tools/kvm_stat: Add command line switch '-L' to log to file

import struct

import re

import subprocess

import signal

from collections import defaultdict, namedtuple

from functools import reduce

from datetime import datetime

    'RESET':       0x00002403,

}

signal_received = False

ENCODING = locale.getpreferredencoding(False)

TRACE_FILTER = re.compile(r'^[^\(]*$')

def log(stats, opts, frmt, keys):

    """Prints statistics as reiterating key block, multiple value blocks."""

    global signal_received

    line = 0

    banner_repeat = 20

    banner_printed = False

    f = None

    def do_banner(opts):

        nonlocal f

        if opts.log_to_file:

            if not f:

                try:

                     f = open(opts.log_to_file, 'a')

                except (IOError, OSError):

                    sys.exit("Error: Could not open file: %s" %

                             opts.log_to_file)

                if isinstance(frmt, CSVFormat) and f.tell() != 0:

                    return

        print(frmt.get_banner(), file=f or sys.stdout)

    def do_statline(opts, values):

        statline = datetime.now().strftime("%Y-%m-%d %H:%M:%S") + \

                   frmt.get_statline(keys, values)

        print(statline, file=f or sys.stdout)

    do_banner(opts)

    banner_printed = True

    while True:

        try:

            time.sleep(opts.set_delay)

            if line % banner_repeat == 0 and not banner_printed:

                print(frmt.get_banner())

            if signal_received:

                banner_printed = True

                line = 0

                f.close()

                do_banner(opts)

                signal_received = False

            if (line % banner_repeat == 0 and not banner_printed and

                not (opts.log_to_file and isinstance(frmt, CSVFormat))):

                do_banner(opts)

                banner_printed = True

            values = stats.get()

            if (not opts.skip_zero_records or

                any(values[k].delta != 0 for k in keys)):

                print(datetime.now().strftime("%Y-%m-%d %H:%M:%S") +

                      frmt.get_statline(keys, values))

                do_statline(opts, values)

                line += 1

                banner_printed = False

        except KeyboardInterrupt:

            break

    if opts.log_to_file:

        f.close()

def handle_signal(sig, frame):

    global signal_received

    signal_received = True

    return

def is_delay_valid(delay):

    """Verify delay is in valid value range."""

    argparser.add_argument('-c', '--csv',

                           action='store_true',

                           default=False,

                           help='log in csv format - requires option -l/--log',

                           help='log in csv format - requires option -l/-L',

                           )

    argparser.add_argument('-d', '--debugfs',

                           action='store_true',

                           default=False,

                           help='run in logging mode (like vmstat)',

                           )

    argparser.add_argument('-L', '--log-to-file',

                           type=str,

                           metavar='FILE',

                           help="like '--log', but logging to a file"

                           )

    argparser.add_argument('-p', '--pid',

                           type=int,

                           default=0,

                           help='omit records with all zeros in logging mode',

                           )

    options = argparser.parse_args()

    if options.csv and not options.log:

    if options.csv and not (options.log or options.log_to_file):

        sys.exit('Error: Option -c/--csv requires -l/--log')

    if options.skip_zero_records and not options.log:

        sys.exit('Error: Option -z/--skip-zero-records requires -l/--log')

    if options.skip_zero_records and not (options.log or options.log_to_file):

        sys.exit('Error: Option -z/--skip-zero-records requires -l/-L')

    try:

        # verify that we were passed a valid regex up front

        re.compile(options.fields)

        sys.stdout.write('  ' + '\n  '.join(sorted(set(event_list))) + '\n')

        sys.exit(0)

    if options.log:

    if options.log or options.log_to_file:

        if options.log_to_file:

            signal.signal(signal.SIGHUP, handle_signal)

        keys = sorted(stats.get().keys())

        if options.csv:

            frmt = CSVFormat(keys)

	run in batch mode for one second

-c::

--csv=<file>::

        log in csv format - requires option -l/--log

--csv::

        log in csv format. Requires option -l/--log or -L/--log-to-file.

        When used with option -L/--log-to-file, the header is only ever

        written to start of file to preserve the format.

-d::

--debugfs::

--log::

        run in logging mode (like vmstat)

-L<file>::

--log-to-file=<file>::

        like -l/--log, but logging to a file. Appends to existing files.

-p<pid>::

--pid=<pid>::

	limit statistics to one virtual machine (pid)