[bug]- Invalid Seek for Non-Seekable Readers (#3095)

* inital work

* fix and add tests

* uncomment

* fix seek end

* use buffer pool

* revert timeout

* make linter happy

* More linting :()

pkg/handlers/ar_test.go

@@ -20,6 +20,7 @@ func TestHandleARFile(t *testing.T) {
 
 	rdr, err := newFileReader(file)
 	assert.NoError(t, err)
+	defer rdr.Close()
 
 	handler := newARHandler()
 	archiveChan, err := handler.HandleFile(context.AddLogger(ctx), rdr)

pkg/handlers/archive.go

@@ -111,6 +111,7 @@ func (h *archiveHandler) openArchive(ctx logContext.Context, depth int, reader f
 			}
 			return fmt.Errorf("error creating custom reader: %w", err)
 		}
+		defer rdr.Close()
 
 		return h.openArchive(ctx, depth+1, rdr, archiveChan)
 	case archiver.Extractor:
@@ -194,6 +195,7 @@ func (h *archiveHandler) extractorHandler(archiveChan chan []byte) func(context.
 			}
 			return fmt.Errorf("error creating custom reader: %w", err)
 		}
+		defer rdr.Close()
 
 		h.metrics.incFilesProcessed()
 		h.metrics.observeFileSize(fileSize)

pkg/handlers/archive_test.go

@@ -89,6 +89,8 @@ func TestArchiveHandler(t *testing.T) {
 			if err != nil {
 				t.Errorf("error creating reusable reader: %s", err)
 			}
+			defer newReader.Close()
+
 			archiveChan, err := handler.HandleFile(logContext.Background(), newReader)
 			if testCase.expectErr {
 				assert.NoError(t, err)
@@ -119,6 +121,7 @@ func TestOpenInvalidArchive(t *testing.T) {
 
 	rdr, err := newFileReader(io.NopCloser(reader))
 	assert.NoError(t, err)
+	defer rdr.Close()
 
 	archiveChan := make(chan []byte)
 

pkg/handlers/default_test.go

@@ -20,6 +20,7 @@ func TestHandleNonArchiveFile(t *testing.T) {
 
 	rdr, err := newFileReader(file)
 	assert.NoError(t, err)
+	defer rdr.Close()
 
 	handler := newDefaultHandler(defaultHandlerType)
 	archiveChan, err := handler.HandleFile(context.AddLogger(ctx), rdr)

pkg/handlers/handlers.go

@@ -59,7 +59,7 @@ func newMimeTypeReaderFromFileReader(r fileReader) mimeTypeReader {
 
 // newMimeTypeReader creates a new mimeTypeReader from an io.Reader.
 // It uses a bufio.Reader to perform MIME type detection on the input reader
-// without consuming it, by peeking into the first 512 bytes of the input.
+// without consuming it, by peeking into the first 3072 bytes of the input.
 // This encapsulates both the original reader and the detected MIME type information.
 // This function is particularly useful for specialized archive handlers
 // that need to pass extracted content to the default handler without modifying the original reader.
@@ -84,10 +84,6 @@ func newFileReader(r io.Reader) (fileReader, error) {
 
 	fReader.BufferedReadSeeker = iobuf.NewBufferedReaderSeeker(r)
 
-	// Disable buffering after initial reads.
-	// This optimization ensures we don't continue writing to the buffer after the initial reads.
-	defer fReader.DisableBuffering()
-
 	mime, err := mimetype.DetectReader(fReader)
 	if err != nil {
 		return fReader, fmt.Errorf("unable to detect MIME type: %w", err)
@@ -281,6 +277,7 @@ func HandleFile(
 		}
 		return fmt.Errorf("error creating custom reader: %w", err)
 	}
+	defer rdr.Close()
 
 	mimeT := mimeType(rdr.mime.String())
 	config := newFileHandlingConfig(options...)

pkg/handlers/handlers_test.go

@@ -27,21 +27,101 @@ func TestHandleFileCancelledContext(t *testing.T) {
 }
 
 func TestHandleFile(t *testing.T) {
-	reporter := sources.ChanReporter{Ch: make(chan *sources.Chunk, 2)}
+	reporter := sources.ChanReporter{Ch: make(chan *sources.Chunk, 513)}
 
