Files
AFFiNE-Mirror/blocksuite/framework/global/src/di/container.ts
2024-12-20 15:38:06 +08:00

460 lines
11 KiB
TypeScript

import { DEFAULT_SERVICE_VARIANT, ROOT_SCOPE } from './consts.js';
import { DuplicateServiceDefinitionError } from './error.js';
import { parseIdentifier } from './identifier.js';
import type { ServiceProvider } from './provider.js';
import { BasicServiceProvider } from './provider.js';
import { stringifyScope } from './scope.js';
import type {
GeneralServiceIdentifier,
ServiceFactory,
ServiceIdentifier,
ServiceIdentifierType,
ServiceIdentifierValue,
ServiceScope,
ServiceVariant,
Type,
TypesToDeps,
} from './types.js';
/**
* A container of services.
*
* Container basically is a tuple of `[scope, identifier, variant, factory]` with some helper methods.
* It just stores the definitions of services. It never holds any instances of services.
*
* # Usage
*
* ```ts
* const services = new Container();
* class ServiceA {
* // ...
* }
* // add a service
* services.add(ServiceA);
*
* class ServiceB {
* constructor(serviceA: ServiceA) {}
* }
* // add a service with dependency
* services.add(ServiceB, [ServiceA]);
* ^ dependency class/identifier, match ServiceB's constructor
*
* const FeatureA = createIdentifier<FeatureA>('Config');
*
* // add a implementation for a service identifier
* services.addImpl(FeatureA, ServiceA);
*
* // override a service
* services.override(ServiceA, NewServiceA);
*
* // create a service provider
* const provider = services.provider();
* ```
*
* # The data structure
*
* The data structure of Container is a three-layer nested Map, used to represent the tuple of
* `[scope, identifier, variant, factory]`.
* Such a data structure ensures that a service factory can be uniquely determined by `[scope, identifier, variant]`.
*
* When a service added:
*
* ```ts
* services.add(ServiceClass)
* ```
*
* The data structure will be:
*
* ```ts
* Map {
* '': Map { // scope
* 'ServiceClass': Map { // identifier
* 'default': // variant
* () => new ServiceClass() // factory
* }
* }
* ```
*
* # Dependency relationship
*
* The dependency relationships of services are not actually stored in the Container,
* but are transformed into a factory function when the service is added.
*
* For example:
*
* ```ts
* services.add(ServiceB, [ServiceA]);
*
* // is equivalent to
* services.addFactory(ServiceB, (provider) => new ServiceB(provider.get(ServiceA)));
* ```
*
* For multiple implementations of the same service identifier, can be defined as:
*
* ```ts
* services.add(ServiceB, [[FeatureA]]);
*
* // is equivalent to
* services.addFactory(ServiceB, (provider) => new ServiceB(provider.getAll(FeatureA)));
* ```
*/
export class Container {
private readonly services = new Map<
string,
Map<string, Map<ServiceVariant, ServiceFactory>>
>();
/**
* @see {@link ContainerEditor.add}
*/
get add() {
return new ContainerEditor(this).add;
}
/**
* @see {@link ContainerEditor.addImpl}
*/
get addImpl() {
return new ContainerEditor(this).addImpl;
}
/**
* Create an empty service container.
*
* same as `new Container()`
*/
static get EMPTY() {
return new Container();
}
/**
* @see {@link ContainerEditor.scope}
*/
get override() {
return new ContainerEditor(this).override;
}
/**
* @see {@link ContainerEditor.scope}
*/
get scope() {
return new ContainerEditor(this).scope;
}
/**
* The number of services in the container.
*/
get size() {
let size = 0;
for (const [, identifiers] of this.services) {
for (const [, variants] of identifiers) {
size += variants.size;
}
}
return size;
}
/**
* @internal Use {@link addImpl} instead.
*/
addFactory<T>(
identifier: GeneralServiceIdentifier<T>,
factory: ServiceFactory<T>,
{ scope, override }: { scope?: ServiceScope; override?: boolean } = {}
) {
// convert scope to string
const normalizedScope = stringifyScope(scope ?? ROOT_SCOPE);
const normalizedIdentifier = parseIdentifier(identifier);
const normalizedVariant =
normalizedIdentifier.variant ?? DEFAULT_SERVICE_VARIANT;
const services =
this.services.get(normalizedScope) ??
new Map<string, Map<ServiceVariant, ServiceFactory>>();
const variants =
services.get(normalizedIdentifier.identifierName) ??
new Map<ServiceVariant, ServiceFactory>();
// throw if service already exists, unless it is an override
if (variants.has(normalizedVariant) && !override) {
throw new DuplicateServiceDefinitionError(normalizedIdentifier);
}
variants.set(normalizedVariant, factory);
services.set(normalizedIdentifier.identifierName, variants);
this.services.set(normalizedScope, services);
}
/**
* @internal Use {@link addImpl} instead.
*/
addValue<T>(
identifier: GeneralServiceIdentifier<T>,
value: T,
{ scope, override }: { scope?: ServiceScope; override?: boolean } = {}
) {
this.addFactory(
parseIdentifier(identifier) as ServiceIdentifier<T>,
() => value,
{
scope,
override,
}
);
}
/**
* Clone the entire service container.
*
* This method is quite cheap as it only clones the references.
*
* @returns A new service container with the same services.
