Daylon Wilkins
50 lines
1.4 KiB
Go
50 lines
1.4 KiB
Go
// Copyright 2023 Dolthub, Inc.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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// Copyright 2015 The Cockroach Authors.
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//
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// Use of this software is governed by the Business Source License
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// included in the file licenses/BSL.txt.
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//
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// As of the Change Date specified in that file, in accordance with
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// the Business Source License, use of this software will be governed
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// by the Apache License, Version 2.0, included in the file
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// licenses/APL.txt.
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//go:build 386 || amd64
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// +build 386 amd64
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package encoding
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import "unsafe"
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// The idea for the fast ones complement is borrowed from fastXORBytes
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// in the crypto standard library.
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const wordSize = int(unsafe.Sizeof(uintptr(0)))
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func onesComplement(b []byte) {
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n := len(b)
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w := n / wordSize
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if w > 0 {
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bw := *(*[]uintptr)(unsafe.Pointer(&b))
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for i := 0; i < w; i++ {
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bw[i] = ^bw[i]
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}
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}
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for i := w * wordSize; i < n; i++ {
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b[i] = ^b[i]
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}
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}
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