cf6402681b
Both functions perform the same logic and they just vary on the base multiplication units. We can refactor the common code into a single place. Docker-DCO-1.1-Signed-off-by: Francisco Carriedo <fcarriedo@gmail.com> (github: fcarriedo)
82 lines
2 KiB
Go
82 lines
2 KiB
Go
package units
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import (
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"fmt"
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"regexp"
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"strconv"
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"strings"
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)
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const (
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decimalKUnit = 1000
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binaryKUnit = 1024
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)
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var sizeRegex *regexp.Regexp
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func init() {
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var err error
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if sizeRegex, err = regexp.Compile("^(\\d+)([kKmMgGtTpP])?[bB]?$"); err != nil {
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panic("Failed to compile the 'size' regular expression")
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}
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}
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var bytePrefixes = [...]string{"B", "kB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB"}
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// HumanSize returns a human-readable approximation of a size
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// using SI standard (eg. "44kB", "17MB")
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func HumanSize(size int64) string {
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i := 0
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sizef := float64(size)
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for sizef >= 1000.0 {
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sizef = sizef / 1000.0
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i++
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}
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return fmt.Sprintf("%.4g %s", sizef, bytePrefixes[i])
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}
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// FromHumanSize returns an integer from a human-readable specification of a
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// size using SI standard (eg. "44kB", "17MB")
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func FromHumanSize(size string) (int64, error) {
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return parseSize(size, decimalKUnit)
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}
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// Parses a human-readable string representing an amount of RAM
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// in bytes, kibibytes, mebibytes, gibibytes, or tebibytes and
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// returns the number of bytes, or -1 if the string is unparseable.
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// Units are case-insensitive, and the 'b' suffix is optional.
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func RAMInBytes(size string) (int64, error) {
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return parseSize(size, binaryKUnit)
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}
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// Parses the human-readable size string into the amount it represents given
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// the desired kilo unit [decimalKiloUnit=1000|binaryKiloUnit=1024]
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func parseSize(size string, kUnit int64) (int64, error) {
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matches := sizeRegex.FindStringSubmatch(size)
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if len(matches) != 3 {
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return -1, fmt.Errorf("Invalid size: '%s'", size)
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}
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theSize, err := strconv.ParseInt(matches[1], 10, 0)
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if err != nil {
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return -1, err
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}
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unitPrefix := strings.ToLower(matches[2])
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switch unitPrefix {
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case "k":
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theSize *= kUnit
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case "m":
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theSize *= kUnit * kUnit
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case "g":
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theSize *= kUnit * kUnit * kUnit
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case "t":
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theSize *= kUnit * kUnit * kUnit * kUnit
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case "p":
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theSize *= kUnit * kUnit * kUnit * kUnit * kUnit
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}
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return theSize, nil
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}
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