def _initialOndata(self, content):
"""
Process initial data which usually includes all other publisher's info,
and send back the new comer's own info.
"""
# The user is a new comer and receive data of all other people in the group.
self._update(content)
digest = self._digestTree.getRoot()
for i in range(len(content)):
syncState = content[i]
if (syncState.name == self._applicationDataPrefixUri
and syncState.seqno.session == self._sessionNo):
# If the user was an old comer, after add the static log he
# needs to increase his sequence number by 1.
tempContent = sync_state_pb2.SyncStateMsg()
# Use getattr to avoid pylint errors.
content2 = getattr(tempContent, "ss").add()
content2.name = self._applicationDataPrefixUri
content2.type = SyncState_UPDATE
content2.seqno.seq = syncState.seqno.seq + 1
content2.seqno.session = self._sessionNo
if self._update(getattr(tempContent, "ss")):
self._onInitialized()
tempContent2 = sync_state_pb2.SyncStateMsg()
if self._sequenceNo >= 0:
# Send the data packet with the new sequence number back.
content2 = getattr(tempContent2, "ss").add()
content2.name = self._applicationDataPrefixUri
content2.type = SyncState_UPDATE
content2.seqno.seq = self._sequenceNo
content2.seqno.session = self._sessionNo
else:
content2 = getattr(tempContent2, "ss").add()
content2.name = self._applicationDataPrefixUri
content2.type = SyncState_UPDATE
content2.seqno.seq = 0
content2.seqno.session = self._sessionNo
self._broadcastSyncState(digest, tempContent2)
if (self._digestTree.find(self._applicationDataPrefixUri,
self._sessionNo) == -1):
# The user hasn't put himself in the digest tree.
logging.getLogger(__name__).info("initial state")
self._sequenceNo += 1
tempContent = sync_state_pb2.SyncStateMsg()
content2 = getattr(tempContent, "ss").add()
content2.name = self._applicationDataPrefixUri
content2.type = SyncState_UPDATE
content2.seqno.seq = self._sequenceNo
content2.seqno.session = self._sessionNo
if self._update(getattr(tempContent, "ss")):
self._onInitialized()
def __init__(self, onReceivedSyncState, onInitialized,
applicationDataPrefix, applicationBroadcastPrefix, sessionNo, face,
keyChain, certificateName, syncLifetime, onRegisterFailed):
self._onReceivedSyncState = onReceivedSyncState
self._onInitialized = onInitialized
self._applicationDataPrefixUri = applicationDataPrefix.toUri()
self._applicationBroadcastPrefix = Name(applicationBroadcastPrefix)
self._sessionNo = sessionNo
self._face = face
self._keyChain = keyChain
self._certificateName = Name(certificateName)
self._syncLifetime = syncLifetime
self._contentCache = MemoryContentCache(face)
self._digestLog = [] # of _DigestLogEntry
self._digestTree = DigestTree()
self._sequenceNo = -1
self._enabled = True
emptyContent = sync_state_pb2.SyncStateMsg()
# Use getattr to avoid pylint errors.
self._digestLog.append(self._DigestLogEntry("00", getattr(emptyContent, "ss")))
# Register the prefix with the contentCache_ and use our own onInterest
# as the onDataNotFound fallback.
self._contentCache.registerPrefix(
self._applicationBroadcastPrefix, onRegisterFailed, self._onInterest)
interest = Interest(self._applicationBroadcastPrefix)
interest.getName().append("00")
interest.setInterestLifetimeMilliseconds(1000)
interest.setMustBeFresh(True)
face.expressInterest(interest, self._onData, self._initialTimeOut)
logging.getLogger(__name__).info("initial sync expressed")
logging.getLogger(__name__).info("%s", interest.getName().toUri())
def _processRecoveryInterest(self, interest, syncDigest, face):
logging.getLogger(__name__).info("processRecoveryInterest")
if self._logFind(syncDigest) != -1:
tempContent = sync_state_pb2.SyncStateMsg()
for i in range(self._digestTree.size()):
content = getattr(tempContent, "ss").add()
content.name = self._digestTree.get(i).getDataPrefix()
content.type = SyncState_UPDATE
content.seqno.seq = self._digestTree.get(i).getSequenceNo()
content.seqno.session = self._digestTree.get(i).getSessionNo()
if len(getattr(tempContent, "ss")) != 0:
