dragonfly/pkg/util/rangeutils/range.go

114 lines
3.2 KiB
Go

/*
* Copyright 2020 The Dragonfly Authors
*
* 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 rangeutils
import (
"fmt"
"strconv"
"strings"
)
const (
separator = "-"
)
type Range struct {
StartIndex uint64
EndIndex uint64
}
func (r Range) String() string {
return fmt.Sprintf("%d%s%d", r.StartIndex, separator, r.EndIndex)
}
// ParseRange parses Range according to range string.
// rangeStr: "start-end"
func ParseRange(rangeStr string) (r *Range, err error) {
ranges := strings.Split(rangeStr, separator)
if len(ranges) != 2 {
return nil, fmt.Errorf("range value(%s) is illegal which should be like 0-45535", rangeStr)
}
startIndex, err := strconv.ParseUint(ranges[0], 10, 64)
if err != nil {
return nil, fmt.Errorf("range(%s) start is not a non-negative number", rangeStr)
}
endIndex, err := strconv.ParseUint(ranges[1], 10, 64)
if err != nil {
return nil, fmt.Errorf("range(%s) end is not a non-negative number", rangeStr)
}
if endIndex < startIndex {
return nil, fmt.Errorf("range(%s) start is larger than end", rangeStr)
}
return &Range{
StartIndex: startIndex,
EndIndex: endIndex,
}, nil
}
// ParseRange parses Range according to range string.
// rangeStr: "bytes=start-end"
func ParseHTTPRange(rangeStr string) (r *Range, err error) {
prefix := "bytes="
if !strings.HasPrefix(rangeStr, prefix) || strings.Count(rangeStr, prefix) != 1 {
return nil, fmt.Errorf("rangeStr %s not start with bytes=", rangeStr)
}
rangeStr = strings.Replace(rangeStr, prefix, "", 1)
ranges := strings.Split(rangeStr, separator)
if len(ranges) != 2 {
return nil, fmt.Errorf("range value(%s) is illegal which should be like 0-45535", rangeStr)
}
startIndex, err := strconv.ParseUint(ranges[0], 10, 64)
if err != nil {
return nil, fmt.Errorf("range(%s) start is not a non-negative number", rangeStr)
}
endIndex, err := strconv.ParseUint(ranges[1], 10, 64)
if err != nil {
return nil, fmt.Errorf("range(%s) end is not a non-negative number", rangeStr)
}
if endIndex < startIndex {
return nil, fmt.Errorf("range(%s) start is larger than end", rangeStr)
}
return &Range{
StartIndex: startIndex,
EndIndex: endIndex,
}, nil
}
func GetBreakRange(breakPoint int64, sourceFileLength int64) (*Range, error) {
if breakPoint < 0 {
return nil, fmt.Errorf("breakPoint is illegal for value: %d", breakPoint)
}
if sourceFileLength < 0 {
return nil, fmt.Errorf("sourceFileLength is illegal for value: %d", sourceFileLength)
}
end := sourceFileLength - 1
if breakPoint > end {
return nil, fmt.Errorf("start: %d is larger than end: %d", breakPoint, end)
}
return &Range{
StartIndex: uint64(breakPoint),
EndIndex: uint64(end),
}, nil
}