p2pool/bitcoin/height_tracker.py

   1 from twisted.internet import defer, task
   2 from twisted.python import log
   3
   4 import p2pool
   5 from p2pool.bitcoin import data as bitcoin_data
   6 from p2pool.util import deferral, forest, jsonrpc, variable
   7
   8 class HeaderWrapper(object):
   9     __slots__ = 'hash previous_hash'.split(' ')
  10
  11     @classmethod
  12     def from_header(cls, header):
  13         return cls(bitcoin_data.hash256(bitcoin_data.block_header_type.pack(header)), header['previous_block'])
  14
  15     def __init__(self, hash, previous_hash):
  16         self.hash, self.previous_hash = hash, previous_hash
  17
  18 class HeightTracker(object):
  19     '''Point this at a factory and let it take care of getting block heights'''
  20
  21     def __init__(self, best_block_func, factory, backlog_needed):
  22         self._best_block_func = best_block_func
  23         self._factory = factory
  24         self._backlog_needed = backlog_needed
  25
  26         self._tracker = forest.Tracker()
  27
  28         self._watch1 = self._factory.new_headers.watch(self._heard_headers)
  29         self._watch2 = self._factory.new_block.watch(self._request)
  30
  31         self._requested = set()
  32         self._clear_task = task.LoopingCall(self._requested.clear)
  33         self._clear_task.start(60)
  34
  35         self._last_notified_size = 0
  36
  37         self.updated = variable.Event()
  38
  39         self._think_task = task.LoopingCall(self._think)
  40         self._think_task.start(15)
  41         self._think2_task = task.LoopingCall(self._think2)
  42         self._think2_task.start(15)
  43
  44     def _think(self):
  45         try:
  46             highest_head = max(self._tracker.heads, key=lambda h: self._tracker.get_height_and_last(h)[0]) if self._tracker.heads else None
  47             if highest_head is None:
  48                 return # wait for think2
  49             height, last = self._tracker.get_height_and_last(highest_head)
  50             if height < self._backlog_needed:
  51                 self._request(last)
  52         except:
  53             log.err(None, 'Error in HeightTracker._think:')
  54
  55     def _think2(self):
  56         self._request(self._best_block_func())
  57
  58     def _heard_headers(self, headers):
  59         changed = False
  60         for header in headers:
  61             hw = HeaderWrapper.from_header(header)
  62             if hw.hash in self._tracker.items:
  63                 continue
  64             changed = True
  65             self._tracker.add(hw)
  66         if changed:
  67             self.updated.happened()
  68         self._think()
  69
  70         if len(self._tracker.items) >= self._last_notified_size + 100:
  71             print 'Have %i/%i block headers' % (len(self._tracker.items), self._backlog_needed)
  72             self._last_notified_size = len(self._tracker.items)
  73
  74     @defer.inlineCallbacks
  75     def _request(self, last):
  76         if last in self._tracker.items:
  77             return
  78         if last in self._requested:
  79             return
  80         self._requested.add(last)
  81         (yield self._factory.getProtocol()).send_getheaders(version=1, have=[], last=last)
  82
  83     def get_height_rel_highest(self, block_hash):
  84         # callers: highest height can change during yields!
  85         best_height, best_last = self._tracker.get_height_and_last(self._best_block_func())
  86         height, last = self._tracker.get_height_and_last(block_hash)
  87         if last != best_last:
  88             return -1000000000 # XXX hack
  89         return height - best_height
  90
  91 @defer.inlineCallbacks
  92 def get_height_rel_highest_func(bitcoind, factory, best_block_func, net):
  93     if '\ngetblock ' in (yield deferral.retry()(bitcoind.rpc_help)()):
  94         @deferral.DeferredCacher
  95         @defer.inlineCallbacks
  96         def height_cacher(block_hash):
  97             try:
  98                 x = yield bitcoind.rpc_getblock('%x' % (block_hash,))
  99             except jsonrpc.Error_for_code(-5): # Block not found
 100                 if not p2pool.DEBUG:
 101                     raise deferral.RetrySilentlyException()
 102                 else:
 103                     raise
 104             defer.returnValue(x['blockcount'] if 'blockcount' in x else x['height'])
 105         best_height_cached = variable.Variable((yield deferral.retry()(height_cacher)(best_block_func())))
 106         def get_height_rel_highest(block_hash):
 107             this_height = height_cacher.call_now(block_hash, 0)
 108             best_height = height_cacher.call_now(best_block_func(), 0)
 109             best_height_cached.set(max(best_height_cached.value, this_height, best_height))
 110             return this_height - best_height_cached.value
 111     else:
 112         get_height_rel_highest = HeightTracker(best_block_func, factory, 5*net.SHARE_PERIOD*net.CHAIN_LENGTH/net.PARENT.BLOCK_PERIOD).get_height_rel_highest
 113     defer.returnValue(get_height_rel_highest)