81 lines
1.7 KiB
Go
81 lines
1.7 KiB
Go
// Copyright 2017, Google
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//
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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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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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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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package base
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import (
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"bytes"
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"errors"
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"fmt"
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)
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func noEscape(c byte) bool {
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switch c {
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case '.', '_', '-', '/', '~', '!', '$', '\'', '(', ')', '*', ';', '=', ':', '@':
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return true
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}
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return false
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}
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func escape(s string) string {
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// cribbed from url.go, kinda
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b := &bytes.Buffer{}
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for i := 0; i < len(s); i++ {
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switch c := s[i]; {
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case c == '/':
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b.WriteByte(c)
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case 'a' <= c && c <= 'z' || 'A' <= c && c <= 'Z' || '0' <= c && c <= '9':
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b.WriteByte(c)
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case noEscape(c):
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b.WriteByte(c)
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default:
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fmt.Fprintf(b, "%%%X", c)
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}
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}
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return b.String()
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}
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func unescape(s string) (string, error) {
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b := &bytes.Buffer{}
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for i := 0; i < len(s); i++ {
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c := s[i]
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switch c {
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case '/':
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b.WriteString("/")
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case '+':
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b.WriteString(" ")
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case '%':
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if len(s)-i < 3 {
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return "", errors.New("unescape: bad encoding")
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}
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b.WriteByte(unhex(s[i+1])<<4 | unhex(s[i+2]))
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i += 2
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default:
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b.WriteByte(c)
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}
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}
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return b.String(), nil
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}
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func unhex(c byte) byte {
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switch {
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case '0' <= c && c <= '9':
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return c - '0'
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case 'a' <= c && c <= 'f':
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return c - 'a' + 10
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case 'A' <= c && c <= 'F':
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return c - 'A' + 10
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}
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return 0
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}
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