Simplify a couple of initialization routines:
* TracepointProvider and DebugfsProvider: Pass pid into __init__() instead
of switching to the requested value in an extra call after initializing
to the default first.
* Pass a single options object into Stats.__init__(), delaying options
evaluation accordingly, instead of evaluating options first and passing
several parts of the options object to Stats.__init__() individually.
* Eliminate Stats.update_provider_pid(), since this 2-line function is now
used in a single place only.
* Remove extra call to update_drilldown() in Tui.__init__() by getting the
value of options.fields right initially when parsing options.
* Simplify get_providers() logic.
* Avoid duplicate fields initialization by handling it once in the
providers' __init__() methods.
Signed-off-by: Stefan Raspl <raspl@xxxxxxxxxxxxxxxxxx>
---
tools/kvm/kvm_stat/kvm_stat | 74 ++++++++++++++++++++++-----------------------
1 file changed, 36 insertions(+), 38 deletions(-)
diff --git a/tools/kvm/kvm_stat/kvm_stat b/tools/kvm/kvm_stat/kvm_stat
index e38791ddb37a..b8522d2ddb0a 100755
--- a/tools/kvm/kvm_stat/kvm_stat
+++ b/tools/kvm/kvm_stat/kvm_stat
@@ -295,6 +295,13 @@ class ArchS390(Arch):
ARCH = Arch.get_arch()
+def is_field_wanted(fields_filter, field):
+ """Indicate whether field is valid according to fields_filter."""
+ if not fields_filter:
+ return True
+ return re.match(fields_filter, field) is not None
+
+
def walkdir(path):
"""Returns os.walk() data for specified directory.
@@ -581,11 +588,11 @@ class TracepointProvider(object):
Manages the events/groups from which it acquires its data.
"""
- def __init__(self):
+ def __init__(self, pid, fields_filter):
self.group_leaders = []
self.filters = get_filters()
- self._fields = self.get_available_fields()
- self._pid = 0
+ self.update_fields(fields_filter)
+ self.pid = pid
def get_available_fields(self):
"""Returns a list of available event's of format 'event name(filter
@@ -613,6 +620,11 @@ class TracepointProvider(object):
fields += extra
return fields
+ def update_fields(self, fields_filter):
+ """Refresh fields, applying fields_filter"""
+ self._fields = [field for field in self.get_available_fields()
+ if is_field_wanted(fields_filter, field)]
+
def setup_traces(self):
"""Creates all event and group objects needed to be able to retrieve
data."""
@@ -723,13 +735,12 @@ class TracepointProvider(object):
class DebugfsProvider(object):
"""Provides data from the files that KVM creates in the kvm debugfs
folder."""
- def __init__(self):
- self._fields = self.get_available_fields()
+ def __init__(self, pid, fields_filter):
+ self.update_fields(fields_filter)
self._baseline = {}
- self._pid = 0
self.do_read = True
self.paths = []
- self.reset()
+ self.pid = pid
def get_available_fields(self):
""""Returns a list of available fields.
@@ -739,6 +750,11 @@ class DebugfsProvider(object):
"""
return walkdir(PATH_DEBUGFS_KVM)[2]
+ def update_fields(self, fields_filter):
+ """Refresh fields, applying fields_filter"""
+ self._fields = [field for field in self.get_available_fields()
+ if is_field_wanted(fields_filter, field)]
+
@property
def fields(self):
return self._fields
@@ -754,9 +770,8 @@ class DebugfsProvider(object):
@pid.setter
def pid(self, pid):
+ self._pid = pid
if pid != 0:
- self._pid = pid
-
vms = walkdir(PATH_DEBUGFS_KVM)[1]
if len(vms) == 0:
self.do_read = False
@@ -818,33 +833,19 @@ class Stats(object):
provider data.
"""
- def __init__(self, providers, pid, fields=None):
- self.providers = providers
- self._pid_filter = pid
- self._fields_filter = fields
+ def __init__(self, options):
+ self.providers = get_providers(options)
+ self._pid_filter = options.pid
+ self._fields_filter = options.fields
self.values = {}
- self.update_provider_pid()
- self.update_provider_filters()
def update_provider_filters(self):
"""Propagates fields filters to providers."""
- def wanted(key):
- if not self._fields_filter:
- return True
- return re.match(self._fields_filter, key) is not None
-
# As we reset the counters when updating the fields we can
# also clear the cache of old values.
self.values = {}
for provider in self.providers:
- provider_fields = [key for key in provider.get_available_fields()
- if wanted(key)]
- provider.fields = provider_fields
-
- def update_provider_pid(self):
- """Propagates pid filters to providers."""
- for provider in self.providers:
- provider.pid = self._pid_filter
+ provider.update_fields(self._fields_filter)
def reset(self):
self.values = {}
@@ -870,7 +871,8 @@ class Stats(object):
if pid != self._pid_filter:
self._pid_filter = pid
self.values = {}
- self.update_provider_pid()
+ for provider in self.providers:
+ provider.pid = self._pid_filter
def get(self):
"""Returns a dict with field -> (value, delta to last value) of all
@@ -896,7 +898,6 @@ class Tui(object):
def __init__(self, stats):
self.stats = stats
self.screen = None
- self.update_drilldown()
def __enter__(self):
"""Initialises curses for later use. Based on curses.wrapper
@@ -1270,7 +1271,7 @@ Press any other key to refresh statistics immediately.
)
optparser.add_option('-f', '--fields',
action='store',
- default=None,
+ default=DEFAULT_REGEX,
dest='fields',
help='fields to display (regex)',
)
@@ -1297,12 +1298,10 @@ def get_providers(options):
"""Returns a list of data providers depending on the passed options."""
providers = []
- if options.tracepoints:
- providers.append(TracepointProvider())
if options.debugfs:
- providers.append(DebugfsProvider())
- if len(providers) == 0:
- providers.append(TracepointProvider())
+ providers.append(DebugfsProvider(options.pid, options.fields))
+ if options.tracepoints or not providers:
+ providers.append(TracepointProvider(options.pid, options.fields))
return providers
@@ -1347,8 +1346,7 @@ def main():
sys.stderr.write('Did you use a (unsupported) tid instead of a pid?\n')
sys.exit('Specified pid does not exist.')
- providers = get_providers(options)
- stats = Stats(providers, options.pid, fields=options.fields)
+ stats = Stats(options)
if options.log:
log(stats)
--
2.11.2
