github.com/m3db/m3@v1.5.0/src/dbnode/x/xio/utils.go

// Copyright (c) 2020 Uber Technologies, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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// THE SOFTWARE.

package xio

import "encoding/binary"

// ToBytes reads and returns the contents of Reader64 as a slice of bytes.
// Should normally return io.EOF as an error.
func ToBytes(reader Reader64) ([]byte, error) {
	var (
		res []byte
		buf [8]byte
	)

	word, bytes, err := reader.Read64()
	for ; err == nil; word, bytes, err = reader.Read64() {
		binary.BigEndian.PutUint64(buf[:], word)
		res = append(res, buf[:bytes]...)
	}

	return res, err
}