class PickleShareDB(collections.MutableMapping): """ The main 'connection' object for PickleShare database """ def __init__(self,root): """ Return a db object that will manage the specied directory""" self.root = Path(root).expanduser().abspath() if not self.root.isdir(): self.root.makedirs() # cache has { 'key' : (obj, orig_mod_time) } self.cache = {} def __getitem__(self,key): """ db['key'] reading """ fil = self.root / key try: mtime = (fil.stat()[stat.ST_MTIME]) except OSError: raise KeyError(key) if fil in self.cache and mtime == self.cache[fil][1]: return self.cache[fil][0] try: # The cached item has expired, need to read obj = pickle.loads(fil.open("rb").read()) except: raise KeyError(key) self.cache[fil] = (obj,mtime) return obj def __setitem__(self,key,value): """ db['key'] = 5 """ fil = self.root / key parent = fil.parent if parent and not parent.isdir(): parent.makedirs() # We specify protocol 2, so that we can mostly go between Python 2 # and Python 3. We can upgrade to protocol 3 when Python 2 is obsolete. pickled = pickle.dump(value,fil.open('wb'), protocol=2) try: self.cache[fil] = (value,fil.mtime) except OSError,e: if e.errno != 2: raise
class PickleShareDB(collections.MutableMapping): """ The main 'connection' object for PickleShare database """ def __init__(self, root): """ Return a db object that will manage the specied directory""" self.root = Path(root).expanduser().abspath() if not self.root.isdir(): self.root.makedirs() # cache has { 'key' : (obj, orig_mod_time) } self.cache = {} def __getitem__(self, key): """ db['key'] reading """ fil = self.root / key try: mtime = (fil.stat()[stat.ST_MTIME]) except OSError: raise KeyError(key) if fil in self.cache and mtime == self.cache[fil][1]: return self.cache[fil][0] try: # The cached item has expired, need to read obj = pickle.loads(fil.open("rb").read()) except: raise KeyError(key) self.cache[fil] = (obj, mtime) return obj def __setitem__(self, key, value): """ db['key'] = 5 """ fil = self.root / key parent = fil.parent if parent and not parent.isdir(): parent.makedirs() # We specify protocol 2, so that we can mostly go between Python 2 # and Python 3. We can upgrade to protocol 3 when Python 2 is obsolete. pickled = pickle.dump(value, fil.open('wb'), protocol=2) try: self.cache[fil] = (value, fil.mtime) except OSError, e: if e.errno != 2: raise
class PickleShareDB(UserDict.DictMixin): """ The main 'connection' object for PickleShare database """ def __init__(self,root): """ Return a db object that will manage the specied directory""" self.root = Path(root).expanduser().abspath() if not self.root.isdir(): self.root.makedirs() # cache has { 'key' : (obj, orig_mod_time) } self.cache = {} def __getitem__(self,key): """ db['key'] reading """ fil = self.root / key try: mtime = (fil.stat()[stat.ST_MTIME]) except OSError: raise KeyError(key) if fil in self.cache and mtime == self.cache[fil][1]: return self.cache[fil][0] try: # The cached item has expired, need to read obj = pickle.load(fil.open()) except: raise KeyError(key) self.cache[fil] = (obj,mtime) return obj def __setitem__(self,key,value): """ db['key'] = 5 """ fil = self.root / key parent = fil.parent if parent and not parent.isdir(): parent.makedirs() pickled = pickle.dump(value,fil.open('w')) try: self.cache[fil] = (value,fil.mtime) except OSError,e: if e.errno != 2: raise
class PickleShareDB(collections.MutableMapping): """ The main 'connection' object for PickleShare database """ def __init__(self,root): """ Return a db object that will manage the specied directory""" self.root = Path(root).expanduser().abspath() if not self.root.isdir(): self.root.makedirs() # cache has { 'key' : (obj, orig_mod_time) } self.cache = {} def __getitem__(self,key): """ db['key'] reading """ fil = self.root / key try: mtime = (fil.stat()[stat.ST_MTIME]) except OSError: raise KeyError(key) if fil in self.cache and mtime == self.cache[fil][1]: return self.cache[fil][0] try: # The cached item has expired, need to read with fil.open("rb") as f: obj = pickle.loads(f.read()) except: raise KeyError(key) self.cache[fil] = (obj,mtime) return obj def __setitem__(self,key,value): """ db['key'] = 5 """ fil = self.root / key parent = fil.parent if parent and not parent.isdir(): parent.makedirs() # We specify protocol 2, so that we can mostly go between Python 2 # and Python 3. We can upgrade to protocol 3 when Python 2 is obsolete. with fil.open('wb') as f: pickled = pickle.dump(value, f, protocol=2) try: self.cache[fil] = (value,fil.mtime) except OSError as e: if e.errno != 2: raise def hset(self, hashroot, key, value): """ hashed set """ hroot = self.root / hashroot if not hroot.isdir(): hroot.makedirs() hfile = hroot / gethashfile(key) d = self.get(hfile, {}) d.update( {key : value}) self[hfile] = d def hget(self, hashroot, key, default = _sentinel, fast_only = True): """ hashed get """ hroot = self.root / hashroot hfile = hroot / gethashfile(key) d = self.get(hfile, _sentinel ) #print "got dict",d,"from",hfile if d is _sentinel: if fast_only: if default is _sentinel: raise KeyError(key) return default # slow mode ok, works even after hcompress() d = self.hdict(hashroot) return d.get(key, default) def hdict(self, hashroot): """ Get all data contained in hashed category 'hashroot' as dict """ hfiles = self.keys(hashroot + "/*") hfiles.sort() last = len(hfiles) and hfiles[-1] or '' if last.endswith('xx'): # print "using xx" hfiles = [last] + hfiles[:-1] all = {} for f in hfiles: # print "using",f try: all.update(self[f]) except KeyError: print("Corrupt",f,"deleted - hset is not threadsafe!") del self[f] self.uncache(f) return all def hcompress(self, hashroot): """ Compress category 'hashroot', so hset is fast again hget will fail if fast_only is True for compressed items (that were hset before hcompress). """ hfiles = self.keys(hashroot + "/*") all = {} for f in hfiles: # print "using",f all.update(self[f]) self.uncache(f) self[hashroot + '/xx'] = all for f in hfiles: p = self.root / f if p.basename() == 'xx': continue p.remove() def __delitem__(self,key): """ del db["key"] """ fil = self.root / key self.cache.pop(fil,None) try: fil.remove() except OSError: # notfound and permission denied are ok - we # lost, the other process wins the conflict pass def _normalized(self, p): """ Make a key suitable for user's eyes """ return str(self.root.relpathto(p)).replace('\\','/') def keys(self, globpat = None): """ All keys in DB, or all keys matching a glob""" if globpat is None: files = self.root.walkfiles() else: files = [Path(p) for p in glob.glob(self.root/globpat)] return [self._normalized(p) for p in files if p.isfile()] def __iter__(self): return iter(list(self.keys())) def __len__(self): return len(list(self.keys())) def uncache(self,*items): """ Removes all, or specified items from cache Use this after reading a large amount of large objects to free up memory, when you won't be needing the objects for a while. """ if not items: self.cache = {} for it in items: self.cache.pop(it,None) def waitget(self,key, maxwaittime = 60 ): """ Wait (poll) for a key to get a value Will wait for `maxwaittime` seconds before raising a KeyError. The call exits normally if the `key` field in db gets a value within the timeout period. Use this for synchronizing different processes or for ensuring that an unfortunately timed "db['key'] = newvalue" operation in another process (which causes all 'get' operation to cause a KeyError for the duration of pickling) won't screw up your program logic. """ wtimes = [0.2] * 3 + [0.5] * 2 + [1] tries = 0 waited = 0 while 1: try: val = self[key] return val except KeyError: pass if waited > maxwaittime: raise KeyError(key) time.sleep(wtimes[tries]) waited+=wtimes[tries] if tries < len(wtimes) -1: tries+=1 def getlink(self,folder): """ Get a convenient link for accessing items """ return PickleShareLink(self, folder) def __repr__(self): return "PickleShareDB('%s')" % self.root
