types

Types Package

Shared domain types used across the SemStreams platform to avoid circular dependencies.

Purpose

This package provides foundational types that multiple packages need to reference. By placing these types in a low-level package with minimal dependencies, we break circular import chains between higher-level packages like config, component, and service.

Design Principles

1. Minimal dependencies - Only imports pkg/errs and standard library
2. No sub-packages - Flat structure keeps the dependency graph simple
3. Pure domain types - Configuration structures and enums, no business logic
4. Shared contracts - Types used by multiple packages to communicate

Types

ComponentType

Enumeration of component categories in the processing pipeline:

const (
    ComponentTypeInput     ComponentType = "input"
    ComponentTypeProcessor ComponentType = "processor"
    ComponentTypeOutput    ComponentType = "output"
    ComponentTypeStorage   ComponentType = "storage"
    ComponentTypeGateway   ComponentType = "gateway"
)

ComponentConfig

Configuration structure for component instances, shared between config and component packages:

type ComponentConfig struct {
    Type    ComponentType   `json:"type"`    // Component category
    Name    string          `json:"name"`    // Factory name (e.g., "udp", "websocket")
    Enabled bool            `json:"enabled"` // Runtime enable/disable
    Config  json.RawMessage `json:"config"`  // Component-specific configuration
}

ServiceConfig

Configuration structure for service instances:

type ServiceConfig struct {
    Name    string          `json:"name"`    // Service identifier
    Enabled bool            `json:"enabled"` // Runtime enable/disable
    Config  json.RawMessage `json:"config"`  // Service-specific configuration
}

PlatformMeta

Platform identity information decoupled from config structures:

type PlatformMeta struct {
    Org      string // Organization namespace (e.g., "c360")
    Platform string // Platform identifier (e.g., "platform1")
}

Usage

import "github.com/c360/semstreams/types"

// Component configuration
cfg := types.ComponentConfig{
    Type:    types.ComponentTypeProcessor,
    Name:    "json_filter",
    Enabled: true,
    Config:  json.RawMessage(`{"field": "status"}`),
}

if err := cfg.Validate(); err != nil {
    // Handle validation error
}

// Service configuration
svcCfg := types.ServiceConfig{
    Name:    "metrics",
    Enabled: true,
}

Import Graph

pkg/errs (leaf package)
    ↑
  types (this package)
    ↑
  ┌──┴──┐
config  component  service  ...

This package sits just above pkg/errs in the dependency hierarchy, allowing it to be imported by most other packages without creating cycles.