1 files changed, 143 insertions, 0 deletions
diff --git a/src/lib/Bcfg2/Server/FileMonitor/__init__.py b/src/lib/Bcfg2/Server/FileMonitor/__init__.py
new file mode 100644
index 000000000..40c3253b9
--- /dev/null
+++ b/src/lib/Bcfg2/Server/FileMonitor/__init__.py
@@ -0,0 +1,143 @@
+"""Bcfg2.Server.FileMonitor provides the support for monitoring files."""
+
+import os
+import fnmatch
+import logging
+import pkgutil
+from time import sleep, time
+
+logger = logging.getLogger(__name__)
+
+class Event(object):
+    def __init__(self, request_id, filename, code):
+        self.requestID = request_id
+        self.filename = filename
+        self.action = code
+
+    def code2str(self):
+        """return static code for event"""
+        return self.action
+
+    def __str__(self):
+        return "%s: %s %s" % (self.__class__.__name__,
+                              self.filename, self.action)
+
+    def __repr__(self):
+        return "%s (request ID %s)" % (str(self), self.requestID)
+
+
+class FileMonitor(object):
+    """File Monitor baseclass."""
+    def __init__(self, ignore=None, debug=False):
+        object.__init__(self)
+        self.debug = debug
+        self.handles = dict()
+        self.events = []
+        if ignore is None:
+            ignore = []
+        self.ignore = ignore
+
+    def __str__(self):
+        return "%s: %s" % (__name__, self.__class__.__name__)
+
+    def __repr__(self):
+        if self.pending():
+            events = "has"
+        else:
+            events = "no"
+        return "%s (%s events, fd %s)" % (str(self), events, self.fileno)
+
+    def should_ignore(self, event):
+        for pattern in self.ignore:
+            if (fnmatch.fnmatch(event.filename, pattern) or 
+                fnmatch.fnmatch(os.path.split(event.filename)[-1], pattern)):
+                if self.debug:
+                    logger.info("Ignoring %s" % event)
+                return True
+        return False
+
+    def pending(self):
+        return bool(self.events)
+
+    def get_event(self):
+        return self.events.pop(0)
+
+    def fileno(self):
+        return 0
+
+    def handle_one_event(self, event):
+        if self.should_ignore(event):
+            return
+        if event.requestID not in self.handles:
+            logger.info("Got event for unexpected id %s, file %s" %
+                        (event.requestID, event.filename))
+            return
+        if self.debug:
+            logger.info("Dispatching event %s %s to obj %s" %
+                        (event.code2str(), event.filename,
+                         self.handles[event.requestID]))
+        try:
+            self.handles[event.requestID].HandleEvent(event)
+        except:
+            logger.error("Error in handling of event for %s" %
+                         event.filename, exc_info=1)
+
+    def handle_event_set(self, lock=None):
+        count = 1
+        event = self.get_event()
+        start = time()
+        if lock:
+            lock.acquire()
+        try:
+            self.handle_one_event(event)
+            while self.pending():
+                self.handle_one_event(self.get_event())
+                count += 1
+        except:
+            pass
+        if lock:
+            lock.release()
+        end = time()
+        logger.info("Handled %d events in %.03fs" % (count, (end - start)))
+
+    def handle_events_in_interval(self, interval):
+        end = time() + interval
+        while time() < end:
+            if self.pending():
+                self.handle_event_set()
+                end = time() + interval
+            else:
+                sleep(0.5)
+
+    def shutdown(self):
+        pass
+
+
+available = dict()
+
+# todo: loading the monitor drivers should be automatic
+from Bcfg2.Server.FileMonitor.Pseudo import Pseudo
+available['pseudo'] = Pseudo
+
+try:
+    from Bcfg2.Server.FileMonitor.Fam import Fam
+    available['fam'] = Fam
+except ImportError:
+    pass
+
+try:
+    from Bcfg2.Server.FileMonitor.Gamin import Gamin
+    available['gamin'] = Gamin
+except ImportError:
+    pass
+
+try:
+    from Bcfg2.Server.FileMonitor.Inotify import Inotify
+    available['inotify'] = Inotify
+except ImportError:
+    pass    
+
+for fdrv in sorted(available.keys(), key=lambda k: available[k].__priority__):
+    if fdrv in available:
+        available['default'] = available[fdrv]
+        break