remove deferral.sleep's canceller, as it wasn't used anywhere and caused incompatibil...

[p2pool.git] / p2pool / util / deferral.py

diff --git a/p2pool/util/deferral.py b/p2pool/util/deferral.py
index 4a5e1a5..6f75b76 100644 (file)
--- a/p2pool/util/deferral.py
+++ b/p2pool/util/deferral.py
@@ -1,5 +1,9 @@
 from __future__ import division
 
+import itertools
+import random
+import sys
+
 from twisted.internet import defer, reactor
 from twisted.python import failure, log
 
@@ -8,7 +12,20 @@ def sleep(t):
     reactor.callLater(t, d.callback, None)
     return d
 
-def retry(message, delay):
+def run_repeatedly(f, *args, **kwargs):
+    current_dc = [None]
+    def step():
+        delay = f(*args, **kwargs)
+        current_dc[0] = reactor.callLater(delay, step)
+    step()
+    def stop():
+        current_dc[0].cancel()
+    return stop
+
+class RetrySilentlyException(Exception):
+    pass
+
+def retry(message='Error:', delay=3, max_retries=None, traceback=True):
     '''
     @retry('Error getting block:', 1)
     @defer.inlineCallbacks
@@ -19,11 +36,17 @@ def retry(message, delay):
     def retry2(func):
         @defer.inlineCallbacks
         def f(*args, **kwargs):
-            while True:
+            for i in itertools.count():
                 try:
                     result = yield func(*args, **kwargs)
-                except:
-                    log.err(None, message)
+                except Exception, e:
+                    if i == max_retries:
+                        raise
+                    if not isinstance(e, RetrySilentlyException):
+                        if traceback:
+                            log.err(None, message)
+                        else:
+                            print >>sys.stderr, message, e
                     yield sleep(delay)
                 else:
                     defer.returnValue(result)
@@ -41,7 +64,8 @@ class ReplyMatcher(object):
         self.map = {}
     
     def __call__(self, id):
-        self.func(id)
+        if id not in self.map:
+            self.func(id)
         df = defer.Deferred()
         def timeout():
             self.map[id].remove((df, timer))
@@ -58,3 +82,104 @@ class ReplyMatcher(object):
         for df, timer in self.map.pop(id):
             df.callback(resp)
             timer.cancel()
+
+class GenericDeferrer(object):
+    '''
+    Converts query with identifier/got response interface to deferred interface
+    '''
+    
+    def __init__(self, max_id, func, timeout=5):
+        self.max_id = max_id
+        self.func = func
+        self.timeout = timeout
+        self.map = {}
+    
+    def __call__(self, *args, **kwargs):
+        while True:
+            id = random.randrange(self.max_id)
+            if id not in self.map:
+                break
+        df = defer.Deferred()
+        def timeout():
+            self.map.pop(id)
+            df.errback(failure.Failure(defer.TimeoutError('in GenericDeferrer')))
+        timer = reactor.callLater(self.timeout, timeout)
+        self.func(id, *args, **kwargs)
+        self.map[id] = df, timer
+        return df
+    
+    def got_response(self, id, resp):
+        if id not in self.map:
+            return
+        df, timer = self.map.pop(id)
+        timer.cancel()
+        df.callback(resp)
+
+class NotNowError(Exception):
+    pass
+
+class DeferredCacher(object):
+    '''
+    like memoize, but for functions that return Deferreds
+    
+    @DeferredCacher
+    def f(x):
+        ...
+        return df
+    
+    @DeferredCacher.with_backing(bsddb.hashopen(...))
+    def f(x):
+        ...
+        return df
+    '''
+    
+    @classmethod
+    def with_backing(cls, backing):
+        return lambda func: cls(func, backing)
+    
+    def __init__(self, func, backing=None):
+        if backing is None:
+            backing = {}
+        
+        self.func = func
+        self.backing = backing
+        self.waiting = {}
+    
+    @defer.inlineCallbacks
+    def __call__(self, key):
+        if key in self.waiting:
+            yield self.waiting[key]
+        
+        if key in self.backing:
+            defer.returnValue(self.backing[key])
+        else:
+            self.waiting[key] = defer.Deferred()
+            try:
+                value = yield self.func(key)
+            finally:
+                self.waiting.pop(key).callback(None)
+        
+        self.backing[key] = value
+        defer.returnValue(value)
+    
+    _nothing = object()
+    def call_now(self, key, default=_nothing):
+        if key in self.backing:
+            return self.backing[key]
+        if key not in self.waiting:
+            self.waiting[key] = defer.Deferred()
+            def cb(value):
+                self.backing[key] = value
+                self.waiting.pop(key).callback(None)
+            def eb(fail):
+                self.waiting.pop(key).callback(None)
+                if fail.check(RetrySilentlyException):
+                    return
+                print
+                print 'Error when requesting noncached value:'
+                fail.printTraceback()
+                print
+            self.func(key).addCallback(cb).addErrback(eb)
+        if default is not self._nothing:
+            return default
+        raise NotNowError(key)