Function parseRangeHeaderForPreview

api/controller/file_preview.go:380–420

parseRangeHeaderForPreview 解析Range请求头，用于预览功能

(rangeHeader string, fileSize int64)

// parseRangeHeaderForPreview 解析Range请求头，用于预览功能
func parseRangeHeaderForPreview(rangeHeader string, fileSize int64) (int64, int64) {
	if !strings.HasPrefix(rangeHeader, "bytes=") {
		return 0, fileSize - 1
	}

	rangeHeader = rangeHeader[6:] // 移除 "bytes="
	parts := strings.Split(rangeHeader, "-")
	if len(parts) != 2 {
		return 0, fileSize - 1
	}

	var start, end int64
	var err error

	if parts[0] == "" {
		// suffix bytes
		suffix, err := strconv.ParseInt(parts[1], 10, 64)
		if err != nil || suffix <= 0 {
			return 0, fileSize - 1
		}
		start = fileSize - suffix
		end = fileSize - 1
	} else {
		start, err = strconv.ParseInt(parts[0], 10, 64)
		if err != nil || start < 0 {
			start = 0
		}

		if parts[1] == "" {
			// bytes=start-
			end = fileSize - 1
		} else {
			end, err = strconv.ParseInt(parts[1], 10, 64)
			if err != nil || end >= fileSize {
				end = fileSize - 1
			}
		}
	}

	return start, end
}

// GetFileBodyContent godoc
// @Summary 获取文件版本内容