54 lines
1.1 KiB
Go
54 lines
1.1 KiB
Go
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// Copyright 2016 Apcera Inc. All rights reserved.
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package util
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import (
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"encoding/binary"
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"io"
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)
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// ByteOrder specifies how to convert byte sequences into 16-, 32-, or 64-bit
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// unsigned integers.
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var ByteOrder binary.ByteOrder
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func init() {
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ByteOrder = binary.LittleEndian
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}
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// EnsureBufBigEnough checks that given buffer is big enough to hold 'needed'
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// bytes, otherwise returns a buffer of a size of at least 'needed' bytes.
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func EnsureBufBigEnough(buf []byte, needed int) []byte {
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if buf == nil {
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return make([]byte, needed)
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} else if needed > len(buf) {
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return make([]byte, int(float32(needed)*1.1))
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}
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return buf
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}
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// WriteInt writes an int (4 bytes) to the given writer using ByteOrder.
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func WriteInt(w io.Writer, v int) error {
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var b [4]byte
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var bs []byte
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bs = b[:4]
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ByteOrder.PutUint32(bs, uint32(v))
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_, err := w.Write(bs)
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return err
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}
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// ReadInt reads an int (4 bytes) from the reader using ByteOrder.
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func ReadInt(r io.Reader) (int, error) {
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var b [4]byte
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var bs []byte
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bs = b[:4]
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_, err := io.ReadFull(r, bs)
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if err != nil {
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return 0, err
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}
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return int(ByteOrder.Uint32(bs)), nil
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}
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