fw=s.makefile(mode='wb')

networkReader=NetworkReader(fr)

networkReader.start()

networkWriter=NetworkWriter(fw)

networkWriter.start()

blocksToTransfer=[]

nodeStack=collections.deque([0]) # root

incoming=networkReader.output # synchronized message queue

outcoming=networkWriter.input

# determine which blocks to send

while len(nodeStack)>0:

  i=nodeStack.pop()

  jsonData={"command":"req", "index":i}

  outcoming.put((jsonData,b""))

  jsonData,binData=incoming.get(timeout=2)

  assert jsonData["index"]==i

  assert jsonData["dataType"]=="hash"

  if localTree.store[i]!=binData:

      nodeStack.append(2*i+2)

      nodeStack.append(2*i+1)

    else: blocksToTransfer.append(i-localTree.leafStart) # leaf

# send the actual data

print(blocksToTransfer)

dataFile=open("clientFile.txt",mode="rb")

for i in blocksToTransfer:

  jsonData={"command":"send", "index":i, "dataType":"data"}

  dataFile.seek(i*localTree.BLOCK_SIZE)

  binData=dataFile.read(localTree.BLOCK_SIZE)

  print("block #{0}: {1}...{2}".format(i,binData[:5],binData[-5:]))

  outcoming.put((jsonData,binData),timeout=2)

jsonData={"command":"end"}

outcoming.put((jsonData,b""),timeout=2)

outcoming.put(None)

print("closing...")

dataFile.close()