#!/usr/bin/env pmpython
#
# Copyright (C) 2014-2016,2020 Red Hat.
#
# 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.
#
# pylint: disable=bad-whitespace,protected-access,redefined-outer-name
# pylint: disable=too-many-nested-blocks,too-many-boolean-expressions
""" Display disk and device-mapper I/O statistics """

import re
import sys
import signal
from pcp import pmapi, pmcc
from cpmapi import PM_CONTEXT_ARCHIVE, PM_MODE_FORW

# use default SIGPIPE handler to avoid broken pipe exceptions
signal.signal(signal.SIGPIPE, signal.SIG_DFL)

IOSTAT_SD_METRICS = [ 'disk.dev.read', 'disk.dev.read_bytes',
                      'disk.dev.write', 'disk.dev.write_bytes',
                      'disk.dev.read_merge', 'disk.dev.write_merge',
                      'disk.dev.blkread', 'disk.dev.blkwrite',
                      'disk.dev.read_rawactive', 'disk.dev.write_rawactive',
                      'disk.dev.avactive']

IOSTAT_DM_METRICS = [ 'disk.dm.read', 'disk.dm.read_bytes',
                      'disk.dm.write', 'disk.dm.write_bytes',
                      'disk.dm.read_merge', 'disk.dm.write_merge',
                      'disk.dm.blkread', 'disk.dm.blkwrite',
                      'disk.dm.read_rawactive', 'disk.dm.write_rawactive',
                      'disk.dm.avactive']

def aggregate(method, aggr_value, value):
    if method == 'sum':
        aggr_value += value
    elif method == 'avg':
        aggr_value += value
    elif method == 'min':
        aggr_value = min(aggr_value, value)
    elif method == 'max':
        aggr_value = max(aggr_value, value)
    else:
        raise pmapi.pmUsageErr
    return aggr_value

class IostatReport(pmcc.MetricGroupPrinter):
    Hcount = 0
    def timeStampDelta(self, group):
        s = group.timestamp.tv_sec - group.prevTimestamp.tv_sec
        u = group.timestamp.tv_usec - group.prevTimestamp.tv_usec
        # u may be negative here, calculation is still correct.
        return s + u / 1000000.0

    def instlist(self, group, name):
        return dict(map(lambda x: (x[1], x[2]), group[name].netValues)).keys()

    def curVals(self, group, name):
        return dict(map(lambda x: (x[1], x[2]), group[name].netValues))

    def prevVals(self, group, name):
        return dict(map(lambda x: (x[1], x[2]), group[name].netPrevValues))

    def report(self, manager):
        regex = IostatOptions.Rflag
        if regex == '':
            regex = '.*'

        aggr = IostatOptions.Gflag
        if aggr and aggr not in ('sum', 'avg', 'min', 'max'):
            print("Error, -G aggregation method must be one of 'sum', 'avg', 'min' or 'max'")
            raise pmapi.pmUsageErr

        precision = IostatOptions.Pflag
        if precision < 0 or precision > 10 :
            print("Precision value must be between 0 and 10")
            raise pmapi.pmUsageErr

        if 'dm' in IostatOptions.xflag:
            subtree = 'disk.dm'
        else:
            subtree = 'disk.dev'
        group = manager["iostat"]

        if group[subtree + '.read_merge'].netPrevValues is None:
            # need two fetches to report rate converted counter metrics
            return

        instlist = self.instlist(group, subtree + '.read')
        dt = self.timeStampDelta(group)
        timestamp = group.contextCache.pmCtime(int(group.timestamp)).rstrip()

        c_rrqm = self.curVals(group, subtree + '.read_merge')
        p_rrqm = self.prevVals(group, subtree + '.read_merge')

        c_wrqm = self.curVals(group, subtree + '.write_merge')
        p_wrqm = self.prevVals(group, subtree + '.write_merge')

        c_r = self.curVals(group, subtree + '.read')
        p_r = self.prevVals(group, subtree + '.read')

        c_w = self.curVals(group, subtree + '.write')
        p_w = self.prevVals(group, subtree + '.write')

