Fix bolt on OpenBSD.

OpenBSD does not include a UBC kernel and writes must be synchronized
with the msync(2) syscall.  In addition, the NoSync field of the DB
struct should be ignored on OpenBSD, since unlike other platforms,
missing msyncs will result in data corruption.

Depends on PR #258.

Fixes #257.

1 files changed, 29 insertions, 0 deletions

diff --git a/bolt_openbsd.go b/bolt_openbsd.go
new file mode 100644
index 0000000..7c1bef1
--- /dev/null
+++ b/bolt_openbsd.go
@@ -0,0 +1,29 @@
+package bolt
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+const (
+	msAsync      = 1 << iota // perform asynchronous writes
+	msSync                   // perform synchronous writes
+	msInvalidate             // invalidate cached data
+)
+
+var odirect int
+
+func msync(db *DB) error {
+	_, _, errno := syscall.Syscall(syscall.SYS_MSYNC, uintptr(unsafe.Pointer(db.data)), uintptr(db.datasz), msInvalidate)
+	if errno != 0 {
+		return errno
+	}
+	return nil
+}
+
+func fdatasync(db *DB) error {
+	if db.data != nil {
+		return msync(db)
+	}
+	return db.file.Sync()
+}