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"""Wrapper module for libpcp_pmda - Performace Co-Pilot Domain Agent API
#
# Copyright (C) 2013-2015,2017-2021 Red Hat.
#
# This file is part of the "pcp" module, the python interfaces for the
# Performance Co-Pilot toolkit.
#
# This program is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by the
# Free Software Foundation; either version 2 of the License, or (at your
# option) any later version.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
# or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
# for more details.
#
# See pmdasimple.py for an example use of this module.
"""
# pylint: disable=too-many-arguments,consider-using-dict-items,no-member
import os
import cpmapi
import cpmda
from pcp.pmapi import pmContext as PCP
from pcp.pmapi import pmInDom, pmDesc, pmUnits, pmErr, pmLabelSet
from ctypes.util import find_library
from ctypes import CDLL, c_int, c_long, c_char_p, c_void_p
from ctypes import addressof, byref, POINTER, Structure
## Performance Co-Pilot PMDA library (C)
LIBPCP_PMDA = CDLL(find_library("pcp_pmda"))
###
## PMDA Indom Cache Services
#
LIBPCP_PMDA.pmdaCacheStore.restype = c_int
LIBPCP_PMDA.pmdaCacheStore.argtypes = [pmInDom, c_int, c_char_p, c_void_p]
LIBPCP_PMDA.pmdaCacheStoreKey.restype = c_int
LIBPCP_PMDA.pmdaCacheStoreKey.argtypes = [
pmInDom, c_int, c_char_p, c_int, c_void_p]
LIBPCP_PMDA.pmdaCacheLookup.restype = c_int
LIBPCP_PMDA.pmdaCacheLookup.argtypes = [
pmInDom, c_int, POINTER(c_char_p), POINTER(c_void_p)]
LIBPCP_PMDA.pmdaCacheLookupName.restype = c_int
LIBPCP_PMDA.pmdaCacheLookupName.argtypes = [
pmInDom, c_char_p, POINTER(c_int), POINTER(c_void_p)]
LIBPCP_PMDA.pmdaCacheLookupKey.restype = c_int
LIBPCP_PMDA.pmdaCacheLookupKey.argtypes = [
pmInDom, c_char_p, c_int, c_void_p, POINTER(c_char_p),
POINTER(c_int), POINTER(c_void_p)]
LIBPCP_PMDA.pmdaCacheOp.restype = c_int
LIBPCP_PMDA.pmdaCacheOp.argtypes = [pmInDom, c_long]
LIBPCP_PMDA.pmdaCacheResize.restype = c_int
LIBPCP_PMDA.pmdaCacheResize.argtypes = [pmInDom, c_int]
LIBPCP_PMDA.pmdaAddLabels.restype = c_int
LIBPCP_PMDA.pmdaAddLabels.argtypes = [POINTER(POINTER(pmLabelSet)), c_char_p]
LIBPCP_PMDA.pmdaAddLabelFlags.restype = c_int
LIBPCP_PMDA.pmdaAddLabelFlags.argtypes = [POINTER(pmLabelSet), c_int]
LIBPCP_PMDA.pmdaAddNotes.restype = c_int
LIBPCP_PMDA.pmdaAddNotes.argtypes = [POINTER(POINTER(pmLabelSet)), c_char_p]
LIBPCP_PMDA.pmdaGetContext.restype = c_int
LIBPCP_PMDA.pmdaGetContext.argtypes = []
def pmdaAddLabels(label):
result_p = POINTER(pmLabelSet)()
status = LIBPCP_PMDA.pmdaAddLabels(byref(result_p), label)
if status < 0:
raise pmErr(status)
return result_p
def pmdaAddLabelFlags(labels, flags):
status = LIBPCP_PMDA.pmdaAddLabelFlags(labels, flags)
if status < 0:
raise pmErr(status)
return status
def pmdaAddNotes(label):
result_p = POINTER(pmLabelSet)()
status = LIBPCP_PMDA.pmdaAddNotes(byref(result_p), label)
if status < 0:
raise pmErr(status)
return result_p
def pmdaGetContext():
status = LIBPCP_PMDA.pmdaGetContext()
if status < 0:
raise pmErr(status)
return status
##
# Definition of structures used by C library libpcp_pmda, derived from <pcp/pmda.h>
#
class pmdaMetric(Structure):
""" Structure describing a metric definition for a PMDA """
_fields_ = [("m_user", c_void_p),
("m_desc", pmDesc)]
def __init__(self, pmid, typeof, indom, sem, units):
Structure.__init__(self)
self.m_user = None
self.m_desc.pmid = pmid
self.m_desc.type = typeof
self.m_desc.indom = indom
self.m_desc.sem = sem
self.m_desc.units = units
def __str__(self):
return "pmdaMetric@%#lx pmid=%#lx type=%d" % (addressof(self), self.m_desc.pmid, self.m_desc.type)
class pmdaInstid(Structure):
""" Structure describing an instance (index/name) a PMDA """
_fields_ = [("i_inst", c_int),
("i_name", c_char_p)]
def __init__(self, instid, name):
Structure.__init__(self)
self.i_inst = instid
self.i_name = name.encode('utf-8')
def __str__(self):
return "pmdaInstid@%#lx index=%d name=%s" % (addressof(self), self.i_inst, self.i_name)
class pmdaIndom(Structure):
""" Structure describing an instance domain within a PMDA """
_fields_ = [("it_indom", pmInDom),
("it_numinst", c_int),
("it_set", POINTER(pmdaInstid))]
def __init__(self, indom, insts):
Structure.__init__(self)
self.it_numinst = 0
self.it_set = None
self.it_indom = indom
self.load_indom(indom, insts)
self.set_instances(indom, insts)
def __iter__(self):
# Generates an iterator for the cache.
if self.it_numinst <= 0:
LIBPCP_PMDA.pmdaCacheOp(self.it_indom,
cpmda.PMDA_CACHE_WALK_REWIND)
while 1:
inst = LIBPCP_PMDA.pmdaCacheOp(self.it_indom,
cpmda.PMDA_CACHE_WALK_NEXT)
if inst < 0:
break
name = self.inst_name_lookup(inst)
if name:
yield (inst, name)
else:
for i in range(self.it_numinst):
inst = self.it_set[i].i_inst
name = self.inst_name_lookup(inst)
if name:
yield (inst, name)
def inst_name_lookup(self, instance):
if self.it_numinst <= 0:
name = (c_char_p)()
sts = LIBPCP_PMDA.pmdaCacheLookup(self.it_indom, instance,
byref(name), None)
if sts == cpmda.PMDA_CACHE_ACTIVE:
return str(name.value.decode())
elif self.it_numinst > 0:
for inst in self.it_set:
if inst.i_inst == instance:
return str(inst.i_name.decode())
return None
def load_indom(self, indom, insts):
if isinstance(insts, dict):
LIBPCP_PMDA.pmdaCacheOp(indom, cpmda.PMDA_CACHE_LOAD)
def load(self):
if self.it_numinst == -1:
LIBPCP_PMDA.pmdaCacheOp(self.it_indom, cpmda.PMDA_CACHE_LOAD)
def set_list_instances(self, insts):
instance_count = len(insts)
instance_array = (pmdaInstid * instance_count)()
for i in range(instance_count):
instance_array[i].i_inst = insts[i].i_inst
instance_array[i].i_name = insts[i].i_name
self.it_set = instance_array
self.it_numinst = instance_count
cpmda.set_need_refresh()
def set_dict_instances(self, indom, insts):
LIBPCP_PMDA.pmdaCacheOp(indom, cpmda.PMDA_CACHE_INACTIVE)
for key in insts.keys():
key8 = key.encode('utf-8')
LIBPCP_PMDA.pmdaCacheStore(indom, cpmda.PMDA_CACHE_ADD, key8, byref(insts[key]))
LIBPCP_PMDA.pmdaCacheOp(indom, cpmda.PMDA_CACHE_SAVE)
self.it_numinst = -1
def set_instances(self, indom, insts):
if insts is None:
self.it_numinst = 0 # not yet known if cache indom or not
elif isinstance(insts, dict):
self.it_numinst = -1 # signifies cache indom (no it_set)
self.set_dict_instances(indom, insts)
else:
self.it_numinst = len(insts) # signifies an old-school array indom
self.set_list_instances(insts)
def __str__(self):
return "pmdaIndom@%#lx indom=%#lx num=%d" % (addressof(self), self.it_indom, self.it_numinst)
def cache_load(self):
if self.it_numinst <= 0:
sts = LIBPCP_PMDA.pmdaCacheOp(self.it_indom, cpmda.PMDA_CACHE_LOAD)
if sts < 0:
raise pmErr(sts)
else:
raise pmErr(cpmapi.PM_ERR_NYI)
def cache_mark_active(self):
if self.it_numinst <= 0:
LIBPCP_PMDA.pmdaCacheOp(self.it_indom, cpmda.PMDA_CACHE_ACTIVE)
else:
raise pmErr(cpmapi.PM_ERR_NYI)
def cache_mark_inactive(self):
if self.it_numinst <= 0:
LIBPCP_PMDA.pmdaCacheOp(self.it_indom, cpmda.PMDA_CACHE_INACTIVE)
else:
raise pmErr(cpmapi.PM_ERR_NYI)
def cache_resize(self, maximum):
if self.it_numinst <= 0:
sts = LIBPCP_PMDA.pmdaCacheResize(self.it_indom, maximum)
if sts < 0:
raise pmErr(sts)
else:
raise pmErr(cpmapi.PM_ERR_NYI)
class pmdaUnits(pmUnits):
""" Wrapper class for PMDAs defining their metrics (avoids pmapi import) """
def __init__(self, dimS, dimT, dimC, scaleS, scaleT, scaleC):
pmUnits.__init__(self, dimS, dimT, dimC, scaleS, scaleT, scaleC)
###
## Convenience Classes for PMDAs
#
class MetricDispatch(object):
""" Helper for PMDA class which manages metric dispatch
table, metric namespace, descriptors and help text.
Overall strategy is to interface to the C code in
python/pmda.c here, using a void* handle to the PMDA
dispatch structure (allocated and managed in C code).
In addition, several dictionaries for metric related
strings are managed here (names, help text) - cached
for quick lookups in callback routines.
"""
##
# overloads
def __init__(self, domain, name, logfile, helpfile):
self._indomtable = []
self._indoms = {}
self._indom_oneline = {}
self._indom_helptext = {}
self._metrictable = []
self._metrics = {}
self._metric_names = {}
self._metric_names_map = {}
self._metric_oneline = {}
self._metric_helptext = {}
cpmda.init_dispatch(domain, name, logfile, helpfile)
def clear_indoms(self):
# Notice we're using the following:
#
# del list[:]
# dict.clear()
#
# instead of:
#
# list = []
# dict = {}
#
# The latter creates a new list/dictionary and assigns it to
# the variable. But, the stashed list/dictionary reference
# down in cpmda still will point to the original
# list/dictionary. Clearing out the existing list/dictionary
# keeps the stashed references working the way we'd like.
del self._indomtable[:]
self._indoms.clear()
self._indom_oneline.clear()
self._indom_helptext.clear()
def clear_metrics(self):
# See note above in clear_indoms() about clearing
# lists/dictionaries.
del self._metrictable[:]
self._metrics.clear()
self._metric_names.clear()
self._metric_names_map.clear()
self._metric_oneline.clear()
self._metric_helptext.clear()
def reset_metrics(self):
self.clear_metrics()
cpmda.set_need_refresh()
##
# general PMDA class methods
def pmns_refresh(self):
cpmda.pmns_refresh(self._metric_names)
def connect_pmcd(self):
cpmda.connect_pmcd()
def add_metric(self, name, metric, oneline='', text=''):
pmid = metric.m_desc.pmid
if name in self._metric_names_map:
raise KeyError('attempt to add_metric with an existing name=%s' % (name))
if pmid in self._metrics:
raise KeyError('attempt to add_metric with an existing PMID')
self._metrictable.append(metric)
self._metrics[pmid] = metric
self._metric_names[pmid] = name
self._metric_names_map[name] = pmid
self._metric_oneline[pmid] = oneline
self._metric_helptext[pmid] = text
cpmda.set_need_refresh()
def remove_metric(self, name, metric):
pmid = metric.m_desc.pmid
if name not in self._metric_names_map:
raise KeyError('attempt to remove non-existant metric name=%s' % (name))
if pmid not in self._metrics:
raise KeyError('attempt to remove_metric with non-existant PMID')
self._metrictable.remove(metric)
self._metrics.pop(pmid)
self._metric_names.pop(pmid)
self._metric_names_map.pop(name)
self._metric_oneline.pop(pmid)
self._metric_helptext.pop(pmid)
cpmda.set_need_refresh()
def add_indom(self, indom, oneline='', text=''):
indomid = indom.it_indom
for entry in self._indomtable:
if entry.it_indom == indomid:
raise KeyError('attempt to add_indom with an existing ID')
self._indomtable.append(indom)
self._indoms[indomid] = indom
self._indom_oneline[indomid] = oneline
self._indom_helptext[indomid] = text
def replace_indom(self, indom, insts):
# Note that this function can take a numeric indom or a
# pmdaIndom.
if isinstance(indom, pmdaIndom):
it_indom = indom.it_indom
replacement = indom
else:
it_indom = indom
replacement = pmdaIndom(it_indom, insts)
# list indoms need to keep the table up-to-date for libpcp_pmda
if isinstance(insts, list):
# _indomtable is persistently shared with pmda.c
for i, entry in enumerate(self._indomtable):
if entry.it_indom == it_indom:
self._indomtable[i] = replacement # replace in place
break
self._indoms[it_indom] = replacement
def inst_lookup(self, indom, instance):
"""
Lookup the value associated with an (internal) instance ID
within a specific instance domain (only valid with indoms
of cache type - array indom will always return None).
"""
entry = self._indoms[indom]
if entry.it_numinst < 0:
value = (c_void_p)()
sts = LIBPCP_PMDA.pmdaCacheLookup(indom, instance, None, byref(value))
if sts == cpmda.PMDA_CACHE_ACTIVE:
return value
return None
def inst_name_lookup(self, indom, instance):
"""
Lookup the name associated with an (internal) instance ID within
a specific instance domain.
"""
entry = self._indoms[indom]
return entry.inst_name_lookup(instance)
def pmid_name_lookup(self, cluster, item):
"""
Lookup the name associated with a performance metric identifier.
"""
try:
name = self._metric_names[cpmda.pmda_pmid(cluster, item)]
except KeyError:
name = None
return name
class PMDA(MetricDispatch):
""" Defines a PCP performance metrics domain agent
Used to add new metrics into the PCP toolkit.
"""
##
# property read methods
def read_name(self):
""" Property for name of this PMDA """
return self._name
def read_domain(self):
""" Property for unique domain number of this PMDA """
return self._domain
##
# property definitions
name = property(read_name, None, None, None)
domain = property(read_domain, None, None, None)
##
# overloads
def __init__(self, name, domain, logfile=None, helpfile=None):
self._name = name
self._domain = domain
if not logfile:
# note: logfile == "-" is special, see pmOpenLog(3).
logfile = name + '.log'
pmdaname = 'pmda' + name
if not helpfile:
helpfile = '%s/%s/help' % (PCP.pmGetConfig('PCP_PMDAS_DIR'), name)
MetricDispatch.__init__(self, domain, pmdaname, logfile, helpfile)
##
# general PMDA class methods
def domain_write(self):
"""
Write out the domain.h file (used during installation)
"""
print('#define %s %d' % (self._name.upper(), self._domain))
def pmns_write(self, root):
"""
Write out the namespace file (used during installation)
"""
pmns = self._metric_names
prefixes = {pmns[key].split('.')[0] for key in pmns}
indent = (root == 'root')
lead = ''
if indent:
lead = '\t'
print('root {')
for prefix in prefixes:
print('%s%s\t%d:*:*' % (lead, prefix, self._domain))
if indent:
print('}')
def pmda_notready(self):
"""
Tell PMCD the PMDA is not ready to process requests.
"""
cpmda.pmda_notready()
def pmda_ready(self):
"""
Tell PMCD the PMDA is ready to process requests.
"""
cpmda.pmda_ready()
def run(self):
"""
All the real work happens herein; we can be called in one of three
situations, determined by environment variables. First couple are
during the agent Install process, where the domain.h and namespace
files need to be created. The third case is the real mccoy, where
an agent is actually being started by pmcd/dbpmda and makes use of
libpcp_pmda to talk PCP protocol.
"""
if 'PCP_PYTHON_DOMAIN' in os.environ:
self.domain_write()
elif 'PCP_PYTHON_PMNS' in os.environ:
self.pmns_write(os.environ['PCP_PYTHON_PMNS'])
else:
self.pmns_refresh()
cpmda.pmid_oneline_refresh(self._metric_oneline)
cpmda.pmid_longtext_refresh(self._metric_helptext)
cpmda.indom_oneline_refresh(self._indom_oneline)
cpmda.indom_longtext_refresh(self._indom_helptext)
cpmda.pmda_dispatch(self._indomtable, self._metrictable)
@staticmethod
def set_fetch(fetch):
return cpmda.set_fetch(fetch)
@staticmethod
def set_label(label):
return cpmda.set_label(label)
@staticmethod
def set_notes(notes):
return cpmda.set_notes(notes)
@staticmethod
def set_refresh(refresh):
return cpmda.set_refresh(refresh)
@staticmethod
def set_instance(instance):
return cpmda.set_instance(instance)
@staticmethod
def set_fetch_callback(fetch_callback):
return cpmda.set_fetch_callback(fetch_callback)
@staticmethod
def set_label_callback(label_callback):
return cpmda.set_label_callback(label_callback)
@staticmethod
def set_notes_callback(notes_callback):
return cpmda.set_notes_callback(notes_callback)
@staticmethod
def set_attribute_callback(attribute_callback):
return cpmda.set_attribute_callback(attribute_callback)
@staticmethod
def set_store_callback(store_callback):
return cpmda.set_store_callback(store_callback)
@staticmethod
def set_endcontext_callback(endcontext_callback):
return cpmda.set_endcontext_callback(endcontext_callback)
@staticmethod
def set_refresh_all(refresh_all):
return cpmda.set_refresh_all(refresh_all)
@staticmethod
def set_refresh_metrics(refresh_metrics):
return cpmda.set_refresh_metrics(refresh_metrics)
@staticmethod
def set_notify_change():
cpmda.set_notify_change()
@staticmethod
def set_user(username):
return cpmapi.pmSetProcessIdentity(username)
@staticmethod
def pmid(cluster, item):
return cpmda.pmda_pmid(cluster, item)
@staticmethod
def pmid_build(domain, cluster, item):
return cpmda.pmid_build(domain, cluster, item)
@staticmethod
def pmid_cluster(cluster):
return cpmda.pmid_cluster(cluster)
@staticmethod
def indom(serial):
return cpmda.pmda_indom(serial)
@staticmethod
def indom_build(domain, serial):
return cpmda.indom_build(domain, serial)
@staticmethod
def units(dim_space, dim_time, dim_count, scale_space, scale_time, scale_count):
return cpmda.pmda_units(dim_space, dim_time, dim_count, scale_space, scale_time, scale_count)
@staticmethod
def uptime(now):
return cpmda.pmda_uptime(now)
@staticmethod
def set_comm_flags(flags):
return cpmda.pmda_set_comm_flags(flags)
@staticmethod
def log(message):
return cpmda.pmda_log(message)
@staticmethod
def dbg(message):
return cpmda.pmda_dbg(message)
@staticmethod
def err(message):
return cpmda.pmda_err(message)
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