github.com/datastax/go-cassandra-native-protocol@v0.0.0-20220706104457-5e8aad05cf90/primitive/integers.go (about)

     1  // Copyright 2020 DataStax
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //      http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package primitive
    16  
    17  import (
    18  	"encoding/binary"
    19  	"fmt"
    20  	"io"
    21  )
    22  
    23  const (
    24  	LengthOfByte  = 1
    25  	LengthOfShort = 2
    26  	LengthOfInt   = 4
    27  	LengthOfLong  = 8
    28  )
    29  
    30  // [byte] ([byte] is not defined in protocol specs but is used by other primitives)
    31  
    32  func ReadByte(source io.Reader) (decoded uint8, err error) {
    33  	if err = binary.Read(source, binary.BigEndian, &decoded); err != nil {
    34  		err = fmt.Errorf("cannot read [byte]: %w", err)
    35  	}
    36  	return decoded, err
    37  }
    38  
    39  func WriteByte(b uint8, dest io.Writer) error {
    40  	if err := binary.Write(dest, binary.BigEndian, b); err != nil {
    41  		return fmt.Errorf("cannot write [byte]: %w", err)
    42  	}
    43  	return nil
    44  }
    45  
    46  // [short]
    47  
    48  func ReadShort(source io.Reader) (decoded uint16, err error) {
    49  	if err = binary.Read(source, binary.BigEndian, &decoded); err != nil {
    50  		err = fmt.Errorf("cannot read [short]: %w", err)
    51  	}
    52  	return decoded, err
    53  }
    54  
    55  func WriteShort(i uint16, dest io.Writer) error {
    56  	if err := binary.Write(dest, binary.BigEndian, i); err != nil {
    57  		return fmt.Errorf("cannot write [short]: %w", err)
    58  	}
    59  	return nil
    60  }
    61  
    62  // [int]
    63  
    64  func ReadInt(source io.Reader) (decoded int32, err error) {
    65  	if err = binary.Read(source, binary.BigEndian, &decoded); err != nil {
    66  		err = fmt.Errorf("cannot read [int]: %w", err)
    67  	}
    68  	return decoded, err
    69  }
    70  
    71  func WriteInt(i int32, dest io.Writer) error {
    72  	if err := binary.Write(dest, binary.BigEndian, i); err != nil {
    73  		return fmt.Errorf("cannot write [int]: %w", err)
    74  	}
    75  	return nil
    76  }
    77  
    78  // [long]
    79  
    80  func ReadLong(source io.Reader) (decoded int64, err error) {
    81  	if err = binary.Read(source, binary.BigEndian, &decoded); err != nil {
    82  		err = fmt.Errorf("cannot read [long]: %w", err)
    83  	}
    84  	return decoded, err
    85  }
    86  
    87  func WriteLong(l int64, dest io.Writer) error {
    88  	if err := binary.Write(dest, binary.BigEndian, l); err != nil {
    89  		return fmt.Errorf("cannot write [long]: %w", err)
    90  	}
    91  	return nil
    92  }