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-rw-r--r--src/lib/Bcfg2/Server/FileMonitor.py315
1 files changed, 315 insertions, 0 deletions
diff --git a/src/lib/Bcfg2/Server/FileMonitor.py b/src/lib/Bcfg2/Server/FileMonitor.py
new file mode 100644
index 000000000..d6b313e6b
--- /dev/null
+++ b/src/lib/Bcfg2/Server/FileMonitor.py
@@ -0,0 +1,315 @@
+"""Bcfg2.Server.FileMonitor provides the support for monitorung files."""
+
+import logging
+import os
+import stat
+from time import sleep, time
+
+logger = logging.getLogger('Bcfg2.Server.FileMonitor')
+
+
+def ShouldIgnore(event):
+ """Test if the event should be suppresed."""
+ # FIXME should move event suppression out of the core
+ if event.filename.split('/')[-1] == '.svn':
+ return True
+ if event.filename.endswith('~') or \
+ event.filename.startswith('#') or event.filename.startswith('.#'):
+ #logger.error("Suppressing event for file %s" % (event.filename))
+ return True
+ return False
+
+
+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
+
+available = {}
+
+
+class FileMonitor(object):
+ """File Monitor baseclass."""
+ def __init__(self, debug=False):
+ object.__init__(self)
+ self.debug = debug
+ self.handles = dict()
+
+ def get_event(self):
+ return None
+
+ def pending(self):
+ return False
+
+ def fileno(self):
+ return 0
+
+ def handle_one_event(self, event):
+ if ShouldIgnore(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 gamin 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)
+
+
+class FamFam(object):
+ """The fam object is a set of callbacks for
+ file alteration events (FAM support).
+ """
+
+ def __init__(self):
+ object.__init__(self)
+ self.fm = _fam.open()
+ self.users = {}
+ self.handles = {}
+ self.debug = False
+
+ def fileno(self):
+ """Return fam file handle number."""
+ return self.fm.fileno()
+
+ def handle_event_set(self, _):
+ self.Service()
+
+ def handle_events_in_interval(self, interval):
+ now = time()
+ while (time() - now) < interval:
+ if self.Service():
+ now = time()
+
+ def AddMonitor(self, path, obj):
+ """Add a monitor to path, installing a callback to obj.HandleEvent."""
+ mode = os.stat(path)[stat.ST_MODE]
+ if stat.S_ISDIR(mode):
+ handle = self.fm.monitorDirectory(path, None)
+ else:
+ handle = self.fm.monitorFile(path, None)
+ self.handles[handle.requestID()] = handle
+ if obj != None:
+ self.users[handle.requestID()] = obj
+ return handle.requestID()
+
+ def Service(self, interval=0.50):
+ """Handle all fam work."""
+ count = 0
+ collapsed = 0
+ rawevents = []
+ start = time()
+ now = time()
+ while (time() - now) < interval:
+ if self.fm.pending():
+ while self.fm.pending():
+ count += 1
+ rawevents.append(self.fm.nextEvent())
+ now = time()
+ unique = []
+ bookkeeping = []
+ for event in rawevents:
+ if ShouldIgnore(event):
+ continue
+ if event.code2str() != 'changed':
+ # process all non-change events
+ unique.append(event)
+ else:
+ if (event.filename, event.requestID) not in bookkeeping:
+ bookkeeping.append((event.filename, event.requestID))
+ unique.append(event)
+ else:
+ collapsed += 1
+ for event in unique:
+ if event.requestID in self.users:
+ try:
+ self.users[event.requestID].HandleEvent(event)
+ except:
+ logger.error("handling event for file %s" % (event.filename), exc_info=1)
+ end = time()
+ logger.info("Processed %s fam events in %03.03f seconds. %s coalesced" %
+ (count, (end - start), collapsed))
+ return count
+
+
+class Fam(FileMonitor):
+ """
+ The fam object is a set of callbacks for
+ file alteration events (FAM support).
+ """
+
+ def __init__(self, debug=False):
+ FileMonitor.__init__(self, debug)
+ self.fm = _fam.open()
+
+ def fileno(self):
+ return self.fm.fileno()
+
+ def AddMonitor(self, path, obj):
+ """Add a monitor to path, installing a callback to obj.HandleEvent."""
