Struct Message 

pub struct Message {
    pub keys: Option<Vec<String>>,
    pub value: Vec<u8>,
    pub tags: Option<Vec<String>>,
}

Message is the response from the user’s Reducer::reduce.

Fields

keys: Option<Vec<String>>

Keys are a collection of strings which will be passed on to the next vertex as is. It can be an empty collection. It is mainly used in creating a partition in Reducer::reduce.

value: Vec<u8>

Value is the value passed to the next vertex.

tags: Option<Vec<String>>

Tags are used for conditional forwarding.

Implementations

impl Message

Represents a message that can be modified and forwarded.

pub fn new(value: Vec<u8>) -> Self

Creates a new message with the specified value.

This constructor initializes the message with no keys, tags, or specific event time.

Arguments

• value - A vector of bytes representing the message’s payload.

Examples

use numaflow::reduce::Message;
let message = Message::new(vec![1, 2, 3, 4]);

pub fn message_to_drop() -> Message

Marks the message to be dropped by creating a new Message with an empty value and a special “DROP” tag.

Examples

use numaflow::reduce::Message;
let dropped_message = Message::message_to_drop();

pub fn with_keys(self, keys: Vec<String>) -> Self

Sets or replaces the keys associated with this message.

Arguments

• keys - A vector of strings representing the keys.

Examples

 use numaflow::reduce::Message;
let message = Message::new(vec![1, 2, 3]).with_keys(vec!["key1".to_string(), "key2".to_string()]);

pub fn with_tags(self, tags: Vec<String>) -> Self

Sets or replaces the tags associated with this message.

Arguments

• tags - A vector of strings representing the tags.

Examples

 use numaflow::reduce::Message;
let message = Message::new(vec![1, 2, 3]).with_tags(vec!["tag1".to_string(), "tag2".to_string()]);

Trait Implementations

impl Debug for Message

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

Formats the value using the given formatter.

impl PartialEq for Message

fn eq(&self, other: &Message) -> 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 Message