lib/src/orm/DatabaseService.ts
garrettmills fcce28081b
All checks were successful
continuous-integration/drone/push Build is passing
AsyncPipe; table schemata; migrations; File logging
2021-07-25 09:15:01 -05:00

70 lines
1.8 KiB
TypeScript

import {Connection} from './connection/Connection'
import {Inject, Singleton} from '../di'
import {ErrorWithContext, uuid4} from '../util'
import {AppClass} from '../lifecycle/AppClass'
import {Logging} from '../service/Logging'
/**
* A singleton, non-unit service that stores and retrieves database connections by name.
*/
@Singleton()
export class DatabaseService extends AppClass {
@Inject()
protected logging!: Logging
/** Mapping of connection name -> connection instance for connections registered with this service. */
protected readonly connections: { [key: string]: Connection } = {}
/**
* Register a new connection instance by name.
* @param name
* @param connection
*/
register(name: string, connection: Connection): this {
if ( this.connections[name] ) {
this.logging.warn(`Overriding duplicate connection: ${name}`)
}
this.connections[name] = connection
return this
}
/**
* Returns true if a connection is registered with the given name.
* @param name
*/
has(name: string): boolean {
return Boolean(this.connections[name])
}
/**
* Get a connection instance by its name. Throws if none exists.
* @param name
*/
get(name = 'default'): Connection {
if ( !this.has(name) ) {
throw new ErrorWithContext(`No such connection is registered: ${name}`)
}
return this.connections[name]
}
/**
* Return an array of the names of all registered connections.
*/
names(): string[] {
return Object.keys(this.connections)
}
/** Get a guaranteed-unique connection name. */
uniqueName(): string {
let name: string
do {
name = uuid4()
} while (this.has(name))
return name
}
}