function

README

Function Package

Temporal workflow activities for dispatching arbitrary Go functions. Uses a registry to map function names to implementations at runtime, executing them as Temporal activities that compose with the generic orchestration patterns in the workflow package.

Key Features

• Function Registry — register named Go functions for Temporal dispatch
• Type-safe payloads — implements workflow.TaskInput and workflow.TaskOutput
• Composable — use with Pipeline, Parallel, Loop, and DAG workflows
• Builder API — fluent construction of function workflow inputs
• Pre-built patterns — common function orchestration patterns included

Documentation

• Function Workflows Guide — comprehensive usage guide with examples
• Architecture — how this package fits in the overall system
• Workflow Patterns — orchestration patterns
• Getting Started — quick start guide

Quick Example

// Register a handler
registry := function.NewRegistry()
registry.Register("greet", func(ctx context.Context, input function.FunctionInput) (*function.FunctionOutput, error) {
    name := input.Args["name"]
    return &function.FunctionOutput{
        Result: map[string]string{"greeting": fmt.Sprintf("Hello, %s!", name)},
    }, nil
})

// Execute via Temporal
input := function.FunctionExecutionInput{
    Name: "greet",
    Args: map[string]string{"name": "World"},
}

Documentation

Overview

Package function provides Temporal workflow activities for dispatching arbitrary Go functions.

It implements the workflow.TaskInput and workflow.TaskOutput interfaces with function-specific payload types and uses a Registry to map function names to their implementations at runtime. Registered functions are executed as Temporal activities and can be composed using the generic orchestration patterns in the workflow package (pipeline, parallel, loop, DAG).

Index

• func RegisterActivity(w worker.Worker, activityFn interface{})
• func RegisterAll(w worker.Worker, activityFn interface{})
• func RegisterWorkflows(w worker.Worker)
• func SetActivityInstrumenter(wrapper func(activityType) activityType)
• type DAGWorkflowInput
• type DataMapping
• type FunctionDAGNode
• type FunctionDAGWorkflowOutput
• type FunctionExecutionInput
• type FunctionExecutionOutput
• type FunctionInput
• type FunctionInputMapping
• type FunctionNodeResult
• type FunctionOutput
• type Handler
• type LoopInput
• type LoopOutput
• type OutputMapping
• type ParallelInput
• type ParallelOutput
• type ParameterizedLoopInput
• type PipelineInput
• type PipelineOutput
• type Registry
  • func NewRegistry() *Registry
  • func (r *Registry) Get(name string) (Handler, error)
  • func (r *Registry) Has(name string) bool
  • func (r *Registry) Register(name string, handler Handler) error

Functions

func RegisterActivity

func RegisterActivity(w worker.Worker, activityFn interface{})

RegisterActivity registers a function execution activity with a worker. Create the activity with activity.NewExecuteFunctionActivity(registry). Calling this function multiple times on the same worker is a no-op for subsequent calls — the activity type is registered at most once per worker.

func RegisterAll

func RegisterAll(w worker.Worker, activityFn interface{})

RegisterAll registers all function workflows and the given activity with a worker. Create the activity with activity.NewExecuteFunctionActivity(registry). Calling this function multiple times on the same worker is a no-op for subsequent calls — idempotency is ensured via job.RegisterWorkflowOnce and job.RegisterActivityOnce.

func RegisterWorkflows

func RegisterWorkflows(w worker.Worker)

RegisterWorkflows registers all function workflows with a worker. Calling this function multiple times on the same worker is a no-op for subsequent calls — each workflow type is registered at most once per worker.

func SetActivityInstrumenter

func SetActivityInstrumenter(wrapper func(activityType) activityType)

SetActivityInstrumenter sets the function that wraps activities with instrumentation. This must only be called once during initialization; subsequent calls are ignored.

