简单的区块链、区块、交易逻辑结构与代码实现。
1.区块链逻辑结构
区块链的逻辑结构
block_chain是一个区块链，block是一个区块，message是消息，transcation是交易。
一个区块链是多个区块的连接；一个区块包含多个消息；一个消息有一个交易。
2.区块链类图
区块链类图
3.代码
以下四个类可直接执行看效果，感受区块链、区块、消息、交易的数据结构。
Transcation.py
import datetime
class Transcation:
def __init__(self,payer,recer,money):
self.payer = payer
self.recer = recer
self.money = money
self.timestamp = datetime.datetime.now()
def __repr__(self):
return str(self.payer) + " pay " + str(self.recer) + " " + str(self.money) + " " + str(self.timestamp)
if __name__ == "__main__":
t1 = Transcation("I","him",10)
print(t1)
NiuMessage.py
import hashlib
import datetime
from Transcation import Transcation
class NiuMessage:
def __init__(self,transcation):
self.transcation = transcation
self.hash = None
self.pre_hash = None
self.timestamp = datetime.datetime.now()
self.payload_hash = self._hash_payload() #交易后的hash
def _hash_payload(self): #对交易时间与数据进行hash
return hashlib.sha256( (str(self.timestamp) + str(self.transcation)).encode("utf-8") ).hexdigest()
def _hash_message(self): #将前一个hash与交易后的hash，再hash
return hashlib.sha256( (str(self.pre_hash) + str(self._hash_payload())).encode("utf-8") ).hexdigest()
def seal(self): #就是将交易hash，设置为现在的hash，这里为什么不能赋值在构造器，因为构造器不能调用两个函数
self.hash = self._hash_message()
def __repr__(self):
mystr = "hash:{} , pre_hash:{} , data:{}".format(self.hash,self.pre_hash,self.transcation)
return mystr
def validate(self,Message): #上个交易的hash与数据要能对上
if (Message.hash != self.pre_hash):
raise InvalidateMessage("交易hash被篡改 ," + str(self))
if(Message.hash != Message._hash_message()):
raise InvalidateMessage("交易数据被篡改 ,"+str(self))
def link(self,Message):
self.pre_hash = Message.hash
class InvalidateMessage(Exception):
def __init__(self,*args,**kwargs):
Exception.__init__(self,*args,**kwargs)
if __name__ == "__main__":
t1 = Transcation("I", "him", 10)
t2 = Transcation("him", "it", 10)
t3 = Transcation("it", "her", 10)
m1 = NiuMessage(t1)
m1.seal()
m2 = NiuMessage(t2)
m2.link(m1)
m2.seal()
m2.validate(m1)
m3 = NiuMessage(t3)
m3.link(m2)
m3.seal()
m3.validate(m2)
print(m1)
print(m2)
print(m3)
#m2.hash="33" '3448aa15999c2f73e61e5bfc4a72286823a6b52d23bf571d9fcbb7ba631bed97'
#m2.transcation = "fda"
#m3.validate(m2)
NiuBlock.py
import hashlib
import datetime
from NiuMessage import NiuMessage
from Transcation import Transcation
from NiuMessage import InvalidateMessage
class NiuBlock:
def __init__(self,*args):
self.hash = None
self.pre_hash = None
self.timestamp = None
self.message_list = [] #存储多个交易记录
if args:
for arg in args:
self.add_message(arg) #一次打包多个交易进区块
def add_message(self,message): #将message放进区块的message列表中
if(len(self.message_list)>0):
message.link(self.message_list[-1]) #message与上一个message相连
message.seal() #这是message的seal，不是block的seal
if (len(self.message_list) > 0):
message.validate(self.message_list[-1]) #这是message的validate，不是block的
self.message_list.append(message)
def link(self,block):
self.pre_hash = block.hash
def seal(self):
self.timestamp = datetime.datetime.now()
self.hash = self.hash_block()
def hash_block(self):
return hashlib.sha256( (str(self.pre_hash) + \
str(self.timestamp) + \
str(self.message_list[-1].hash)).encode("utf-8") ).hexdigest()
def validate(self,block):#验证block
if (block.hash != self.pre_hash):
raise InvalidBlockException("区块hash被篡改 ," + str(self))
def validate_message_list(self):#验证消息列表
for i,message in enumerate(self.message_list):
if i>0 :
message.validate(self.message_list[i-1])
return str(self) + " ,数据ok"
def __repr__(self):
return "money block=hash:{},pre_hash:{},len:{},timestamp:{}".\
format(self.hash,self.pre_hash,len(self.message_list),self.timestamp)
class InvalidBlockException(Exception):
def __init__(self,*args,**kwargs):
Exception.__init__(self,*args,**kwargs)
if __name__ == "__main__":
try:
t1 = Transcation("I", "him", 10)
t2 = Transcation("him", "it", 10)
t3 = Transcation("it", "her", 10)
m1 = NiuMessage(t1)
m2 = NiuMessage(t2)
m3 = NiuMessage(t3)
niu = NiuBlock(m1,m2,m3)
niu.seal()
#m2.hash = "hehe"
#niu.message_list[1] = m3
print(niu.validate_message_list()) #仅是校验message，还不是校验区块之间的连接
except InvalidateMessage as e:
print(e)
except InvalidBlockException as e:
print(e)
NiuBlockChain.py
from NiuMessage import NiuMessage
from Transcation import Transcation
from NiuMessage import InvalidateMessage
from NiuBlock import InvalidBlockException
from NiuBlock import NiuBlock
class NiuBlockChain:
def __init__(self):
self.block_list = []
def __repr__(self):
mystr = "block chain:\n"
for i,block in enumerate(blockchain.block_list):
mystr += "block {} , {} \n".format(i,block)
for j,message in enumerate(block.message_list):
mystr += " message {}\n".format(message)
return mystr
def add_block(self,block):
if(len(self.block_list) > 0):
block.link(self.block_list[-1])
block.seal()
if (len(self.block_list) > 0):
block.validate(self.block_list[-1])
self.block_list.append(block)
def validate_block_list(self):
for i,block in enumerate(self.block_list):
if i>0 :
try:
block.validate(self.block_list[i-1])
except InvalidateBlockChainException as e:
raise InvalidateBlockChainException("无效blockchain，区块被修改")
return str(self) + " ,数据ok"
class InvalidateBlockChainException(Exception):
def __init__(self, *args, **kwargs):
Exception.__init__(self, *args, **kwargs)
if __name__ == "__main__":
try:
blockchain = NiuBlockChain()
t1 = Transcation("I", "him", 10)
t2 = Transcation("him", "it", 10)
t3 = Transcation("it", "her", 10)
t4 = Transcation("her", "mm", 10)
t5 = Transcation("mm", "gg", 10)
t6 = Transcation("gg", "pp", 10)
m1 = NiuMessage(t1)
m2 = NiuMessage(t2)
m3 = NiuMessage(t3)
m4 = NiuMessage(t4)
m5 = NiuMessage(t5)
m6 = NiuMessage(t6)
b1 = NiuBlock(m1,m2)
blockchain.add_block(b1)
b2 = NiuBlock(m3)
blockchain.add_block(b2)
b3 = NiuBlock(m4,m5,m6)
blockchain.add_block(b3)
#blockchain.add_block(b2) 测试区块被修改
print(blockchain.validate_block_list())
except InvalidateMessage as e:
print(e)
except InvalidBlockException as e:
print(e)
except InvalidateBlockChainException as e:
print(e)
NiuBlockChain执行结果
可以看出区块链区块之间由hash连接，区块中交易的消息也是由hash连接，一旦任何数据被修改，hash之间就连接不上了。
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