22、Go语言实用工具与标准库概览

Go语言实用工具与标准库概览

1. Utility.go文件解析

Utility.go 文件提供了一些辅助函数和共享值，以下是其代码内容：

package main
import (
    "bytes"
    "image"
    "io/ioutil"
    "log"
    "net/http"
    "strings"
)
const NanosPerMs = 1_000_000
const FilePrefix = "file:" // local (vs. HTTP) file
func LoadImage(url string) (img image.Image, kind string, err error) {
    switch {
    case strings.HasPrefix(url, FilePrefix):
        url = url[len(FilePrefix):]
        var b []byte
        b, err = ioutil.ReadFile(url) // read image from file
        if err != nil {
            return
        }
        r := bytes.NewReader(b)
        img, kind, err = image.Decode(r)
        if err != nil {
            return
        }
    default:
        var resp *http.Res