Types

type DAGWorkflowInput

type DAGWorkflowInput = payload.DAGWorkflowInput

Type aliases for extended (DAG) types re-exported from function/payload.

type DataMapping

type DataMapping = payload.DataMapping

Type aliases for extended (DAG) types re-exported from function/payload.

type FunctionDAGNode

type FunctionDAGNode = payload.FunctionDAGNode

Type aliases for extended (DAG) types re-exported from function/payload.

type FunctionDAGWorkflowOutput

type FunctionDAGWorkflowOutput = payload.FunctionDAGWorkflowOutput

Type aliases for extended (DAG) types re-exported from function/payload.

type FunctionExecutionInput

type FunctionExecutionInput = payload.FunctionExecutionInput

Type aliases re-exported from function/payload for convenience. External callers can use function.FunctionExecutionInput instead of function/payload.FunctionExecutionInput.

type FunctionExecutionOutput

type FunctionExecutionOutput = payload.FunctionExecutionOutput

Type aliases re-exported from function/payload for convenience. External callers can use function.FunctionExecutionInput instead of function/payload.FunctionExecutionInput.

type FunctionInput

type FunctionInput struct {
	Args    map[string]string `json:"args,omitempty"`
	Data    []byte            `json:"data,omitempty"`
	Env     map[string]string `json:"env,omitempty"`
	WorkDir string            `json:"work_dir,omitempty"`
}

FunctionInput is the input passed to registered handler functions.

type FunctionInputMapping

type FunctionInputMapping = payload.FunctionInputMapping

Type aliases for extended (DAG) types re-exported from function/payload.

type FunctionNodeResult

type FunctionNodeResult = payload.FunctionNodeResult

Type aliases for extended (DAG) types re-exported from function/payload.

type FunctionOutput

type FunctionOutput struct {
	Result map[string]string `json:"result,omitempty"`
	Data   []byte            `json:"data,omitempty"`
}

FunctionOutput is the output returned by registered handler functions.

type Handler

type Handler func(ctx context.Context, input FunctionInput) (*FunctionOutput, error)

Handler is the function signature for registered handlers.

type LoopInput

type LoopInput = payload.LoopInput

Type aliases re-exported from function/payload for convenience. External callers can use function.FunctionExecutionInput instead of function/payload.FunctionExecutionInput.

type LoopOutput

type LoopOutput = payload.LoopOutput

Type aliases re-exported from function/payload for convenience. External callers can use function.FunctionExecutionInput instead of function/payload.FunctionExecutionInput.

type OutputMapping

type OutputMapping = payload.OutputMapping

Type aliases for extended (DAG) types re-exported from function/payload.

type ParallelInput

type ParallelInput = payload.ParallelInput

Type aliases re-exported from function/payload for convenience. External callers can use function.FunctionExecutionInput instead of function/payload.FunctionExecutionInput.

type ParallelOutput

type ParallelOutput = payload.ParallelOutput

Type aliases re-exported from function/payload for convenience. External callers can use function.FunctionExecutionInput instead of function/payload.FunctionExecutionInput.

type ParameterizedLoopInput

type ParameterizedLoopInput = payload.ParameterizedLoopInput

Type aliases re-exported from function/payload for convenience. External callers can use function.FunctionExecutionInput instead of function/payload.FunctionExecutionInput.

type PipelineInput

type PipelineInput = payload.PipelineInput

Type aliases re-exported from function/payload for convenience. External callers can use function.FunctionExecutionInput instead of function/payload.FunctionExecutionInput.

type PipelineOutput

type PipelineOutput = payload.PipelineOutput

Type aliases re-exported from function/payload for convenience. External callers can use function.FunctionExecutionInput instead of function/payload.FunctionExecutionInput.

type Registry

type Registry struct {
	// contains filtered or unexported fields
}

Registry maps function names to handlers.

func NewRegistry

func NewRegistry() *Registry

NewRegistry creates a new empty function registry.

func (*Registry) Get

func (r *Registry) Get(name string) (Handler, error)

Get retrieves a handler by name.

func (*Registry) Has

func (r *Registry) Has(name string) bool

Has returns true if a handler with the given name is registered.

func (*Registry) Register

func (r *Registry) Register(name string, handler Handler) error

Register adds a named handler to the registry. Returns an error if a handler with the same name is already registered.