gather logs - update "FilterLogFromScanner" function and add some tests

pkg/gatherers/common/gather_logs.go

@@ -164,24 +164,28 @@ func FilterLogFromScanner(scanner *bufio.Scanner, messagesToSearch []string, reg
 	cb func(lines []string) []string) (string, error) {
 	var result []string
 
+	var messagesRegexp *regexp.Regexp
+	if regexSearch {
+		messagesRegexp = regexp.MustCompile(strings.Join(messagesToSearch, "|"))
+	}
+
 	for scanner.Scan() {
 		line := scanner.Text()
 		if len(messagesToSearch) == 0 {
 			result = append(result, line)
 			continue
 		}
 
-		for _, messageToSearch := range messagesToSearch {
-			if regexSearch {
-				matches, err := regexp.MatchString(messageToSearch, line)
-				if err != nil {
-					return "", err
-				}
-				if matches {
+		if regexSearch && messagesRegexp != nil {
+			matches := messagesRegexp.MatchString(line)
+			if matches {
+				result = append(result, line)
+			}
+		} else {
+			for _, messageToSearch := range messagesToSearch {
+				if strings.Contains(strings.ToLower(line), strings.ToLower(messageToSearch)) {
 					result = append(result, line)
 				}
-			} else if strings.Contains(strings.ToLower(line), strings.ToLower(messageToSearch)) {
-				result = append(result, line)
 			}
 		}
 	}

pkg/gatherers/common/gather_logs_test.go

@@ -1,8 +1,11 @@
 package common
 
 import (
+	"bufio"
 	"context"
 	"fmt"
+	"runtime"
+	"strings"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -13,6 +16,29 @@ import (
 	"github.com/openshift/insights-operator/pkg/utils/marshal"
 )
 
+// nolint: lll, misspell
+var testText = `Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. 
+Ullamcorper eget nulla facilisi etiam dignissim diam quis enim.
+Rhoncus mattis rhoncus urna neque viverra.
+Tempus urna et pharetra pharetra massa. Enim tortor at auctor urna nunc.
+Id volutpat lacus laoreet non curabitur.
+Feugiat pretium nibh ipsum consequat nisl vel.
+Morbi tristique senectus et netus.
+Tellus mauris a diam maecenas sed enim ut sem viverra.
+Nunc scelerisque viverra mauris in aliquam.
+Facilisis volutpat est velit egestas. Et netus et malesuada fames ac turpis egestas.
+Sapien eget mi proin sed libero enim sed. Urna id volutpat lacus laoreet non. 
+Scelerisque eu ultrices vitae auctor.
+Volutpat maecenas volutpat blandit aliquam etiam. 
+Sit amet nisl purus in mollis nunc sed id. 
+Tortor at auctor urna nunc id.
+Purus in mollis nunc sed.
+Enim ut tellus elementum sagittis vitae et leo.Quis viverra nibh cras pulvinar mattis nunc sed blandit libero.
+Morbi tempus iaculis urna id volutpat lacus laoreet.
+Pellentesque elit ullamcorper dignissim cras tincidunt lobortis.
+Vitae proin sagittis nisl rhoncus. 
+Tortor condimentum lacinia quis vel eros donec ac odio tempor.`
+
 func testGatherLogs(t *testing.T, regexSearch bool, stringToSearch string, shouldExist bool) {
 	const testPodName = "test"
 	const testLogFileName = "errors"
@@ -101,3 +127,65 @@ func Test_GatherLogs(t *testing.T) {
 		testGatherLogs(t, true, "[0-9]99", false)
 	})
 }
+
+func Test_FilterLogFromScanner(t *testing.T) {
+	tests := []struct {
+		name             string
+		messagesToSearch []string
+		isRegexSearch    bool
+		expectedOutput   string
+	}{
+		{
+			name:             "simple non-regex search",
+			messagesToSearch: []string{"Pellentesque"},
+			isRegexSearch:    false,
+			expectedOutput:   "Pellentesque elit ullamcorper dignissim cras tincidunt lobortis.",
+		},
+		{
+			name:             "non-regex search with empty messages",
+			messagesToSearch: []string{},
+			isRegexSearch:    false,
+			expectedOutput:   testText,
+		},
+		{
+			name:             "advanced non-regex search",
+			messagesToSearch: []string{"Pellentesque", "scelerisque", "this is not there"},
+			isRegexSearch:    false,
+			// nolint lll
+			expectedOutput: "Nunc scelerisque viverra mauris in aliquam.\nScelerisque eu ultrices vitae auctor.\nPellentesque elit ullamcorper dignissim cras tincidunt lobortis.",
+		},
+		{
+			name:             "Regex search with empty messages",
+			messagesToSearch: []string{},
+			isRegexSearch:    true,
+			expectedOutput:   testText,
+		},
+		{
+			name:             "advanced regex search",
+			messagesToSearch: []string{"Pellentesque", "scelerisque", "this is not there"},
+			isRegexSearch:    true,
+			expectedOutput:   "Nunc scelerisque viverra mauris in aliquam.\nPellentesque elit ullamcorper dignissim cras tincidunt lobortis.",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			reader := strings.NewReader(testText)
+			result, err := FilterLogFromScanner(bufio.NewScanner(reader), tt.messagesToSearch, tt.isRegexSearch, nil)
+			assert.NoError(t, err)
+			assert.Equal(t, tt.expectedOutput, result)
+		})
+	}
+}
+
+func Benchmark_FilterLogFromScanner(b *testing.B) {
+	var m runtime.MemStats
+	messagesToSearch := []string{"Pellentesque", "scelerisque", "this is not there"}
+	reader := strings.NewReader(testText)
+	for i := 0; i <= b.N; i++ {
+		// nolint errcheck
+		FilterLogFromScanner(bufio.NewScanner(reader), messagesToSearch, true, nil)
+		runtime.ReadMemStats(&m)
+		b.Logf("Size of allocated heap objects: %d MB, Size of heap in use: %d MB", m.Alloc/1024/1024, m.HeapInuse/1024/1024)
+	}
+}