/
range.go
67 lines (59 loc) · 1.84 KB
/
range.go
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// Copyright © 2019 NVIDIA Corporation
//
// 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 httputil
import (
"errors"
"fmt"
"net/http"
"regexp"
"strconv"
)
var contentRangeRE = regexp.MustCompile("^bytes (\\d+)-(\\d+)/(\\d+)$")
type ContentRange struct {
First uint64
Last uint64
Total uint64
}
func (cr ContentRange) Len() uint64 {
return cr.Last - cr.First + 1
}
func (cr ContentRange) Terminal() bool {
return cr.Last == cr.Total-1
}
func GetContentRange(resp *http.Response) (*ContentRange, error) {
cr := resp.Header.Get("Content-Range")
if cr == "" {
return nil, errors.New("empty/missing Content-Range header")
}
parts := contentRangeRE.FindStringSubmatch(cr)
if len(parts) != 4 {
return nil, fmt.Errorf("invalid Content-Range header %q", cr)
}
first, err := strconv.ParseUint(parts[1], 10, 64)
if err != nil {
return nil, fmt.Errorf("invalid Content-Range header %q", cr)
}
last, err := strconv.ParseUint(parts[2], 10, 64)
if err != nil {
return nil, fmt.Errorf("invalid Content-Range header %q", cr)
}
total, err := strconv.ParseUint(parts[3], 10, 64)
if err != nil {
return nil, fmt.Errorf("invalid Content-Range header %q", cr)
}
if total > 0 && (first > last || first >= total || last >= total) {
return nil, fmt.Errorf("invalid Content-Range header %q", cr)
}
return &ContentRange{first, last, total}, nil
}