Use writer.Write instead of fmt.FPrintf

pkg/constants/constants.go

@@ -82,4 +82,12 @@ const (
 	// TermUI Display Constants
 	MESSAGE_TEXT_PADDING                = 4
 	MESSAGE_TEXT_LINES_MARGIN_TO_BOTTOM = 4
+
+	// This is the initial size of the buffer allocated.
+	// Under the hood, an array of size N is allocated in memory
+	BUF_INIT_SIZE = 4096 // 4KB
+
+	// This is the muximum size the buffer can grow to
+	// Its not what the buffer will be allocated to initially
+	SCANNER_MAX_SIZE = 10 * 1024 * 1024 // 10MB
 )

pkg/redact/literal.go

@@ -3,8 +3,9 @@ package redact
 import (
 	"bufio"
 	"bytes"
-	"fmt"
 	"io"
+
+	"github.com/replicatedhq/troubleshoot/pkg/constants"
 )
 
 type literalRedactor struct {
@@ -35,22 +36,18 @@ func (r literalRedactor) Redact(input io.Reader, path string) io.Reader {
 			}
 		}()
 
-		mask := []byte(MASK_TEXT)
+		buf := make([]byte, constants.BUF_INIT_SIZE)
+		scanner := bufio.NewScanner(input)
+		scanner.Buffer(buf, constants.SCANNER_MAX_SIZE)
 
-		reader := bufio.NewReader(input)
 		lineNum := 0
-		for {
+		for scanner.Scan() {
 			lineNum++
-			var line []byte
-			line, err = readLine(reader)
-			if err != nil {
-				return
-			}
+			line := scanner.Bytes()
 
-			clean := bytes.ReplaceAll(line, r.match, mask)
+			clean := bytes.ReplaceAll(line, r.match, maskTextBytes)
 
-			// io.WriteString would be nicer, but scanner strips new lines
-			fmt.Fprintf(writer, "%s\n", clean)
+			_, err = writer.Write(append(clean, '\n')) // Append newline since scanner strips it
 			if err != nil {
 				return
 			}
@@ -65,6 +62,9 @@ func (r literalRedactor) Redact(input io.Reader, path string) io.Reader {
 				})
 			}
 		}
+		if scanErr := scanner.Err(); scanErr != nil {
+			err = scanErr
+		}
 	}()
 	return out
 }

pkg/redact/multi_line.go

@@ -3,7 +3,6 @@ package redact
 import (
 	"bufio"
 	"bytes"
-	"fmt"
 	"io"
 	"regexp"
 )
@@ -54,8 +53,14 @@ func (r *MultiLineRedactor) Redact(input io.Reader, path string) io.Reader {
 		line1, line2, err := getNextTwoLines(reader, nil)
 		if err != nil {
 			// this will print 2 blank lines for empty input...
-			fmt.Fprintf(writer, "%s\n", line1)
-			fmt.Fprintf(writer, "%s\n", line2)
+			_, err = writer.Write(append(line1, '\n'))
+			if err != nil {
+				return
+			}
+			_, err = writer.Write(append(line2, '\n'))
+			if err != nil {
+				return
+			}
 			return
 		}
 
@@ -68,7 +73,10 @@ func (r *MultiLineRedactor) Redact(input io.Reader, path string) io.Reader {
 			if r.scan != nil {
 				lowerLine1 := bytes.ToLower(line1)
 				if !r.scan.Match(lowerLine1) {
-					fmt.Fprintf(writer, "%s\n", line1)
+					_, err = writer.Write(append(line1, '\n'))
+					if err != nil {
+						return
+					}
 					line1, line2, err = getNextTwoLines(reader, line2)
 					flushLastLine = true
 					continue
@@ -77,16 +85,19 @@ func (r *MultiLineRedactor) Redact(input io.Reader, path string) io.Reader {
 
 			// If line1 matches re1, then transform line2 using re2
 			if !r.re1.Match(line1) {
-				fmt.Fprintf(writer, "%s\n", line1)
+				_, err = writer.Write(append(line1, '\n'))
+				if err != nil {
+					return
+				}
 				line1, line2, err = getNextTwoLines(reader, line2)
 				flushLastLine = true
 				continue
 			}
 			flushLastLine = false
 			clean := r.re2.ReplaceAll(line2, substStr)
 
