# SocketsContainer

**Kind:** Class

**Source:** [`packages/websockets/sockets-container.ts`](https://github.com/nestjs/nest/blob/master/packages/websockets/sockets-container.ts#L4)

**Part of:** [Websockets](subsystem-packages-websockets)

`SocketsContainer` manages the collection of `ServerAndEventStreamsHost` instances used by the WebSocket layer. It provides lookup, registration, enumeration, and cleanup operations so socket server hosts can be reused and managed consistently during application lifecycle events.

## Methods

| Method | Signature | Returns |
|---|---|---|
| `getAll` | `getAll()` | `Map<string | RegExp, ServerAndEventStreamsHost>` |
| `getOneByConfig` | `getOneByConfig(options: T)` | `ServerAndEventStreamsHost` |
| `addOne` | `addOne(options: T, host: ServerAndEventStreamsHost)` | `void` |
| `clear` | `clear()` | `void` |

## Diagram

```mermaid
graph LR
  A[WebSocket Configuration] --> B[SocketsContainer]
  B -->|addOne| C[ServerAndEventStreamsHost]
  B -->|getOneByConfig| C
  B -->|getAll| D[Map of Socket Hosts]
  B -->|clear| E[Release Registered Hosts]
```

## Usage

```ts
import { SocketsContainer } from './sockets-container';
import { ServerAndEventStreamsHost } from './server-and-event-streams-host';

const socketsContainer = new SocketsContainer();

// Create or obtain a configured host from the WebSocket bootstrap flow.
const host = new ServerAndEventStreamsHost(/* websocket adapter */);

// Register the host using the socket server configuration.
socketsContainer.addOne(
  { port: 3000, path: '/socket.io' },
  host,
);

// Reuse the registered host when processing the same configuration.
const registeredHost = socketsContainer.getOneByConfig({
  port: 3000,
  path: '/socket.io',
});

// Inspect all active socket hosts.
console.log(socketsContainer.getAll());

// Clear registrations during application shutdown or test cleanup.
socketsContainer.clear();
```

## AI Coding Instructions

- Register hosts through `addOne()` rather than mutating the map returned by `getAll()`.
- Use the same socket configuration values when calling `addOne()` and `getOneByConfig()` so host reuse works correctly.
- Treat `SocketsContainer` as application infrastructure; create and populate it during WebSocket server bootstrap.
- Call `clear()` during teardown to prevent socket host state from leaking between application instances or tests.

## How it works

## `SocketsContainer`

`SocketsContainer` is an in-memory collection of `ServerAndEventStreamsHost` objects, indexed by a hash derived from gateway configuration objects. Its backing collection is a `Map<string | RegExp, ServerAndEventStreamsHost>`, although its internal key-generation method returns a `string`. [packages/websockets/sockets-container.ts:4-8] [packages/websockets/sockets-container.ts:33-37]

A stored host has a `server` plus `init`, `connection`, and `disconnect` RxJS subjects. [packages/websockets/interfaces/server-and-event-streams-host.interface.ts:6-11]