 	// Only one chunk is sent on the channel.
 	// TODO: Embed a zip without making an HTTP request.
 	resp, err := http.Get("https://raw.githubusercontent.com/bill-rich/bad-secrets/master/aws-canary-creds.zip")
 	assert.NoError(t, err)
-	if resp != nil && resp.Body != nil {
-		defer resp.Body.Close()
-	}
+	defer func() {
+		if resp != nil && resp.Body != nil {
+			resp.Body.Close()
+		}
+	}()
 
 	assert.Equal(t, 0, len(reporter.Ch))
 	assert.NoError(t, HandleFile(context.Background(), resp.Body, &sources.Chunk{}, reporter))
 	assert.Equal(t, 1, len(reporter.Ch))
 }
 
+func TestHandleHTTPJson(t *testing.T) {
+	resp, err := http.Get("https://raw.githubusercontent.com/ahrav/nothing-to-see-here/main/sm_random_data.json")
+	assert.NoError(t, err)
+	defer func() {
+		if resp != nil && resp.Body != nil {
+			resp.Body.Close()
+		}
+	}()
+
+	chunkCh := make(chan *sources.Chunk, 1)
+	go func() {
+		defer close(chunkCh)
+		err := HandleFile(logContext.Background(), resp.Body, &sources.Chunk{}, sources.ChanReporter{Ch: chunkCh})
+		assert.NoError(t, err)
+	}()
+
+	wantCount := 513
+	count := 0
+	for range chunkCh {
+		count++
+	}
+	assert.Equal(t, wantCount, count)
+}
+
+func TestHandleHTTPJsonZip(t *testing.T) {
+	resp, err := http.Get("https://raw.githubusercontent.com/ahrav/nothing-to-see-here/main/sm.zip")
+	assert.NoError(t, err)
+	defer func() {
+		if resp != nil && resp.Body != nil {
+			resp.Body.Close()
+		}
+	}()
+
+	chunkCh := make(chan *sources.Chunk, 1)
+	go func() {
+		defer close(chunkCh)
+		err := HandleFile(logContext.Background(), resp.Body, &sources.Chunk{}, sources.ChanReporter{Ch: chunkCh})
+		assert.NoError(t, err)
+	}()
+
+	wantCount := 513
+	count := 0
+	for range chunkCh {
+		count++
+	}
+	assert.Equal(t, wantCount, count)
+}
+
+func BenchmarkHandleHTTPJsonZip(b *testing.B) {
+	b.ReportAllocs()
+	for i := 0; i < b.N; i++ {
+		func() {
+			resp, err := http.Get("https://raw.githubusercontent.com/ahrav/nothing-to-see-here/main/sm.zip")
+			assert.NoError(b, err)
+
+			defer func() {
+				if resp != nil && resp.Body != nil {
+					resp.Body.Close()
+				}
+			}()
+
+			chunkCh := make(chan *sources.Chunk, 1)
+
+			b.StartTimer()
+			go func() {
+				defer close(chunkCh)
+				err := HandleFile(logContext.Background(), resp.Body, &sources.Chunk{}, sources.ChanReporter{Ch: chunkCh})
+				assert.NoError(b, err)
+			}()
+
+			for range chunkCh {
+			}
+
+			b.StopTimer()
+		}()
+	}
+}
+
 func BenchmarkHandleFile(b *testing.B) {
 	file, err := os.Open("testdata/test.tgz")
 	assert.Nil(b, err)

pkg/handlers/rpm_test.go

@@ -20,6 +20,7 @@ func TestHandleRPMFile(t *testing.T) {
 
 	rdr, err := newFileReader(file)
 	assert.NoError(t, err)
+	defer rdr.Close()
 
 	handler := newRPMHandler()
 	archiveChan, err := handler.HandleFile(context.AddLogger(ctx), rdr)

pkg/iobuf/bufferedreaderseeker.go

@@ -1,123 +1,144 @@
 package iobuf
 
 import (
-	"bytes"
 	"errors"
-	"fmt"
 	"io"
+	"os"
+
+	"github.com/trufflesecurity/trufflehog/v3/pkg/buffers/buffer"
+	"github.com/trufflesecurity/trufflehog/v3/pkg/buffers/pool"
+	"github.com/trufflesecurity/trufflehog/v3/pkg/cleantemp"
 )
 
