Skip to content

Commit

Permalink
Merge pull request #40 from kolyshkin/no-regex
Browse files Browse the repository at this point in the history 
Remove regexp use
  • Loading branch information
@thaJeztah
thaJeztah committed May 17, 2022
2 parents 519db1e + 7375726 commit e682442
Show file tree
Hide file tree
Showing 2 changed files with 128 additions and 13 deletions.
70 changes: 58 additions & 12 deletions size.go
View file
Expand Up @@ -2,7 +2,6 @@ package units

import (
"fmt"
"regexp"
"strconv"
"strings"
)
Expand All @@ -26,16 +25,17 @@ const (
PiB = 1024 * TiB
)

type unitMap map[string]int64
type unitMap map[byte]int64

var (
decimalMap = unitMap{"k": KB, "m": MB, "g": GB, "t": TB, "p": PB}
binaryMap = unitMap{"k": KiB, "m": MiB, "g": GiB, "t": TiB, "p": PiB}
sizeRegex = regexp.MustCompile(`^(\d+(\.\d+)*) ?([kKmMgGtTpP])?[iI]?[bB]?$`)
decimalMap = unitMap{'k': KB, 'm': MB, 'g': GB, 't': TB, 'p': PB}
binaryMap = unitMap{'k': KiB, 'm': MiB, 'g': GiB, 't': TiB, 'p': PiB}
)

var decimapAbbrs = []string{"B", "kB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB"}
var binaryAbbrs = []string{"B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB", "ZiB", "YiB"}
var (
decimapAbbrs = []string{"B", "kB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB"}
binaryAbbrs = []string{"B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB", "ZiB", "YiB"}
)

func getSizeAndUnit(size float64, base float64, _map []string) (float64, string) {
i := 0
Expand Down Expand Up @@ -89,20 +89,66 @@ func RAMInBytes(size string) (int64, error) {

// Parses the human-readable size string into the amount it represents.
func parseSize(sizeStr string, uMap unitMap) (int64, error) {
matches := sizeRegex.FindStringSubmatch(sizeStr)
if len(matches) != 4 {
// TODO: rewrite to use strings.Cut if there's a space
// once Go < 1.18 is deprecated.
sep := strings.LastIndexAny(sizeStr, "01234567890. ")
if sep == -1 {
// There should be at least a digit.
return -1, fmt.Errorf("invalid size: '%s'", sizeStr)
}
var num, sfx string
if sizeStr[sep] != ' ' {
num = sizeStr[:sep+1]
sfx = sizeStr[sep+1:]
} else {
// Omit the space separator.
num = sizeStr[:sep]
sfx = sizeStr[sep+1:]
}

size, err := strconv.ParseFloat(matches[1], 64)
size, err := strconv.ParseFloat(num, 64)
if err != nil {
return -1, err
}
// Backward compatibility: reject negative sizes.
if size < 0 {
return -1, fmt.Errorf("invalid size: '%s'", sizeStr)
}

if len(sfx) == 0 {
return int64(size), nil
}

unitPrefix := strings.ToLower(matches[3])
if mul, ok := uMap[unitPrefix]; ok {
// Process the suffix.

if len(sfx) > 3 { // Too long.
goto badSuffix
}
sfx = strings.ToLower(sfx)
// Trivial case: b suffix.
if sfx[0] == 'b' {
if len(sfx) > 1 { // no extra characters allowed after b.
goto badSuffix
}
return int64(size), nil
}
// A suffix from the map.
if mul, ok := uMap[sfx[0]]; ok {
size *= float64(mul)
} else {
goto badSuffix
}

// The suffix may have extra "b" or "ib" (e.g. KiB or MB).
switch {
case len(sfx) == 2 && sfx[1] != 'b':
goto badSuffix
case len(sfx) == 3 && sfx[1:] != "ib":
goto badSuffix
}

return int64(size), nil

badSuffix:
return -1, fmt.Errorf("invalid suffix: '%s'", sfx)
}
71 changes: 70 additions & 1 deletion size_test.go
View file
Expand Up @@ -83,6 +83,10 @@ func TestHumanSize(t *testing.T) {
}

func TestFromHumanSize(t *testing.T) {
assertSuccessEquals(t, 0, FromHumanSize, "0")
assertSuccessEquals(t, 0, FromHumanSize, "0b")
assertSuccessEquals(t, 0, FromHumanSize, "0B")
assertSuccessEquals(t, 0, FromHumanSize, "0 B")
assertSuccessEquals(t, 32, FromHumanSize, "32")
assertSuccessEquals(t, 32, FromHumanSize, "32b")
assertSuccessEquals(t, 32, FromHumanSize, "32B")
Expand All @@ -98,11 +102,59 @@ func TestFromHumanSize(t *testing.T) {
assertSuccessEquals(t, 32.5*KB, FromHumanSize, "32.5kB")
assertSuccessEquals(t, 32.5*KB, FromHumanSize, "32.5 kB")
assertSuccessEquals(t, 32, FromHumanSize, "32.5 B")
assertSuccessEquals(t, 300, FromHumanSize, "0.3 K")
assertSuccessEquals(t, 300, FromHumanSize, ".3kB")