+ mode = os.stat(path)[stat.ST_MODE]
+ if stat.S_ISDIR(mode):
+ handle = self.fm.monitorDirectory(path, None)
+ else:
+ handle = self.fm.monitorFile(path, None)
+ if obj != None:
+ self.handles[handle.requestID()] = obj
+ return handle.requestID()
+
+ def pending(self):
+ return self.fm.pending()
+
+ def get_event(self):
+ return self.fm.nextEvent()
+
+
+class Pseudo(FileMonitor):
+ """
+ The fam object is a set of callbacks for
+ file alteration events (static monitor support).
+ """
+
+ def __init__(self, debug=False):
+ FileMonitor.__init__(self, debug=False)
+ self.pending_events = []
+
+ def pending(self):
+ return len(self.pending_events) != 0
+
+ def get_event(self):
+ return self.pending_events.pop()
+
+ def AddMonitor(self, path, obj):
+ """add a monitor to path, installing a callback to obj.HandleEvent"""
+ handleID = len(list(self.handles.keys()))
+ mode = os.stat(path)[stat.ST_MODE]
+ handle = Event(handleID, path, 'exists')
+ if stat.S_ISDIR(mode):
+ dirList = os.listdir(path)
+ self.pending_events.append(handle)
+ for includedFile in dirList:
+ self.pending_events.append(Event(handleID,
+ includedFile,
+ 'exists'))
+ self.pending_events.append(Event(handleID, path, 'endExist'))
+ else:
+ self.pending_events.append(Event(handleID, path, 'exists'))
+ if obj != None:
+ self.handles[handleID] = obj
+ return handleID
+
+
+try:
+ from gamin import WatchMonitor, GAMCreated, GAMExists, GAMEndExist, \
+ GAMChanged, GAMDeleted, GAMMoved
+
+ class GaminEvent(Event):
+ """
+ This class provides an event analogous to
+ python-fam events based on gamin sources.
+ """
+ def __init__(self, request_id, filename, code):
+ Event.__init__(self, request_id, filename, code)
+ action_map = {GAMCreated: 'created', GAMExists: 'exists',
+ GAMChanged: 'changed', GAMDeleted: 'deleted',
+ GAMEndExist: 'endExist', GAMMoved: 'moved'}
+ if code in action_map:
+ self.action = action_map[code]
+
+ class Gamin(FileMonitor):
+ """
+ The fam object is a set of callbacks for
+ file alteration events (Gamin support)
+ """
+ def __init__(self, debug=False):
+ FileMonitor.__init__(self, debug)
+ self.mon = WatchMonitor()
+ self.counter = 0
+ self.events = []
+
+ def fileno(self):
+ return self.mon.get_fd()
+
+ def queue(self, path, action, request_id):
+ """queue up the event for later handling"""
+ self.events.append(GaminEvent(request_id, path, action))
+
+ def AddMonitor(self, path, obj):
+ """Add a monitor to path, installing a callback to obj.HandleEvent."""
+ handle = self.counter
+ self.counter += 1
+ mode = os.stat(path)[stat.ST_MODE]
+
+ # Flush queued gamin events
+ while self.mon.event_pending():
+ self.mon.handle_one_event()
+
+ if stat.S_ISDIR(mode):
+ self.mon.watch_directory(path, self.queue, handle)
+ else:
+ self.mon.watch_file(path, self.queue, handle)
+ self.handles[handle] = obj
+ return handle
+
+ def pending(self):
+ return len(self.events) > 0 or self.mon.event_pending()
+
+ def get_event(self):
+ if self.mon.event_pending():
+ self.mon.handle_one_event()
+ return self.events.pop(0)
+
+ available['gamin'] = Gamin
+except ImportError:
+ # fall back to _fam
+ pass
+
+try:
+ import _fam
+ available['fam'] = FamFam
+except ImportError:
+ pass
+available['pseudo'] = Pseudo
+
+for fdrv in ['gamin', 'fam', 'pseudo']:
+ if fdrv in available:
+ available['default'] = available[fdrv]
+ break
generated by cgit v1.2.3-1-g7c22 (git 2.25.1) at 2024-07-06 05:31:30 +0000