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/main.cpp b/dbus-top/main.cpp
new file mode 100644
index 0000000..d56b72e
--- /dev/null
+++ b/dbus-top/main.cpp
@@ -0,0 +1,392 @@
+// 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.
+
+#include "main.hpp"
+
+#include "analyzer.hpp"
+#include "bargraph.hpp"
+#include "dbus_capture.hpp"
+#include "histogram.hpp"
+#include "menu.hpp"
+#include "sensorhelper.hpp"
+#include "views.hpp"
+
+#include <fmt/printf.h>
+#include <ncurses.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#include <iomanip>
+#include <sstream>
+#include <thread>
+
+DBusTopWindow* g_current_active_view;
+SummaryView* g_summary_window;
+SensorDetailView* g_sensor_detail_view;
+DBusStatListView* g_dbus_stat_list_view;
+FooterView* g_footer_view;
+BarGraph<float>* g_bargraph = nullptr;
+Histogram<float>* g_histogram;
+std::vector<DBusTopWindow*> g_views;
+int g_highlighted_view_index = INVALID;
+sd_bus* g_bus = nullptr;
+SensorSnapshot* g_sensor_snapshot;
+DBusConnectionSnapshot* g_connection_snapshot;
+DBusTopStatistics* g_dbus_statistics; // At every update interval,
+                                      // dbus_top_analyzer::g_dbus_statistics's
+                                      // value is copied to this one for display
+void ReinitializeUI();
+int maxx, maxy, halfx, halfy;
+
+void ActivateWindowA()
+{
+    g_views[0]->visible_=true;
+    g_views[0]->maximize_=true;
+    g_views[1]->visible_=false;
+    g_views[2]->visible_=false;
+}
+
+void ActivateWindowB()
+{
+    g_views[1]->visible_=true;
+    g_views[1]->maximize_=true;
+    g_views[0]->visible_=false;
+    g_views[2]->visible_=false;
+}
+void ActivateWindowC()
+{
+    g_views[2]->visible_=true;
+    g_views[2]->maximize_=true;
+    g_views[0]->visible_=false;
+    g_views[1]->visible_=false;
+}
+void ActivateAllWindows()
+{
+    g_views[0]->maximize_ = false;
+    g_views[1]->maximize_=false;
+    g_views[2]->maximize_=false;
+    g_views[0]->visible_=true;
+    g_views[1]->visible_=true;
+    g_views[2]->visible_= true;
+}
+
+void InitColorPairs()
+{
+    init_pair(1, COLOR_WHITE, COLOR_BLACK); // Does not work on actual machine
+    init_pair(2, COLOR_BLACK, COLOR_WHITE);
+}
+
+// Returns number of lines drawn
+int DrawTextWithWidthLimit(WINDOW* win, std::string txt, int y, int x,
+                           int width, const std::string& delimiters)
+{
+    int ret = 0;
+    std::string curr_word, curr_line;
+    while (txt.empty() == false)
+    {
+        ret++;
+        if (static_cast<int>(txt.size()) > width)
+        {
+            mvwprintw(win, y, x, txt.substr(0, width).c_str());
+            txt = txt.substr(width);
+        }
+        else
+        {
+            mvwprintw(win, y, x, txt.c_str());
+            break;
+        }
+        y++;
+    }
+    return ret;
+}
+
+void UpdateWindowSizes()
+{
+    /* calculate window sizes and locations */
+    if (getenv("FIXED_TERMINAL_SIZE"))
+    {
+        maxx = 100;
+        maxy = 30;
+    }
+    else
+    {
+        getmaxyx(stdscr, maxy, maxx);
+        halfx = maxx >> 1;
+        halfy = maxy >> 1;
+    }
+    for (DBusTopWindow* v : g_views)
+    {
+        v->OnResize(maxx, maxy);
+        if(v->maximize_){
+            v->rect={0,0,maxx,maxy-MARGIN_BOTTOM};
+            v->UpdateWindowSizeAndPosition();
+        }
+    }
+}
+
+std::string FloatToString(float value)
+{
+    return fmt::sprintf("%.2f", value);
+}
+
+void DBusTopRefresh()
+{
+    UpdateWindowSizes();
+    for (DBusTopWindow* v : g_views)
+    {
+        v->Render();
+    }
+    DBusTopWindow* focused_view = g_current_active_view;
+    if (focused_view)
+    {
+        focused_view->DrawBorderIfNeeded(); // focused view border: on top
+    }
+    refresh();
+}
+
+// This function is called by the Capture thread
+void DBusTopStatisticsCallback(DBusTopStatistics* stat, Histogram<float>* hist)
+{
+    if (stat == nullptr)
+        return;
+    // Makes a copy for display
+    // TODO: Add a mutex here for safety
+    stat->Assign(g_dbus_statistics);
+    hist->Assign(g_histogram);
+    float interval_secs = stat->seconds_since_last_sample_;
+    if (interval_secs == 0)
+    {
+        interval_secs = GetSummaryIntervalInMillises() / 1000.0f;
+    }
+    g_summary_window->UpdateDBusTopStatistics(stat);
+    stat->SetSortFieldsAndReset(g_dbus_stat_list_view->GetSortFields());
+    // ReinitializeUI(); // Don't do it here, only when user presses [R]
+    DBusTopRefresh();
+}
+
+void CycleHighlightedView()
+{
+    int new_index = 0;
+    if (g_highlighted_view_index == INVALID)
+    {
+        new_index = 0;
+    }
+    else
+    {
+        new_index = g_highlighted_view_index + 1;
+    }
+    while (new_index < static_cast<int>(g_views.size()) &&
+           g_views[new_index]->selectable_ == false)
+    {
+        new_index++;
+    }
+    if (new_index >= static_cast<int>(g_views.size()))
+    {
+        new_index = INVALID;
+    }
+    // Un-highlight all
+    for (DBusTopWindow* v : g_views)
+    {
+        v->focused_ = false;
+    }
+    if (new_index != INVALID)
+    {
+        g_views[new_index]->focused_ = true;
+        g_current_active_view = g_views[new_index];
+    }
