From 271fed0fd65d795a1e40f6ee2f7bdbe8d43d7418 Mon Sep 17 00:00:00 2001
From: David Wilson <dw@botanicus.net>
Date: Thu, 5 Oct 2017 00:52:42 +0530
Subject: [PATCH] Import mitop example script.

---
 examples/mitop.py | 185 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 185 insertions(+)
 create mode 100644 examples/mitop.py

diff --git a/examples/mitop.py b/examples/mitop.py
new file mode 100644
index 00000000..2e11d515
--- /dev/null
+++ b/examples/mitop.py
@@ -0,0 +1,185 @@
+
+import curses
+import subprocess
+import sys
+import time
+
+import mitogen.core
+import mitogen.master
+import mitogen.utils
+
+
+class Host(object):
+    # Incremented once for each received ps output, copied to task struct. Used
+    # to find dead tasks.
+    name = None
+    context = None
+    recv = None
+
+    def __init__(self):
+        self.procs = {}  #: pid -> Process()
+
+class Process(object):
+    host = None
+    user = None
+    pid = None
+    ppid = None
+    pgid = None
+    command = None
+    rss = None
+    pcpu = None
+    rss = None
+
+
+def send_once(sender):
+    args = ['ps', '-axwwo', 'user,pid,ppid,pgid,%cpu,rss,command']
+    output = subprocess.check_output(args)
+    sender.put(output)
+
+
+@mitogen.core.takes_router
+def remote_main(context_id, handle, delay, router):
+    context = mitogen.core.Context(router, context_id)
+    sender = mitogen.core.Sender(context, handle)
+
+    while True:
+        send_once(sender)
+        time.sleep(delay)
+
+    if sys.platform == 'darwin':
+        darwin_main(sender, delay)
+    elif sys.platform == 'linux':
+        linux_main(sender, delay)
+
+
+def parse_output(host, s):
+    prev_pids = set(host.procs)
+
+    for line in s.splitlines()[1:]:
+        bits = line.split(None, 6)
+        pid = int(bits[1])
+        prev_pids.discard(pid)
+
+        try:
+            proc = host.procs[pid]
+        except KeyError:
+            host.procs[pid] = proc = Process()
+            proc.hostname = host.name
+
+        proc.user = bits[0]
+        proc.pid = pid
+        proc.ppid = int(bits[2])
+        proc.pgid = int(bits[3])
+        proc.pcpu = float(bits[4])
+        proc.rss = int(bits[5]) / 1024
+        proc.command = bits[6]
+
+    # These PIDs had no update, so probably they are dead now.
+    for pid in prev_pids:
+        del host.procs[pid]
+
+
+class Painter(object):
+    def __init__(self, hosts):
+        self.stdscr = curses.initscr()
+        self.height, self.width = self.stdscr.getmaxyx()
+        curses.cbreak()
+        curses.noecho()
+        self.stdscr.keypad(1)
+        self.hosts = hosts
+        self.format = (
+            '%(hostname)10.10s '
+            '%(pid)7.7s '
+            '%(ppid)7.7s '
+            '%(pcpu)6.6s '
+            '%(rss)5.5s '
+            '%(command)20s'
+        )
+
+    def close(self):
+        curses.endwin()
+
+    def paint(self):
+        self.stdscr.clear()
+        self.stdscr.addstr(0, 0, time.ctime())
+
+        all_procs = []
+        for host in self.hosts:
+            all_procs.extend(host.procs.itervalues())
+
+        all_procs.sort(key=(lambda proc: -proc.pcpu))
+
+        self.stdscr.addstr(1, 0, self.format % {
+            'hostname': 'HOST',
+            'pid': 'PID',
+            'ppid': 'PPID',
+            'pcpu': '%CPU',
+            'rss': 'RSS',
+            'command': 'COMMAND',
+        })
+        for i, proc in enumerate(all_procs):
+            if (i+3) >= self.height:
+                break
+            self.stdscr.addstr(2+i, 0, self.format % vars(proc))
+
+        self.stdscr.refresh()
+
+
+def local_main(painter, router, select, delay):
+    next_paint = 0
+    while True:
+        recv, (msg, data) = select.get()
+        parse_output(recv.host, data)
+        if next_paint < time.time():
+            next_paint = time.time() + delay
+            painter.paint()
+
+
+def main(router, argv):
+    #mitogen.utils.log_to_file(level='DEBUG')
+    mitogen.utils.log_to_file()
+
+    if not len(argv):
+        print 'mitop: Need a list of SSH hosts to connect to.'
+        sys.exit(1)
+
+    delay = 1.0
+    select = mitogen.master.Select(oneshot=False)
+    hosts = []
+
+    for hostname in argv:
+        print 'Starting on', hostname
+        host = Host()
+        host.name = hostname
+        if host.name == 'localhost':
+            host.context = router.local()
+        else:
+            host.context = router.ssh(hostname=host.name)
+
+        host.recv = mitogen.core.Receiver(router)
+        host.recv.host = host
+        host.recv.host_main = False
+        host.tasks = []
+        select.add(host.recv)
+
+        call_recv = host.context.call_async(remote_main,
+            mitogen.context_id,
+            host.recv.handle,
+            delay,
+        )
+        call_recv.host = host
+        call_recv.host_main = True
+        select.add(call_recv)
+        hosts.append(host)
+
+    painter = Painter(hosts)
+    try:
+        try:
+            local_main(painter, router, select, delay)
+        except KeyboardInterrupt:
+            pass
+    finally:
+        painter.close()
+
+if __name__ == '__main__':
+    mitogen.utils.run_with_router(main, sys.argv[1:])