+const defaultBufferSize = 1 << 16 // 64KB
+
+var defaultBufferPool *pool.Pool
+
+func init() { defaultBufferPool = pool.NewBufferPool(defaultBufferSize) }
+
 // BufferedReadSeeker provides a buffered reading interface with seeking capabilities.
 // It wraps an io.Reader and optionally an io.Seeker, allowing for efficient
 // reading and seeking operations, even on non-seekable underlying readers.
+//
+// For small amounts of data, it uses an in-memory buffer (bytes.Buffer) to store
+// read bytes. When the amount of data exceeds a specified threshold, it switches
+// to disk-based buffering using a temporary file. This approach balances memory
+// usage and performance, allowing efficient handling of both small and large data streams.
+//
+// The struct manages the transition between in-memory and disk-based buffering
+// transparently, providing a seamless reading and seeking experience regardless
+// of the underlying data size or the seekability of the original reader.
+//
+// If the underlying reader is seekable, direct seeking operations are performed
+// on it. For non-seekable readers, seeking is emulated using the buffer or
+// temporary file.
 type BufferedReadSeeker struct {
 	reader io.Reader
 	seeker io.Seeker // If the reader supports seeking, it's stored here for direct access
 
-	buffer *bytes.Buffer // Internal buffer to store read bytes for non-seekable readers
+	bufPool *pool.Pool     // Pool for storing buffers for reuse.
+	buf     *buffer.Buffer // Buffer for storing data under the threshold in memory.
 
 	bytesRead int64 // Total number of bytes read from the underlying reader
 	index     int64 // Current position in the virtual stream
 
-	// Flag to control buffering. This flag is used to indicate whether buffering is active.
-	// Buffering is enabled during initial reads (e.g., for MIME type detection and format identification).
-	// Once these operations are done, buffering should be disabled to prevent further writes to the buffer
-	// and to optimize subsequent reads directly from the underlying reader. This helps avoid excessive
-	// memory usage while still providing the necessary functionality for initial detection operations.
-	activeBuffering bool
+	threshold      int64    // Threshold for switching to file buffering
+	tempFile       *os.File // Temporary file for disk-based buffering
+	tempFileName   string   // Name of the temporary file
+	diskBufferSize int64    // Size of data written to disk
+
+	// Fields to provide a quick way to determine the total size of the reader
+	// without having to seek.
+	totalSize int64 // Total size of the reader
+	sizeKnown bool  // Whether the total size of the reader is known
 }
 
 // NewBufferedReaderSeeker creates and initializes a BufferedReadSeeker.
 // It takes an io.Reader and checks if it supports seeking.
 // If the reader supports seeking, it is stored in the seeker field.
 func NewBufferedReaderSeeker(r io.Reader) *BufferedReadSeeker {
-	var (
-		seeker          io.Seeker
-		buffer          *bytes.Buffer
-		activeBuffering = true
-	)
-	if s, ok := r.(io.Seeker); ok {
-		seeker = s
-		activeBuffering = false
-	}
+	const defaultThreshold = 1 << 24 // 16MB threshold for switching to file buffering
 
-	const mimeTypeBufferSize = 3072 // Approx buffer size for MIME type detection
+	seeker, _ := r.(io.Seeker)
 
+	var buf *buffer.Buffer
 	if seeker == nil {
-		buffer = bytes.NewBuffer(make([]byte, 0, mimeTypeBufferSize))
+		buf = defaultBufferPool.Get()
 	}
 
 	return &BufferedReadSeeker{
-		reader:          r,
-		seeker:          seeker,
-		buffer:          buffer,
-		bytesRead:       0,
-		index:           0,
-		activeBuffering: activeBuffering,
+		reader:    r,
+		seeker:    seeker,
+		bufPool:   defaultBufferPool,
+		buf:       buf,
+		threshold: defaultThreshold,
 	}
 }
 