assertSuccessEquals(t, 0, FromHumanSize, "0.")
assertSuccessEquals(t, 0, FromHumanSize, "0. ")
assertSuccessEquals(t, 0, FromHumanSize, "0.b")
assertSuccessEquals(t, 0, FromHumanSize, "0.B")
assertSuccessEquals(t, 0, FromHumanSize, "-0")
assertSuccessEquals(t, 0, FromHumanSize, "-0b")
assertSuccessEquals(t, 0, FromHumanSize, "-0B")
assertSuccessEquals(t, 0, FromHumanSize, "-0 b")
assertSuccessEquals(t, 0, FromHumanSize, "-0 B")
assertSuccessEquals(t, 32, FromHumanSize, "32.")
assertSuccessEquals(t, 32, FromHumanSize, "32.b")
assertSuccessEquals(t, 32, FromHumanSize, "32.B")
assertSuccessEquals(t, 32, FromHumanSize, "32. b")
assertSuccessEquals(t, 32, FromHumanSize, "32. B")

// We do not tolerate extra leading or trailing spaces
// (except for a space after the number and a missing suffix).
assertSuccessEquals(t, 0, FromHumanSize, "0 ")

assertError(t, FromHumanSize, " 0")
assertError(t, FromHumanSize, " 0b")
assertError(t, FromHumanSize, " 0B")
assertError(t, FromHumanSize, " 0 B")
assertError(t, FromHumanSize, "0b ")
assertError(t, FromHumanSize, "0B ")
assertError(t, FromHumanSize, "0 B ")

assertError(t, FromHumanSize, "")
assertError(t, FromHumanSize, "hello")
assertError(t, FromHumanSize, ".")
assertError(t, FromHumanSize, ". ")
assertError(t, FromHumanSize, " ")
assertError(t, FromHumanSize, " ")
assertError(t, FromHumanSize, " .")
assertError(t, FromHumanSize, " . ")
assertError(t, FromHumanSize, "-32")
assertError(t, FromHumanSize, ".3kB")
assertError(t, FromHumanSize, "-32b")
assertError(t, FromHumanSize, "-32B")
assertError(t, FromHumanSize, "-32 b")
assertError(t, FromHumanSize, "-32 B")
assertError(t, FromHumanSize, "32b.")
assertError(t, FromHumanSize, "32B.")
assertError(t, FromHumanSize, "32 b.")
assertError(t, FromHumanSize, "32 B.")
assertError(t, FromHumanSize, "32 bb")
assertError(t, FromHumanSize, "32 BB")
assertError(t, FromHumanSize, "32 b b")
assertError(t, FromHumanSize, "32 B B")
assertError(t, FromHumanSize, "32 b")
assertError(t, FromHumanSize, "32 B")
assertError(t, FromHumanSize, " 32 ")
assertError(t, FromHumanSize, "32m b")
assertError(t, FromHumanSize, "32bm")
Expand All @@ -128,6 +180,8 @@ func TestRAMInBytes(t *testing.T) {
assertSuccessEquals(t, 32, RAMInBytes, "32.3")
tmp := 32.3 * MiB
assertSuccessEquals(t, int64(tmp), RAMInBytes, "32.3 mb")
tmp = 0.3 * MiB
assertSuccessEquals(t, int64(tmp), RAMInBytes, "0.3MB")

assertError(t, RAMInBytes, "")
assertError(t, RAMInBytes, "hello")
Expand All @@ -137,7 +191,20 @@ func TestRAMInBytes(t *testing.T) {
assertError(t, RAMInBytes, "32bm")
}

func BenchmarkParseSize(b *testing.B) {
for i := 0; i < b.N; i++ {
for _, s := range []string{
"", "32", "32b", "32 B", "32k", "32.5 K", "32kb", "32 Kb",
"32.8Mb", "32.9Gb", "32.777Tb", "32Pb", "0.3Mb", "-1",
} {
FromHumanSize(s)
RAMInBytes(s)
}
}
}

func assertEquals(t *testing.T, expected, actual interface{}) {
t.Helper()
if expected != actual {
t.Errorf("Expected '%v' but got '%v'", expected, actual)
}
Expand All @@ -153,13 +220,15 @@ func (fn parseFn) String() string {
}

func assertSuccessEquals(t *testing.T, expected int64, fn parseFn, arg string) {
t.Helper()
res, err := fn(arg)
if err != nil || res != expected {
t.Errorf("%s(\"%s\") -> expected '%d' but got '%d' with error '%v'", fn, arg, expected, res, err)
}
}

func assertError(t *testing.T, fn parseFn, arg string) {
t.Helper()
res, err := fn(arg)
if err == nil && res != -1 {
t.Errorf("%s(\"%s\") -> expected error but got '%d'", fn, arg, res)
Expand Down

0 comments on commit e682442

Please sign in to comment.