io_utilities.h

Go to the documentation of this file.

// Copyright (C) 2011-2023 Internet Systems Consortium, Inc. ("ISC")
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
#ifndef IO_UTILITIES_H
#define IO_UTILITIES_H
 
#include <exceptions/exceptions.h>
#include <cstddef>
 
namespace isc {
namespace util {
 
inline uint16_t
readUint16(const void* buffer, size_t length) {
    if (length < sizeof(uint16_t)) {
        isc_throw(isc::OutOfRange,
                  "Length (" << length << ") of buffer is insufficient " <<
                  "to read a uint16_t");
    }
 
    const uint8_t* byte_buffer = static_cast<const uint8_t*>(buffer);
 
    uint16_t result = (static_cast<uint16_t>(byte_buffer[0])) << 8;
    result |= static_cast<uint16_t>(byte_buffer[1]);
 
    return (result);
}
 
inline uint8_t*
writeUint16(uint16_t value, void* buffer, size_t length) {
    if (length < sizeof(uint16_t)) {
        isc_throw(isc::OutOfRange,
                  "Length (" << length << ") of buffer is insufficient " <<
                  "to write a uint16_t");
    }
 
    uint8_t* byte_buffer = static_cast<uint8_t*>(buffer);
 
    byte_buffer[0] = static_cast<uint8_t>((value & 0xff00U) >> 8);
    byte_buffer[1] = static_cast<uint8_t>(value & 0x00ffU);
 
    return (byte_buffer + sizeof(uint16_t));
}
 
inline uint32_t
readUint32(const void* buffer, size_t length) {
    if (length < sizeof(uint32_t)) {
        isc_throw(isc::OutOfRange,
                  "Length (" << length << ") of buffer is insufficient " <<
                  "to read a uint32_t");
    }
 
    const uint8_t* byte_buffer = static_cast<const uint8_t*>(buffer);
 
    uint32_t result = (static_cast<uint32_t>(byte_buffer[0])) << 24;
    result |= (static_cast<uint32_t>(byte_buffer[1])) << 16;
    result |= (static_cast<uint32_t>(byte_buffer[2])) << 8;
    result |= (static_cast<uint32_t>(byte_buffer[3]));
 
    return (result);
}
 
inline uint8_t*
writeUint32(uint32_t value, void* buffer, size_t length) {
    if (length < sizeof(uint32_t)) {
        isc_throw(isc::OutOfRange,
                  "Length (" << length << ") of buffer is insufficient " <<
                  "to write a uint32_t");
    }
 
    uint8_t* byte_buffer = static_cast<uint8_t*>(buffer);
 
    byte_buffer[0] = static_cast<uint8_t>((value & 0xff000000U) >> 24);
    byte_buffer[1] = static_cast<uint8_t>((value & 0x00ff0000U) >> 16);
    byte_buffer[2] = static_cast<uint8_t>((value & 0x0000ff00U) >> 8);
    byte_buffer[3] = static_cast<uint8_t>((value & 0x000000ffU));
 
    return (byte_buffer + sizeof(uint32_t));
}
 
inline uint64_t
readUint64(const void* buffer, size_t length) {
    if (length < sizeof(uint64_t)) {
        isc_throw(isc::OutOfRange,
                  "Length (" << length << ") of buffer is insufficient " <<
                  "to read a uint64_t");
    }
 
    const uint8_t* byte_buffer = static_cast<const uint8_t*>(buffer);
 
    uint64_t result = (static_cast<uint64_t>(byte_buffer[0])) << 56;
    result |= (static_cast<uint64_t>(byte_buffer[1])) << 48;
    result |= (static_cast<uint64_t>(byte_buffer[2])) << 40;
    result |= (static_cast<uint64_t>(byte_buffer[3])) << 32;
    result |= (static_cast<uint64_t>(byte_buffer[4])) << 24;
    result |= (static_cast<uint64_t>(byte_buffer[5])) << 16;
    result |= (static_cast<uint64_t>(byte_buffer[6])) << 8;
    result |= (static_cast<uint64_t>(byte_buffer[7]));
 
    return (result);
}
 
inline uint8_t*
writeUint64(uint64_t value, void* buffer, size_t length) {
    if (length < sizeof(uint64_t)) {
        isc_throw(isc::OutOfRange,
                  "Length (" << length << ") of buffer is insufficient " <<
                  "to write a uint64_t");
    }
 
    uint8_t* byte_buffer = static_cast<uint8_t*>(buffer);
 
    byte_buffer[0] = static_cast<uint8_t>((value & 0xff00000000000000UL) >> 56);
    byte_buffer[1] = static_cast<uint8_t>((value & 0x00ff000000000000UL) >> 48);
    byte_buffer[2] = static_cast<uint8_t>((value & 0x0000ff0000000000UL) >> 40);
    byte_buffer[3] = static_cast<uint8_t>((value & 0x000000ff00000000UL) >> 32);
    byte_buffer[4] = static_cast<uint8_t>((value & 0x00000000ff000000UL) >> 24);
    byte_buffer[5] = static_cast<uint8_t>((value & 0x0000000000ff0000UL) >> 16);
    byte_buffer[6] = static_cast<uint8_t>((value & 0x000000000000ff00UL) >> 8);
    byte_buffer[7] = static_cast<uint8_t>((value & 0x00000000000000ffUL));
 
    return (byte_buffer + sizeof(uint64_t));
}
 
} // namespace util
} // namespace isc
 
#endif // IO_UTILITIES_H