github.com/dolthub/dolt/go@v0.40.5-0.20240520175717-68db7794bea6/store/val/prefix.go (about)

     1  // Copyright 2023 Dolthub, Inc.
     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 val
    16  
    17  // TrimValueToPrefixLength trims |value| to |prefixLength| if it is longer
    18  // and if it is either a []byte or string type. If |prefixLength| is zero,
    19  // then |value| will be returned without being trimmed.
    20  func TrimValueToPrefixLength(value interface{}, prefixLength uint16) interface{} {
    21  	if prefixLength == 0 {
    22  		return value
    23  	}
    24  
    25  	switch v := value.(type) {
    26  	case string:
    27  		if prefixLength > uint16(len(v)) {
    28  			prefixLength = uint16(len(v))
    29  		}
    30  		value = v[:prefixLength]
    31  	case []uint8:
    32  		if prefixLength > uint16(len(v)) {
    33  			prefixLength = uint16(len(v))
    34  		}
    35  		value = v[:prefixLength]
    36  	}
    37  
    38  	return value
    39  }