70 lines
2.1 KiB
Go
70 lines
2.1 KiB
Go
// Copyright 2024 PingCAP, 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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package util
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import (
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"encoding/binary"
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"math"
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"testing"
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"github.com/stretchr/testify/require"
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)
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func TestLongestCommonPrefixLen(t *testing.T) {
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cases := []struct {
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s1 string
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s2 string
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l int
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}{
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{"", "", 0},
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{"", "a", 0},
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{"a", "", 0},
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{"a", "a", 1},
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{"ab", "a", 1},
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{"a", "ab", 1},
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{"b", "ab", 0},
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{"ba", "ab", 0},
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}
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for _, ca := range cases {
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re := longestCommonPrefixLen([]byte(ca.s1), []byte(ca.s2))
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require.Equal(t, ca.l, re)
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}
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}
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func TestGetStepValue(t *testing.T) {
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cases := []struct {
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lower []byte
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upper []byte
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l int
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v uint64
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}{
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{[]byte{}, []byte{}, 0, math.MaxUint64},
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{[]byte{0}, []byte{128}, 0, binary.BigEndian.Uint64([]byte{128, 255, 255, 255, 255, 255, 255, 255})},
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{[]byte{'a'}, []byte{'z'}, 0, binary.BigEndian.Uint64([]byte{'z' - 'a', 255, 255, 255, 255, 255, 255, 255})},
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{[]byte("abc"), []byte{'z'}, 0, binary.BigEndian.Uint64([]byte{'z' - 'a', 255 - 'b', 255 - 'c', 255, 255, 255, 255, 255})},
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{[]byte("abc"), []byte("xyz"), 0, binary.BigEndian.Uint64([]byte{'x' - 'a', 'y' - 'b', 'z' - 'c', 255, 255, 255, 255, 255})},
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{[]byte("abc"), []byte("axyz"), 1, binary.BigEndian.Uint64([]byte{'x' - 'b', 'y' - 'c', 'z', 255, 255, 255, 255, 255})},
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{[]byte("abc0123456"), []byte("xyz01234"), 0, binary.BigEndian.Uint64([]byte{'x' - 'a', 'y' - 'b', 'z' - 'c', 0, 0, 0, 0, 0})},
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}
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for _, ca := range cases {
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l := longestCommonPrefixLen(ca.lower, ca.upper)
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require.Equal(t, ca.l, l)
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v0 := getStepValue(ca.lower[l:], ca.upper[l:], 1)
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require.Equal(t, v0, ca.v)
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}
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}
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