resource/lvm/lowlevel/size.go
// Copyright © 2016 Asteris, LLC
//
// 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 lowlevel
import (
"fmt"
"regexp"
"strconv"
"github.com/pkg/errors"
)
// NB: Implement proper case handling as LVM does
// upper case is S.I. (power of 10)
// lower case is powers of 1024
// also special suffixes `S` and `s` exists for sectors
// Related ssue: https://github.com/asteris-llc/converge/issues/448
// Cover values for `66%FREE` and likewise (refer LVM manpages for details).
// See also size_test.go for more usage examples
var pctRE = regexp.MustCompile(`^(?i)(\d+)%(PVS|VG|FREE)$`)
// Cover values for `50G` and likewise (refer LVM manpages for details).
// See also size_test.go for more usage examples.
// Difference between lower/upper cases letters not supported now, see NB above
var sizeRE = regexp.MustCompile(`^(?i)(\d+)([bskmgtpe])b?$`)
// LvmSize represent parsed and validated LVM compatible size
type LvmSize struct {
Size int64
Relative bool
Unit string
}
// String reconstruct size to LVM compatible form
func (size *LvmSize) String() string {
return fmt.Sprintf("%d%s", size.Size, size.Unit)
}
// Option reconstruct -l/-L parameter from size.Relative
func (size *LvmSize) Option() string {
if size.Relative {
return "-l"
}
return "-L"
}
// CommandLine return part of command line for calling LVM tools like lvcreate
func (size *LvmSize) CommandLine() [2]string {
s := size.String()
o := size.Option()
return [2]string{o, s}
}
// ParseSize parsing and validating sizes in format acceptable by LVM tools
func ParseSize(sizeToParse string) (*LvmSize, error) {
var err error
size := &LvmSize{}
if m := pctRE.FindStringSubmatch(sizeToParse); m != nil {
size.Relative = true
size.Unit = "%" + m[2]
size.Size, err = strconv.ParseInt(m[1], 10, 64)
if err != nil {
return nil, errors.Wrap(err, "Parse LVM size")
}
if size.Size > 100 {
return nil, fmt.Errorf("size in %% can't be more than 100%%: %d", size.Size)
}
} else if m := sizeRE.FindStringSubmatch(sizeToParse); m != nil {
size.Relative = false
size.Unit = m[2]
size.Size, err = strconv.ParseInt(m[1], 10, 64)
if err != nil {
return nil, err
}
} else {
return nil, fmt.Errorf("size parse error: %s", sizeToParse)
}
return size, nil
}