crowdfund.py

cf_code=''''
# storage[-1] = last campaign id
# campaigns:
#      id: creator
#    id+1: goal
#    id+2: end timestamp
#    id+3: pointer to place next donation
#    id+4: total contribution counter
# id+2i+5: ith contributor
# id+2i+6: ith contribution

# Start a campaign, data [0, id, recipient, goal, time limit]
if msg.data[0] == 0:
    id = msg.data[1] * 2 ^ 32
    if contract.storage[id]:
        return(0)
    contract.storage[id] = msg.data[2] # Campaign recipient
    contract.storage[id + 1] = msg.data[3] # Goal
    contract.storage[id + 2] = block.timestamp + msg.data[4] # Time limit
    contract.storage[id + 3] = id + 5 # Index of next contribution
    return(msg.data[1])

# Contribute to a campaign [1, id]
elif msg.data[0] == 1:
    id = msg.data[1] * 2^32

    # Update contribution total
    total_contributed = contract.storage[id + 4] + msg.value
    contract.storage[id + 4] = total_contributed

    # Record new contribution
    sub_index = contract.storage[id + 3]
    contract.storage[sub_index] = msg.sender
    contract.storage[sub_index + 1] = msg.value
    contract.storage[id + 3] = sub_index + 2

    # Enough funding?
    if total_contributed >= contract.storage[id + 1]:
        send(contract.storage[id], total_contributed)
        v = id
        f = sub_index + 2
        while v < f:
            contract.storage[v] = 0
            v += 1
        return(1)

    # Expired?
    if block.timestamp > contract.storage[id + 2]:
        v = id
        f = sub_index + 2
        while v < id + 5:
            contract.storage[v] = 0
            v += 1
        while v < f:
            send(contract.storage[v], contract.storage[v + 1])
            contract.storage[v] = 0
            contract.storage[v + 1] = 0
            v += 2
        return(2)

# Progress report [2, id]
elif msg.data[0] == 2:
    return(contract.storage[msg.data[1] * 2^32] + 4)
'''

import serpent
from pyethereum import transactions, blocks, processblock, utils
import time

code = serpent.compile(cf_code)
key = utils.sha3('cow')
addr = utils.privtoaddr(key)
key2 = utils.sha3('cow2')
addr2 = utils.privtoaddr(key2)
key_host = utils.sha3('host')
add_host = utils.privtoaddr(key_host)

#initialize the block                                                                                                                                                                                          
genesis = blocks.genesis({addr: 10**18, addr2: 10**18, add_host: 10**18})

#This is to initialize the contract                                                                                                                                                                            
tx1 = transactions.contract(0,10**12,10000,0,code).sign(key_host)
result, contract = processblock.apply_transaction(genesis, tx1)

print genesis.get_balance(contract)
print 'balance of add %s is: %s' %(addr, str(genesis.get_balance(addr)))
print 'balance of add %s is: %s' %(addr2, str(genesis.get_balance(addr2)))
print genesis.to_dict()

#nonce, gasprice, startgas, to, value, data
print str(genesis.timestamp)
tx2 = transactions.Transaction(0, 10**12, 10000, contract, 10,  serpent.encode_datalist([0, 1, addr, 10**16, 100])).sign(key)
result, ans = processblock.apply_transaction(genesis,tx2)

print "balance of contract: " , contract, genesis.get_balance(contract)
print 'Done creating campaign'
print 'balance of add %s is: %s' %(addr, str(genesis.get_balance(addr)))
print 'balance of add %s is: %s' %(addr2, str(genesis.get_balance(addr2)))
print genesis.to_dict()

for i in range(2):
    genesis.finalize()
    t = (genesis.timestamp or int(time.time())) + 60
    genesis = blocks.Block.init_from_parent(genesis, add_host, '', t)

#nonce, gasprice, startgas, to, value, data
tx3 = transactions.Transaction(0, 10**12, 10000, contract, 10**17,  serpent.encode_datalist([1, 1])).sign(key2)
result, ans = processblock.apply_transaction(genesis,tx3)

print "balance of contract: " , genesis.get_balance(contract)
print result, serpent.decode_datalist(ans)
print 'Done crowfunding campaign'
print 'balance of add %s is: %s' %(addr, str(genesis.get_balance(addr)))
print 'balance of add %s is: %s' %(addr2, str(genesis.get_balance(addr2)))
print genesis.to_dict()


#################====================
tx4 = transactions.Transaction(1, 10**12, 10000, contract, 10**17,  serpent.encode_datalist([1, 2])).sign(key2)
result, ans = processblock.apply_transaction(genesis,tx4)
print "balance of contract: " , genesis.get_balance(contract)
print result, serpent.decode_datalist(ans)
print 'Keep sending the money'
print 'balance of add %s is: %s' %(addr, str(genesis.get_balance(addr)))
print 'balance of add %s is: %s' %(addr2, str(genesis.get_balance(addr2)))
print genesis.to_dict()