+    else
+    {
+        g_current_active_view = nullptr;
+    }
+    g_highlighted_view_index = new_index;
+    DBusTopRefresh();
+}
+
+int UserInputThread()
+{
+    while (true)
+    {
+        int c = getch();
+        DBusTopWindow* curr_view = g_current_active_view;
+        // If a view is currently focused on
+        if (curr_view)
+        {
+            switch (c)
+            {
+                case '\e': // 27 in dec, 0x1B in hex, escape key
+                {
+                    getch();
+                    c = getch();
+                    switch (c)
+                    {
+                        case 'A':
+                            curr_view->OnKeyDown("up");
+                            break;
+                        case 'B':
+                            curr_view->OnKeyDown("down");
+                            break;
+                        case 'C':
+                            curr_view->OnKeyDown("right");
+                            break;
+                        case 'D':
+                            curr_view->OnKeyDown("left");
+                            break;
+                        case '\e':
+                            curr_view->OnKeyDown("escape");
+                            break;
+                    }
+                    break;
+                }
+                case '\n': // 10 in dec, 0x0A in hex, line feed
+                {
+                    curr_view->OnKeyDown("enter");
+                    break;
+                }
+                case 'q':
+                case 'Q': // Q key
+                {
+                    curr_view->OnKeyDown("escape");
+                    break;
+                }
+                case 'a':
+                case 'A': // A key
+                {
+                    curr_view->OnKeyDown("a");
+                    break;
+                }
+                case 'd':
+                case 'D': // D key
+                {
+                    curr_view->OnKeyDown("d");
+                    break;
+                }
+                case 33: // Page up
+                {
+                    curr_view->OnKeyDown("pageup");
+                    break;
+                }
+                case 34: // Page down
+                {
+                    curr_view->OnKeyDown("pagedown");
+                    break;
+                }
+                case ' ': // Spacebar
+                {
+                    curr_view->OnKeyDown("space");
+                    break;
+                }
+            }
+        }
+        // The following keys are registered both when a view is selected and
+        // when it is not
+        switch (c)
+        {
+            case '\t': // 9 in dec, 0x09 in hex, tab
+            {
+                CycleHighlightedView();
+                break;
+            }
+            case 'r':
+            case 'R':
+            {
+                ReinitializeUI();
+                DBusTopRefresh();
+                break;
+            }
+            case 'x':
+            case 'X':
+            {
+                clear();
+                ActivateWindowA();
+                break;
+            }
+            case 'y':
+            case 'Y':
+            {
+                clear();
+                ActivateWindowB();
+                break;
+            }
+            case 'z':
+            case 'Z':
+            {
+                clear();
+                ActivateWindowC();
+                break;
+            }
+            case 'h':
+            case 'H':
+            {
+                ActivateAllWindows();
+                DBusTopRefresh();
+            }
+            default:
+                break;
+        }
+    }
+    exit(0);
+}
+
+void ReinitializeUI()
+{
+    endwin();
+    initscr();
+    use_default_colors();
+    noecho();
+    for (int i = 0; i < static_cast<int>(g_views.size()); i++)
+    {
+        g_views[i]->RecreateWindow();
+    }
+}
+
+int main(int argc, char** argv)
+{
+    int r = AcquireBus(&g_bus);
+    if (r <= 0)
+    {
+        printf("Error acquiring bus for monitoring\n");
+        exit(0);
+    }
+
+    printf("Listing all sensors for display\n");
+    // ListAllSensors creates connection snapshot and sensor snapshot
+    dbus_top_analyzer::ListAllSensors();
+    g_bargraph = new BarGraph<float>(300);
+    g_histogram = new Histogram<float>();
+
+    initscr();
+    use_default_colors();
+    start_color();
+    noecho();
+
+    clear();
+    g_dbus_statistics = new DBusTopStatistics();
+    g_summary_window = new SummaryView();
+    g_sensor_detail_view = new SensorDetailView();
+    g_dbus_stat_list_view = new DBusStatListView();
+    g_footer_view = new FooterView();
+    g_views.push_back(g_summary_window);
+    g_views.push_back(g_sensor_detail_view);
+    g_views.push_back(g_dbus_stat_list_view);
+    g_views.push_back(g_footer_view);
+
+    g_sensor_detail_view->UpdateSensorSnapshot(g_sensor_snapshot);
+    UpdateWindowSizes();
+    dbus_top_analyzer::SetDBusTopStatisticsCallback(&DBusTopStatisticsCallback);
+    std::thread capture_thread(DbusCaptureThread);
+    std::thread user_input_thread(UserInputThread);
+    capture_thread.join();
+
+    return 0;
+}