blob: 5e36f0415d13c21574877b04a3ee0ce9e3fa56b2 [file] [log] [blame]
#!/usr/bin/env python
# -*- coding: utf-8 -*-
Backend management.
Creating new backends
A new backend named 'foo-bar' corresponds to Python module
A backend module should provide a docstring, whose first non-empty line will be
considered its short description.
All backends must generate their contents through the 'tracetool.out' routine.
Backend attributes
========= ====================================================================
Attribute Description
========= ====================================================================
PUBLIC If exists and is set to 'True', the backend is considered "public".
========= ====================================================================
Backend functions
All the following functions are optional, and no output will be generated if
they do not exist.
=============================== ==============================================
Function Description
=============================== ==============================================
generate_<format>_begin(events) Generate backend- and format-specific file
header contents.
generate_<format>_end(events) Generate backend- and format-specific file
footer contents.
generate_<format>(event) Generate backend- and format-specific contents
for the given event.
=============================== ==============================================
__author__ = "Lluís Vilanova <>"
__copyright__ = "Copyright 2012-2014, Lluís Vilanova <>"
__license__ = "GPL version 2 or (at your option) any later version"
__maintainer__ = "Stefan Hajnoczi"
__email__ = ""
import os
import tracetool
def get_list(only_public = False):
"""Get a list of (name, description) pairs."""
res = [("nop", "Tracing disabled.")]
modnames = []
for filename in os.listdir(tracetool.backend.__path__[0]):
if filename.endswith('.py') and filename != '':
modnames.append(filename.rsplit('.', 1)[0])
for modname in sorted(modnames):
module = tracetool.try_import("tracetool.backend." + modname)
# just in case; should never fail unless non-module files are put there
if not module[0]:
module = module[1]
public = getattr(module, "PUBLIC", False)
if only_public and not public:
doc = module.__doc__
if doc is None:
doc = ""
doc = doc.strip().split("\n")[0]
name = modname.replace("_", "-")
res.append((name, doc))
return res
def exists(name):
"""Return whether the given backend exists."""
if len(name) == 0:
return False
if name == "nop":
return True
name = name.replace("-", "_")
return tracetool.try_import("tracetool.backend." + name)[1]
class Wrapper:
def __init__(self, backend, format):
self._backend = backend.replace("-", "_")
self._format = format.replace("-", "_")
assert exists(self._backend)
assert tracetool.format.exists(self._format)
def _run_function(self, name, *args, **kwargs):
func = tracetool.try_import("tracetool.backend." + self._backend,
name % self._format, None)[1]
if func is not None:
func(*args, **kwargs)
def generate_begin(self, events):
self._run_function("generate_%s_begin", events)
def generate(self, event):
self._run_function("generate_%s", event)
def generate_end(self, events):
self._run_function("generate_%s_end", events)