From c651b50db543a304f5bb3cac6d74f2c633b02dd9 Mon Sep 17 00:00:00 2001
From: Vladimir Mihailenco <vladimir.webdev@gmail.com>
Date: Sun, 5 Aug 2018 15:07:10 +0300
Subject: [PATCH] internal/proto: cleanup bufio reader

---
 internal/proto/bufio_reader.go | 41 ++++++++++++----------------------
 internal/proto/reader.go       |  6 +----
 2 files changed, 15 insertions(+), 32 deletions(-)

diff --git a/internal/proto/bufio_reader.go b/internal/proto/bufio_reader.go
index 6e392e6..7ca05d6 100644
--- a/internal/proto/bufio_reader.go
+++ b/internal/proto/bufio_reader.go
@@ -1,7 +1,6 @@
 package proto
 
 import (
-	"bufio"
 	"bytes"
 	"errors"
 	"io"
@@ -145,10 +144,7 @@ func (b *BufioReader) ReadSlice(delim byte) (line []byte, err error) {
 
 		// Buffer full?
 		if b.Buffered() >= len(b.buf) {
-			b.r = b.w
-			line = b.buf
-			err = bufio.ErrBufferFull
-			break
+			b.grow(len(b.buf) + defaultBufSize)
 		}
 
 		b.fill() // buffer is not full
@@ -157,23 +153,8 @@ func (b *BufioReader) ReadSlice(delim byte) (line []byte, err error) {
 	return
 }
 
-func (b *BufioReader) ReadLine() (line []byte, isPrefix bool, err error) {
+func (b *BufioReader) ReadLine() (line []byte, err error) {
 	line, err = b.ReadSlice('\n')
-	if err == bufio.ErrBufferFull {
-		// Handle the case where "\r\n" straddles the buffer.
-		if len(line) > 0 && line[len(line)-1] == '\r' {
-			// Put the '\r' back on buf and drop it from line.
-			// Let the next call to ReadLine check for "\r\n".
-			if b.r == 0 {
-				// should be unreachable
-				panic("bufio: tried to rewind past start of buffer")
-			}
-			b.r--
-			line = line[:len(line)-1]
-		}
-		return line, true, nil
-	}
-
 	if len(line) == 0 {
 		if err != nil {
 			line = nil
@@ -192,6 +173,18 @@ func (b *BufioReader) ReadLine() (line []byte, isPrefix bool, err error) {
 	return
 }
 
+func (b *BufioReader) ReadByte() (byte, error) {
+	for b.r == b.w {
+		if b.err != nil {
+			return 0, b.readErr()
+		}
+		b.fill() // buffer is empty
+	}
+	c := b.buf[b.r]
+	b.r++
+	return c, nil
+}
+
 func (b *BufioReader) ReadN(n int) ([]byte, error) {
 	b.grow(n)
 	for b.Buffered() < n {
@@ -202,12 +195,6 @@ func (b *BufioReader) ReadN(n int) ([]byte, error) {
 			return buf, b.readErr()
 		}
 
-		// Buffer is full?
-		if b.Buffered() >= len(b.buf) {
-			b.r = b.w
-			return b.buf, bufio.ErrBufferFull
-		}
-
 		b.fill()
 	}
 
diff --git a/internal/proto/reader.go b/internal/proto/reader.go
index 70fef5e..26167eb 100644
--- a/internal/proto/reader.go
+++ b/internal/proto/reader.go
@@ -1,7 +1,6 @@
 package proto
 
 import (
-	"bufio"
 	"fmt"
 	"io"
 	"strconv"
@@ -54,13 +53,10 @@ func (r *Reader) ReadN(n int) ([]byte, error) {
 }
 
 func (r *Reader) ReadLine() ([]byte, error) {
-	line, isPrefix, err := r.src.ReadLine()
+	line, err := r.src.ReadLine()
 	if err != nil {
 		return nil, err
 	}
-	if isPrefix {
-		return nil, bufio.ErrBufferFull
-	}
 	if len(line) == 0 {
 		return nil, fmt.Errorf("redis: reply is empty")
 	}