Merge pull request #76 from montaro/logging-interface-handle-buffer-overflow

Enable defining a handler for buffer overflow when using the library as a python logging handler

Author: repeatedly

.gitignore

@@ -9,3 +9,4 @@
 /.tox
 /build
 /dist
+.idea/

README.rst

@@ -188,7 +188,7 @@ module.
 
     logging.basicConfig(level=logging.INFO)
     l = logging.getLogger('fluent.test')
-    h = handler.FluentHandler('app.follow', host='host', port=24224)
+    h = handler.FluentHandler('app.follow', host='host', port=24224, buffer_overflow_handler=handler)
     formatter = handler.FluentRecordFormatter(custom_format)
     h.setFormatter(formatter)
     l.addHandler(h)
@@ -211,6 +211,18 @@ You can also customize formatter via logging.config.dictConfig
 
     logging.config.dictConfig(conf['logging'])
 
+You can inject your own custom proc to handle buffer overflow in the event of connection failure. This will mitigate the loss of data instead of simply throwing data away.
+
+.. code:: python
+
+    import msgpack
+    from io import BytesIO
+
+    def handler(pendings):
+        unpacker = msgpack.Unpacker(BytesIO(pendings))
+        for unpacked in unpacker:
+            print(unpacked)
+
 A sample configuration ``logging.yaml`` would be:
 
 .. code:: python
@@ -242,6 +254,7 @@ A sample configuration ``logging.yaml`` would be:
                 host: localhost
                 port: 24224
                 tag: test.logging
+                buffer_overflow_handler: handler
                 formatter: fluent_fmt
                 level: DEBUG
             none:

fluent/handler.py

@@ -115,12 +115,14 @@ def __init__(self,
                  host='localhost',
                  port=24224,
                  timeout=3.0,
-                 verbose=False):
+                 verbose=False,
+                 buffer_overflow_handler=None):
 
         self.tag = tag
         self.sender = sender.FluentSender(tag,
                                           host=host, port=port,
-                                          timeout=timeout, verbose=verbose)
+                                          timeout=timeout, verbose=verbose,
+                                          buffer_overflow_handler=buffer_overflow_handler)
         logging.Handler.__init__(self)
 
     def emit(self, record):