outcoming.writeMsg({"command": "ack"})

		elif jsonData["command"]=="req":

			outcoming.writeMsg(*self._requestHash(jsonData))

		elif jsonData["command"]=="send" and jsonData["dataType"]=="data":

			outcoming.writeMsg(*self._receiveData(jsonData,binData))

		elif jsonData["command"]=="end":

			self._finalize()

			return False

		else:

			assert False, jsonData["command"]

		return True

	def _requestHash(self,jsonData):

		log.info("received request for node #{0}".format(jsonData["index"]))

		assert jsonData["index"]<len(self._tree.store)

		nodeHash=self._tree.store[jsonData["index"]]

		jsonResponse={"command":"send", "index":jsonData["index"], "dataType":"hash"}

		binResponse=nodeHash

		return (jsonResponse,binResponse)

	def _receiveData(self,jsonData,binData):

		log.info("received data block #{0}: {1}...{2}".format(jsonData["index"],binData[:5],binData[-5:]))

		if not self._dataFile:

			self._dataFile=open(self._filename, mode="rb+")

		i=jsonData["index"]

		if self._lastWrite+1!=i:

			self._dataFile.seek(i * self.BLOCK_SIZE)

		self._dataFile.write(binData)

		self._lastWrite=i

		if self._treeFile:

			self._newLeaves[i + self._tree.leafStart]= hashlib.sha256(binData).digest()[HashTree.HASH_LEN:]

		return ({"command": "ack", "index": i},)

	def _finalize(self):

		log.info("closing session...")

		if self._dataFile:

			self._dataFile.close()

		if self._treeFile:

			log.info("updating hash tree...")

				self._tree.updateLeaf(k, v)

			self._tree.save(self._treeFile)

		log.info("done")