Function extractObjMetadata

utils.go:204–250

Extract only necessary metadata header key/values by filtering them out with a list of custom header keys.

(header http.Header)

// Extract only necessary metadata header key/values by
// filtering them out with a list of custom header keys.
func extractObjMetadata(header http.Header) http.Header {
	preserveKeys := []string{
		"Content-Type",
		"Cache-Control",
		"Content-Encoding",
		"Content-Language",
		"Content-Disposition",
		"X-Amz-Storage-Class",
		"X-Amz-Object-Lock-Mode",
		"X-Amz-Object-Lock-Retain-Until-Date",
		"X-Amz-Object-Lock-Legal-Hold",
		"X-Amz-Website-Redirect-Location",
		"X-Amz-Server-Side-Encryption",
		"X-Amz-Tagging-Count",
		"X-Amz-Meta-",
		"X-Minio-Meta-",
		// Add new headers to be preserved.
		// if you add new headers here, please extend
		// PutObjectOptions{} to preserve them
		// upon upload as well.
	}
	filteredHeader := make(http.Header)
	for k, v := range header {
		var found bool
		for _, prefix := range preserveKeys {
			if !strings.HasPrefix(k, prefix) {
				continue
			}
			found = true
			if prefix == "X-Amz-Meta-" || prefix == "X-Minio-Meta-" {
				for index, val := range v {
					if strings.HasPrefix(val, "=?") {
						decoder := mime.WordDecoder{}
						if decoded, err := decoder.DecodeHeader(val); err == nil {
							v[index] = decoded
						}
					}
				}
			}
			break
		}
		if found {
			filteredHeader[k] = v
		}
	}
	return filteredHeader
}

const (
	// RFC 7231#section-7.1.1.1 timetamp format. e.g Tue, 29 Apr 2014 18:30:38 GMT