 // Read reads len(out) bytes from the reader starting at the current index.
 // It handles both seekable and non-seekable underlying readers efficiently.
 func (br *BufferedReadSeeker) Read(out []byte) (int, error) {
-	// For seekable readers, read directly from the underlying reader.
 	if br.seeker != nil {
+		// For seekable readers, read directly from the underlying reader.
 		n, err := br.reader.Read(out)
-		br.index += int64(n)
-		br.bytesRead = max(br.bytesRead, br.index)
-		return n, err
-	}
-
-	// For non-seekable readers, use buffered reading.
-	outLen := int64(len(out))
-	if outLen == 0 {
-		return 0, nil
-	}
-
-	// If the current read position (br.index) is within the buffer's valid data range,
-	// read from the buffer. This ensures previously read data (e.g., for mime type detection)
-	// is included in subsequent reads, providing a consistent view of the reader's content.
-	if br.index < int64(br.buffer.Len()) {
-		n := copy(out, br.buffer.Bytes()[br.index:])
-		br.index += int64(n)
-		return n, nil
-	}
-
-	if !br.activeBuffering {
-		// If buffering is not active, read directly from the underlying reader.
-		n, err := br.reader.Read(out)
-		br.index += int64(n)
-		br.bytesRead = max(br.bytesRead, br.index)
-		return n, err
-	}
-
-	// Ensure there are enough bytes in the buffer to read from.
-	if outLen+br.index > int64(br.buffer.Len()) {
-		bytesToRead := int(outLen + br.index - int64(br.buffer.Len()))
-		readerBytes := make([]byte, bytesToRead)
-		n, err := br.reader.Read(readerBytes)
-		br.buffer.Write(readerBytes[:n])
-		br.bytesRead += int64(n)
-
-		if err != nil {
-			return n, err
+		if n > 0 {
+			br.bytesRead += int64(n)
 		}
+		return n, err
 	}
 
-	// Ensure the read does not exceed the buffer length.
-	endIndex := br.index + outLen
-	bufLen := int64(br.buffer.Len())
-	if endIndex > bufLen {
-		endIndex = bufLen
+	var (
+		totalBytesRead int
+		err            error
+	)
+
+	// If the current read position is within the in-memory buffer.
+	if br.index < int64(br.buf.Len()) {
+		totalBytesRead = copy(out, br.buf.Bytes()[br.index:])
+		br.index += int64(totalBytesRead)
+		if totalBytesRead == len(out) {
+			return totalBytesRead, nil
+		}
+		out = out[totalBytesRead:]
 	}
 
-	if br.index >= bufLen {
-		return 0, io.EOF
+	// If we've exceeded the in-memory threshold and have a temp file.
+	if br.tempFile != nil && br.index < br.diskBufferSize {
+		if _, err := br.tempFile.Seek(br.index-int64(br.buf.Len()), io.SeekStart); err != nil {
+			return totalBytesRead, err
+		}
+		m, err := br.tempFile.Read(out)
+		totalBytesRead += m
+		br.index += int64(m)
+		if err != nil && !errors.Is(err, io.EOF) {
+			return totalBytesRead, err
+		}
+		if totalBytesRead == len(out) {
+			return totalBytesRead, nil
+		}
+		out = out[totalBytesRead:]
 	}
 
-	n := copy(out, br.buffer.Bytes()[br.index:endIndex])
-	br.index += int64(n)
-	return n, nil
+	if len(out) == 0 {
+		return totalBytesRead, nil
+	}
+
+	// If we still need to read more data.
+	var raderBytes int
+	raderBytes, err = br.reader.Read(out)
+	totalBytesRead += raderBytes
+	br.index += int64(raderBytes)
+
+	if writeErr := br.writeData(out[:raderBytes]); writeErr != nil {
+		return totalBytesRead, writeErr
+	}
+
+	if errors.Is(err, io.EOF) {
+		br.totalSize = br.bytesRead
+		br.sizeKnown = true
+	}
+
+	return totalBytesRead, err
 }
 
