1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
|
# BlockStore: a helper class that keeps a map of blocks and implements
# helper functions for responding to getheaders and getdata,
# and for constructing a getheaders message
#
from .mininode import *
import dbm
from io import BytesIO
class BlockStore(object):
def __init__(self, datadir):
self.blockDB = dbm.open(datadir + "/blocks", 'c')
self.currentBlock = 0L
self.headers_map = dict()
def close(self):
self.blockDB.close()
def get(self, blockhash):
serialized_block = None
try:
serialized_block = self.blockDB[repr(blockhash)]
except KeyError:
return None
f = BytesIO(serialized_block)
ret = CBlock()
ret.deserialize(f)
ret.calc_sha256()
return ret
def get_header(self, blockhash):
try:
return self.headers_map[blockhash]
except KeyError:
return None
# Note: this pulls full blocks out of the database just to retrieve
# the headers -- perhaps we could keep a separate data structure
# to avoid this overhead.
def headers_for(self, locator, hash_stop, current_tip=None):
if current_tip is None:
current_tip = self.currentBlock
current_block_header = self.get_header(current_tip)
if current_block_header is None:
return None
response = msg_headers()
headersList = [ current_block_header ]
maxheaders = 2000
while (headersList[0].sha256 not in locator.vHave):
prevBlockHash = headersList[0].hashPrevBlock
prevBlockHeader = self.get_header(prevBlockHash)
if prevBlockHeader is not None:
headersList.insert(0, prevBlockHeader)
else:
break
headersList = headersList[:maxheaders] # truncate if we have too many
hashList = [x.sha256 for x in headersList]
index = len(headersList)
if (hash_stop in hashList):
index = hashList.index(hash_stop)+1
response.headers = headersList[:index]
return response
def add_block(self, block):
block.calc_sha256()
try:
self.blockDB[repr(block.sha256)] = bytes(block.serialize())
except TypeError as e:
print "Unexpected error: ", sys.exc_info()[0], e.args
self.currentBlock = block.sha256
self.headers_map[block.sha256] = CBlockHeader(block)
def add_header(self, header):
self.headers_map[header.sha256] = header
def get_blocks(self, inv):
responses = []
for i in inv:
if (i.type == 2): # MSG_BLOCK
block = self.get(i.hash)
if block is not None:
responses.append(msg_block(block))
return responses
def get_locator(self, current_tip=None):
if current_tip is None:
current_tip = self.currentBlock
r = []
counter = 0
step = 1
lastBlock = self.get(current_tip)
while lastBlock is not None:
r.append(lastBlock.hashPrevBlock)
for i in range(step):
lastBlock = self.get(lastBlock.hashPrevBlock)
if lastBlock is None:
break
counter += 1
if counter > 10:
step *= 2
locator = CBlockLocator()
locator.vHave = r
return locator
class TxStore(object):
def __init__(self, datadir):
self.txDB = dbm.open(datadir + "/transactions", 'c')
def close(self):
self.txDB.close()
def get(self, txhash):
serialized_tx = None
try:
serialized_tx = self.txDB[repr(txhash)]
except KeyError:
return None
f = BytesIO(serialized_tx)
ret = CTransaction()
ret.deserialize(f)
ret.calc_sha256()
return ret
def add_transaction(self, tx):
tx.calc_sha256()
try:
self.txDB[repr(tx.sha256)] = bytes(tx.serialize())
except TypeError as e:
print "Unexpected error: ", sys.exc_info()[0], e.args
def get_transactions(self, inv):
responses = []
for i in inv:
if (i.type == 1): # MSG_TX
tx = self.get(i.hash)
if tx is not None:
responses.append(msg_tx(tx))
return responses
|
