Merge branch 'collectd-4.9' into collectd-4.10

[collectd.git] / src / collectd-python.pod

diff --git a/src/collectd-python.pod b/src/collectd-python.pod
index 8742104..267296c 100644 (file)
--- a/src/collectd-python.pod
+++ b/src/collectd-python.pod
@@ -1,3 +1,13 @@
+# Permission is hereby granted, free of charge, to any person obtaining a
+# copy of this software and associated documentation files (the "Software"),
+# to deal in the Software without restriction, including without limitation
+# the rights to use, copy, modify, merge, publish, distribute, sublicense,
+# and/or sell copies of the Software, and to permit persons to whom the
+# Software is furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+
 =head1 NAME
 
 collectd-python - Documentation of collectd's C<python plugin>
@@ -38,8 +48,8 @@ At least python I<version 2.3> is required.
 Loads the Python plugin I<Plugin>. Unlike most other LoadPlugin lines, this one
 should be a block containing the line "Globals true". This will cause collectd
 to export the name of all objects in the python interpreter for all plugins to
-see. If you don't do this or your platform does not support it, the embeded
-interpreter will start anywa but you won't be able to load certain python
+see. If you don't do this or your platform does not support it, the embedded
+interpreter will start anyway but you won't be able to load certain python
 modules, e.g. "time".
 
 =item B<Encoding> I<Name>
@@ -105,6 +115,15 @@ environment variable, e.g. I<export PAGER=less> before starting collectd.
 Depending on your version of python this might or might not result in an
 B<OSError> exception which can be ignored.
 
+If you really need to spawn new processes from python you can register an init
+callback and reset the action for SIGCHLD to the default behavior. Please note
+that this I<will> break the exec plugin. Do not even load the exec plugin if
+you intend to do this!
+
+There is an example script located in B<contrib/python/getsigchld.py>  to do
+this. If you import this from I<collectd.conf> SIGCHLD will be handled
+normally and spawning processes from python will work as intended.
+
 =back
 
 =item E<lt>B<Module> I<Name>E<gt> block
@@ -231,9 +250,31 @@ collectd you're done.
 The following complex types are used to pass values between the Python plugin
 and collectd:
 
+=head2 Signed
+
+The Signed class is just a long. It has all its methods and behaves exactly
+like any other long object. It is used to indicate if an integer was or should
+be stored as a signed or unsigned integer object.
+
+ class Signed(long)
+
+This is a long by another name. Use it in meta data dicts
+to choose the way it is stored in the meta data.
+
+=head2 Unsigned
+
+The Unsigned class is just a long. It has all its methods and behaves exactly
+like any other long object. It is used to indicate if an integer was or should
+be stored as a signed or unsigned integer object.
+
+ class Unsigned(long)
+
+This is a long by another name. Use it in meta data dicts
+to choose the way it is stored in the meta data.
+
 =head2 Config
 
-The Config class is an object which keeps the informations provided in the
+The Config class is an object which keeps the information provided in the
 configuration file. The sequence of children keeps one entry for each
 configuration option. Each such entry is another Config instance, which
 may nest further if nested blocks are used.
@@ -394,6 +435,16 @@ If the sequence does not have the correct size upon dispatch a I<RuntimeError>
 exception will be raised. If the content of the sequence is not a number, a
 I<TypeError> exception will be raised.
 
+=item meta
+
+These are the meta data for this Value object.
+It has to be a dictionary of numbers, strings or bools. All keys must be
+strings. I<int> and <long> objects will be dispatched as signed integers unless
+they are between 2**63 and 2**64-1, which will result in a unsigned integer.
+You can force one of these storage classes by using the classes
+B<collectd.Signed> and B<collectd.Unsigned>. A meta object received by a write
+callback will always contain B<Signed> or B<Unsigned> objects.
+
 =back
 
 =head2 Notification
@@ -652,14 +703,8 @@ dispatched by the python plugin after upgrades.
 
 =item
 
-This plugin is not compatible with python3. Trying to compile it with python3
-will fail because of the ways string, unicode and bytearray bahavior was
-changed.
-
-=item
-
 Not all aspects of the collectd API are accessible from python. This includes
-but is not limited to meta-data, filters and data sets.
+but is not limited to filters and data sets.
 
 =back