bwilliams
49b824d5a2
ParseByteSize accepts "-1" or "-1B" as ByteSizeNoLimit, and String gives it back as "-1". A setting for which no limit is unsafe can reject it.
72 lines
2.0 KiB
Go
72 lines
2.0 KiB
Go
package util
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import (
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"fmt"
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"math"
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"strconv"
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"strings"
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"github.com/dustin/go-humanize"
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)
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// ByteSize is a size in bytes, configured as a string such as "32KiB", "1MB"
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// or "1.5 GB" (see ParseByteSize). KB, MB, ... are powers of 1000 and KiB,
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// MiB, ... powers of 1024; a bare number is bytes. ByteSizeNoLimit (-1) means
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// no limit; no other size is negative.
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type ByteSize int64
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// ByteSizeNoLimit is the size that means no limit, written "-1". A setting
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// for which no limit is unsafe rejects it.
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const ByteSizeNoLimit ByteSize = -1
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// byteUnits are the units String may use, largest first.
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var byteUnits = []struct {
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name string
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size int64
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}{
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{"EiB", humanize.EiByte}, {"EB", humanize.EByte},
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{"PiB", humanize.PiByte}, {"PB", humanize.PByte},
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{"TiB", humanize.TiByte}, {"TB", humanize.TByte},
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{"GiB", humanize.GiByte}, {"GB", humanize.GByte},
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{"MiB", humanize.MiByte}, {"MB", humanize.MByte},
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{"KiB", humanize.KiByte}, {"KB", humanize.KByte},
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}
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// ParseByteSize parses a size such as "32KiB", "1 MB" or "4096". Unit names
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// are case-insensitive. "-1" (or "-1B") is ByteSizeNoLimit; any other
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// negative size is an error.
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func ParseByteSize(s string) (ByteSize, error) {
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trimmed := strings.TrimSpace(s)
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if trimmed == "-1" || strings.EqualFold(trimmed, "-1B") {
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return ByteSizeNoLimit, nil
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}
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if strings.HasPrefix(trimmed, "-") {
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return 0, fmt.Errorf("byte size %q is negative; only -1 (no limit) is allowed", s)
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}
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n, err := humanize.ParseBytes(s)
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if err != nil {
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return 0, err
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}
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if n > math.MaxInt64 {
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return 0, fmt.Errorf("byte size %q is too large", s)
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}
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return ByteSize(n), nil
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}
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// String formats b exactly, in the largest unit that divides it (e.g. "32KiB",
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// "1MB"), or in bytes ("1500B"), so it parses back to the same value.
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// ByteSizeNoLimit is "-1".
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func (b ByteSize) String() string {
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if b == ByteSizeNoLimit {
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return "-1"
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}
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if b != 0 {
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for _, u := range byteUnits {
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if int64(b)%u.size == 0 {
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return strconv.FormatInt(int64(b)/u.size, 10) + u.name
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}
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}
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}
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return strconv.FormatInt(int64(b), 10) + "B"
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}
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