Make MessageReader a type of bytes.Buffer

conn.go

@@ -497,7 +497,7 @@ func (c *Conn) SelectValueTo(w io.Writer, sql string, arguments ...interface{})
 				return err
 			}
 
-			r := newMessageReader(body)
+			r := (*MessageReader)(body)
 			switch t {
 			case readyForQuery:
 				c.rxReadyForQuery(r)
@@ -950,7 +950,7 @@ func (c *Conn) rxMsg() (t byte, r *MessageReader, err error) {
 		return
 	}
 
-	r = newMessageReader(body)
+	r = (*MessageReader)(body)
 	return
 }
 

message_reader.go

@@ -3,113 +3,45 @@ package pgx
 import (
 	"bytes"
 	"encoding/binary"
-	"fmt"
 )
 
 // MessageReader is a helper that reads values from a PostgreSQL message.
-// To avoid verbose error handling it internally records errors and no-ops
-// any calls that occur after an error. At the end of a sequence of reads
-// the Err field should be checked to see if any errors occurred.
-type MessageReader struct {
-	buf *bytes.Buffer
-	Err error
-}
-
-func newMessageReader(buf *bytes.Buffer) *MessageReader {
-	return &MessageReader{buf: buf}
-}
+type MessageReader bytes.Buffer
 
 func (r *MessageReader) ReadByte() (b byte) {
-	if r.Err != nil {
-		return
-	}
-
-	b, r.Err = r.buf.ReadByte()
+	b, _ = (*bytes.Buffer)(r).ReadByte()
 	return
 }
 
 func (r *MessageReader) ReadInt16() (n int16) {
-	if r.Err != nil {
-		return
-	}
-
-	size := 2
-	b := r.buf.Next(size)
-	if len(b) != size {
-		r.Err = fmt.Errorf("Unable to read %d bytes, only read %d", size, len(b))
-	}
-
+	b := (*bytes.Buffer)(r).Next(2)
 	return int16(binary.BigEndian.Uint16(b))
 }
 
 func (r *MessageReader) ReadInt32() (n int32) {
-	if r.Err != nil {
-		return
-	}
-
-	size := 4
-	b := r.buf.Next(size)
-	if len(b) != size {
-		r.Err = fmt.Errorf("Unable to read %d bytes, only read %d", size, len(b))
-	}
-
+	b := (*bytes.Buffer)(r).Next(4)
 	return int32(binary.BigEndian.Uint32(b))
 }
 
 func (r *MessageReader) ReadInt64() (n int64) {
-	if r.Err != nil {
-		return
-	}
-
-	size := 8
-	b := r.buf.Next(size)
-	if len(b) != size {
-		r.Err = fmt.Errorf("Unable to read %d bytes, only read %d", size, len(b))
-	}
-
+	b := (*bytes.Buffer)(r).Next(8)
 	return int64(binary.BigEndian.Uint64(b))
 }
 
 func (r *MessageReader) ReadOid() (oid Oid) {
-	if r.Err != nil {
-		return
-	}
-
-	size := 4
-	b := r.buf.Next(size)
-	if len(b) != size {
-		r.Err = fmt.Errorf("Unable to read %d bytes, only read %d", size, len(b))
-	}
-
+	b := (*bytes.Buffer)(r).Next(4)
 	return Oid(binary.BigEndian.Uint32(b))
 }
 
 // ReadString reads a null terminated string
 func (r *MessageReader) ReadCString() (s string) {
-	if r.Err != nil {
-		return
-	}
-
-	var b []byte
-	b, r.Err = r.buf.ReadBytes(0)
-	if r.Err != nil {
-		return
-	}
-
+	b, _ := (*bytes.Buffer)(r).ReadBytes(0)
 	return string(b[:len(b)-1])
 }
 
 // ReadString reads count bytes and returns as string
 func (r *MessageReader) ReadString(count int32) (s string) {
-	if r.Err != nil {
-		return
-	}
-
 	size := int(count)
-	b := r.buf.Next(size)
-	if len(b) != size {
-		r.Err = fmt.Errorf("Unable to read %d bytes, only read %d", size, len(b))
-	}
-
+	b := (*bytes.Buffer)(r).Next(size)
 	return string(b)
 }