# TODO: Check if this works in Python 3.
#pylint: disable=E1103
array = tempContent.SerializeToString()
#pylint: enable=E1103
data = Data(interest.getName())
data.setContent(Blob(array))
if interest.getName().get(-1).toEscapedString() == "00":
# Limit the lifetime of replies to interest for "00" since
# they can be different.
data.getMetaInfo().setFreshnessPeriod(1000)
self._keyChain.sign(data, self._certificateName)
try:
face.putData(data)
except Exception as ex:
logging.getLogger(__name__).error(
"Error in face.putData: %s", str(ex))
return
logging.getLogger(__name__).info("send recovery data back")
logging.getLogger(__name__).info("%s", interest.getName().toUri())
def _onData(self, interest, data):
"""
Process Sync Data.
"""
if not self._enabled:
# Ignore callbacks after the application calls shutdown().
return
logging.getLogger(__name__).info(
"Sync ContentObject received in callback")
logging.getLogger(__name__).info("name: %s", data.getName().toUri())
# TODO: Check if this works in Python 3.
tempContent = sync_state_pb2.SyncStateMsg()
#pylint: disable=E1103
tempContent.ParseFromString(data.getContent().toRawStr())
#pylint: enable=E1103
content = getattr(tempContent, "ss")
if self._digestTree.getRoot() == "00":
isRecovery = True
#processing initial sync data
self._initialOndata(content)
else:
self._update(content)
if (interest.getName().size() ==
self._applicationBroadcastPrefix.size() + 2):
# Assume this is a recovery interest.
isRecovery = True
else:
isRecovery = False
# Send the interests to fetch the application data.
syncStates = []
for i in range(len(content)):
syncState = content[i]
# Only report UPDATE sync states.
if syncState.type == SyncState_UPDATE:
if len(syncState.application_info) > 0:
applicationInfo = Blob(syncState.application_info, True)
else:
applicationInfo = Blob()
syncStates.append(
self.SyncState(syncState.name, syncState.seqno.session,
syncState.seqno.seq, applicationInfo))
try:
self._onReceivedSyncState(syncStates, isRecovery)
except:
logging.exception("Error in onReceivedSyncState")
name = Name(self._applicationBroadcastPrefix)
name.append(self._digestTree.getRoot())
syncInterest = Interest(name)
syncInterest.setInterestLifetimeMilliseconds(self._syncLifetime)
self._face.expressInterest(syncInterest, self._onData,
self._syncTimeout)
logging.getLogger(__name__).info("Syncinterest expressed:")
logging.getLogger(__name__).info("%s", name.toUri())
def publishNextSequenceNo(self, applicationInfo=None):
"""
Increment the sequence number, create a sync message with the new
sequence number and publish a data packet where the name is
the applicationBroadcastPrefix + the root digest of the current digest
tree. Then add the sync message to the digest tree and digest log which
creates a new root digest. Finally, express an interest for the next sync
update with the name applicationBroadcastPrefix + the new root digest.
After this, your application should publish the content for the new
sequence number. You can get the new sequence number with getSequenceNo().
Note: Your application must call processEvents. Since processEvents
modifies the internal ChronoSync data structures, your application should
make sure that it calls processEvents in the same thread as
publishNextSequenceNo() (which also modifies the data structures).
:param Blob applicationInfo: (optional) This appends applicationInfo to
the content of the sync messages. This same info is provided to the
receiving application in the SyncState state object provided to the
onReceivedSyncState callback.
