nsscash: add alignBufferTo() helper

[nsscash/nsscash.git] / misc.go

diff --git a/misc.go b/misc.go
new file mode 100644 (file)
index 0000000..2e60507
--- /dev/null
+++ b/misc.go
@@ -0,0 +1,37 @@
+// Miscellaneous functions
+
+// Copyright (C) 2019  Simon Ruderich
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package main
+
+import (
+       "bytes"
+       "fmt"
+)
+
+func alignBufferTo(b *bytes.Buffer, align int) {
+       if align <= 0 {
+               panic(fmt.Sprintf("invalid alignment %v", align))
+       }
+
+       l := b.Len()
+       if l%align == 0 {
+               return
+       }
+       for i := 0; i < align-l%align; i++ {
+               b.WriteByte(0)
+       }
+}