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resize.go
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resize.go
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// Licensed to Apache Software Foundation (ASF) under one or more contributor
// license agreements. See the NOTICE file distributed with
// this work for additional information regarding copyright
// ownership. Apache Software Foundation (ASF) licenses this file to you under
// the Apache License, Version 2.0 (the "License"); you may
// not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied. See the License for the
// specific language governing permissions and limitations
// under the License.
package bytes
import "math/bits"
// ResizeOver resizes the byte slice to the nearest power of 2.
func ResizeOver(b []byte, n int) []byte {
if n <= cap(b) {
return b[:n]
}
nNew := roundToNearestPow2(n)
bNew := make([]byte, nNew)
return bNew[:n]
}
// ResizeExact resizes the byte slice to the exact size.
func ResizeExact(b []byte, n int) []byte {
if n <= cap(b) {
return b[:n]
}
return make([]byte, n)
}
func roundToNearestPow2(n int) int {
pow2 := uint8(bits.Len(uint(n - 1)))
return 1 << pow2
}