46 lines
1.1 KiB
Go
46 lines
1.1 KiB
Go
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package utils
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import (
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"net/http"
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"strconv"
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"time"
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)
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func SetNeverCacheHeader(header http.Header) {
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header.Set("Cache-Control", "max-age=0, no-cache, no-store, must-revalidate")
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header.Set("Pragma", "no-cache")
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}
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func SetLastModifiedHeader(header http.Header, modTime time.Time) {
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if !modTime.IsZero() {
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header.Set("Last-Modified", modTime.UTC().Format(http.TimeFormat))
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}
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}
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func SetCacheHeaderWithAge(header http.Header, maxAge uint, modifiedTime time.Time) {
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header.Set("Cache-Control", "max-age="+strconv.Itoa(int(maxAge))+", must-revalidate")
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if maxAge > 0 {
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checkerSecondsBetween := int64(time.Now().UTC().Sub(modifiedTime.UTC()).Seconds())
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if checkerSecondsBetween < 0 {
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checkerSecondsBetween *= -1
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}
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header.Set("Age", strconv.FormatUint(uint64(checkerSecondsBetween)%uint64(maxAge), 10))
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}
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}
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func SwitchToNonCachingHeaders(header http.Header) {
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SetNeverCacheHeader(header)
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if header.Get("Last-Modified") != "" {
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header.Del("Last-Modified")
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}
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if header.Get("Age") != "" {
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header.Del("Age")
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}
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if header.Get("Expires") != "" {
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header.Del("Expires")
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}
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if header.Get("ETag") != "" {
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header.Del("ETag")
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}
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}
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