streaming: Unembed iface.Private in streaming-based interfaces (#533)

`iface.Private` was embedded in the newly defined interfaces for streaming to
prevent others from implementing them incase they needed to be modified.

Since the all of the development for streaming has occurred outside of 'dev',
and since it's unlikely for these interfaces to be merged to 'dev' without
already certifying and agreeing on them, unembed these to simplify mocking uses
and to clear out extra code.

protocol/binary/protocol.go

@@ -26,7 +26,6 @@ import (
 	"fmt"
 	"io"
 
-	"go.uber.org/thriftrw/internal/iface"
 	"go.uber.org/thriftrw/protocol/envelope"
 	"go.uber.org/thriftrw/protocol/stream"
 	"go.uber.org/thriftrw/wire"
@@ -36,9 +35,7 @@ import (
 var Default = new(Protocol)
 
 // Protocol implements the Thrift Binary Protocol.
-type Protocol struct {
-	iface.Private
-}
+type Protocol struct{}
 
 var _ stream.Protocol = (*Protocol)(nil)
 var _ stream.RequestReader = (*Protocol)(nil)

protocol/binary/stream_reader.go

@@ -27,7 +27,6 @@ import (
 	"math"
 	"sync"
 
-	"go.uber.org/thriftrw/internal/iface"
 	"go.uber.org/thriftrw/protocol/stream"
 	"go.uber.org/thriftrw/wire"
 )
@@ -62,8 +61,6 @@ func fixedWidth(t wire.Type) int64 {
 
 // StreamReader provides an implementation of a "stream.Reader".
 type StreamReader struct {
-	iface.Private
-
 	reader io.Reader
 	buffer [8]byte
 

protocol/binary/stream_writer.go

@@ -25,7 +25,6 @@ import (
 	"math"
 	"sync"
 
-	"go.uber.org/thriftrw/internal/iface"
 	"go.uber.org/thriftrw/protocol/stream"
 )
 
@@ -37,9 +36,6 @@ var streamWriterPool = sync.Pool{
 // StreamWriter implements basic logic for writing the Thrift Binary Protocol
 // to an io.Writer.
 type StreamWriter struct {
-	// Private implementation to satisfy the private Writer interface.
-	iface.Impl
-
 	writer io.Writer
 
 	// This buffer is re-used every time we need a slice of up to 8 bytes.

protocol/stream/stream.go

@@ -25,15 +25,12 @@ package stream
 import (
 	"io"
 
-	"go.uber.org/thriftrw/internal/iface"
 	"go.uber.org/thriftrw/wire"
 )
 
 // Protocol defines a specific way for a Thrift value to be encoded or
 // decoded, implemented in a streaming fashion.
 type Protocol interface {
-	iface.Private // this interface is meant for internal implementations only
-
 	// Writer returns a streaming implementation of an encoder for a
 	// Thrift value.
 	Writer(w io.Writer) Writer
@@ -84,8 +81,6 @@ type ListHeader struct {
 // Writer defines an encoder for a Thrift value, implemented in a streaming
 // fashion.
 type Writer interface {
-	iface.Private // this interface is meant for internal implementations only
-
 	WriteBool(b bool) error
 	WriteInt8(i int8) error
 	WriteInt16(i int16) error
@@ -114,8 +109,6 @@ type Writer interface {
 // Reader defines an decoder for a Thrift value, implemented in a streaming
 // fashion.
 type Reader interface {
-	iface.Private // this interface is meant for internal implementations only
-
 	ReadBool() (bool, error)
 	ReadInt8() (int8, error)
 	ReadInt16() (int16, error)