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author | Sol Jerome <sol.jerome@gmail.com> | 2012-03-24 11:20:07 -0500 |
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committer | Sol Jerome <sol.jerome@gmail.com> | 2012-03-24 11:20:07 -0500 |
commit | dab1d03d81c538966d03fb9318a4588a9e803b44 (patch) | |
tree | f51e27fa55887e9fb961766805fe43f0da56c5b9 /src/lib/Bcfg2/Server/FileMonitor.py | |
parent | 5cd6238df496a3cea178e4596ecd87967cce1ce6 (diff) | |
download | bcfg2-dab1d03d81c538966d03fb9318a4588a9e803b44.tar.gz bcfg2-dab1d03d81c538966d03fb9318a4588a9e803b44.tar.bz2 bcfg2-dab1d03d81c538966d03fb9318a4588a9e803b44.zip |
Allow to run directly from a git checkout (#1037)
Signed-off-by: Sol Jerome <sol.jerome@gmail.com>
Diffstat (limited to 'src/lib/Bcfg2/Server/FileMonitor.py')
-rw-r--r-- | src/lib/Bcfg2/Server/FileMonitor.py | 315 |
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 |