        c_rkb = self.curVals(group, subtree + '.read_bytes')
        p_rkb = self.prevVals(group, subtree + '.read_bytes')

        c_wkb = self.curVals(group, subtree + '.write_bytes')
        p_wkb = self.prevVals(group, subtree + '.write_bytes')

        c_ractive = self.curVals(group, subtree + '.read_rawactive')
        p_ractive = self.prevVals(group, subtree + '.read_rawactive')

        c_wactive = self.curVals(group, subtree + '.write_rawactive')
        p_wactive = self.prevVals(group, subtree + '.write_rawactive')

        c_avactive = self.curVals(group, subtree + '.avactive')
        p_avactive = self.prevVals(group, subtree + '.avactive')

        if precision == 1:
            utilspace=precision+5
            avgrqszspace=precision+7
            awaitspace=precision+6
            rrqmspace=precision+5
            wrqmspace=precision+5
            headfmtavgspace=precision+7
            headfmtquspace=precision+7
        elif precision == 0:
            utilspace=precision+5
            avgrqszspace=precision+8
            awaitspace=precision+7
            rrqmspace=precision+6
            wrqmspace=precision+6
            headfmtavgspace=avgrqszspace
            headfmtquspace=precision+8
        else:
            utilspace=precision+5
            avgrqszspace=precision+6
            awaitspace=precision+5
            rrqmspace=precision+5
            wrqmspace=precision+5
            headfmtavgspace=avgrqszspace
            headfmtquspace=precision+6

        if "t" in IostatOptions.xflag:
            headfmt = "%-24s %-12s %*s %*s %*s %*s %*s %*s %*s %*s %*s %*s %*s %*s"
            valfmt = "%-24s %-12s %*.*f %*.*f %*.*f %*.*f %*.*f %*.*f %*.*f %*.*f %*.*f %*.*f %*.*f %*.*f"
        else:
            headfmt = "%-12s %*s %*s %*s %*s %*s %*s %*s %*s %*s %*s %*s %*s"
            valfmt = "%-12s %*.*f %*.*f %*.*f %*.*f %*.*f %*.*f %*.*f %*.*f %*.*f %*.*f %*.*f %*.*f"

        if "h" not in IostatOptions.xflag:
            self.Hcount += 1
            if self.Hcount == 24:
                self.Hcount = 1
            if self.Hcount == 1:
                if "t" in IostatOptions.xflag:
                    heading = ('# Timestamp', 'Device',rrqmspace)
                else:
                    heading = ('# Device',rrqmspace)
                heading = heading + tuple(
                           ['rrqm/s',wrqmspace, 'wrqm/s',precision+5,
                           'r/s',precision+4, 'w/s',precision+6,
                           'rkB/s',precision+6, 'wkB/s',
                           avgrqszspace,'avgrq-sz',precision+6,
                           'avgqu-sz',precision+5, 'await',precision+5,
                           'r_await', precision+5,'w_await',utilspace, '%util'])
                print(headfmt % heading)

        if p_rrqm == {} or p_wrqm == {} or p_r == {} or p_w == {} or \
           p_ractive == {} or p_wactive == {} or p_avactive == {} or \
           p_rkb == {} or p_wkb == {}:
            # no values for some metric (e.g. near start of archive)
            if "t" in IostatOptions.xflag:
                headfmt = "%-24s %-12s %*s %*s %*s %*s %*s %*s %*s %*s %*s %*s %*s %*s"
                print(headfmt % (timestamp, 'NODATA',
                    rrqmspace, '?', rrqmspace, '?',
                    precision+5, '?', precision+4, '?',
                    precision+6, '?', precision+6, '?',
                    headfmtavgspace, '?', headfmtquspace, '?',
                    precision+5, '?', awaitspace, '?',
                    awaitspace,'?', utilspace, '?'))
            return

        try:
            if IostatOptions.Gflag:
                aggr_rrqm = aggr_wrqm = aggr_r = aggr_w = aggr_rkb = aggr_wkb = aggr_avgrqsz = 0.0
                aggr_avgqsz = aggr_await = aggr_r_await = aggr_w_await = aggr_util = 0.0
                aggr_count = 0

