58 lines
1.2 KiB
Go
58 lines
1.2 KiB
Go
package cache
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import (
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"io"
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"log"
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"net/http"
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"os"
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)
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func (c *Cache) nextMirror() string {
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idx := c.mirrorIdx.Add(1) - 1
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return c.cfg.mirrorURLs[idx%uint32(len(c.cfg.mirrorURLs))]
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}
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func downloadToDisk(url, destPath string, c http.Client) error {
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log.Printf("fetching %v", url)
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// set the user agent
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req, err := http.NewRequest("GET", url, nil)
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if err != nil {
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log.Printf("failed to create request: %v", err)
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return &UpstreamError{StatusCode: http.StatusInternalServerError}
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}
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req.Header.Set("User-Agent", userAgent)
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resp, err := c.Do(req)
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if err != nil {
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log.Printf("error fetching %s: %v", url, err)
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return err
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}
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if resp.StatusCode != 200 {
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log.Printf("GET %s returned %d", url, resp.StatusCode)
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return &UpstreamError{StatusCode: resp.StatusCode}
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}
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defer resp.Body.Close()
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// use a tmp file for the initial fetch in case it fails
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tempPath := destPath + ".tmp"
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tmpFile, err := os.Create(tempPath)
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if err != nil {
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return err
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}
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defer tmpFile.Close()
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_, err = io.Copy(tmpFile, resp.Body)
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if err != nil {
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os.Remove(tempPath)
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return err
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}
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// mv file to final location
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if err := os.Rename(tempPath, destPath); err != nil {
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os.Remove(tempPath)
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return err
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}
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return nil
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}
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