go.temporal.io/server@v1.23.0/common/collection/util.go (about)

     1  // The MIT License
     2  //
     3  // Copyright (c) 2020 Temporal Technologies Inc.  All rights reserved.
     4  //
     5  // Copyright (c) 2020 Uber Technologies, Inc.
     6  //
     7  // Permission is hereby granted, free of charge, to any person obtaining a copy
     8  // of this software and associated documentation files (the "Software"), to deal
     9  // in the Software without restriction, including without limitation the rights
    10  // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
    11  // copies of the Software, and to permit persons to whom the Software is
    12  // furnished to do so, subject to the following conditions:
    13  //
    14  // The above copyright notice and this permission notice shall be included in
    15  // all copies or substantial portions of the Software.
    16  //
    17  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    18  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    19  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    20  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    21  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    22  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
    23  // THE SOFTWARE.
    24  
    25  package collection
    26  
    27  import (
    28  	"encoding/binary"
    29  	"encoding/hex"
    30  )
    31  
    32  // UUIDHashCode is a hash function for hashing string uuid
    33  // if the uuid is malformed, then the hash function always
    34  // returns 0 as the hash value
    35  func UUIDHashCode(input interface{}) uint32 {
    36  	key, ok := input.(string)
    37  	if !ok {
    38  		return 0
    39  	}
    40  	if len(key) != UUIDStringLength {
    41  		return 0
    42  	}
    43  	// Use the first 4 bytes of the uuid as the hash
    44  	b, err := hex.DecodeString(key[:8])
    45  	if err != nil {
    46  		return 0
    47  	}
    48  	return binary.BigEndian.Uint32(b)
    49  }