gh #14: Log monitor for the callback functions

utFileMonitor.py

@@ -0,0 +1,119 @@
+import sys
+import os
+import re
+import time
+import threading
+
+dir_path = os.path.dirname(os.path.realpath(__file__))
+sys.path.append(dir_path+"/../../../")
+sys.path.append(dir_path)
+
+from framework.core.logModule import logModule
+from framework.core.commandModules.consoleInterface import consoleInterface
+from interactiveShell import InteractiveShell
+
+class utFileMonitor:
+    """This Class monitors the log files. If there are any new lines added to the file, then reports back
+    """
+    def __init__(self, session:consoleInterface, callbackFile:str, callbackFunction = None, prompt:str=":", log:logModule = None):
+        """init function
+
+        Args:
+            session (consoleInterface): console interface to operate on
+            callbackFile (str) : Log file to be monitored
+            callbackFunction : callback function
+            prompt (str): prompt to wait on
+            log (logModule): log module
+        """
+        self.session = session
+        self.log=log
+        if log is None:
+            self.log = logModule(self.__class__.__name__)
+            self.log.setLevel( self.log.DEBUG )
+        self.prompt = prompt
+        self.callbackFunction = callbackFunction
+        self.exitThread = False
+        self.thread = threading.Thread(target=self.monitorFile, args=(callbackFile,))
+
+    def monitorFile(self, filePath:str):
+        """Thread function
+
+        Args:
+            filePath (str): Log file to be monitored
+        """
+        initial_file_size = 0
+        current_file_size = 0
+        self.session.write("")
+        out = self.session.read_until(self.prompt)
+        while self.exitThread == False:
+            self.session.write(f"stat -c '%s' {filePath}")
+            out = self.session.read_until(self.prompt)
+            if("No such file or directory" in out):
+                time.sleep(0.1)
+                continue
+
+            msg =  out.split("\r\n")
+            if(len(msg) >= 2):
+                msg.pop(0)
+                msg.pop(len(msg) - 1)
+            if(msg[0].isdigit()):
+                current_file_size = int(msg[0])
+
+            if current_file_size != initial_file_size :
+                self.session.write(f"tail -c +{initial_file_size + 1} {filePath}")
+                out = self.session.read_until(self.prompt)
+                msg =  out.split("\r\n")
+                if(len(msg) >= 2):
+                    msg.pop(0)
+                    msg.pop(len(msg) - 1)
+                self.callbackFunction("\r\n".join(msg))
+                initial_file_size = current_file_size
+            time.sleep(0.1)
+
+    def start(self):
+        """
+        Starts the thread.
+        """
+        self.thread.start()
+
+    def join(self):
+        """
+        Waits for the thread to finish.
+        """
+        self.thread.join()
+
+    def stop(self):
+        """
+        Stops the thread
+        """
+        self.exitThread = True
+
+    def __del__(self):
+        self.thread.join()
+
+def testCallback(msg:str):
+    print(msg)
+
+# Test and example usage code
+if __name__ == '__main__':
+
+    # test the class
+    shell = InteractiveShell()
+    result = shell.open()
+    print("Shell:[{}]".format(result))
+
+    # Create file monitor object (assuming monitor file /opt/callback.txt)
+    test = utFileMonitor(shell, "/opt/callback.txt", testCallback)
+
+    # Start the monitor
+    test.start()
+
+    # Monitor for 5 sec. If there any updates to the file testCallback should print the message
+    time.sleep(5)
+
+    # Stop the monitor
+    test.start()
+
+    del test
+
+    shell.close()