From 30c896841c65c78cb4cf048c0c26c8e62ee0cf05 Mon Sep 17 00:00:00 2001
From: Determinant <ted.sybil@gmail.com>
Date: Sat, 27 Dec 2014 13:29:20 +0800
Subject: init

---
 lab_monitor_server.py | 162 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 162 insertions(+)
 create mode 100644 lab_monitor_server.py

(limited to 'lab_monitor_server.py')

diff --git a/lab_monitor_server.py b/lab_monitor_server.py
new file mode 100644
index 0000000..76aa240
--- /dev/null
+++ b/lab_monitor_server.py
@@ -0,0 +1,162 @@
+import time, json, os, re
+import logging, threading
+from socket import socket, AF_UNIX, SHUT_WR, error as SocketError
+from struct import pack, unpack
+from time import sleep
+from tornado import gen
+from tornado.ioloop import IOLoop
+from tornado.web import RequestHandler, Application, url, StaticFileHandler
+from rwlock import RWLock
+
+logging.basicConfig(level=logging.DEBUG, format='[%(levelname)s] (%(threadName)-10s) %(message)s',)
+MAX_LENGTH = 2048
+MAX_RECORDS = 32
+PORT = 2333
+lock = RWLock()
+local_socket_address = "./lab_monitor.socket"
+cmd_socket = None
+stat_res = {}
+is_exiting = threading.Event()
+id_cnt = 0
+reclaimed_ids = []
+
+class ActionError(Exception):
+    pass
+
+def add_monitor(mesg):
+    if len(reclaimed_ids):
+        jid = reclaimed_ids.pop()
+    else:
+        global id_cnt
+        jid = id_cnt
+        id_cnt += 1
+    if mesg.has_key("name"):
+        name = mesg["name"]
+    else:
+        name = "monitor-{0}".format(jid)
+    metadata = None
+    if mesg.has_key("metadata"):
+        metadata = mesg["metadata"]
+    stat_res[jid] = {"name": name, "records": [],
+                    "rcnt": 0, "jid": jid, "metadata": metadata}
+    return json.dumps(jid)
+
+def del_monitor(mesg):
+    mid = check_id(mesg)
+    del stat_res[mid]
+    reclaimed_ids.append(mid)
+    return ""
+
+def check_id(mesg):
+    if mesg.has_key("jid"):
+        try:
+            jid = int(mesg["jid"])
+        except ValueError:
+            raise ActionError("invalid value of jid field")
+    else:
+        raise ActionError("jid field not specified")
+    if not stat_res.has_key(jid):
+        raise ActionError("the jid does not exist")
+    logging.debug("jid: {0}".format(jid))
+    return jid
+
+def add_record(mesg):
+    mid = check_id(mesg)
+    if mesg.has_key("record"):
+        rec = stat_res[mid]["records"]
+        while len(rec) >= MAX_RECORDS:
+            rec.pop(0)
+        rec.append({'rid': stat_res[mid]["rcnt"], 'rec': mesg["record"]})
+        stat_res[mid]["rcnt"] += 1
+    return ""
+def alter_records(mesg):
+    mid = check_id(mesg)
+    if mesg.has_key("records"):
+        stat_res[mid]["records"] = mesg["records"]
+    return ""
+def clear_records(mesg):
+    mid = check_id(mesg)
+    stat_res[mid]["records"] = []
+    return ""
+
+action_map = {"create": add_monitor,
+                "drop": del_monitor,
+                "add": add_record,
+                "clear": clear_records,
+                "alter": alter_records}
+
+def command_server():
+    global c, cmd_socket, is_exiting
+    try:
+        os.unlink(local_socket_address)
+    except OSError:
+        if os.path.exists(local_socket_address):
+            raise
+    cmd_socket = socket(AF_UNIX)
+    cmd_socket.bind(local_socket_address)
+    cmd_socket.listen(5)
+    while not is_exiting.isSet():
+        logging.debug("accepting")
+        (conn, addr) = cmd_socket.accept()
+        logging.debug("accepted")
+        received = conn.recv(4)
+        if not received:
+            continue
+        length, = unpack("<i", received)
+        if length <= 0 or length > MAX_LENGTH:
+            logging.debug("invalid header: {0}".format(length))
+            conn.close() # invalid header
+            continue
+        try:#
+            mesg = json.loads(conn.recv(length))
+            if not isinstance(mesg, dict):
+                logging.debug("not a javascript object")
+                continue
+            if not mesg.has_key("action"):
+                raise ActionError("action not specified")
+            logging.debug("action: {0}".format(mesg["action"]))
+            try:
+                lock.acquire_write()
+                conn.send(action_map[mesg["action"]](mesg))
+            finally:
+                lock.release()
+        except ValueError:
+            logging.debug("malformed json string")
+        except ActionError as e:
+            logging.debug(e)
+        except KeyError as e:
+            logging.debug("action not found: {0}".format(mesg["action"]))
+        except SocketError as e:
+            logging.debug("socket error: {0}".format(e))
+        finally:
+            conn.close()
+
+cmd = threading.Thread(target=command_server)
+cmd.setDaemon(True)
+cmd.start()
+
+def cmd_shutdown():
+    global is_exiting, cmd_socket, local_socket_address, cmd
+    is_exiting.set();
+    cmd_socket.close()
+    socket(AF_UNIX).connect(local_socket_address)
+    cmd.join()
+class AJAXHandler(RequestHandler):
+    @gen.coroutine
+    def get(self):
+        try:
+            def grab_lock(self, callback=None):
+                lock.acquire_read()
+                self.write(stat_res)
+                callback()
+            yield gen.Task(grab_lock, self)
+        finally:
+            lock.release()
+try:
+    app = Application([url(r"/ajax", AJAXHandler),
+                        url(r'/()', StaticFileHandler, {'path': "./index.html"}),
+                        url(r'/(.*)', StaticFileHandler, {'path': "./"})])
+    app.listen(PORT)
+    IOLoop.current().start()
+except KeyboardInterrupt:
+    cmd_shutdown()
-- 
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