Struct DoraNode 

pub struct DoraNode { /* private fields */ }

Allows sending outputs and retrieving node information.

The main purpose of this struct is to send outputs via Dora. There are also functions available for retrieving the node configuration.

Implementations

impl DoraNode

pub fn init_from_env() -> Result<(Self, EventStream)>

Initiate a node from environment variables set by the Dora daemon.

This is the recommended initialization function for Dora nodes, which are spawned by Dora daemon instances.

use dora_node_api::DoraNode;

let (mut node, mut events) = DoraNode::init_from_env().expect("Could not init node.");

pub fn init_from_node_id(node_id: NodeId) -> Result<(Self, EventStream)>

Initiate a node from a dataflow id and a node id.

This initialization function should be used for dynamic nodes.

use dora_node_api::DoraNode;
use dora_node_api::dora_core::config::NodeId;

let (mut node, mut events) = DoraNode::init_from_node_id(NodeId::from("plot".to_string())).expect("Could not init node plot");

pub fn init_flexible(node_id: NodeId) -> Result<(Self, EventStream)>

Dynamic initialization function for nodes that are sometimes used as dynamic nodes.

This function first tries initializing the traditional way through init_from_env. If this fails, it falls back to init_from_node_id.

pub fn send_output_raw<F>( &mut self, output_id: DataId, parameters: MetadataParameters, data_len: usize, data: F, ) -> Result<()>

where F: FnOnce(&mut [u8]),

Send raw data from the node to the other nodes.

We take a closure as an input to enable zero copy on send.

use dora_node_api::{DoraNode, MetadataParameters};
use dora_core::config::DataId;

let (mut node, mut events) = DoraNode::init_from_env().expect("Could not init node.");

let output = DataId::from("output_id".to_owned());

let data: &[u8] = &[0, 1, 2, 3];
let parameters = MetadataParameters::default();

node.send_output_raw(
   output,
   parameters,
   data.len(),
   |out| {
        out.copy_from_slice(data);
    }).expect("Could not send output");

Ignores the output if the given output_id is not specified as node output in the dataflow configuration file.

pub fn send_output( &mut self, output_id: DataId, parameters: MetadataParameters, data: impl Array, ) -> Result<()>

Sends the give Arrow array as an output message.

Uses shared memory for efficient data transfer if suitable.

This method might copy the message once to move it to shared memory.

Ignores the output if the given output_id is not specified as node output in the dataflow configuration file.

pub fn send_output_bytes( &mut self, output_id: DataId, parameters: MetadataParameters, data_len: usize, data: &[u8], ) -> Result<()>

Send the given raw byte data as output.

Might copy the data once to move it into shared memory.

Ignores the output if the given output_id is not specified as node output in the dataflow configuration file.

pub fn send_typed_output<F>( &mut self, output_id: DataId, type_info: ArrowTypeInfo, parameters: MetadataParameters, data_len: usize, data: F, ) -> Result<()>

where F: FnOnce(&mut [u8]),

Send the give raw byte data with the provided type information.

It is recommended to use a function like send_output instead.

Ignores the output if the given output_id is not specified as node output in the dataflow configuration file.

pub fn send_output_sample( &mut self, output_id: DataId, type_info: ArrowTypeInfo, parameters: MetadataParameters, sample: Option<DataSample>, ) -> Result<()>

Sends the given DataSample as output, combined with the given type information.

It is recommended to use a function like send_output instead.

Ignores the output if the given output_id is not specified as node output in the dataflow configuration file.

pub fn close_outputs(&mut self, outputs_ids: Vec<DataId>) -> Result<()>

Report the given outputs IDs as closed.

The node is not allowed to send more outputs with the closed IDs.

Closing outputs early can be helpful to receivers.

pub fn id(&self) -> &NodeId

Returns the ID of the node as specified in the dataflow configuration file.

pub fn dataflow_id(&self) -> &DataflowId

Returns the unique identifier for the running dataflow instance.

Dora assigns each dataflow instance a random identifier when started.

pub fn node_config(&self) -> &NodeRunConfig

Returns the input and output configuration of this node.

pub fn allocate_data_sample(&mut self, data_len: usize) -> Result<DataSample>

Allocates a DataSample of the specified size.

The data sample will use shared memory when suitable to enable efficient data transfer when sending an output message.

pub fn dataflow_descriptor(&self) -> Result<&Descriptor>

Returns the full dataflow descriptor that this node is part of.

This method returns the parsed dataflow YAML file.

Trait Implementations

impl Drop for DoraNode

fn drop(&mut self)

Executes the destructor for this type.