Morevna Changeset - 44cf81f3b6b8

Changeset - 44cf81f3b6b8

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Laman - 8 years ago 2017-10-01 20:35:44

server can also serve data blocks

1 file changed with 23 insertions and 10 deletions:

src/server.py

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src/server.py

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 import hashlib
 import socket
 import logging as log
 from hashtree import HashTree
 from networkers import NetworkReader,NetworkWriter
 import config as conf
 class Connection:
 	def __init__(self,serverSocket):
 		self._socket, address = serverSocket.accept()
 		log.info('Connected by {0}'.format(address))
 		fr=self._socket.makefile(mode="rb")
 		fw=self._socket.makefile(mode="wb")
 		self.incoming=NetworkReader(fr)
 		self.outcoming=NetworkWriter(fw)
 	def __enter__(self):
 		return self.incoming,self.outcoming
 	def __exit__(self, exc_type, exc_val, exc_tb):
 		self._socket.close()
 class Server:
 	def __init__(self,filename,treeFile=""):
 		self._filename=filename
 		self._treeFile=treeFile
 		if treeFile:
 			self._tree=HashTree.load(treeFile)
 		else:
 			self._tree=HashTree.fromFile(filename)
 		self._newLeaves=dict()
 		self.BLOCK_SIZE=self._tree.BLOCK_SIZE
 		self._ss = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
 		self._ss.bind(("", conf.port))
 		self._ss.listen(1)
-		self._lastWrite=-1
+		self._lastIndex=-1
 		self._dataFile=None
 	def serve(self):
 		while True:
 			with Connection(self._ss) as (incoming, outcoming):
 				try:
 					while True:
 						if not self._serveOne(incoming,outcoming): return
 				except AssertionError:
 					continue
 	def _serveOne(self,incoming,outcoming):
 		jsonData,binData=incoming.readMsg()
 		if jsonData["command"]=="init":
 			assert jsonData["blockSize"]==self.BLOCK_SIZE
 			assert jsonData["blockCount"]==self._tree.leafCount
 			outcoming.writeMsg({"command": "ack"})
 		elif jsonData["command"]=="req":
 			outcoming.writeMsg(*self._requestHash(jsonData))
 			if jsonData["dataType"]=="data":
 				outcoming.writeMsg(*self._requestData(jsonData["index"]))
 			else:
 				outcoming.writeMsg(*self._requestHash(jsonData["index"]))
 		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"]]
 	def _requestHash(self,index):
 		log.info("received request for node #{0}".format(index))
 		assert index<len(self._tree.store)
 		nodeHash=self._tree.store[index]
 		jsonResponse={"command":"send", "index":index, "dataType":"hash"}
 		binResponse=nodeHash
 		jsonResponse={"command":"send", "index":jsonData["index"], "dataType":"hash"}
 		binResponse=nodeHash
 		return (jsonResponse,binResponse)
 	def _requestData(self,index):
 		log.info("received request for data block #{0}".format(index))
 		jsonResponse={"command":"send", "index":index, "dataType":"data"}
 		if self._lastIndex+1!=index:
 			self._dataFile.seek(index*self.BLOCK_SIZE)
 		binResponse=self._dataFile.read(self.BLOCK_SIZE)
 		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:
+		if self._lastIndex+1!=i:
 			self._dataFile.seek(i * self.BLOCK_SIZE)
 		self._dataFile.write(binData)
-		self._lastWrite=i
+		self._lastIndex=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...")
 			for (k,v) in self._newLeaves.items():
 				self._tree.updateLeaf(k, v)
 			self._tree.save(self._treeFile)
 		log.info("done")

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