fix CopyTo for files and sockets

was ignoring buffering

builtin/copyto.go

@@ -4,9 +4,7 @@
 package builtin
 
 import (
-	"fmt"
 	"io"
-	"sync"
 
 	. "github.com/apmckinlay/gsuneido/core"
 )
@@ -16,12 +14,6 @@ type writer interface {
 	writer() io.Writer
 }
 
-var bufs = sync.Pool{New: func() any {
-	return new([rwsize]byte)
-}}
-
-const rwsize = 32 * 1024 // same as Go io.Copy
-
 // CopyTo copies from src to to, up to nbytes or until src eof.
 // Called by CopyTo in file, socket, and runpiped.
 func CopyTo(th *Thread, src io.Reader, to, nbytes Value) Value {
@@ -31,13 +23,6 @@ func CopyTo(th *Thread, src io.Reader, to, nbytes Value) Value {
 	}
 	dst := tow.writer()
 
-	if _, ok = src.(io.WriterTo); !ok {
-		fmt.Println("ERROR: CopyTo: src should have WriteTo")
-	}
-	if _, ok = dst.(io.ReaderFrom); !ok {
-		fmt.Println("ERROR: CopyTo: dst should have ReadFrom")
-	}
-
 	var n int64
 	if nbytes != False {
 		n = ToInt64(nbytes)
@@ -46,10 +31,7 @@ func CopyTo(th *Thread, src io.Reader, to, nbytes Value) Value {
 		}
 		src = io.LimitReader(src, int64(n))
 	}
-
-	array := bufs.Get().(*[rwsize]byte)
-	defer bufs.Put(array)
-	nw, err := io.CopyBuffer(dst, src, array[:]) // the actual copy
+	nw, err := dst.(io.ReaderFrom).ReadFrom(src)
 	if err != nil {
 		panic("ERROR: CopyTo: " + err.Error())
 	}

builtin/file.go

@@ -183,11 +183,11 @@ func file_Read(this, arg Value) Value {
 var _ = method(file_CopyTo, "(dest, nbytes = false)")
 
 func file_CopyTo(th *Thread, this Value, args []Value) Value {
-	return CopyTo(th, sfOpenRead(this).f, args[0], args[1])
+	return CopyTo(th, sfOpenRead(this).r, args[0], args[1])
 }
 
 func (sf *suFile) writer() io.Writer {
-	return sfOpenWrite(sf).f
+	return sfOpenWrite(sf).w
 }
 
 var _ = method(file_Readline, "()")

builtin/socketclient.go

@@ -160,7 +160,7 @@ func sock_Writeline(this, arg Value) Value {
 var _ = method(sock_CopyTo, "(dest, nbytes = false)")
 
 func sock_CopyTo(th *Thread, this Value, args []Value) Value {
-	return CopyTo(th, scOpen(this).conn, args[0], args[1])
+	return CopyTo(th, scOpen(this).rdr, args[0], args[1])
 }
 
 func (sc *suSocketClient) writer() io.Writer {