dbus-top: initial commits

This commit covers the basic functionalities of the dbus-top tool.

The UI is divided into 3 windows as follows:

  +--------------------------+  Window list
  |         Window A         |  A: Summary statistics
  +------------+-------------+  B: Sensor list or detail
  |  Window B  |   Window C  |  C: Detailed statistics
  +------------+-------------+

To navigate the UI:
* Use tab to navigate each window

When a window is highlighted:
  In Window B:
  * Press esc key 3 times to leave the current sensor selection

  In Window C:
  * Press [Enter] to show/hide pop-up menu for column selectio
  * Press [Left]  to move highlight cursor to the left
  * Press [Right] to move highlight cursor to the right
  * Press [A] to sort by the highlighted column in ascending order
  * Press [D] to sort by the highlighted column in descending order

To add recipe to Yocto and build the recipe:
1) Copy and paste the content of the .bb file into a folder that can be
   detected by bitbake, such as meta-phosphor/recipes-phosphor/ipmi.
2) run "devtool modify -n dbus-top (path_to_openbmc_tools)/dbus-top/".

Signed-off-by: Adedeji Adebisi <adedejiadebisi01@gmail.com>
Change-Id: Id58ba30b815cfd9d18f54cf477d749dbdbc4545b
diff --git a/dbus-top/xmlparse.hpp b/dbus-top/xmlparse.hpp
new file mode 100644
index 0000000..3a76e9a
--- /dev/null
+++ b/dbus-top/xmlparse.hpp
@@ -0,0 +1,67 @@
+// Copyright 2021 Google LLC
+//
+// 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.
+
+#pragma once
+
+#include <map>
+#include <string>
+#include <vector>
+
+class XMLNode
+{
+  public:
+    std::string tag;
+    std::map<std::string, std::string> fields;
+    std::vector<XMLNode*> children;
+    std::vector<XMLNode*> interfaces;
+    XMLNode(const std::string& t) : tag(t)
+    {}
+
+    void AddChild(XMLNode* x)
+    {
+        children.push_back(x);
+    }
+
+    void do_Print(int indent)
+    {
+        for (int i = 0; i < indent; i++)
+            printf("  ");
+        printf("%s", tag.c_str());
+        if (fields["name"] != "")
+        {
+            printf(" name=[%s]", fields["name"].c_str());
+        }
+        printf("\n");
+        for (XMLNode* ch : children)
+        {
+            ch->do_Print(indent + 1);
+        }
+    }
+
+    void Print()
+    {
+        do_Print(0);
+    }
+
+    void SetName(const std::string& n)
+    {
+        fields["name"] = n;
+    }
+    
+    std::vector<std::string> GetChildNodeNames();
+    std::vector<std::string> GetInterfaceNames();
+};
+
+XMLNode* ParseXML(const std::string& sv);
+void DeleteTree(XMLNode* x);