switch to go vendoring

vendor/github.com/tus/tusd/pkg/handler/body_reader.go

@@ -0,0 +1,53 @@
+package handler
+
+import (
+	"io"
+	"sync/atomic"
+)
+
+// bodyReader is an io.Reader, which is intended to wrap the request
+// body reader. If an error occurr during reading the request body, it
+// will not return this error to the reading entity, but instead store
+// the error and close the io.Reader, so that the error can be checked
+// afterwards. This is helpful, so that the stores do not have to handle
+// the error but this can instead be done in the handler.
+// In addition, the bodyReader keeps track of how many bytes were read.
+type bodyReader struct {
+	reader       io.Reader
+	err          error
+	bytesCounter int64
+}
+
+func newBodyReader(r io.Reader) *bodyReader {
+	return &bodyReader{
+		reader: r,
+	}
+}
+
+func (r *bodyReader) Read(b []byte) (int, error) {
+	if r.err != nil {
+		return 0, io.EOF
+	}
+
+	n, err := r.reader.Read(b)
+	atomic.AddInt64(&r.bytesCounter, int64(n))
+	r.err = err
+
+	if err == io.EOF {
+		return n, io.EOF
+	} else {
+		return n, nil
+	}
+}
+
+func (r bodyReader) hasError() error {
+	if r.err == io.EOF {
+		return nil
+	}
+
+	return r.err
+}
+
+func (r *bodyReader) bytesRead() int64 {
+	return atomic.LoadInt64(&r.bytesCounter)
+}