Struct MessageTransformer 

pub struct MessageTransformer { /* private fields */ }

Registry of named transformation pipelines.

Example

use oxirs_stream::message_transformer::*;
use std::collections::HashMap;

let mut transformer = MessageTransformer::new();
let pipeline = TransformPipeline::new(
    MessageFormat::Json,
    MessageFormat::Avro,
    vec![FieldMapping::with_transform("name", "NAME", TransformFn::ToUpper)],
);
transformer.add_pipeline("upper", pipeline);

let mut fields = HashMap::new();
fields.insert("name".to_string(), "alice".to_string());
let payload = MessagePayload::new(fields, MessageFormat::Json);
let result = transformer.transform("upper", payload)?;
assert_eq!(result.fields["NAME"], "ALICE");

Implementations

impl MessageTransformer

pub fn new() -> Self

Create an empty transformer.

pub fn add_pipeline(&mut self, name: &str, pipeline: TransformPipeline)

Register a named pipeline. Overwrites any existing pipeline with the same name.

pub fn transform( &self, pipeline_name: &str, payload: MessagePayload, ) -> Result<MessagePayload, TransformError>

Apply the named pipeline to payload.

Each FieldMapping in the pipeline is applied in order:

1. The value of source_field is read from the payload.
2. The optional TransformFn is applied.
3. The result is stored under target_field in the output payload.

Fields present in the payload but not mentioned by any mapping are dropped.

pub fn chain_pipelines( &self, names: &[&str], payload: MessagePayload, ) -> Result<MessagePayload, TransformError>

Apply a sequence of pipelines in order.

The output of each pipeline is fed as the input to the next. The format of the intermediate payloads is updated by each pipeline.

pub fn list_pipelines(&self) -> Vec<&str>

Return the names of all registered pipelines (order unspecified).

pub fn pipeline_count(&self) -> usize

Return the number of registered pipelines.

pub fn has_pipeline(&self, name: &str) -> bool

Check whether a pipeline with the given name exists.

pub fn remove_pipeline(&mut self, name: &str) -> bool

Remove a pipeline by name. Returns true if it was present.

Trait Implementations

impl Debug for MessageTransformer

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

Formats the value using the given formatter.

impl Default for MessageTransformer

fn default() -> MessageTransformer

Returns the “default value” for a type.