wip - Database#discard

- needs docs
- needs tests

ext/sqlite3/database.c

@@ -155,6 +155,31 @@ closed_p(VALUE self)
     return Qfalse;
 }
 
+// TODO DOCUMENT
+static VALUE
+discard(VALUE self)
+{
+  sqlite3RubyPtr ctx;
+  sqlite3_file *sfile;
+  int status;
+
+  TypedData_Get_Struct(self, sqlite3Ruby, &database_type, ctx);
+
+  status = sqlite3_file_control(ctx->db, NULL, SQLITE_FCNTL_FILE_POINTER, &sfile);
+  if (status == 0 && sfile->pMethods != NULL) {
+    sfile->pMethods->xClose(sfile);
+  }
+
+  status = sqlite3_file_control(ctx->db, NULL, SQLITE_FCNTL_JOURNAL_POINTER, &sfile);
+  if (status == 0 && sfile->pMethods != NULL) {
+    sfile->pMethods->xClose(sfile);
+  }
+
+  ctx->db = NULL;
+
+  return Qnil;
+}
+
 /* call-seq: total_changes
  *
  * Returns the total number of changes made to this database instance
@@ -890,6 +915,7 @@ init_sqlite3_database(void)
     rb_define_method(cSqlite3Database, "collation", collation, 2);
     rb_define_method(cSqlite3Database, "close", sqlite3_rb_close, 0);
     rb_define_method(cSqlite3Database, "closed?", closed_p, 0);
+    rb_define_method(cSqlite3Database, "discard", discard, 0);
     rb_define_method(cSqlite3Database, "total_changes", total_changes, 0);
     rb_define_method(cSqlite3Database, "trace", trace, -1);
     rb_define_method(cSqlite3Database, "last_insert_row_id", last_insert_row_id, 0);