-			// io.WriteString would be nicer, but reader strips new lines
-			fmt.Fprintf(writer, "%s\n%s\n", line1, clean)
+			out := append(append(line1, '\n'), append(clean, '\n')...) // line1 + \n + clean + \n
+			_, err = writer.Write(out)
 			if err != nil {
 				return
 			}
@@ -106,7 +117,10 @@ func (r *MultiLineRedactor) Redact(input io.Reader, path string) io.Reader {
 		}
 
 		if flushLastLine {
-			fmt.Fprintf(writer, "%s\n", line1)
+			_, err = writer.Write(append(line1, '\n')) // Append newline since scanner strips it
+			if err != nil {
+				return
+			}
 		}
 	}()
 	return out

pkg/redact/multi_line_test.go

@@ -8,7 +8,7 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-func Test_NewMultiLineRedactorr(t *testing.T) {
+func Test_NewMultiLineRedactor(t *testing.T) {
 	tests := []struct {
 		name        string
 		selector    LineRedactor

pkg/redact/redact.go

@@ -25,6 +25,7 @@ var (
 	// A regex cache to avoid recompiling the same regexes over and over
 	regexCache     = map[string]*regexp.Regexp{}
 	regexCacheLock sync.Mutex
+	maskTextBytes  = []byte(MASK_TEXT)
 )
 
 func init() {
@@ -113,6 +114,7 @@ func ResetRedactionList() {
 
 func buildAdditionalRedactors(path string, redacts []*troubleshootv1beta2.Redact) ([]Redactor, error) {
 	additionalRedactors := []Redactor{}
+
 	for i, redact := range redacts {
 		if redact == nil {
 			continue
@@ -488,7 +490,7 @@ func readLine(r *bufio.Reader) ([]byte, error) {
 		var line []byte
 		line, isPrefix, err := r.ReadLine()
 		if err != nil {
-			return []byte{}, err
+			return nil, err
 		}
 
 		completeLine = append(completeLine, line...)

pkg/redact/single_line.go

@@ -3,9 +3,10 @@ package redact
 import (
 	"bufio"
 	"bytes"
-	"fmt"
 	"io"
 	"regexp"
+
+	"github.com/replicatedhq/troubleshoot/pkg/constants"
 )
 
 type SingleLineRedactor struct {
@@ -34,15 +35,6 @@ func NewSingleLineRedactor(re LineRedactor, maskText, path, name string, isDefau
 	return &SingleLineRedactor{scan: scanCompiled, re: compiled, maskText: maskText, filePath: path, redactName: name, isDefault: isDefault}, nil
 }
 
-const (
-	// This is the initial size of the buffer allocated.
-	// Under the hood, an array of size N is allocated in memory
-	BUF_INIT_SIZE = 4096 // 4KB
-
-	// This is the muximum size the buffer can grow to
-	SCANNER_MAX_SIZE = 1024 * 1024 // 1MB
-)
-
 func (r *SingleLineRedactor) Redact(input io.Reader, path string) io.Reader {
 	out, writer := io.Pipe()
 
@@ -58,9 +50,9 @@ func (r *SingleLineRedactor) Redact(input io.Reader, path string) io.Reader {
 
 		substStr := []byte(getReplacementPattern(r.re, r.maskText))
 
-		buf := make([]byte, BUF_INIT_SIZE)
+		buf := make([]byte, constants.BUF_INIT_SIZE)
 		scanner := bufio.NewScanner(input)
-		scanner.Buffer(buf, SCANNER_MAX_SIZE)
+		scanner.Buffer(buf, constants.SCANNER_MAX_SIZE)
 
 		lineNum := 0
 		for scanner.Scan() {
@@ -71,22 +63,26 @@ func (r *SingleLineRedactor) Redact(input io.Reader, path string) io.Reader {
 			if r.scan != nil {
 				lowerLine := bytes.ToLower(line)
 				if !r.scan.Match(lowerLine) {
-					fmt.Fprintf(writer, "%s\n", line)
+					_, err = writer.Write(append(line, '\n')) // Append newline since scanner strips it
+					if err != nil {
+						return
+					}
 					continue
 				}
 			}
 
 			// if scan matches, but re does not, do not redact
 			if !r.re.Match(line) {
-				fmt.Fprintf(writer, "%s\n", line)
+				_, err = writer.Write(append(line, '\n')) // Append newline since scanner strips it
+				if err != nil {
+					return
+				}
 				continue
 			}
 
 			clean := r.re.ReplaceAll(line, substStr)
 
-			// io.WriteString would be nicer, but scanner strips new lines
-			fmt.Fprintf(writer, "%s\n", clean)
-
+			_, err = writer.Write(append(clean, '\n')) // Append newline since scanner strips it
 			if err != nil {
 				return
 			}

pkg/redact/single_line_test.go

@@ -2,7 +2,7 @@ package redact
 
 import (
 	"bytes"
-	"io/ioutil"
+	"io"
 	"testing"
 
 	"github.com/stretchr/testify/require"
@@ -320,7 +320,7 @@ func TestNewSingleLineRedactor(t *testing.T) {
 			req.NoError(err)
 
 			outReader := reRunner.Redact(bytes.NewReader([]byte(tt.inputString)), "")
-			gotBytes, err := ioutil.ReadAll(outReader)
+			gotBytes, err := io.ReadAll(outReader)
 			req.NoError(err)
 			req.Equal(tt.wantString, string(gotBytes))