2 """Some utitlity functions for use in apt-p2p's khashmir DHT."""
4 from twisted.trial import unittest
6 from khash import HASH_LENGTH
9 """Given a list of khashmir instances, finds min, max, and average number of nodes in tables."""
14 for bucket in buckets:
18 c = count(node.table.buckets)
27 return {'min':min, 'max':max, 'avg':avg}
30 """Extract the contact info from a compact node representation.
33 @param s: the compact representation
35 @return: the node ID, IP address and port to contact the node on
36 @raise ValueError: if the compact representation doesn't exist
38 if (len(s) != HASH_LENGTH+6):
41 host = '.'.join([str(ord(i)) for i in s[HASH_LENGTH:(HASH_LENGTH+4)]])
42 port = (ord(s[HASH_LENGTH+4]) << 8) | ord(s[HASH_LENGTH+5])
43 return {'id': id, 'host': host, 'port': port}
45 def compact(id, host, port):
46 """Create a compact representation of node contact info.
49 @param id: the node ID
51 @param host: the IP address of the node
53 @param port: the port number to contact the node on
55 @return: the compact representation
56 @raise ValueError: if the compact representation doesn't exist
59 s = id + ''.join([chr(int(i)) for i in host.split('.')]) + \
60 chr((port & 0xFF00) >> 8) + chr(port & 0xFF)
66 """Format a byte size for reading by the user.
69 @param s: the number of bytes
71 @return: the formatted size with appropriate units
74 r = str(int(s*1000.0)/1000.0) + 'B'
76 r = str(int(s*100.0)/100.0) + 'B'
78 r = str(int(s*10.0)/10.0) + 'B'
82 r = str(int((s/1024.0)*100.0)/100.0) + 'KiB'
84 r = str(int((s/1024.0)*10.0)/10.0) + 'KiB'
86 r = str(int(s/1024)) + 'KiB'
88 r = str(int((s/1048576.0)*100.0)/100.0) + 'MiB'
89 elif (s < 107374182L):
90 r = str(int((s/1048576.0)*10.0)/10.0) + 'MiB'
91 elif (s < 1073741824L):
92 r = str(int(s/1048576)) + 'MiB'
93 elif (s < 1099511627776L):
94 r = str(int((s/1073741824.0)*100.0)/100.0) + 'GiB'
96 r = str(int((s/1099511627776.0)*100.0)/100.0) + 'TiB'
99 class TestUtil(unittest.TestCase):
100 """Tests for the utilities."""
103 myid = '\xca\xec\xb8\x0c\x00\xe7\x07\xf8~])\x8f\x9d\xe5_B\xff\x1a\xc4!'
104 host = '165.234.1.34'
107 def test_compact(self):
108 d = uncompact(compact(self.myid, self.host, self.port))
109 self.failUnlessEqual(d['id'], self.myid)
110 self.failUnlessEqual(d['host'], self.host)
111 self.failUnlessEqual(d['port'], self.port)