            for inst in sorted(instlist):
                # basic stats
                rrqm = (c_rrqm[inst] - p_rrqm[inst]) / dt
                wrqm = (c_wrqm[inst] - p_wrqm[inst]) / dt
                r = (c_r[inst] - p_r[inst]) / dt
                w = (c_w[inst] - p_w[inst]) / dt
                rkb = (c_rkb[inst] - p_rkb[inst]) / dt
                wkb = (c_wkb[inst] - p_wkb[inst]) / dt

                # totals
                tot_rios = (float)(c_r[inst] - p_r[inst])
                tot_wios = (float)(c_w[inst] - p_w[inst])
                tot_ios = (float)(tot_rios + tot_wios)

                # total active time in seconds (same units as dt)
                tot_active = (float)(c_avactive[inst] - p_avactive[inst]) / 1000.0

                avgrqsz = t_await = r_await = w_await = util = 0.0

                # average request size units are KB (sysstat reports in units of sectors)
                if tot_ios:
                    avgrqsz = (float)((c_rkb[inst] - p_rkb[inst]) + (c_wkb[inst] - p_wkb[inst])) / tot_ios

                # average queue length
                avgqsz = (float)((c_ractive[inst] - p_ractive[inst]) +
                                 (c_wactive[inst] - p_wactive[inst])) / dt / 1000.0

                # await, r_await, w_await
                if tot_ios:
                    t_await = ((c_ractive[inst] - p_ractive[inst]) + (c_wactive[inst] - p_wactive[inst])) / tot_ios

                if tot_rios:
                    r_await = (c_ractive[inst] - p_ractive[inst]) / tot_rios

                if tot_wios:
                    w_await = (c_wactive[inst] - p_wactive[inst]) / tot_wios

                # device utilization (percentage of active time / interval)
                if tot_active:
                    util = 100.0 * tot_active / dt

                device = inst	# prepare name for printing
                badcounters = (rrqm < 0 or wrqm < 0 or r < 0 or w < 0 or
                               t_await < 0 or avgrqsz < 0 or avgqsz < 0 or util < 0)

                if "t" in IostatOptions.xflag:
                    if badcounters:
                        print(headfmt % (timestamp, device,rrqmspace,
                                         '?',wrqmspace, '?',precision+5,
                                         '?',precision+4, '?',precision+6,
                                         '?',precision+6, '?',headfmtavgspace,
                                         '?',headfmtquspace, '?', precision+5,
                                         '?',awaitspace, '?', awaitspace,
                                         '?',utilspace, '?'))
                    else:
                        if IostatOptions.Rflag and re.search(regex,device) is None:
                            continue

                        if IostatOptions.Gflag:
                            aggr_count += 1

                        if "noidle" in IostatOptions.xflag:
                            if rrqm == 0 and wrqm == 0 and r == 0 and w == 0:
                                continue

                        if not IostatOptions.Gflag:
                            print(valfmt % (timestamp, device,rrqmspace,precision,
                                            rrqm,wrqmspace,precision,
                                            wrqm,precision+5,precision,
                                            r,precision+4,precision,
                                            w,precision+6,precision,
                                            rkb,precision+6,precision,
                                            wkb,avgrqszspace,precision+1,
                                            avgrqsz,avgrqszspace,precision+1,
                                            avgqsz,precision+5,precision,
                                            t_await,awaitspace,precision,
                                            r_await,awaitspace,precision,
                                            w_await,utilspace,precision, util))
                else:
                    if badcounters:
                        print(headfmt % (device,rrqmspace, '?',wrqmspace,
                                         '?',precision+5, '?',precision+4,
                                         '?',precision+6, '?',precision+6,
                                         '?',headfmtavgspace,
                                         '?',headfmtquspace,
                                         '?',precision+5, '?',awaitspace,
                                         '?',awaitspace, '?',utilspace, '?'))
                    else:
                        if IostatOptions.Rflag and re.search(regex,device) is None:
                            continue

