From 4c3a1f2f343637b615c26a27a55afa12dd5aaed5 Mon Sep 17 00:00:00 2001
From: Henrique Dias <mail@hacdias.com>
Date: Thu, 18 Jan 2024 17:46:10 +0100
Subject: [PATCH] gateway: remove dead, unexported lazySeek

---
 gateway/lazyseek.go      | 61 -------------------------
 gateway/lazyseek_test.go | 98 ----------------------------------------
 2 files changed, 159 deletions(-)
 delete mode 100644 gateway/lazyseek.go
 delete mode 100644 gateway/lazyseek_test.go

diff --git a/gateway/lazyseek.go b/gateway/lazyseek.go
deleted file mode 100644
index e0ec44a82..000000000
--- a/gateway/lazyseek.go
+++ /dev/null
@@ -1,61 +0,0 @@
-package gateway
-
-import (
-	"errors"
-	"fmt"
-	"io"
-)
-
-// The HTTP server uses seek to determine the file size. Actually _seeking_ can
-// be slow so we wrap the seeker in a _lazy_ seeker.
-type lazySeeker struct {
-	reader io.ReadSeeker
-
-	size       int64
-	offset     int64
-	realOffset int64
-}
-
-func (s *lazySeeker) Seek(offset int64, whence int) (int64, error) {
-	switch whence {
-	case io.SeekEnd:
-		return s.Seek(s.size+offset, io.SeekStart)
-	case io.SeekCurrent:
-		return s.Seek(s.offset+offset, io.SeekStart)
-	case io.SeekStart:
-		if offset < 0 {
-			return s.offset, errors.New("invalid seek offset")
-		}
-		s.offset = offset
-		return s.offset, nil
-	default:
-		return s.offset, fmt.Errorf("invalid whence: %d", whence)
-	}
-}
-
-func (s *lazySeeker) Read(b []byte) (int, error) {
-	// If we're past the end, EOF.
-	if s.offset >= s.size {
-		return 0, io.EOF
-	}
-
-	// actually seek
-	for s.offset != s.realOffset {
-		off, err := s.reader.Seek(s.offset, io.SeekStart)
-		if err != nil {
-			return 0, err
-		}
-		s.realOffset = off
-	}
-	off, err := s.reader.Read(b)
-	s.realOffset += int64(off)
-	s.offset += int64(off)
-	return off, err
-}
-
-func (s *lazySeeker) Close() error {
-	if closer, ok := s.reader.(io.Closer); ok {
-		return closer.Close()
-	}
-	return nil
-}
diff --git a/gateway/lazyseek_test.go b/gateway/lazyseek_test.go
deleted file mode 100644
index fdc6d2b34..000000000
--- a/gateway/lazyseek_test.go
+++ /dev/null
@@ -1,98 +0,0 @@
-package gateway
-
-import (
-	"errors"
-	"io"
-	"strings"
-	"testing"
-
-	"github.com/stretchr/testify/require"
-)
-
-type badSeeker struct {
-	io.ReadSeeker
-}
-
-var errBadSeek = errors.New("bad seeker")
-
-func (bs badSeeker) Seek(offset int64, whence int) (int64, error) {
-	off, err := bs.ReadSeeker.Seek(0, io.SeekCurrent)
-	if err != nil {
-		panic(err)
-	}
-	return off, errBadSeek
-}
-
-func TestLazySeekerError(t *testing.T) {
-	underlyingBuffer := strings.NewReader("fubar")
-	s := &lazySeeker{
-		reader: badSeeker{underlyingBuffer},
-		size:   underlyingBuffer.Size(),
-	}
-	off, err := s.Seek(0, io.SeekEnd)
-	require.NoError(t, err)
-	require.Equal(t, s.size, off, "expected to seek to the end")
-
-	// shouldn't have actually seeked.
-	b, err := io.ReadAll(s)
-	require.NoError(t, err)
-	require.Equal(t, 0, len(b), "expected to read nothing")
-
-	// shouldn't need to actually seek.
-	off, err = s.Seek(0, io.SeekStart)
-	require.NoError(t, err)
-	require.Equal(t, int64(0), off, "expected to seek to the start")
-
-	b, err = io.ReadAll(s)
-	require.NoError(t, err)
-	require.Equal(t, "fubar", string(b), "expected to read string")
-
-	// should fail the second time.
-	off, err = s.Seek(0, io.SeekStart)
-	require.NoError(t, err)
-	require.Equal(t, int64(0), off, "expected to seek to the start")
-
-	// right here...
-	b, err = io.ReadAll(s)
-	require.NotNil(t, err)
-	require.Equal(t, errBadSeek, err)
-	require.Equal(t, 0, len(b), "expected to read nothing")
-}
-
-func TestLazySeeker(t *testing.T) {
-	underlyingBuffer := strings.NewReader("fubar")
-	s := &lazySeeker{
-		reader: underlyingBuffer,
-		size:   underlyingBuffer.Size(),
-	}
-	expectByte := func(b byte) {
-		t.Helper()
-		var buf [1]byte
-		n, err := io.ReadFull(s, buf[:])
-		require.NoError(t, err)
-		require.Equal(t, 1, n, "expected to read one byte, read %d", n)
-		require.Equal(t, b, buf[0])
-	}
-	expectSeek := func(whence int, off, expOff int64, expErr string) {
-		t.Helper()
-		n, err := s.Seek(off, whence)
-		if expErr == "" {
-			require.NoError(t, err)
-		} else {
-			require.EqualError(t, err, expErr)
-		}
-		require.Equal(t, expOff, n)
-	}
-
-	expectSeek(io.SeekEnd, 0, s.size, "")
-	b, err := io.ReadAll(s)
-	require.NoError(t, err)
-	require.Equal(t, 0, len(b), "expected to read nothing")
-	expectSeek(io.SeekEnd, -1, s.size-1, "")
-	expectByte('r')
-	expectSeek(io.SeekStart, 0, 0, "")
-	expectByte('f')
-	expectSeek(io.SeekCurrent, 1, 2, "")
-	expectByte('b')
-	expectSeek(io.SeekCurrent, -100, 3, "invalid seek offset")
-}