Initial commit, with basic functionality.

src/filesystem.h

@@ -0,0 +1,69 @@
+// This file is part of Moonfire NVR, a security camera digital video recorder.
+// Copyright (C) 2016 Scott Lamb <slamb@slamb.org>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// In addition, as a special exception, the copyright holders give
+// permission to link the code of portions of this program with the
+// OpenSSL library under certain conditions as described in each
+// individual source file, and distribute linked combinations including
+// the two.
+//
+// You must obey the GNU General Public License in all respects for all
+// of the code used other than OpenSSL. If you modify file(s) with this
+// exception, you may extend this exception to your version of the
+// file(s), but you are not obligated to do so. If you do not wish to do
+// so, delete this exception statement from your version. If you delete
+// this exception statement from all source files in the program, then
+// also delete it here.
+//
+// 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 General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+// filesystem.h: helpers for dealing with the local filesystem.
+
+#ifndef MOONFIRE_NVR_FILESYSTEM_H
+#define MOONFIRE_NVR_FILESYSTEM_H
+
+#include <dirent.h>
+#include <stdarg.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include <functional>
+#include <iostream>
+#include <string>
+
+#include <event2/buffer.h>
+#include <event2/http.h>
+#include <glog/logging.h>
+#include <re2/stringpiece.h>
+
+namespace moonfire_nvr {
+
+// Return value for *ForEach callbacks.
+enum class IterationControl {
+  kContinue,  // indicates the caller should proceed with the loop.
+  kBreak      // indicates the caller should terminate the loop with success.
+};
+
+// Execute |fn| for each directory entry in |dir_path|, stopping early
+// (successfully) if the callback returns IterationControl::kBreak.
+//
+// On success, returns true.
+// On failure, returns false and updates |error_msg|.
+bool DirForEach(const std::string &dir_path,
+                std::function<IterationControl(const dirent *)> fn,
+                std::string *error_msg);
+
+}  // namespace moonfire_nvr
+
+#endif  // MOONFIRE_NVR_FILESYSTEM_H