    pub parameters: BTreeMap<String, Parameter>,
    /* private fields */
}

Additional data that is sent as part of output messages.

Includes a timestamp and additional user-provided parameters. The payload is a self-describing Arrow IPC stream, so the message carries no separate type descriptor.

Fields

parameters: BTreeMap<String, Parameter>

Implementations

impl Metadata

pub const CURRENT_VERSION: u16 = 1

Current metadata wire-format version, stamped on every outgoing message.

Bumped from 0 to 1 when the ArrowTypeInfo sidecar was dropped and the wire format became Arrow-IPC-only. A receiver can compare metadata_version against this to detect a peer speaking an incompatible format and report it clearly instead of failing with a cryptic positional-deserialization error.

pub fn new(timestamp: Timestamp) -> Metadata

pub fn from_parameters( timestamp: Timestamp, parameters: BTreeMap<String, Parameter>, ) -> Metadata

pub fn metadata_version(&self) -> u16

The wire-format version stamped on this metadata. Compare against CURRENT_VERSION on receive to reject peers using an incompatible format.

pub fn timestamp(&self) -> Timestamp

pub fn open_telemetry_context(&self) -> String

Trait Implementations

impl Clone for Metadata

fn clone(&self) -> Metadata

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Metadata

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Metadata

fn deserialize<__D>( __deserializer: __D, ) -> Result<Metadata, <__D as Deserializer<'de>>::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for Metadata

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

Equality operator ==.

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

Inequality operator !=.

impl Serialize for Metadata

fn serialize<__S>( &self, __serializer: __S, ) -> Result<<__S as Serializer>::Ok, <__S as Serializer>::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for Metadata