mirror of https://github.com/perkeep/perkeep.git
75 lines
1.7 KiB
Go
75 lines
1.7 KiB
Go
/*
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Copyright 2011 Google Inc.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package httprange
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import (
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"http"
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"regexp"
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"strconv"
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)
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// Default is {0, -1} to read all of a file.
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type Range struct {
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skipBytes int64
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limitBytes int64 // or -1 to read all
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}
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func (rr *Range) SkipBytes() int64 {
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return rr.skipBytes
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}
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// LimitBytes reads the max number of bytes to read, or -1 for no limit.
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func (rr *Range) LimitBytes() int64 {
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return rr.limitBytes
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}
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func (rr *Range) IsWholeFile() bool {
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return rr.skipBytes == 0 && rr.limitBytes == -1
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}
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var WholeRange = &Range{0, -1}
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var rangePattern = regexp.MustCompile(`bytes=([0-9]+)-([0-9]*)`)
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func FromRequest(req *http.Request) *Range {
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rrange := req.Header.Get("Range")
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if rrange == "" {
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return WholeRange
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}
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return FromString(rrange)
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}
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func FromString(rrange string) *Range {
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matches := rangePattern.FindStringSubmatch(rrange)
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if len(matches) == 0 {
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return WholeRange
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}
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skipBytes, _ := strconv.Atoi64(matches[1])
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lastByteInclusive := int64(-1)
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if len(matches[2]) > 0 {
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lastByteInclusive, _ = strconv.Atoi64(matches[2])
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}
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limitBytes := int64(-1)
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if lastByteInclusive != -1 {
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limitBytes = lastByteInclusive - skipBytes + 1
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if limitBytes < 0 {
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limitBytes = 0
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}
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}
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return &Range{skipBytes, limitBytes}
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}
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