Add backup. Close #104

backup.go

@@ -0,0 +1,42 @@
+package sqlite3
+
+/*
+#include <sqlite3.h>
+#include <stdlib.h>
+*/
+import "C"
+import (
+	"unsafe"
+)
+
+type Backup struct {
+	b *C.sqlite3_backup
+}
+
+func (c *SQLiteConn) Backup(dest string, conn *SQLiteConn, src string) (*Backup, error) {
+	destptr := C.CString(dest)
+	defer C.free(unsafe.Pointer(destptr))
+	srcptr := C.CString(src)
+	defer C.free(unsafe.Pointer(srcptr))
+
+	if b := C.sqlite3_backup_init(c.db, destptr, conn.db, srcptr); b != nil {
+		return &Backup{b: b}, nil
+	}
+	return nil, c.lastError()
+}
+
+func (b *Backup) Step(p int) error {
+	return Error{Code: ErrNo(C.sqlite3_backup_step(b.b, C.int(p)))}
+}
+
+func (b *Backup) Remaining() int {
+	return int(C.sqlite3_backup_remaining(b.b))
+}
+
+func (b *Backup) PageCount() int {
+	return int(C.sqlite3_backup_pagecount(b.b))
+}
+
+func (b *Backup) Finish() error {
+	return Error{Code: ErrNo(C.sqlite3_backup_finish(b.b))}
+}