[lttng-dev] [PATCH] Python agent: Support Agent protocol v2.0

[Mathieu Desnoyers]

Merged into UST master, thanks!

Mathieu

----- On Oct 23, 2015, at 5:12 PM, Jeremie Galarneau jeremie.galarneau at efficios.com wrote:

> Signed-off-by: Jérémie Galarneau <jeremie.galarneau at efficios.com>
> ---
> liblttng-ust-python-agent/lttngust/agent.py |  2 +-
> liblttng-ust-python-agent/lttngust/cmd.py   | 26 +++++++++++++++++++++++---
> 2 files changed, 24 insertions(+), 4 deletions(-)
> 
> diff --git a/liblttng-ust-python-agent/lttngust/agent.py
> b/liblttng-ust-python-agent/lttngust/agent.py
> index 84cfd83..ebfa2de 100644
> --- a/liblttng-ust-python-agent/lttngust/agent.py
> +++ b/liblttng-ust-python-agent/lttngust/agent.py
> @@ -40,7 +40,7 @@ except ImportError:
> 
> 
> _PROTO_DOMAIN = 5
> -_PROTO_MAJOR = 1
> +_PROTO_MAJOR = 2
> _PROTO_MINOR = 0
> 
> 
> diff --git a/liblttng-ust-python-agent/lttngust/cmd.py
> b/liblttng-ust-python-agent/lttngust/cmd.py
> index fe180fa..382de68 100644
> --- a/liblttng-ust-python-agent/lttngust/cmd.py
> +++ b/liblttng-ust-python-agent/lttngust/cmd.py
> @@ -2,6 +2,7 @@
> #
> # Copyright (C) 2015 - Philippe Proulx <pproulx at efficios.com>
> # Copyright (C) 2014 - David Goulet <dgoulet at efficios.com>
> +# Copyright (C) 2015 - Jérémie Galarneau <jeremie.galarneau at efficios.com>
> #
> # This library is free software; you can redistribute it and/or modify it under
> # the terms of the GNU Lesser General Public License as published by the Free
> @@ -29,6 +30,10 @@ _server_cmd_header_struct = struct.Struct('>QII')
> _SERVER_CMD_HEADER_SIZE = _server_cmd_header_struct.size
> 
> 
> +# agent protocol symbol size
> +_LTTNG_SYMBOL_NAME_LEN = 256
> +
> +
> class _ServerCmdHeader(object):
>     def __init__(self, data_size, cmd_id, cmd_version):
>         self.data_size = data_size
> @@ -64,21 +69,36 @@ class _ServerCmdList(_ServerCmd):
> class _ServerCmdEnable(_ServerCmd):
>     _NAME_OFFSET = 8
>     _loglevel_struct = struct.Struct('>II')
> +    # filter expression size
> +    _filter_exp_len_struct = struct.Struct('>I')
> 
> -    def __init__(self, header, loglevel, loglevel_type, name):
> +    def __init__(self, header, loglevel, loglevel_type, name, filter_exp):
>         super(self.__class__, self).__init__(header)
>         self.loglevel = loglevel
>         self.loglevel_type = loglevel_type
>         self.name = name
> +        self.filter_expression = filter_exp
> +        dbg._pdebug('server enable command {}'.format(self.__dict__))
> 
>     @classmethod
>     def from_data(cls, header, data):
>         try:
>             loglevel, loglevel_type = cls._loglevel_struct.unpack_from(data)
> -            data_name = data[cls._loglevel_struct.size:]
> +            name_start = cls._loglevel_struct.size
> +            name_end = name_start + _LTTNG_SYMBOL_NAME_LEN
> +            data_name = data[name_start:name_end]
>             name = data_name.rstrip(b'\0').decode()
> 
> -            return cls(header, loglevel, loglevel_type, name)
> +            filter_exp_start = name_end + cls._filter_exp_len_struct.size
> +            filter_exp_len, = cls._filter_exp_len_struct.unpack_from(
> +                data[name_end:filter_exp_start])
> +            print(filter_exp_len)
> +            filter_exp_end = filter_exp_start + filter_exp_len
> +
> +            filter_exp = data[filter_exp_start:filter_exp_end].rstrip(
> +                b'\0').decode()
> +
> +            return cls(header, loglevel, loglevel_type, name, filter_exp)
>         except (Exception) as e:
>             dbg._pdebug('cannot decode enable command: {}'.format(e))
>             return None
> --
> 2.6.2

-- 
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com