diff options
Diffstat (limited to 'src/lib/Server/FileMonitor.py')
| -rw-r--r-- | src/lib/Server/FileMonitor.py | 235 |
1 files changed, 235 insertions, 0 deletions
diff --git a/src/lib/Server/FileMonitor.py b/src/lib/Server/FileMonitor.py new file mode 100644 index 000000000..347e37b7b --- /dev/null +++ b/src/lib/Server/FileMonitor.py @@ -0,0 +1,235 @@ +from time import time +import logging, os, stat + +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.endswith('.tmp') \ + or event.filename.startswith('#') or event.filename.startswith('.#'): + logger.error("Suppressing event for file %s" % (event.filename)) + return True + return False + +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 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): + '''Handle all fam work''' + count = 0 + collapsed = 0 + rawevents = [] + start = time() + now = time() + while (time() - now) < 0.10: + 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 self.users.has_key(event.requestID): + 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 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 + + +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 action_map.has_key(code): + self.action = action_map[code] + +class GaminFam(object): + '''The fam object is a set of callbacks for file alteration events (Gamin support)''' + def __init__(self): + object.__init__(self) + self.mon = WatchMonitor() + self.handles = {} + self.counter = 0 + self.events = [] + self.debug = False + + def fileno(self): + '''return fam file handle number''' + 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] + 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 Service(self): + '''Handle all gamin work''' + count = 0 + collapsed = 0 + start = time() + now = time() + while (time() - now) < 0.10: + if self.mon.event_pending(): + while self.mon.event_pending(): + count += 1 + self.mon.handle_one_event() + now = time() + unique = [] + bookkeeping = [] + for event in self.events: + 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 + self.events = [] + for event in unique: + if event.requestID not in self.handles: + logger.info("Got event for unexpected id %s, file %s" % + (event.requestID, event.filename)) + continue + 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) + end = time() + logger.info("Processed %s gamin events in %03.03f seconds. %s collapsed" % + (count, (end - start), collapsed)) + return count + +class PseudoFam(object): + '''The fam object is a set of callbacks for file alteration events (FAM support)''' + + def __init__(self): + object.__init__(self) + self.users = {} + self.handles = {} + self.debug = False + self.pending = [] + + def AddMonitor(self, path, obj): + '''add a monitor to path, installing a callback to obj.HandleEvent''' + handleID = len(self.handles.keys()) + mode = os.stat(path)[stat.ST_MODE] + handle = GaminEvent(handleID, path, 'exists') + if stat.S_ISDIR(mode): + dirList = os.listdir(path) + self.pending.append(handle) + for includedFile in dirList: + self.pending.append(GaminEvent(handleID, includedFile, 'exists')) + self.pending.append(GaminEvent(handleID, path, 'endExist')) + else: + self.pending.append(GaminEvent(handleID, path, 'exists')) + self.handles[handleID] = handle + if obj != None: + self.users[handleID] = obj + return handleID + + def Service(self): + '''Handle all fam work''' + count = 0 + rawevents = [] + for event in self.pending: + count += 1 + rawevents.append(event) + self.pending = [] + for event in rawevents: + if self.users.has_key(event.requestID): + self.users[event.requestID].HandleEvent(event) + return count + +available = {} +try: + from gamin import WatchMonitor, GAMCreated, GAMExists, GAMEndExist, GAMChanged, GAMDeleted, GAMMoved + available['gamin'] = GaminFam +except ImportError: + # fall back to _fam + pass +try: + import _fam + available['fam'] = FamFam +except ImportError: + pass +available['pseudo'] = PseudoFam + +for fdrv in ['gamin', 'fam', 'pseudo']: + if fdrv in available: + default = available[fdrv] + break |