                        if IostatOptions.Gflag:
                            aggr_count += 1

                        if "noidle" in IostatOptions.xflag:
                            if rrqm == 0 and wrqm == 0 and r == 0 and w == 0:
                                continue

                        if not IostatOptions.Gflag:
                            print(valfmt % (device,rrqmspace, precision,
                                            rrqm,wrqmspace,precision,
                                            wrqm,precision+5,precision,
                                            r,precision+4,precision,
                                            w,precision+6,precision,
                                            rkb,precision+6,precision,
                                            wkb,avgrqszspace,precision+1,
                                            avgrqsz,avgrqszspace,precision+1,
                                            avgqsz,precision+5,precision,
                                            t_await,awaitspace,precision,
                                            r_await,awaitspace,precision,
                                            w_await,utilspace,precision, util))

                if IostatOptions.Gflag and not badcounters:
                    aggr_rrqm = aggregate(aggr, aggr_rrqm, rrqm)
                    aggr_wrqm = aggregate(aggr, aggr_wrqm, wrqm)
                    aggr_r = aggregate(aggr, aggr_r, r)
                    aggr_w = aggregate(aggr, aggr_w, w)
                    aggr_rkb = aggregate(aggr, aggr_rkb, rkb)
                    aggr_wkb = aggregate(aggr, aggr_wkb, wkb)
                    aggr_avgrqsz = aggregate(aggr, aggr_avgrqsz, avgrqsz)
                    aggr_avgqsz = aggregate(aggr, aggr_avgqsz, avgqsz)
                    aggr_await = aggregate(aggr, aggr_await, t_await)
                    aggr_r_await = aggregate(aggr, aggr_r_await, r_await)
                    aggr_w_await = aggregate(aggr, aggr_w_await, w_await)
                    aggr_util = aggregate(aggr, aggr_util, util)
            # end of loop

            if IostatOptions.Gflag:
                if IostatOptions.Gflag == 'avg' and aggr_count > 0:
                    aggr_rrqm /= aggr_count
                    aggr_wrqm /= aggr_count
                    aggr_r /= aggr_count
                    aggr_w /= aggr_count
                    aggr_rkb /= aggr_count
                    aggr_wkb /= aggr_count
                    aggr_avgrqsz /= aggr_count
                    aggr_avgqsz /= aggr_count
                    aggr_await /= aggr_count
                    aggr_r_await /= aggr_count
                    aggr_w_await /= aggr_count
                    aggr_util /= aggr_count


                # report aggregate values - the 'device' here is reported as the regex used for the aggregation
                device = '%s(%s)' % (aggr, regex)
                if "t" in IostatOptions.xflag:
                    print(valfmt % (timestamp, device,rrqmspace, precision,
                                    aggr_rrqm,wrqmspace,precision,
                                    aggr_wrqm,precision+5,precision,
                                    aggr_r,precision+4,precision,
                                    aggr_w,precision+6,precision,
                                    aggr_rkb,precision+6,precision,
                                    aggr_wkb,avgrqszspace,precision+1,
                                    aggr_avgrqsz,avgrqszspace,precision+1,
                                    aggr_avgqsz,precision+5,precision,
                                    aggr_await,awaitspace,precision,
                                    aggr_r_await,awaitspace,precision,
                                    aggr_w_await,utilspace,precision, aggr_util))
                else:
                    print(valfmt % (device,rrqmspace, precision,
                                    aggr_rrqm,wrqmspace,precision,
                                    aggr_wrqm,precision+5,precision,
                                    aggr_r,precision+4,precision,
                                    aggr_w,precision+6,precision,
                                    aggr_rkb,precision+6,precision,
                                    aggr_wkb,avgrqszspace,precision+1,
                                    aggr_avgrqsz,avgrqszspace,precision+1,
                                    aggr_avgqsz,precision+5,precision,
                                    aggr_await,awaitspace,precision,
                                    aggr_r_await,awaitspace,precision,
                                    aggr_w_await,utilspace,precision, aggr_util))

