Issue #1876 Implement line tracking for filesystem chunks in handleChunksWithError

pkg/handlers/handlers.go

@@ -3,6 +3,7 @@ package handlers
 import (
 	"archive/zip"
 	"bufio"
+	"bytes"
 	"context"
 	"errors"
 	"fmt"
@@ -11,6 +12,7 @@ import (
 
 	"github.com/gabriel-vasile/mimetype"
 	"github.com/mholt/archives"
+	"google.golang.org/protobuf/proto"
 
 	logContext "github.com/trufflesecurity/trufflehog/v3/pkg/context"
 	"github.com/trufflesecurity/trufflehog/v3/pkg/feature"
@@ -405,6 +407,8 @@ func handleChunksWithError(
 	chunkSkel *sources.Chunk,
 	reporter sources.ChunkReporter,
 ) error {
+	var linesConsumed int64
+
 	for {
 		select {
 		case dataOrErr, ok := <-dataErrChan:
@@ -422,7 +426,13 @@ func handleChunksWithError(
 			}
 			if len(dataOrErr.Data) > 0 {
 				chunk := *chunkSkel
+				if chunk.SourceMetadata != nil {
+					if cloned, ok := proto.Clone(chunk.SourceMetadata).(*source_metadatapb.MetaData); ok {
+						chunk.SourceMetadata = cloned
+					}
+				}
 				chunk.Data = dataOrErr.Data
+				linesConsumed = updateFilesystemLineMetadata(&chunk, linesConsumed)
 				if err := reporter.ChunkOk(ctx, chunk); err != nil {
 					return fmt.Errorf("error reporting chunk: %w", err)
 				}
@@ -433,6 +443,38 @@ func handleChunksWithError(
 	}
 }
 
+// updateFilesystemLineMetadata sets the 1-based starting line for filesystem chunks and
+// updates the running total of lines consumed so subsequent chunks can be
+// correctly anchored. Only the unique portion of the chunk (excluding the peek
+// overlap) contributes to the running count so that lines aren't double counted.
+//
+// This relies on HandleFile's default chunk reader, which emits chunks that
+// contain DefaultChunkSize bytes of unique data followed by a DefaultPeekSize
+// overlap with the next chunk.
+func updateFilesystemLineMetadata(chunk *sources.Chunk, linesConsumed int64) int64 {
+	if chunk.SourceMetadata == nil {
+		return linesConsumed
+	}
+	fsMeta := chunk.SourceMetadata.GetFilesystem()
+	if fsMeta == nil {
+		return linesConsumed
+	}
+
+	fsMeta.Line = linesConsumed + 1
+
+	data := chunk.Data
+	if len(data) == 0 {
+		return linesConsumed
+	}
+
+	uniqueLen := len(data)
+	if uniqueLen > sources.DefaultChunkSize {
+		uniqueLen = sources.DefaultChunkSize
+	}
+
+	return linesConsumed + int64(bytes.Count(data[:uniqueLen], []byte("\n")))
+}
+
 // isFatal determines whether the given error is a fatal error that should
 // terminate processing the current file, or a non-critical error that can be logged and ignored.
 // "Fatal" errors include context cancellation, deadline exceeded, and the

pkg/handlers/handlers_test.go

@@ -17,9 +17,12 @@ import (
 	"time"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 	diskbufferreader "github.com/trufflesecurity/disk-buffer-reader"
 
 	"github.com/trufflesecurity/trufflehog/v3/pkg/context"
+	"github.com/trufflesecurity/trufflehog/v3/pkg/pb/source_metadatapb"
+	"github.com/trufflesecurity/trufflehog/v3/pkg/pb/sourcespb"
 	"github.com/trufflesecurity/trufflehog/v3/pkg/sources"
 )
 
@@ -153,6 +156,53 @@ func BenchmarkHandleFile(b *testing.B) {
 	}
 }
 
+func TestHandleChunksWithErrorSetsFilesystemLine(t *testing.T) {
+	chunkCh := make(chan *sources.Chunk, 2)
+	reporter := sources.ChanReporter{Ch: chunkCh}
+
+	chunkSkel := &sources.Chunk{
+		SourceType: sourcespb.SourceType_SOURCE_TYPE_FILESYSTEM,
+		SourceMetadata: &source_metadatapb.MetaData{
+			Data: &source_metadatapb.MetaData_Filesystem{
+				Filesystem: &source_metadatapb.Filesystem{File: "test.txt"},
+			},
+		},
+	}
+
+	chunkSize := sources.DefaultChunkSize
+	peekSize := sources.DefaultPeekSize
+
+	chunkOneMain := bytes.Repeat([]byte("a\n"), chunkSize/2)
+	chunkOnePeek := bytes.Repeat([]byte("p\n"), peekSize/2)
+	chunkOne := append(chunkOneMain, chunkOnePeek...)
+
+	chunkTwo := bytes.Repeat([]byte("b\n"), 10)
+
+	dataErrChan := make(chan DataOrErr, 2)
+	dataErrChan <- DataOrErr{Data: chunkOne}
+	dataErrChan <- DataOrErr{Data: chunkTwo}
+	close(dataErrChan)
+
+	require.NoError(t, handleChunksWithError(context.Background(), dataErrChan, chunkSkel, reporter))
+
+	close(chunkCh)
+	var chunks []*sources.Chunk
+	for ch := range chunkCh {
+		chunks = append(chunks, ch)
+	}
+
+	require.Len(t, chunks, 2)
+
+	firstMeta := chunks[0].SourceMetadata.GetFilesystem()
+	require.NotNil(t, firstMeta)
+	require.Equal(t, int64(1), firstMeta.GetLine())
+
+	linesInFirstChunk := int64(bytes.Count(chunkOne[:chunkSize], []byte("\n")))
+	secondMeta := chunks[1].SourceMetadata.GetFilesystem()
+	require.NotNil(t, secondMeta)
+	require.Equal(t, linesInFirstChunk+1, secondMeta.GetLine())
+}
+
 func TestSkipArchive(t *testing.T) {
 	file, err := os.Open("testdata/test.tgz")
 	assert.Nil(t, err)