Ausgabe der neuen DB Einträge

venv/lib/python3.9/site-packages/queuelib/rrqueue.py

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+from collections import deque
+
+class RoundRobinQueue(object):
+    """A round robin queue implemented using multiple internal queues (typically,
+    FIFO queues). The internal queue must implement the following methods:
+        * push(obj)
+        * pop()
+        * close()
+        * __len__()
+    The constructor receives a qfactory argument, which is a callable used to
+    instantiate a new (internal) queue when a new key is allocated. The
+    qfactory function is called with the key number as first and only
+    argument.
+    start_keys is a sequence of domains to start with. If the queue was
+    previously closed leaving some domain buckets non-empty, those domains
+    should be passed in start_keys.
+
+    The queue maintains a fifo queue of keys.  The key that went last is
+    poped first and the next queue for that key is then poped.  This allows
+    for a round robin
+    """
+
+    def __init__(self, qfactory, start_domains=()):
+        self.queues = {}
+        self.qfactory = qfactory
+        for key in start_domains:
+            self.queues[key] = self.qfactory(key)
+
+        self.key_queue = deque(start_domains)
+
+    def push(self, obj, key):
+        if key not in self.key_queue:
+            self.queues[key] = self.qfactory(key)
+            self.key_queue.appendleft(key)  # it's new, might as well pop first
+
+        q = self.queues[key]
+        q.push(obj) # this may fail (eg. serialization error)
+
+    def pop(self):
+        m = None
+        # pop until we find a valid object, closing necessary queues
+        while m is None:
+            try:
+                key = self.key_queue.pop()
+            except IndexError:
+                return
+
+            q = self.queues[key]
+            m = q.pop()
+
+            if len(q) == 0:
+                del self.queues[key]
+                q.close()
+            else:
+                self.key_queue.appendleft(key)
+
+            if m:
+                return m
+
+    def close(self):
+        active = []
+        for k, q in self.queues.items():
+            if len(q):
+                active.append(k)
+            q.close()
+        return active
+
+    def __len__(self):
+        return sum(len(x) for x in self.queues.values()) if self.queues else 0