Struct ChangeEvent 

pub struct ChangeEvent {
    pub operation: OperationType,
    pub namespace: Namespace,
    pub document_key: Option<Document>,
    pub full_document: Option<Document>,
    pub update_description: Option<UpdateDescription>,
    pub cluster_time: DateTime<Utc>,
    pub resume_token: Document,
}

A MongoDB change stream event.

This is the primary type that flows through the Rigatoni pipeline. It represents a single change operation from MongoDB change streams.

Memory Layout

The struct uses owned data for all fields to ensure safe transfer between async tasks and threads. Fields that may not be present use Option<T>.

Approximate memory size: 200-500 bytes depending on document sizes.

Examples

use rigatoni_core::event::{ChangeEvent, OperationType};

fn process_event(event: &ChangeEvent) {
    match event.operation {
        OperationType::Insert => {
            println!("New document in {}", event.collection_name());
            if let Some(doc) = &event.full_document {
                println!("Data: {:?}", doc);
            }
        }
        OperationType::Update => {
            println!("Document updated in {}", event.collection_name());
            if let Some(desc) = &event.update_description {
                let keys: Vec<_> = desc.updated_fields.keys().collect();
                println!("Changed fields: {:?}", keys);
            }
        }
        OperationType::Delete => {
            println!("Document deleted from {}", event.collection_name());
            println!("Key: {:?}", event.document_key);
        }
        _ => println!("Other operation: {:?}", event.operation),
    }
}

Fields

operation: OperationType

Type of operation that occurred

namespace: Namespace

Namespace (database + collection) where the operation occurred

document_key: Option<Document>

Document key (_id and shard key if sharded)

Present for all operations except invalidate. For invalidate events, this will be None.

full_document: Option<Document>

Full document after the operation

Present for: insert (always), replace (always), update (if configured), delete (never, unless configured for pre-images).

update_description: Option<UpdateDescription>

Description of what changed in an update operation

Present only for update operations.

cluster_time: DateTime<Utc>

Timestamp of the operation in the oplog

resume_token: Document

Resume token for this event

Can be used to resume the change stream from this point.

Implementations

impl ChangeEvent

pub fn is_insert(&self) -> bool

Returns true if this is an insert operation.

pub fn is_update(&self) -> bool

Returns true if this is an update operation.

pub fn is_delete(&self) -> bool

Returns true if this is a delete operation.

pub fn is_replace(&self) -> bool

Returns true if this is a replace operation.

pub fn is_invalidate(&self) -> bool

Returns true if this is an invalidate operation.

pub fn collection_name(&self) -> &str

Returns the collection name.

pub fn database_name(&self) -> &str

Returns the database name.

pub fn full_namespace(&self) -> String

Returns the fully qualified namespace as “database.collection”.

pub fn document_id(&self) -> Option<&Bson>

Returns the document ID if present in the document key.

Most MongoDB documents have an _id field in the document key. Returns None if document_key is not present (e.g., invalidate events).

pub const fn has_full_document(&self) -> bool

Returns true if this event has a full document.

Useful for checking if the document data is available.

pub const fn has_update_description(&self) -> bool

Returns true if this event has update description.

Only present for update operations.

pub fn estimated_size_bytes(&self) -> usize

Returns the size estimate of this event in bytes.

Useful for batching and memory management.

Trait Implementations

impl Clone for ChangeEvent

fn clone(&self) -> ChangeEvent

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ChangeEvent

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for ChangeEvent

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for ChangeEvent

fn eq(&self, other: &ChangeEvent) -> 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 Serialize for ChangeEvent

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl TryFrom<ChangeStreamEvent<Document>> for ChangeEvent

Conversion from MongoDB driver’s ChangeStreamEvent.

This enables seamless integration with the official MongoDB Rust driver. Returns an error if the resume token cannot be converted to a BSON document.

type Error = ConversionError

The type returned in the event of a conversion error.

fn try_from(event: ChangeStreamEvent<Document>) -> Result<Self, Self::Error>

Performs the conversion.

impl StructuralPartialEq for ChangeEvent