VPP Object Model (VOM)

The VOM is a C++ library for use by clients/agents of VPP for programming
state. It uses the binary APIs to do so. Various other common client side
functions are also provided. Please see om.hpp for a more detailed description.

Change-Id: Ib756bfe99817093815a9e26ccf464aa5583fc523
Signed-off-by: Neale Ranns <neale.ranns@cisco.com>
Co-authored-by: Mohsin Kazmi <sykazmi@cisco.com>
diff --git a/src/vpp-api/vom/logger.hpp b/src/vpp-api/vom/logger.hpp
new file mode 100644
index 0000000..0adc677
--- /dev/null
+++ b/src/vpp-api/vom/logger.hpp
@@ -0,0 +1,107 @@
+/*
+ * Copyright (c) 2017 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __VOM_LOGGER_H__
+#define __VOM_LOGGER_H__
+
+#include <fstream>
+#include <iostream>
+
+#include "vom/enum_base.hpp"
+
+namespace VOM {
+struct log_level_t : enum_base<log_level_t>
+{
+  const static log_level_t CRITICAL;
+  const static log_level_t ERROR;
+  const static log_level_t WARNING;
+  const static log_level_t INFO;
+  const static log_level_t DEBUG;
+
+private:
+  /**
+   * Private constructor taking the value and the string name
+   */
+  log_level_t(int v, const std::string& s);
+};
+
+/**
+ * Ideally we'd use the boost logger but that is not prevelent
+ * in many distros. So something simple here instead.
+ */
+class log_t
+{
+public:
+  /**
+   * Construct a logger
+   */
+  log_t();
+
+  /**
+   * Return the stream
+   */
+  std::ostream& stream(const char* file, int line);
+
+  /**
+   * The configured level
+   */
+  const log_level_t& level() const;
+
+  /**
+   * set the logging level
+   */
+  void set(const log_level_t& level);
+
+  /**
+   * set a file to receive the logging data
+   */
+  void set(const std::string& ofile);
+
+private:
+  /**
+   * the configured logging level
+   */
+  log_level_t m_level;
+
+  /**
+   * Opened file for debugging
+   */
+  std::ofstream m_file_stream;
+
+  /**
+   * Pointer to the output stream
+   */
+  std::ostream* m_o_stream;
+};
+
+/**
+ * Return a log object into which VPP objects can write
+ */
+log_t& logger();
+
+#define VOM_LOG(lvl)                                                           \
+  if (lvl >= logger().level())                                                 \
+  logger().stream(__FILE__, __LINE__)
+};
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "mozilla")
+ * End:
+ */
+
+#endif