github.com/datastax/go-cassandra-native-protocol@v0.0.0-20220706104457-5e8aad05cf90/primitive/string_multimap.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  	"fmt"
    19  	"io"
    20  )
    21  
    22  // [string multimap]
    23  
    24  func ReadStringMultiMap(source io.Reader) (decoded map[string][]string, err error) {
    25  	if length, err := ReadShort(source); err != nil {
    26  		return nil, fmt.Errorf("cannot read [string multimap] length: %w", err)
    27  	} else {
    28  		decoded := make(map[string][]string, length)
    29  		for i := uint16(0); i < length; i++ {
    30  			if key, err := ReadString(source); err != nil {
    31  				return nil, fmt.Errorf("cannot read [string multimap] entry %d key: %w", i, err)
    32  			} else if value, err := ReadStringList(source); err != nil {
    33  				return nil, fmt.Errorf("cannot read [string multimap] entry %d value: %w", i, err)
    34  			} else {
    35  				decoded[key] = value
    36  			}
    37  		}
    38  		return decoded, nil
    39  	}
    40  }
    41  
    42  func WriteStringMultiMap(m map[string][]string, dest io.Writer) error {
    43  	if err := WriteShort(uint16(len(m)), dest); err != nil {
    44  		return fmt.Errorf("cannot write [string multimap] length: %w", err)
    45  	}
    46  	for key, value := range m {
    47  		if err := WriteString(key, dest); err != nil {
    48  			return fmt.Errorf("cannot write [string multimap] entry '%v' key: %w", key, err)
    49  		}
    50  		if err := WriteStringList(value, dest); err != nil {
    51  			return fmt.Errorf("cannot write [string multimap] entry '%v' value: %w", key, err)
    52  		}
    53  	}
    54  	return nil
    55  }
    56  
    57  func LengthOfStringMultiMap(m map[string][]string) int {
    58  	length := LengthOfShort
    59  	for key, value := range m {
    60  		length += LengthOfString(key) + LengthOfStringList(value)
    61  	}
    62  	return length
    63  }