
from __future__ import absolute_import, print_function
import re, resource, sys, time

from bup import git, bloom, midx, options, _helpers
from bup.io import byte_stream
from bup.helpers import log


_linux_warned = 0
def linux_memstat():
    global _linux_warned
    #fields = ['VmSize', 'VmRSS', 'VmData', 'VmStk', 'ms']
    d = {}
    try:
        f = open(b'/proc/self/status', 'rb')
    except IOError as e:
        if not _linux_warned:
            log('Warning: %s\n' % e)
            _linux_warned = 1
        return {}
    for line in f:
        # Note that on Solaris, this file exists but is binary.  If that
        # happens, this split() might not return two elements.  We don't
        # really need to care about the binary format since this output
        # isn't used for much and report() can deal with missing entries.
        t = re.split(br':\s*', line.strip(), 1)
        if len(t) == 2:
            k,v = t
            d[k] = v
    return d


last = last_u = last_s = start = 0
def report(count, out):
    global last, last_u, last_s, start
    headers = ['RSS', 'MajFlt', 'user', 'sys', 'ms']
    ru = resource.getrusage(resource.RUSAGE_SELF)
    now = time.time()
    rss = int(ru.ru_maxrss // 1024)
    if not rss:
        rss = linux_memstat().get(b'VmRSS', b'??')
    fields = [rss,
              ru.ru_majflt,
              int((ru.ru_utime - last_u) * 1000),
              int((ru.ru_stime - last_s) * 1000),
              int((now - last) * 1000)]
    fmt = '%9s  ' + ('%10s ' * len(fields))
    if count >= 0:
        line = fmt % tuple([count] + fields)
        out.write(line.encode('ascii') + b'\n')
    else:
        start = now
        out.write((fmt % tuple([''] + headers)).encode('ascii') + b'\n')
    out.flush()

    # don't include time to run report() in usage counts
    ru = resource.getrusage(resource.RUSAGE_SELF)
    last_u = ru.ru_utime
    last_s = ru.ru_stime
    last = time.time()


optspec = """
bup memtest [-n elements] [-c cycles]
--
n,number=  number of objects per cycle [10000]
c,cycles=  number of cycles to run [100]
ignore-midx  ignore .midx files, use only .idx files
existing   test with existing objects instead of fake ones
"""

def main(argv):
    o = options.Options(optspec)
    opt, flags, extra = o.parse_bytes(argv[1:])

    if extra:
        o.fatal('no arguments expected')

    git.check_repo_or_die()
    sys.stdout.flush()
    out = byte_stream(sys.stdout)

    report(-1, out)
    _helpers.random_sha()
    report(0, out)

    with git.PackIdxList(git.repo(b'objects/pack'),
                         ignore_midx=opt.ignore_midx) as m:

        if opt.existing:
            def foreverit(mi):
                while 1:
                    for e in mi:
                        yield e
            objit = iter(foreverit(m))

        for c in range(opt.cycles):
            for n in range(opt.number):
                if opt.existing:
                    bin = next(objit)
                    assert(m.exists(bin))
                else:
                    bin = _helpers.random_sha()

                    # technically, a randomly generated object id might exist.
                    # but the likelihood of that is the likelihood of finding
                    # a collision in sha-1 by accident, which is so unlikely that
                    # we don't care.
                    assert(not m.exists(bin))
            report((c+1)*opt.number, out)

    if bloom._total_searches:
        out.write(b'bloom: %d objects searched in %d steps: avg %.3f steps/object\n'
                  % (bloom._total_searches, bloom._total_steps,
                     bloom._total_steps*1.0/bloom._total_searches))
    if midx._total_searches:
        out.write(b'midx: %d objects searched in %d steps: avg %.3f steps/object\n'
                  % (midx._total_searches, midx._total_steps,
                     midx._total_steps*1.0/midx._total_searches))
    if git._total_searches:
        out.write(b'idx: %d objects searched in %d steps: avg %.3f steps/object\n'
                  % (git._total_searches, git._total_steps,
                     git._total_steps*1.0/git._total_searches))
    out.write(b'Total time: %.3fs\n' % (time.time() - start))
