72 lines
1.2 KiB
Go
72 lines
1.2 KiB
Go
// Copyright 2015, David Howden
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package tag
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import (
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"io"
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"io/ioutil"
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)
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func discardN(r io.Reader, n int64) error {
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_, err := io.CopyN(ioutil.Discard, r, n)
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return err
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}
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func getBit(b byte, n uint) bool {
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x := byte(1 << n)
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return (b & x) == x
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}
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func get7BitChunkedInt(b []byte) int {
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var n int
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for _, x := range b {
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n = n << 7
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n |= int(x)
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}
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return n
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}
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func getInt(b []byte) int {
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var n int
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for _, x := range b {
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n = n << 8
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n |= int(x)
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}
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return n
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}
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func readBytes(r io.Reader, n int) ([]byte, error) {
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b := make([]byte, n)
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_, err := io.ReadFull(r, b)
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if err != nil {
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return nil, err
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}
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return b, nil
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}
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func readString(r io.Reader, n int) (string, error) {
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b, err := readBytes(r, n)
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if err != nil {
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return "", err
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}
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return string(b), nil
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}
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func readInt(r io.Reader, n int) (int, error) {
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b, err := readBytes(r, n)
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if err != nil {
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return 0, err
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}
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return getInt(b), nil
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}
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func read7BitChunkedInt(r io.Reader, n int) (int, error) {
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b, err := readBytes(r, n)
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if err != nil {
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return 0, err
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}
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return get7BitChunkedInt(b), nil
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}
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