开发者笔记 - 每天积累一点

防止不存在函数 fnull

用于处理一些值不存在的函数

敲碎时间的人 3个月前更新

import _ from 'lodash';
const existy = function (x) {
  return x !== null;
}

/**
 * @params { Function } fn, 用于封装处理的函数
 *
 * @returns { Function } fn,返回用于增强处理的函数
 **/
const fnull = function(fn) {
  var defauts = _.drop(arguments);
  return function() {
    var args = _.map(arguments, function( e, i) {
      return existy(e)? e: defauts[i];

Swift获取类和struct实例的内存地址

简文星 4个月前更新

// https://stackoverflow.com/a/45777692/5536516

import Foundation

struct MemoryAddress<T>: CustomStringConvertible {

    let intValue: Int

    var description: String {
        let length = 2 + 2 * MemoryLayout<UnsafeRawPointer>.size
        return String(format: "%0\(length)p", intValue)
    }

    // for structures
    init(of structPointer: UnsafePointer<T>) {

Java版本防抖函数Debouncer

防抖函数debounce作用是让某个函数在某段时间内，无论它被触发多少次，它都只执行最后一次的触发

JV 5个月前发布

import lombok.RequiredArgsConstructor;
import lombok.val;
import java.time.Duration;
import java.time.Instant;
import java.util.concurrent.*;
import static java.util.concurrent.TimeUnit.MILLISECONDS;

/**
 * A utility for debouncing function calls.
 */
public class Debouncer<T> {

    private final ScheduledExecutorService executorService;
    private final ConcurrentHashMap<Object, DebouncedTask<T>> buffer = new ConcurrentHashMap<>();
    private final Duration debounceDuration;

Angular面包屑组件

结合路由的data，自动生成路由的面包屑

Matt 5个月前更新

import { Component } from '@angular/core';
import { Observable } from 'rxjs';

import { Breadcrumb } from './breadcrumb.model';
import { BreadcrumbService } from './breadcrumb.service';

@Component({
  selector: 'breadcrumb',
  templateUrl: './breadcrumb.component.html',
  styleUrls: ['./breadcrumb.component.scss']
})
export class BreadcrumbComponent {

  breadcrumbs$: Observable<Breadcrumb[]>;

Java高效转换List<char[]>为char[]的代码

基于CharBuffer高效展开List

JV 5个月前发布

/**
     * 要高效把List<char[]>展开为char[]要注意：
     * 1. 使用Buffer，对应于char的Buffer是CharBuffer
     * 2. 避免使用多次复制
     * 3. 避免字符串转换
     * @param list
     * @return
     */
    char[] flatten(List<char[]> list) {
        //为了高效分配空间，预先计算转换的空间大小
        CharBuffer fullBuffer = CharBuffer.allocate(
                list.stream().mapToInt(array -> array.length).sum());
        list.forEach(fullBuffer::put);
        
        //注意点：CharBuffer.array()返回的是buffer内的数组，避免数据的多次复制。

Vuetify确认对话框组件

此vue对话框组件基于composition-api实现

vuer 5个月前更新

<script>
import { defineComponent, reactive, toRefs } from "@vue/composition-api";
export default defineComponent({
  setup() {
    const state = reactive({
      dialog: false,
      resolve: null,
      reject: null,
      message: null,
      title: null,
      options: {
        color: "primary",
        width: 290,
        zIndex: 200
      }

Go语言客户端SSL认证代码示例

帅Guo 5个月前更新

package main

import (
	"crypto/tls"
	"crypto/x509"
	"flag"
	"io/ioutil"
	"log"
	"net/http"
)

var (
	certFile = flag.String("cert", "someCertFile", "A PEM eoncoded certificate file.")
	keyFile  = flag.String("key", "someKeyFile", "A PEM encoded private key file.")
	caFile   = flag.String("CA", "someCertCAFile", "A PEM eoncoded CA's certificate file.")

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