*/
clone(): Container {
const di = new Container();
for (const [scope, identifiers] of this.services) {
const s = new Map();
for (const [identifier, variants] of identifiers) {
s.set(identifier, new Map(variants));
}
di.services.set(scope, s);
}
return di;
}
/**
* @internal
*/
getFactory(
identifier: ServiceIdentifierValue,
scope: ServiceScope = ROOT_SCOPE
): ServiceFactory | undefined {
return this.services
.get(stringifyScope(scope))
?.get(identifier.identifierName)
?.get(identifier.variant ?? DEFAULT_SERVICE_VARIANT);
}
/**
* @internal
*/
getFactoryAll(
identifier: ServiceIdentifierValue,
scope: ServiceScope = ROOT_SCOPE
): Map<ServiceVariant, ServiceFactory> {
return new Map(
this.services.get(stringifyScope(scope))?.get(identifier.identifierName)
);
}
/**
* Create a service provider from the container.
*
* @example
* ```ts
* provider() // create a service provider for root scope
* provider(ScopeA, parentProvider) // create a service provider for scope A
* ```
*
* @param scope The scope of the service provider, default to the root scope.
* @param parent The parent service provider, it is required if the scope is not the root scope.
*/
provider(
scope: ServiceScope = ROOT_SCOPE,
parent: ServiceProvider | null = null
): ServiceProvider {
return new BasicServiceProvider(this, scope, parent);
}
}
/**
* A helper class to edit a service container.
*/
class ContainerEditor {
private currentScope: ServiceScope = ROOT_SCOPE;
/**
* Add a service to the container.
*
* @see {@link Container}
*
* @example
* ```ts
* add(ServiceClass, [dependencies, ...])
* ```
*/
add = <
T extends new (...args: any) => any,
const Deps extends TypesToDeps<ConstructorParameters<T>> = TypesToDeps<
ConstructorParameters<T>
>,
>(
cls: T,
...[deps]: Deps extends [] ? [] : [Deps]
): this => {
this.container.addFactory<any>(
cls as any,
dependenciesToFactory(cls, deps as any),
{ scope: this.currentScope }
);
return this;
};
/**
* Add an implementation for identifier to the container.
*
* @see {@link Container}
*
* @example
* ```ts
* addImpl(ServiceIdentifier, ServiceClass, [dependencies, ...])
* or
* addImpl(ServiceIdentifier, Instance)
* or
* addImpl(ServiceIdentifier, Factory)
* ```
*/
addImpl = <
Arg1 extends ServiceIdentifier<any>,
Arg2 extends Type<Trait> | ServiceFactory<Trait> | Trait,
Trait = ServiceIdentifierType<Arg1>,
Deps extends Arg2 extends Type<Trait>
? TypesToDeps<ConstructorParameters<Arg2>>
: [] = Arg2 extends Type<Trait>
? TypesToDeps<ConstructorParameters<Arg2>>
: [],
Arg3 extends Deps = Deps,
>(
identifier: Arg1,
arg2: Arg2,
...[arg3]: Arg3 extends [] ? [] : [Arg3]
): this => {
if (arg2 instanceof Function) {
this.container.addFactory<any>(
identifier,
dependenciesToFactory(arg2, arg3 as any[]),
{ scope: this.currentScope }
);
} else {
this.container.addValue(identifier, arg2 as any, {
scope: this.currentScope,
});
}
return this;
};
/**
* same as {@link addImpl} but this method will override the service if it exists.
*
* @see {@link Container}
*
* @example
* ```ts
* override(OriginServiceClass, NewServiceClass, [dependencies, ...])
* or
* override(ServiceIdentifier, ServiceClass, [dependencies, ...])
* or
* override(ServiceIdentifier, Instance)
* or
* override(ServiceIdentifier, Factory)
* ```
*/
override = <
Arg1 extends ServiceIdentifier<any>,
Arg2 extends Type<Trait> | ServiceFactory<Trait> | Trait,
Trait = ServiceIdentifierType<Arg1>,
Deps extends Arg2 extends Type<Trait>
? TypesToDeps<ConstructorParameters<Arg2>>
: [] = Arg2 extends Type<Trait>
? TypesToDeps<ConstructorParameters<Arg2>>
: [],
Arg3 extends Deps = Deps,
>(
identifier: Arg1,
arg2: Arg2,
...[arg3]: Arg3 extends [] ? [] : [Arg3]
): this => {
if (arg2 instanceof Function) {
this.container.addFactory<any>(
identifier,
dependenciesToFactory(arg2, arg3 as any[]),
{ scope: this.currentScope, override: true }
);
} else {
this.container.addValue(identifier, arg2 as any, {
scope: this.currentScope,
override: true,
});
}
return this;
};
/**
* Set the scope for the service registered subsequently
*
* @example
*
* ```ts
* const ScopeA = createScope('a');
*
* services.scope(ScopeA).add(XXXService, ...);
* ```
*/
scope = (scope: ServiceScope): ContainerEditor => {
this.currentScope = scope;
return this;
};
constructor(private readonly container: Container) {}
}
/**
* Convert dependencies definition to a factory function.
*/
function dependenciesToFactory(
cls: any,
deps: any[] = []
): ServiceFactory<any> {
return (provider: ServiceProvider) => {
const args = [];
for (const dep of deps) {
let isAll;
let identifier;
if (Array.isArray(dep)) {
if (dep.length !== 1) {
throw new Error('Invalid dependency');
}
isAll = true;
identifier = dep[0];
} else {
isAll = false;
identifier = dep;
}
if (isAll) {
args.push(Array.from(provider.getAll(identifier).values()));
} else {
args.push(provider.get(identifier));
}
}
if (isConstructor(cls)) {
return new cls(...args, provider);
} else {
return cls(...args, provider);
}
};
}
// a hack to check if a function is a constructor
// https://github.com/zloirock/core-js/blob/232c8462c26c75864b4397b7f643a4f57c6981d5/packages/core-js/internals/is-constructor.js#L15
function isConstructor(cls: unknown) {
try {
Reflect.construct(function () {}, [], cls as never);
return true;
} catch {
return false;
}
}