Struct AsyncEvent

pub struct AsyncEvent<'a, T>
where
    T: EventSource,
{
    pub plugin_id: u32,
    pub name: &'a CStr,
    pub data: T,
}

The event type that can be emitted from async event plugins Asynchronous event

This is the event type generated by async event plugins. This differs from the autogenerated falco_event_schema::types::PPME_ASYNCEVENT_E type in the following ways:

• none of the fields are Options
• the name is just a &CStr
• serde serialization/deserialization is not supported
• does not depend on the whole falco_event_schema crate

It handles encoding and decoding the payload automatically, so you can use any type that can be converted from/to a byte buffer (including a raw &[u8]) as the payload.

To store an arbitrary type inside the payload, make sure the data implements FromBytes, ToBytes and EventSource, for example:

use std::io::Write;
use falco_event::events::{AnyEventPayload, RawEvent};
use falco_event::fields::{FromBytes, FromBytesError, ToBytes};
use falco_plugin::event::{EventSource, AsyncEvent};
use falco_plugin::event::events::Event;

struct MyEvent {
    param1: u32,
    param2: u32,
}

impl EventSource for MyEvent {
    const SOURCE: Option<&'static str> = Some("my_plugin");
}

impl FromBytes<'_> for MyEvent {
    fn from_bytes(buf: &mut &[u8]) -> Result<Self, FromBytesError> {
        if buf.len() < 2 * size_of::<u32>() {
            return Err(FromBytesError::InvalidLength);
        }

        let param1 = u32::from_le_bytes(buf[..size_of::<u32>()].try_into().unwrap());
        let param2 = u32::from_le_bytes(buf[size_of::<u32>()..].try_into().unwrap());
        *buf = &buf[2 * size_of::<u32>()..];
        Ok(MyEvent { param1, param2 })
    }
}

impl ToBytes for MyEvent {
    fn binary_size(&self) -> usize {
        2 * size_of::<u32>()
    }

   fn write<W: Write>(&self, mut writer: W) -> std::io::Result<()> {
        writer.write_all(&self.param1.to_le_bytes())?;
        writer.write_all(&self.param2.to_le_bytes())?;
        Ok(())
    }

    fn default_repr() -> impl ToBytes {
        MyEvent { param1: 0, param2: 0 }
    }
}

// in a plugin trait implementation:
type Event<'a> = Event<AsyncEvent<'a, MyEvent>>;

Note: this SDK also provides support for JSON-encoded payloads since it’s already necessary to talk to the Falco Plugin API. JSON is not a good choice for high-volume events, as it takes a lot of space and is pretty slow, compared to binary formats. See the source of plugin::event:json for what is needed to support a different serialization format and consider using e.g. bincode instead.

Fields

plugin_id: u32

ID of the plugin that generated this event

name: &'a CStr

Name of the plugin that generated this event

data: T

Payload, as a custom type

Trait Implementations

impl<'a, T> Debug for AsyncEvent<'a, T>

where T: EventSource + Debug,

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

Formats the value using the given formatter.

impl<'a, T> Default for AsyncEvent<'a, T>

where T: EventSource + Default,

fn default() -> AsyncEvent<'a, T>

Returns the “default value” for a type.

impl<'a, T> EventPayload for AsyncEvent<'a, T>

where T: EventSource,

const ID: u16 = 402u16

const SOURCE: Option<&'static str> = <T as EventSource>::SOURCE

impl<'raw_event, 'a, T> FromRawEvent<'raw_event> for AsyncEvent<'a, T>

where T: EventSource + FromBytes<'raw_event>, 'raw_event: 'a,

fn parse(raw: &RawEvent<'raw_event>) -> Result<Self, PayloadFromBytesError>

Parse a raw event into the type implementing this trait

impl<'a, T> PayloadToBytes for AsyncEvent<'a, T>

where T: EventSource + ToBytes,

fn binary_size(&self) -> usize

Get the binary size of the payload

fn write<W: Write>(&self, metadata: &EventMetadata, writer: W) -> Result<()>

Write the payload to a writer implementing [std::io::Write].