xautoclaim (#1529)

Author: AvitalFineRedis

redis/client.py

@@ -316,6 +316,12 @@ def parse_xclaim(response, **options):
     return parse_stream_list(response)
 
 
+def parse_xautoclaim(response, **options):
+    if options.get('parse_justid', False):
+        return response[1]
+    return parse_stream_list(response[1])
+
+
 def parse_xinfo_stream(response):
     data = pairs_to_dict(response, decode_keys=True)
     first = data['first-entry']
@@ -684,6 +690,7 @@ class Redis:
         'SSCAN': parse_scan,
         'TIME': lambda x: (int(x[0]), int(x[1])),
         'XCLAIM': parse_xclaim,
+        'XAUTOCLAIM': parse_xautoclaim,
         'XGROUP CREATE': bool_ok,
         'XGROUP DELCONSUMER': int,
         'XGROUP DESTROY': bool,
@@ -2601,6 +2608,46 @@ def xadd(self, name, fields, id='*', maxlen=None, approximate=True,
             pieces.extend(pair)
         return self.execute_command('XADD', name, *pieces)
 
+    def xautoclaim(self, name, groupname, consumername, min_idle_time,
+                   start_id=0, count=None, justid=False):
+        """
+        Transfers ownership of pending stream entries that match the specified
+        criteria. Conceptually, equivalent to calling XPENDING and then XCLAIM,
+        but provides a more straightforward way to deal with message delivery
+        failures via SCAN-like semantics.
+        name: name of the stream.
+        groupname: name of the consumer group.
+        consumername: name of a consumer that claims the message.
+        min_idle_time: filter messages that were idle less than this amount of
+        milliseconds.
+        start_id: filter messages with equal or greater ID.
+        count: optional integer, upper limit of the number of entries that the
+        command attempts to claim. Set to 100 by default.
+        justid: optional boolean, false by default. Return just an array of IDs
+        of messages successfully claimed, without returning the actual message
+        """
+        try:
+            if int(min_idle_time) < 0:
+                raise DataError("XAUTOCLAIM min_idle_time must be a non"
+                                "negative integer")
+        except TypeError:
+            pass
+
+        kwargs = {}
+        pieces = [name, groupname, consumername, min_idle_time, start_id]
+
+        try:
+            if int(count) < 0:
+                raise DataError("XPENDING count must be a integer >= 0")
+            pieces.extend([b'COUNT', count])
+        except TypeError:
+            pass
+        if justid:
+            pieces.append(b'JUSTID')
+            kwargs['parse_justid'] = True
+
+        return self.execute_command('XAUTOCLAIM', *pieces, **kwargs)
+
     def xclaim(self, name, groupname, consumername, min_idle_time, message_ids,
                idle=None, time=None, retrycount=None, force=False,
                justid=False):

tests/test_commands.py

@@ -2374,13 +2374,59 @@ def test_xadd_nomkstream(self, r):
         r.xadd(stream, {'some': 'other'}, nomkstream=True)
         assert r.xlen(stream) == 3
 
+    @skip_if_server_version_lt('6.2.0')
+    def test_xautoclaim(self, r):
+        stream = 'stream'
+        group = 'group'
+        consumer1 = 'consumer1'
+        consumer2 = 'consumer2'
+
+        message_id1 = r.xadd(stream, {'john': 'wick'})
+        message_id2 = r.xadd(stream, {'johny': 'deff'})
+        message = get_stream_message(r, stream, message_id1)
+        r.xgroup_create(stream, group, 0)
+
+        # trying to claim a message that isn't already pending doesn't
+        # do anything
+        response = r.xautoclaim(stream, group, consumer2, min_idle_time=0)
+        assert response == []
+
+        # read the group as consumer1 to initially claim the messages
+        r.xreadgroup(group, consumer1, streams={stream: '>'})
+
+        # claim one message as consumer2
+        response = r.xautoclaim(stream, group, consumer2,
+                                min_idle_time=0, count=1)
+        assert response == [message]
+
+        # reclaim the messages as consumer1, but use the justid argument
+        # which only returns message ids
+        assert r.xautoclaim(stream, group, consumer1, min_idle_time=0,
+                            start_id=0, justid=True) == \
+               [message_id1, message_id2]
+        assert r.xautoclaim(stream, group, consumer1, min_idle_time=0,
+                            start_id=message_id2, justid=True) == \
+               [message_id2]
+
+    @skip_if_server_version_lt('6.2.0')
+    def test_xautoclaim_negative(self, r):
+        stream = 'stream'
+        group = 'group'
+        consumer = 'consumer'
+        with pytest.raises(redis.DataError):
+            r.xautoclaim(stream, group, consumer, min_idle_time=-1)
+        with pytest.raises(ValueError):
+            r.xautoclaim(stream, group, consumer, min_idle_time="wrong")
+        with pytest.raises(redis.DataError):
+            r.xautoclaim(stream, group, consumer, min_idle_time=0,
+                         count=-1)
+
     @skip_if_server_version_lt('5.0.0')
     def test_xclaim(self, r):
         stream = 'stream'
         group = 'group'
         consumer1 = 'consumer1'
         consumer2 = 'consumer2'
-
         message_id = r.xadd(stream, {'john': 'wick'})
         message = get_stream_message(r, stream, message_id)
         r.xgroup_create(stream, group, 0)