minio/strconv-bytes.go
Harshavardhana d2557bb538 XL: GetObject caching implemented for XL. (#2017)
The object cache implementation is XL cache, which defaults
to 8GB worth of read cache. Currently GetObject() transparently
writes to this cache upon first client read and then subsequently
serves reads from the same cache.

Currently expiration is not implemented.
2016-07-03 17:15:38 -07:00

118 lines
2.5 KiB
Go

/*
* Minio Cloud Storage, (C) 2016 Minio, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package main
import (
"fmt"
"math"
"strconv"
"strings"
"unicode"
)
// IEC Sizes, kibis of bits
const (
Byte = 1 << (iota * 10)
KiByte
MiByte
GiByte
TiByte
PiByte
EiByte
)
// Scientific notation Sizes.
const (
IByte = 1
KByte = IByte * 1000
MByte = KByte * 1000
GByte = MByte * 1000
TByte = GByte * 1000
PByte = TByte * 1000
EByte = PByte * 1000
)
// This table represents both IEC and SI notations with their corresponding values.
var bytesSizeTable = map[string]uint64{
"b": Byte,
"kib": KiByte,
"kb": KByte,
"mib": MiByte,
"mb": MByte,
"gib": GiByte,
"gb": GByte,
"tib": TiByte,
"tb": TByte,
"pib": PiByte,
"pb": PByte,
"eib": EiByte,
"eb": EByte,
// Without suffix
"": Byte,
"ki": KiByte,
"k": KByte,
"mi": MiByte,
"m": MByte,
"gi": GiByte,
"g": GByte,
"ti": TiByte,
"t": TByte,
"pi": PiByte,
"p": PByte,
"ei": EiByte,
"e": EByte,
}
// strconvBytes parses a string representation of bytes into the number
// of bytes it represents.
//
// See Also: Bytes, IBytes.
//
// ParseBytes("42MB") -> 42000000, nil
// ParseBytes("42mib") -> 44040192, nil
func strconvBytes(s string) (uint64, error) {
lastDigit := 0
// Calculates the final integer value.
for _, r := range s {
// This supports decimals as well.
if !(unicode.IsDigit(r) || r == '.') {
break
}
lastDigit++
}
// Float parsing to deal with decimal inputs.
f, err := strconv.ParseFloat(s[:lastDigit], 64)
if err != nil {
return 0, err
}
// Fetch the corresponding byte size for notation.
byteSize := strings.ToLower(strings.TrimSpace(s[lastDigit:]))
size, ok := bytesSizeTable[byteSize]
if !ok {
return 0, fmt.Errorf("Unrecognized size notation name: %v", byteSize)
}
f *= float64(size)
// Return an error if final value overflows uint64 max.
if f >= math.MaxUint64 {
return 0, fmt.Errorf("too large: %v", s)
}
// Success.
return uint64(f), nil
}