Pull request: querylog: imp perf

Merge in DNS/adguard-home from contains-fold to master

Squashed commit of the following:

commit 45c79b4b7618c8f3108766cc776b5bd3f0571761
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Wed May 19 21:26:09 2021 +0300

    querylog: imp perf

internal/querylog/searchcriterion_test.go

@@ -0,0 +1,121 @@
+package querylog
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestContainsFold(t *testing.T) {
+	testCases := []struct {
+		name     string
+		inS      string
+		inSubstr string
+		want     bool
+	}{{
+		name:     "empty",
+		inS:      "",
+		inSubstr: "",
+		want:     true,
+	}, {
+		name:     "shorter",
+		inS:      "a",
+		inSubstr: "abc",
+		want:     false,
+	}, {
+		name:     "same_len_true",
+		inS:      "abc",
+		inSubstr: "abc",
+		want:     true,
+	}, {
+		name:     "same_len_true_fold",
+		inS:      "abc",
+		inSubstr: "aBc",
+		want:     true,
+	}, {
+		name:     "same_len_false",
+		inS:      "abc",
+		inSubstr: "def",
+		want:     false,
+	}, {
+		name:     "longer_true",
+		inS:      "abcdedef",
+		inSubstr: "def",
+		want:     true,
+	}, {
+		name:     "longer_false",
+		inS:      "abcded",
+		inSubstr: "ghi",
+		want:     false,
+	}, {
+		name:     "longer_true_fold",
+		inS:      "abcdedef",
+		inSubstr: "dEf",
+		want:     true,
+	}, {
+		name:     "longer_false_fold",
+		inS:      "abcded",
+		inSubstr: "gHi",
+		want:     false,
+	}, {
+		name:     "longer_true_cyr_fold",
+		inS:      "абвгдедеё",
+		inSubstr: "дЕЁ",
+		want:     true,
+	}, {
+		name:     "longer_false_cyr_fold",
+		inS:      "абвгдедеё",
+		inSubstr: "жЗИ",
+		want:     false,
+	}, {
+		name:     "no_letters_true",
+		inS:      "1.2.3.4",
+		inSubstr: "2.3.4",
+		want:     true,
+	}, {
+		name:     "no_letters_false",
+		inS:      "1.2.3.4",
+		inSubstr: "2.3.5",
+		want:     false,
+	}}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			if tc.want {
+				assert.True(t, containsFold(tc.inS, tc.inSubstr))
+			} else {
+				assert.False(t, containsFold(tc.inS, tc.inSubstr))
+			}
+		})
+	}
+}
+
+var sink bool
+
+func BenchmarkContainsFold(b *testing.B) {
+	const s = "aaahBbBhccchDDDeEehFfFhGGGhHhh"
+	const substr = "HHH"
+
+	// Compare our implementation of containsFold against a stupid solution
+	// of calling strings.ToLower and strings.Contains.
+	b.Run("containsfold", func(b *testing.B) {
+		b.ReportAllocs()
+
+		for i := 0; i < b.N; i++ {
+			sink = containsFold(s, substr)
+		}
+
+		assert.True(b, sink)
+	})
+
+	b.Run("tolower_contains", func(b *testing.B) {
+		b.ReportAllocs()
+
+		for i := 0; i < b.N; i++ {
+			sink = strings.Contains(strings.ToLower(s), strings.ToLower(substr))
+		}
+
+		assert.True(b, sink)
+	})
+}