@antv/x6/src/util/function/function.ts

JavaScript diagramming library that uses SVG and HTML for rendering.

export { isFunction, once, noop, debounce, defer } from 'lodash-es'

type Fn = (...args: any[]) => any

export function apply<T extends Fn>(
  fn: T,
  ctx: ThisParameterType<T>,
  args?: Parameters<T>,
): ReturnType<T> {
  if (args) {
    switch (args.length) {
      case 0:
        return fn.call(ctx)
      case 1:
        return fn.call(ctx, args[0])
      case 2:
        return fn.call(ctx, args[0], args[1])
      case 3:
        return fn.call(ctx, args[0], args[1], args[2])
      case 4:
        return fn.call(ctx, args[0], args[1], args[2], args[3])
      case 5:
        return fn.call(ctx, args[0], args[1], args[2], args[3], args[4])
      case 6:
        return fn.call(
          ctx,
          args[0],
          args[1],
          args[2],
          args[3],
          args[4],
          args[5],
        )
      default:
        return fn.apply(ctx, args)
    }
  }

  return fn.call(ctx)
}

export function call<T extends Fn>(
  fn: T,
  ctx: ThisParameterType<T>,
  ...args: Parameters<T>
): ReturnType<T> {
  return apply(fn, ctx, args)
}

function repush<T>(array: T[], item: T) {
  for (let i = 0, ii = array.length; i < ii; i += 1) {
    if (array[i] === item) {
      return array.push(array.splice(i, 1)[0])
    }
  }
}

export function cacher<T extends Fn>(
  fn: T,
  ctx?: ThisParameterType<T>,
  postProcessor?: (v: any, hasCache?: boolean) => any,
): T {
  const keys: string[] = []
  const cache: { [kry: string]: any } = {}
  const f = (...args: Parameters<T>) => {
    let hasCache = false
    const key = args.join('\u2400')
    if (key in cache) {
      hasCache = true
      repush(keys, key)
    } else {
      if (keys.length >= 1000) {
        delete cache[keys.shift()!]
      }
      keys.push(key)
      cache[key] = apply(fn, ctx || (null as ThisParameterType<T>), args)
    }

    return postProcessor ? postProcessor(cache[key], hasCache) : cache[key]
  }

  return f as T
}