"""
applicationInfo = (applicationInfo if isinstance(
applicationInfo, Blob) else Blob(applicationInfo))
self._sequenceNo += 1
syncMessage = sync_state_pb2.SyncStateMsg()
content = getattr(syncMessage, "ss").add()
content.name = self._applicationDataPrefixUri
content.type = SyncState_UPDATE
content.seqno.seq = self._sequenceNo
content.seqno.session = self._sessionNo
if not applicationInfo.isNull() and applicationInfo.size() > 0:
content.application_info = applicationInfo.toBytes()
self._broadcastSyncState(self._digestTree.getRoot(), syncMessage)
if not self._update(getattr(syncMessage, "ss")):
# Since we incremented the sequence number, we expect there to be a
# new digest log entry.
raise RuntimeError(
"ChronoSync: update did not create a new digest log entry")
# TODO: Should we have an option to not express an interest if this is the
# final publish of the session?
interest = Interest(self._applicationBroadcastPrefix)
interest.getName().append(self._digestTree.getRoot())
interest.setInterestLifetimeMilliseconds(self._syncLifetime)
self._face.expressInterest(interest, self._onData, self._syncTimeout)
def _initialTimeOut(self, interest):
"""
Initial sync interest timeout, which means there are no other publishers
yet.
"""
if not self._enabled:
# Ignore callbacks after the application calls shutdown().
return
logging.getLogger(__name__).info("initial sync timeout")
logging.getLogger(__name__).info("no other people")
self._sequenceNo += 1
if self._sequenceNo != 0:
# Since there were no other users, we expect sequence no 0.
raise RuntimeError(
"ChronoSync: sequenceNo_ is not the expected value of 0 for first use."
)
tempContent = sync_state_pb2.SyncStateMsg()
content = getattr(tempContent, "ss").add()
content.name = self._applicationDataPrefixUri
content.type = SyncState_UPDATE
content.seqno.seq = self._sequenceNo
content.seqno.session = self._sessionNo
self._update(getattr(tempContent, "ss"))
try:
self._onInitialized()
except:
logging.exception("Error in onInitialized")
name = Name(self._applicationBroadcastPrefix)
name.append(self._digestTree.getRoot())
retryInterest = Interest(name)
retryInterest.setInterestLifetimeMilliseconds(self._syncLifetime)
self._face.expressInterest(retryInterest, self._onData,
self._syncTimeout)
logging.getLogger(__name__).info("Syncinterest expressed:")
logging.getLogger(__name__).info("%s", name.toUri())
def _processSyncInterest(self, index, syncDigest, face):
"""
Common interest processing, using digest log to find the difference
after syncDigest.
:return: True if sent a data packet to satisfy the interest, otherwise
False.
:rtype: bool
"""
nameList = [] # of str
sequenceNoList = [] # of int
sessionNoList = [] # of int
for j in range(index + 1, len(self._digestLog)):
temp = self._digestLog[j].getData() # array of sync_state_pb2.SyncState.
for i in range(len(temp)):
syncState = temp[i]
if syncState.type != SyncState_UPDATE:
continue
if self._digestTree.find(
syncState.name, syncState.seqno.session) != -1:
n = -1
for k in range(len(nameList)):
if nameList[k] == syncState.name:
n = k
break
if n == -1:
nameList.append(syncState.name)
sequenceNoList.append(syncState.seqno.seq)
sessionNoList.append(syncState.seqno.session)
else:
sequenceNoList[n] = syncState.seqno.seq
sessionNoList[n] = syncState.seqno.session
tempContent = sync_state_pb2.SyncStateMsg()
for i in range(len(nameList)):
content = getattr(tempContent, "ss").add()
content.name = nameList[i]
content.type = SyncState_UPDATE
content.seqno.seq = sequenceNoList[i]
content.seqno.session = sessionNoList[i]
sent = False
if len(getattr(tempContent, "ss")) != 0:
name = Name(self._applicationBroadcastPrefix)
name.append(syncDigest)
# TODO: Check if this works in Python 3.
#pylint: disable=E1103
array = tempContent.SerializeToString()
#pylint: enable=E1103
data = Data(name)
data.setContent(Blob(array))
self._keyChain.sign(data, self._certificateName)
try:
face.putData(data)
except Exception as ex:
logging.getLogger(__name__).error(
"Error in face.putData: %s", str(ex))
return
sent = True
logging.getLogger(__name__).info("Sync Data send")
logging.getLogger(__name__).info("%s", name.toUri())
return sent
