init: v1.0.0

grand/util.go

@@ -0,0 +1,21 @@
+package grand
+
+import (
+	"io"
+)
+
+// MustRead tries to fill p with len(p) bytes from r. If it haven't read enough bytes, then an
+// error returns. So if nil error returns, then p must have read len(p) bytes. Otherwise, only
+// p[:n] are read from r.
+func MustRead(r io.Reader, p []byte) (int, error) {
+	n := 0
+	for len(p) > 0 {
+		m, err := r.Read(p)
+		if err != nil {
+			return n + m, err
+		}
+		p = p[m:]
+		n += m
+	}
+	return n, nil
+}