Merge PR ceph#59566 into main

* refs/pull/59566/head:
	cephfs-top: fix exception on small sized windows
	cephfs-top: fix exception on large sized windows

Reviewed-by: Venky Shankar <[email protected]>
Reviewed-by: Neeraj Pratap Singh <[email protected]>
Reviewed-by: Dhairya Parmar <[email protected]>

Author: vshankar

src/tools/cephfs/top/cephfs-top

@@ -45,6 +45,7 @@ FS_TOP_SUPPORTED_VER = 2
 ITEMS_PAD_LEN = 3
 ITEMS_PAD = " " * ITEMS_PAD_LEN
 DEFAULT_REFRESH_INTERVAL = 1
+DEFAULT_PAD_WIDTH = 300  # for medium size windows
 
 # metadata provided by mgr/stats
 FS_TOP_MAIN_WINDOW_COL_CLIENT_ID = "client_id"
@@ -290,7 +291,7 @@ class FSTop(FSTopBase):
         self.conffile = args.conffile
         self.refresh_interval_secs = args.delay
         self.PAD_HEIGHT = 10000  # height of the fstop_pad
-        self.PAD_WIDTH = 300  # width of the fstop_pad
+        self.PAD_WIDTH = DEFAULT_PAD_WIDTH  # width of the fstop_pad
         self.exit_ev = threading.Event()
 
     def handle_signal(self, signum, _):
@@ -358,6 +359,12 @@ class FSTop(FSTopBase):
             # If the terminal do not support the visibility
             # requested it will raise an exception
             pass
+
+        # Check the window size before creating the pad. For large windows,
+        # PAD_WIDTH = window width.
+        h, w = self.stdscr.getmaxyx()
+        if (w > DEFAULT_PAD_WIDTH):
+            self.PAD_WIDTH = w
         self.fstop_pad = curses.newpad(self.PAD_HEIGHT, self.PAD_WIDTH)
         self.run_all_display()
 
@@ -934,6 +941,15 @@ class FSTop(FSTopBase):
         self.header.addstr(5, 0, help, curses.A_DIM)
         return True
 
+    def handle_header(self, stats_json, help, screen_title, color_id=0):
+        try:
+            return self.create_header(stats_json, help, screen_title, color_id)
+        except curses.error:
+            curses.endwin()
+            sys.stderr.write("Error creating header. Please increase the window width to use "
+                             "cephfs-top.\n")
+            exit()
+
     def run_display(self):
         # clear the pads to have a smooth refresh
         self.header.erase()
@@ -983,7 +999,7 @@ class FSTop(FSTopBase):
                     current_states["limit"] = None
                 self.header.erase()  # erase previous text
                 self.fsstats.erase()
-                self.create_header(stats_json, help, screen_title, 3)
+                self.handle_header(stats_json, help, screen_title, 3)
             else:
                 self.tablehead_y = 0
                 help = "COMMANDS: " + help_commands
@@ -996,7 +1012,7 @@ class FSTop(FSTopBase):
                 else:
                     num_client = len(client_metadata)
                 vscrollEnd += num_client
-                if self.create_header(stats_json, help, screen_title, 3):
+                if self.handle_header(stats_json, help, screen_title, 3):
                     self.create_table_header()
                     self.create_clients(stats_json, fs)
 
@@ -1030,7 +1046,10 @@ class FSTop(FSTopBase):
             elif cmd == curses.KEY_END:
                 hscrollOffset = self.PAD_WIDTH - self.viewportWidth - 1
             elif cmd == curses.KEY_RESIZE:
-                # terminal resize event. Update the viewport dimensions
+                # terminal resize event.
+                # Update the pad dimensions
+                self.PAD_WIDTH = DEFAULT_PAD_WIDTH
+                # Update the viewport dimensions
                 windowsize = self.stdscr.getmaxyx()
                 self.viewportHeight, self.viewportWidth = windowsize[0] - 1, windowsize[1] - 1
 
@@ -1112,7 +1131,7 @@ class FSTop(FSTopBase):
                 current_states["limit"] = None
                 self.header.erase()  # erase previous text
                 self.fsstats.erase()
-                self.create_header(stats_json, help, screen_title, 2)
+                self.handle_header(stats_json, help, screen_title, 2)
             else:
                 self.tablehead_y = 0
                 num_client = 0
@@ -1128,7 +1147,7 @@ class FSTop(FSTopBase):
                     else:
                         num_client = len(client_metadata)
                     vscrollEnd += num_client
-                    if self.create_header(stats_json, help, screen_title, 2):
+                    if self.handle_header(stats_json, help, screen_title, 2):
                         if not index:  # do it only for the first fs
                             self.create_table_header()
                         self.create_clients(stats_json, fs)
@@ -1163,7 +1182,10 @@ class FSTop(FSTopBase):
             elif cmd == curses.KEY_END:
                 hscrollOffset = self.PAD_WIDTH - self.viewportWidth - 1
             elif cmd == curses.KEY_RESIZE:
-                # terminal resize event. Update the viewport dimensions
+                # terminal resize event.
+                # Update the pad dimensions
+                self.PAD_WIDTH = DEFAULT_PAD_WIDTH
+                # Update the viewport dimensions
                 windowsize = self.stdscr.getmaxyx()
                 self.viewportHeight, self.viewportWidth = windowsize[0] - 1, windowsize[1] - 1
             if cmd: