From d0ced131bf9b63e3197d5f997e6fe796df69ccec Mon Sep 17 00:00:00 2001

From: David Hildenbrand <david@redhat.com>

Date: Tue, 17 Oct 2017 19:15:51 +0200

Subject: [PATCH 46/69] tools/kvm_stat: simplify initializers

RH-Author: David Hildenbrand <david@redhat.com>

Message-id: <20171017191605.2378-26-david@redhat.com>

Patchwork-id: 77333

O-Subject: [RHEL-7.5 qemu-kvm-rhev PATCH 25/39] tools/kvm_stat: simplify initializers

Bugzilla: 1497137

RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>

RH-Acked-by: Cornelia Huck <cohuck@redhat.com>

RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

RH-Acked-by: Thomas Huth <thuth@redhat.com>

Upstream-status: linux.git c469117df05955901d2950b6130770e526b1dbf4

commit c469117df05955901d2950b6130770e526b1dbf4

Author: Stefan Raspl <raspl@linux.vnet.ibm.com>

Date:   Wed Jun 7 21:08:32 2017 +0200

    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: Stefan Raspl <raspl@linux.vnet.ibm.com>

    Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Signed-off-by: David Hildenbrand <david@redhat.com>

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>

---

 scripts/kvm/kvm_stat | 74 +++++++++++++++++++++++++---------------------------

 1 file changed, 36 insertions(+), 38 deletions(-)

diff --git a/scripts/kvm/kvm_stat b/scripts/kvm/kvm_stat

index e38791d..b8522d2 100755

--- a/scripts/kvm/kvm_stat

+++ b/scripts/kvm/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)

-- 

1.8.3.1