        except KeyError:
            # instance missing from previous sample
            pass

class IostatOptions(pmapi.pmOptions):
    # class attributes
    xflag = []
    uflag = None
    Pflag = 2
    Rflag = ""
    Gflag = ""
    def checkOptions(self, manager):
        if IostatOptions.uflag:
            if manager._options.pmGetOptionInterval():
                print("Error: -t incompatible with -u")
                return False
            if manager.type != PM_CONTEXT_ARCHIVE:
                print("Error: -u can only be specified with -a archive")
                return False
        return True

    def extraOptions(self, opt, optarg, index):
        if opt == "x":
            IostatOptions.xflag += optarg.replace(',', ' ').split(' ')
        elif opt == "u":
            IostatOptions.uflag = True
        elif opt == "P":
            IostatOptions.Pflag = int(optarg)
        elif opt == "R":
            IostatOptions.Rflag = optarg
        elif opt == "G":
            IostatOptions.Gflag = optarg

    def __init__(self):
        pmapi.pmOptions.__init__(self, "A:a:D:G:h:O:P:R:S:s:T:t:uVZ:z?x:")
        self.pmSetOptionCallback(self.extraOptions)
        self.pmSetLongOptionHeader("General options")
        self.pmSetLongOptionAlign()
        self.pmSetLongOptionArchive()
        self.pmSetLongOptionDebug()
        self.pmSetLongOption("aggregate", 1, "G", "method",
                             "aggregate values for devices matching -R regex"
                             "using 'method' (sum, avg, min or max)")
        self.pmSetLongOptionHost()
        self.pmSetLongOptionOrigin()
        self.pmSetLongOption("precision", 1, "P", "N", "N digits after the decimal separator")
        self.pmSetLongOption("regex", 1, "R", "pattern",
                             "only report for devices names matching pattern, "
                             "e.g. 'sd[a-zA-Z]+'. See also -G.")
        self.pmSetLongOptionStart()
        self.pmSetLongOptionSamples()
        self.pmSetLongOptionFinish()
        self.pmSetLongOptionInterval()
        self.pmSetLongOption("no-interpolation", 0, "u", "", "disable interpolation mode with archives")
        self.pmSetLongOptionVersion()
        self.pmSetLongOptionTimeZone()
        self.pmSetLongOptionHostZone()
        self.pmSetLongOptionHelp()
        self.pmSetLongOptionHeader("Extended options")
        self.pmSetLongOption("", 1, 'x', "LIST", "comma separated extended options: [[dm],[t],[h],[noidle]]")
        self.pmSetLongOptionText("\t\tdm\tshow device-mapper statistics (default is sd devices)")
        self.pmSetLongOptionText("\t\tt\tprecede every line with a timestamp in ctime format")
        self.pmSetLongOptionText("\t\th\tsuppress headings")
        self.pmSetLongOptionText("\t\tnoidle\tdo not display idle devices")

if __name__ == '__main__':
    try:
        opts = IostatOptions()
        manager = pmcc.MetricGroupManager.builder(opts, sys.argv)
        if not opts.checkOptions(manager):
            raise pmapi.pmUsageErr

        if IostatOptions.uflag:
            # -u turns off interpolation
            manager.pmSetMode(PM_MODE_FORW, manager._options.pmGetOptionOrigin(), 0)

        if "dm" in IostatOptions.xflag :
            namelist = IOSTAT_DM_METRICS
        else:
            namelist = IOSTAT_SD_METRICS
        missing = manager.checkMissingMetrics(namelist)
        if missing is not None:
            sys.stderr.write('Error: not all required metrics are available\nMissing %s\n' % (missing))
            sys.exit(1)
        manager["iostat"] = namelist
        manager.printer = IostatReport()
        sts = manager.run()
        sys.exit(sts)
    except pmapi.pmErr as error:
        sys.stderr.write('%s: %s\n' % (error.progname(), error.message()))
    except pmapi.pmUsageErr as usage:
        usage.message()
        sys.exit(1)
    except KeyboardInterrupt:
        pass