 // Seek sets the offset for the next Read or Write to offset.
@@ -125,45 +146,25 @@ func (br *BufferedReadSeeker) Read(out []byte) (int, error) {
 func (br *BufferedReadSeeker) Seek(offset int64, whence int) (int64, error) {
 	if br.seeker != nil {
 		// Use the underlying Seeker if available.
-		newIndex, err := br.seeker.Seek(offset, whence)
-		if err != nil {
-			return 0, fmt.Errorf("error seeking in reader: %w", err)
-		}
-		if newIndex > br.bytesRead {
-			br.bytesRead = newIndex
-		}
-		return newIndex, nil
+		return br.seeker.Seek(offset, whence)
 	}
 
 	// Manual seeking for non-seekable readers.
 	newIndex := br.index
 
-	const bufferSize = 64 * 1024 // 64KB chunk size for reading
-
 	switch whence {
 	case io.SeekStart:
 		newIndex = offset
 	case io.SeekCurrent:
 		newIndex += offset
 	case io.SeekEnd:
-		// Read the entire reader to determine its length
-		buffer := make([]byte, bufferSize)
-		for {
-			n, err := br.reader.Read(buffer)
-			if n > 0 {
-				if br.activeBuffering {
-					br.buffer.Write(buffer[:n])
-				}
-				br.bytesRead += int64(n)
-			}
-			if errors.Is(err, io.EOF) {
-				break
-			}
-			if err != nil {
+		// If we already know the total size, we can use it directly.
+		if !br.sizeKnown {
+			if err := br.readToEnd(); err != nil {
 				return 0, err
 			}
 		}
-		newIndex = min(br.bytesRead+offset, br.bytesRead)
+		newIndex = br.totalSize + offset
 	default:
 		return 0, errors.New("invalid whence value")
 	}
@@ -172,27 +173,161 @@ func (br *BufferedReadSeeker) Seek(offset int64, whence int) (int64, error) {
 		return 0, errors.New("can not seek to before start of reader")
 	}
 
+	// For non-seekable readers, we need to ensure we've read up to the new index.
+	if br.seeker == nil && newIndex > br.bytesRead {
+		if err := br.readUntil(newIndex); err != nil {
+			return 0, err
+		}
+	}
+
 	br.index = newIndex
 
+	// Update bytesRead only if we've moved beyond what we've read so far.
+	if br.index > br.bytesRead {
+		br.bytesRead = br.index
+	}
+
 	return newIndex, nil
 }
 
+func (br *BufferedReadSeeker) readToEnd() error {
+	buf := br.bufPool.Get()
+	defer br.bufPool.Put(buf)
+
+	for {
+		n, err := io.CopyN(buf, br.reader, defaultBufferSize)
+		if n > 0 {
+			// Write the data from the buffer.
+			if writeErr := br.writeData(buf.Bytes()[:n]); writeErr != nil {
+				return writeErr
+			}
+		}
+		// Reset the buffer for the next iteration.
+		buf.Reset()
+		if errors.Is(err, io.EOF) {
+			break
+		}
+		if err != nil {
+			return err
+		}
+	}
+	br.totalSize = br.bytesRead
+	br.sizeKnown = true
+
+	return nil
+}
+
+func (br *BufferedReadSeeker) writeData(data []byte) error {
+	_, err := br.buf.Write(data)
+	if err != nil {
+		return err
+	}
+	br.bytesRead += int64(len(data))
+
+	// Check if we've reached or exceeded the threshold.
+	if br.buf.Len() < int(br.threshold) {
+		return nil
+	}
+
+	if br.tempFile == nil {
+		if err := br.createTempFile(); err != nil {
+			return err
+		}
+	}
+
+	// Flush the buffer to disk.
+	return br.flushBufferToDisk()
+}
+
+func (br *BufferedReadSeeker) readUntil(index int64) error {
+	buf := br.bufPool.Get()
+	defer br.bufPool.Put(buf)
+
+	for br.bytesRead < index {
+		remaining := index - br.bytesRead
+		bufSize := int64(defaultBufferSize)
+		if remaining < bufSize {
+			bufSize = remaining
+		}
+
+		n, err := io.CopyN(buf, br, bufSize)
+		if err != nil && !errors.Is(err, io.EOF) {
+			return err
+		}
+
+		if n == 0 {
+			break
+		}
+
+		buf.Reset()
+	}
+
+	return nil
+}
+
+func (br *BufferedReadSeeker) createTempFile() error {
+	tempFile, err := os.CreateTemp(os.TempDir(), cleantemp.MkFilename())
+	if err != nil {
+		return err
+	}
+	br.tempFile = tempFile
+	br.tempFileName = tempFile.Name()
+
+	return nil
+}
+
+func (br *BufferedReadSeeker) flushBufferToDisk() error {
+	if _, err := br.buf.WriteTo(br.tempFile); err != nil {
+		return err
+	}
+	br.diskBufferSize = int64(br.buf.Len())
+
+	return nil
+}
+
 // ReadAt reads len(out) bytes into out starting at offset off in the underlying input source.
 // It uses Seek and Read to implement random access reading.
 func (br *BufferedReadSeeker) ReadAt(out []byte, offset int64) (int, error) {
-	startIndex, err := br.Seek(offset, io.SeekStart)
-	if err != nil {
+	if br.seeker != nil {
+		// Use the underlying Seeker if available.
+		_, err := br.Seek(offset, io.SeekStart)
+		if err != nil {
+			return 0, err
+		}
+		return br.Read(out)
+	}
+
+	// For non-seekable readers, use our buffering logic.
+	currentIndex := br.index
+
+	if _, err := br.Seek(offset, io.SeekStart); err != nil {
 		return 0, err
 	}
 
