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Commit c469117d authored by Stefan Raspl's avatar Stefan Raspl Committed by Paolo Bonzini
Browse files

tools/kvm_stat: simplify initializers 



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: default avatarStefan Raspl <raspl@linux.vnet.ibm.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 5e3823a4

tools/kvm/kvm_stat/kvm_stat

+36 −38
Original line number Diff line number Diff line
@@ -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):

        if pid != 0:

        self._pid = pid



        if pid != 0:

            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)