class PickleShareDB(collections.MutableMapping): """ The main 'connection' object for PickleShare database """ def __init__(self, root): """ Return a db object that will manage the specied directory""" self.root = Path(root).expanduser().abspath() if not self.root.isdir(): self.root.makedirs() # cache has { 'key' : (obj, orig_mod_time) } self.cache = {} def __getitem__(self, key): """ db['key'] reading """ fil = self.root / key try: mtime = (fil.stat()[stat.ST_MTIME]) except OSError: raise KeyError(key) if fil in self.cache and mtime == self.cache[fil][1]: return self.cache[fil][0] try: # The cached item has expired, need to read with fil.open("rb") as f: obj = pickle.loads(f.read()) except: raise KeyError(key) self.cache[fil] = (obj, mtime) return obj def __setitem__(self, key, value): """ db['key'] = 5 """ fil = self.root / key parent = fil.parent if parent and not parent.isdir(): parent.makedirs() # We specify protocol 2, so that we can mostly go between Python 2 # and Python 3. We can upgrade to protocol 3 when Python 2 is obsolete. with fil.open('wb') as f: pickled = pickle.dump(value, f, protocol=2) try: self.cache[fil] = (value, fil.mtime) except OSError as e: if e.errno != 2: raise def hset(self, hashroot, key, value): """ hashed set """ hroot = self.root / hashroot if not hroot.isdir(): hroot.makedirs() hfile = hroot / gethashfile(key) d = self.get(hfile, {}) d.update({key: value}) self[hfile] = d def hget(self, hashroot, key, default=_sentinel, fast_only=True): """ hashed get """ hroot = self.root / hashroot hfile = hroot / gethashfile(key) d = self.get(hfile, _sentinel) #print "got dict",d,"from",hfile if d is _sentinel: if fast_only: if default is _sentinel: raise KeyError(key) return default # slow mode ok, works even after hcompress() d = self.hdict(hashroot) return d.get(key, default) def hdict(self, hashroot): """ Get all data contained in hashed category 'hashroot' as dict """ hfiles = self.keys(hashroot + "/*") hfiles.sort() last = len(hfiles) and hfiles[-1] or '' if last.endswith('xx'): # print "using xx" hfiles = [last] + hfiles[:-1] all = {} for f in hfiles: # print "using",f try: all.update(self[f]) except KeyError: print("Corrupt", f, "deleted - hset is not threadsafe!") del self[f] self.uncache(f) return all def hcompress(self, hashroot): """ Compress category 'hashroot', so hset is fast again hget will fail if fast_only is True for compressed items (that were hset before hcompress). """ hfiles = self.keys(hashroot + "/*") all = {} for f in hfiles: # print "using",f all.update(self[f]) self.uncache(f) self[hashroot + '/xx'] = all for f in hfiles: p = self.root / f if p.basename() == 'xx': continue p.remove() def __delitem__(self, key): """ del db["key"] """ fil = self.root / key self.cache.pop(fil, None) try: fil.remove() except OSError: # notfound and permission denied are ok - we # lost, the other process wins the conflict pass def _normalized(self, p): """ Make a key suitable for user's eyes """ return str(self.root.relpathto(p)).replace('\\', '/') def keys(self, globpat=None): """ All keys in DB, or all keys matching a glob""" if globpat is None: files = self.root.walkfiles() else: files = [Path(p) for p in glob.glob(self.root / globpat)] return [self._normalized(p) for p in files if p.isfile()] def __iter__(self): return iter(list(self.keys())) def __len__(self): return len(list(self.keys())) def uncache(self, *items): """ Removes all, or specified items from cache Use this after reading a large amount of large objects to free up memory, when you won't be needing the objects for a while. """ if not items: self.cache = {} for it in items: self.cache.pop(it, None) def waitget(self, key, maxwaittime=60): """ Wait (poll) for a key to get a value Will wait for `maxwaittime` seconds before raising a KeyError. The call exits normally if the `key` field in db gets a value within the timeout period. Use this for synchronizing different processes or for ensuring that an unfortunately timed "db['key'] = newvalue" operation in another process (which causes all 'get' operation to cause a KeyError for the duration of pickling) won't screw up your program logic. """ wtimes = [0.2] * 3 + [0.5] * 2 + [1] tries = 0 waited = 0 while 1: try: val = self[key] return val except KeyError: pass if waited > maxwaittime: raise KeyError(key) time.sleep(wtimes[tries]) waited += wtimes[tries] if tries < len(wtimes) - 1: tries += 1 def getlink(self, folder): """ Get a convenient link for accessing items """ return PickleShareLink(self, folder) def __repr__(self): return "PickleShareDB('%s')" % self.root