-	if startIndex != offset {
-		return 0, io.EOF
+	n, err := br.Read(out)
+	if err != nil {
+		return n, err
 	}
 
-	return br.Read(out)
+	// Seek back to the original position.
+	if _, err = br.Seek(currentIndex, io.SeekStart); err != nil {
+		return n, err
+	}
+
+	return n, err
 }
 
-// DisableBuffering stops the buffering process.
-// This is useful after initial reads (e.g., for MIME type detection and format identification)
-// to prevent further writes to the buffer, optimizing subsequent reads.
-func (br *BufferedReadSeeker) DisableBuffering() { br.activeBuffering = false }
+// Close closes the BufferedReadSeeker and releases any resources used.
+// It closes the temporary file if one was created and removes it from disk and
+// returns the buffer to the pool.
+func (br *BufferedReadSeeker) Close() error {
+	if br.buf != nil {
+		br.bufPool.Put(br.buf)
+	}
+
+	if br.tempFile != nil {
+		br.tempFile.Close()
+		return os.Remove(br.tempFileName)
+	}
+	return nil
+}

pkg/iobuf/bufferedreaderseeker_test.go

@@ -13,7 +13,6 @@ func TestBufferedReaderSeekerRead(t *testing.T) {
 	tests := []struct {
 		name              string
 		reader            io.Reader
-		activeBuffering   bool
 		reads             []int
 		expectedReads     []int
 		expectedBytes     [][]byte
@@ -25,7 +24,6 @@ func TestBufferedReaderSeekerRead(t *testing.T) {
 		{
 			name:              "read from seekable reader",
 			reader:            strings.NewReader("test data"),
-			activeBuffering:   true,
 			reads:             []int{4},
 			expectedReads:     []int{4},
 			expectedBytes:     [][]byte{[]byte("test")},
@@ -35,7 +33,6 @@ func TestBufferedReaderSeekerRead(t *testing.T) {
 		{
 			name:              "read from non-seekable reader with buffering",
 			reader:            bytes.NewBufferString("test data"),
-			activeBuffering:   true,
 			reads:             []int{4},
 			expectedReads:     []int{4},
 			expectedBytes:     [][]byte{[]byte("test")},
@@ -46,7 +43,6 @@ func TestBufferedReaderSeekerRead(t *testing.T) {
 		{
 			name:              "read from non-seekable reader without buffering",
 			reader:            bytes.NewBufferString("test data"),
-			activeBuffering:   false,
 			reads:             []int{4},
 			expectedReads:     []int{4},
 			expectedBytes:     [][]byte{[]byte("test")},
@@ -56,7 +52,6 @@ func TestBufferedReaderSeekerRead(t *testing.T) {
 		{
 			name:              "read beyond buffer",
 			reader:            strings.NewReader("test data"),
-			activeBuffering:   true,
 			reads:             []int{10},
 			expectedReads:     []int{9},
 			expectedBytes:     [][]byte{[]byte("test data")},
@@ -66,7 +61,6 @@ func TestBufferedReaderSeekerRead(t *testing.T) {
 		{
 			name:              "read with empty reader",
 			reader:            strings.NewReader(""),
-			activeBuffering:   true,
 			reads:             []int{4},
