github.com/vescale/zgraph@v0.0.0-20230410094002-959c02d50f95/codec/vertex_key.go (about)

     1  // Copyright 2022 zGraph Authors. All rights reserved.
     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 codec
    16  
    17  import "errors"
    18  
    19  const VertexKeyLen = 1 /*prefix*/ + 8 /*graphID*/ + 8 /*vertexID*/
    20  
    21  // VertexKey encodes the vertex key.
    22  // The key format is: ${Prefix}${GraphID}${VertexID}.
    23  func VertexKey(graphID, vertexID int64) []byte {
    24  	result := make([]byte, 0, VertexKeyLen)
    25  	result = append(result, prefix...)
    26  	result = EncodeInt(result, graphID)
    27  	result = EncodeInt(result, vertexID)
    28  	return result
    29  }
    30  
    31  // ParseVertexKey parses the vertex key.
    32  func ParseVertexKey(key []byte) (graphID, vertexID int64, err error) {
    33  	if len(key) < VertexKeyLen {
    34  		return 0, 0, errors.New("insufficient key length")
    35  	}
    36  	_, graphID, err = DecodeInt(key[len(prefix):])
    37  	if err != nil {
    38  		return
    39  	}
    40  	_, vertexID, err = DecodeInt(key[len(prefix)+8:])
    41  	return
    42  }