github.com/datastax/go-cassandra-native-protocol@v0.0.0-20220706104457-5e8aad05cf90/message/execute.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  	"encoding/hex"
    19  	"errors"
    20  	"fmt"
    21  	"io"
    22  
    23  	"github.com/datastax/go-cassandra-native-protocol/primitive"
    24  )
    25  
    26  // Execute is a request message that executes a prepared statement, identified by its prepared query id.
    27  // +k8s:deepcopy-gen=true
    28  // +k8s:deepcopy-gen:interfaces=github.com/datastax/go-cassandra-native-protocol/message.Message
    29  type Execute struct {
    30  	// QueryId is the prepared query id to execute.
    31  	QueryId []byte
    32  	// the ID of the result set metadata that was sent along with response to PREPARE message.
    33  	// Valid in protocol version 5 and DSE protocol version 2. See PreparedResult.
    34  	ResultMetadataId []byte
    35  	Options          *QueryOptions
    36  }
    37  
    38  func (m *Execute) IsResponse() bool {
    39  	return false
    40  }
    41  
    42  func (m *Execute) GetOpCode() primitive.OpCode {
    43  	return primitive.OpCodeExecute
    44  }
    45  
    46  func (m *Execute) String() string {
    47  	return "EXECUTE " + hex.EncodeToString(m.QueryId)
    48  }
    49  
    50  type executeCodec struct{}
    51  
    52  func (c *executeCodec) Encode(msg Message, dest io.Writer, version primitive.ProtocolVersion) error {
    53  	execute, ok := msg.(*Execute)
    54  	if !ok {
    55  		return errors.New(fmt.Sprintf("expected *message.Execute, got %T", msg))
    56  	}
    57  	if len(execute.QueryId) == 0 {
    58  		return errors.New("EXECUTE missing query id")
    59  	} else if err := primitive.WriteShortBytes(execute.QueryId, dest); err != nil {
    60  		return fmt.Errorf("cannot write EXECUTE query id: %w", err)
    61  	}
    62  	if version.SupportsResultMetadataId() {
    63  		if len(execute.ResultMetadataId) == 0 {
    64  			return errors.New("EXECUTE missing result metadata id")
    65  		} else if err := primitive.WriteShortBytes(execute.ResultMetadataId, dest); err != nil {
    66  			return fmt.Errorf("cannot write EXECUTE result metadata id: %w", err)
    67  		}
    68  	}
    69  	if err := EncodeQueryOptions(execute.Options, dest, version); err != nil {
    70  		return fmt.Errorf("cannot write EXECUTE options: %w", err)
    71  	}
    72  	return nil
    73  }
    74  
    75  func (c *executeCodec) EncodedLength(msg Message, version primitive.ProtocolVersion) (size int, err error) {
    76  	execute, ok := msg.(*Execute)
    77  	if !ok {
    78  		return -1, errors.New(fmt.Sprintf("expected *message.Execute, got %T", msg))
    79  	}
    80  	size += primitive.LengthOfShortBytes(execute.QueryId)
    81  	if version.SupportsResultMetadataId() {
    82  		size += primitive.LengthOfShortBytes(execute.ResultMetadataId)
    83  	}
    84  	if lengthOfQueryOptions, err := LengthOfQueryOptions(execute.Options, version); err == nil {
    85  		return size + lengthOfQueryOptions, nil
    86  	} else {
    87  		return -1, fmt.Errorf("cannot compute size EXECUTE query options: %w", err)
    88  	}
    89  }
    90  
    91  func (c *executeCodec) Decode(source io.Reader, version primitive.ProtocolVersion) (msg Message, err error) {
    92  	var execute = &Execute{
    93  		Options: nil,
    94  	}
    95  	if execute.QueryId, err = primitive.ReadShortBytes(source); err != nil {
    96  		return nil, fmt.Errorf("cannot read EXECUTE query id: %w", err)
    97  	} else if len(execute.QueryId) == 0 {
    98  		return nil, errors.New("EXECUTE missing query id")
    99  	}
   100  	if version.SupportsResultMetadataId() {
   101  		if execute.ResultMetadataId, err = primitive.ReadShortBytes(source); err != nil {
   102  			return nil, fmt.Errorf("cannot read EXECUTE result metadata id: %w", err)
   103  		} else if len(execute.ResultMetadataId) == 0 {
   104  			return nil, errors.New("EXECUTE missing result metadata id")
   105  		}
   106  	}
   107  	if execute.Options, err = DecodeQueryOptions(source, version); err != nil {
   108  		return nil, fmt.Errorf("cannot read EXECUTE query options: %w", err)
   109  	}
   110  	return execute, nil
   111  }
   112  
   113  func (c *executeCodec) GetOpCode() primitive.OpCode {
   114  	return primitive.OpCodeExecute
   115  }