 			expectedReads:     []int{0},
 			expectedBytes:     [][]byte{[]byte("")},
@@ -77,7 +71,6 @@ func TestBufferedReaderSeekerRead(t *testing.T) {
 		{
 			name:              "read exact buffer size",
 			reader:            strings.NewReader("test"),
-			activeBuffering:   true,
 			reads:             []int{4},
 			expectedReads:     []int{4},
 			expectedBytes:     [][]byte{[]byte("test")},
@@ -87,7 +80,6 @@ func TestBufferedReaderSeekerRead(t *testing.T) {
 		{
 			name:              "read less than buffer size",
 			reader:            strings.NewReader("te"),
-			activeBuffering:   true,
 			reads:             []int{4},
 			expectedReads:     []int{2},
 			expectedBytes:     [][]byte{[]byte("te")},
@@ -97,7 +89,6 @@ func TestBufferedReaderSeekerRead(t *testing.T) {
 		{
 			name:              "read more than buffer size without buffering",
 			reader:            bytes.NewBufferString("test data"),
-			activeBuffering:   false,
 			reads:             []int{4},
 			expectedReads:     []int{4},
 			expectedBytes:     [][]byte{[]byte("test")},
@@ -107,7 +98,6 @@ func TestBufferedReaderSeekerRead(t *testing.T) {
 		{
 			name:              "multiple reads with buffering",
 			reader:            bytes.NewBufferString("test data"),
-			activeBuffering:   true,
 			reads:             []int{4, 5},
 			expectedReads:     []int{4, 5},
 			expectedBytes:     [][]byte{[]byte("test"), []byte(" data")},
@@ -118,7 +108,6 @@ func TestBufferedReaderSeekerRead(t *testing.T) {
 		{
 			name:              "multiple reads without buffering",
 			reader:            bytes.NewBufferString("test data"),
-			activeBuffering:   false,
 			reads:             []int{4, 5},
 			expectedReads:     []int{4, 5},
 			expectedBytes:     [][]byte{[]byte("test"), []byte(" data")},
@@ -132,7 +121,6 @@ func TestBufferedReaderSeekerRead(t *testing.T) {
 			t.Parallel()
 
 			brs := NewBufferedReaderSeeker(tt.reader)
-			brs.activeBuffering = tt.activeBuffering
 
 			for i, readSize := range tt.reads {
 				buf := make([]byte, readSize)
@@ -151,10 +139,12 @@ func TestBufferedReaderSeekerRead(t *testing.T) {
 			}
 
 			assert.Equal(t, tt.expectedBytesRead, brs.bytesRead)
-			assert.Equal(t, tt.expectedIndex, brs.index)
+			if brs.seeker == nil {
+				assert.Equal(t, tt.expectedIndex, brs.index)
+			}
 
-			if brs.buffer != nil && len(tt.expectedBuffer) > 0 {
-				assert.Equal(t, tt.expectedBuffer, brs.buffer.Bytes())
+			if brs.buf != nil && len(tt.expectedBuffer) > 0 {
+				assert.Equal(t, tt.expectedBuffer, brs.buf.Bytes())
 			} else {
 				assert.Nil(t, tt.expectedBuffer)
 			}
@@ -240,7 +230,7 @@ func TestBufferedReaderSeekerSeek(t *testing.T) {
 			reader:       bytes.NewBufferString("test data"),
 			offset:       20,
 			whence:       io.SeekEnd,
-			expectedPos:  9,
+			expectedPos:  29,
 			expectedErr:  false,
 			expectedRead: []byte{},
 		},