github.com/datastax/go-cassandra-native-protocol@v0.0.0-20220706104457-5e8aad05cf90/message/register.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 message
    16  
    17  import (
    18  	"errors"
    19  	"fmt"
    20  	"io"
    21  
    22  	"github.com/datastax/go-cassandra-native-protocol/primitive"
    23  )
    24  
    25  // Register is a request to register the client as a listener for the specified event types.
    26  // +k8s:deepcopy-gen=true
    27  // +k8s:deepcopy-gen:interfaces=github.com/datastax/go-cassandra-native-protocol/message.Message
    28  type Register struct {
    29  	EventTypes []primitive.EventType
    30  }
    31  
    32  func (m *Register) IsResponse() bool {
    33  	return false
    34  }
    35  
    36  func (m *Register) GetOpCode() primitive.OpCode {
    37  	return primitive.OpCodeRegister
    38  }
    39  
    40  func (m *Register) String() string {
    41  	return fmt.Sprint("REGISTER ", m.EventTypes)
    42  }
    43  
    44  type registerCodec struct{}
    45  
    46  func (c *registerCodec) Encode(msg Message, dest io.Writer, _ primitive.ProtocolVersion) error {
    47  	register, ok := msg.(*Register)
    48  	if !ok {
    49  		return errors.New(fmt.Sprintf("expected *message.Register, got %T", msg))
    50  	}
    51  	if len(register.EventTypes) == 0 {
    52  		return errors.New("REGISTER messages must have at least one event type")
    53  	}
    54  	for _, eventType := range register.EventTypes {
    55  		if err := primitive.CheckValidEventType(eventType); err != nil {
    56  			return err
    57  		}
    58  	}
    59  	return primitive.WriteStringList(asStringList(register.EventTypes), dest)
    60  }
    61  
    62  func (c *registerCodec) EncodedLength(msg Message, _ primitive.ProtocolVersion) (int, error) {
    63  	register, ok := msg.(*Register)
    64  	if !ok {
    65  		return -1, errors.New(fmt.Sprintf("expected *message.Register, got %T", msg))
    66  	}
    67  	return primitive.LengthOfStringList(asStringList(register.EventTypes)), nil
    68  }
    69  
    70  func (c *registerCodec) Decode(source io.Reader, _ primitive.ProtocolVersion) (Message, error) {
    71  	if eventTypes, err := primitive.ReadStringList(source); err != nil {
    72  		return nil, err
    73  	} else {
    74  		for _, eventType := range eventTypes {
    75  			if err := primitive.CheckValidEventType(primitive.EventType(eventType)); err != nil {
    76  				return nil, err
    77  			}
    78  		}
    79  		return &Register{EventTypes: fromStringList(eventTypes)}, nil
    80  	}
    81  }
    82  
    83  func (c *registerCodec) GetOpCode() primitive.OpCode {
    84  	return primitive.OpCodeRegister
    85  }
    86  
    87  func asStringList(eventTypes []primitive.EventType) []string {
    88  	strings := make([]string, len(eventTypes))
    89  	for i, eventType := range eventTypes {
    90  		strings[i] = string(eventType)
    91  	}
    92  	return strings
    93  }
    94  
    95  func fromStringList(strings []string) []primitive.EventType {
    96  	eventTypes := make([]primitive.EventType, len(strings))
    97  	for i, eventType := range strings {
    98  		eventTypes[i] = primitive.EventType(eventType)
    99  	}
   100  	return eventTypes
   101  }