/
main.go
94 lines (88 loc) · 2.81 KB
/
main.go
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// Copyright © 2017 Ashwin Gokhale ashwin.gokhale98@gmail.com
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package main
import (
"errors"
"net/http"
"strconv"
"strings"
"time"
"runtime"
"github.com/PuerkitoBio/purell"
"github.com/goware/urlx"
"github.com/spf13/cobra"
)
var (
downloader = &Downloader{
threads: 1,
client: &http.Client{},
}
url string
single bool
root = &cobra.Command{
Use: "gget [url]",
Short: "GGet is a multithreaded accelerated downloader",
Long: `GGet uses go routines to split up the download
of files into multiple concurrent processes`,
PreRunE: func(cmd *cobra.Command, args []string) error {
if downloader.threads < 0 {
return errors.New("Invalid thread count: " + strconv.Itoa(downloader.threads))
}
if downloader.filename == "" {
downloader.filename = url[strings.LastIndex(url, "/")+1:]
}
return nil
},
RunE: run,
Args: func(cmd *cobra.Command, args []string) error {
if len(args) != 1 {
return errors.New("Must specify a url")
}
u, err := urlx.NormalizeString(purell.MustNormalizeURLString(args[0],purell.FlagsUsuallySafeGreedy))
url = u
if err != nil { return err }
return nil
},
}
)
func init() {
root.PersistentFlags().IntVarP(&downloader.threads,"threads","t", runtime.NumCPU(), "Number of threads to run")
root.PersistentFlags().StringVarP(&(downloader.filename),"filename", "f", "", "Specify a filename")
root.PersistentFlags().BoolVarP(&single, "single-threaded", "s", false, "Use single threaded download")
}
func run(cmd *cobra.Command, args []string) error {
startTime := time.Now()
Info("Going to download %s from %s", downloader.filename, url)
resp, err := downloader.client.Head(url)
if err != nil { return err }
contentLength := resp.Header.Get("Content-Length")
ranges := resp.Header.Get("Accept-Ranges")
if contentLength == "" {
Info("Content length not specified")
return downloader.singleThreaded(startTime)
}
if ranges != "bytes" {
Info("Server does not accept byte ranges")
return downloader.singleThreaded(startTime)
}
if single || downloader.threads <= 1 {
return downloader.singleThreaded(startTime)
}
length, err := strconv.Atoi(contentLength)
if err != nil { return err }
return downloader.threadedDownload(length, startTime)
}
func main() {
root.Execute()
}