#!/usr/bin/env python3

from ctypes import CDLL
from time import sleep, time
import os

"""
    Execute the command
    find /sys/fs/cgroup -name memory.pressure
    to find available memory.pressue files (except /proc/pressure/memory).
    (actual for cgroup2)
"""

psi_path = '/proc/pressure/memory'

def mlockall():

    MCL_CURRENT = 1
    MCL_FUTURE = 2
    MCL_ONFAULT = 4

    libc = CDLL('libc.so.6', use_errno=True)

    result = libc.mlockall(
        MCL_CURRENT | MCL_FUTURE | MCL_ONFAULT
    )
    if result != 0:
        result = libc.mlockall(
            MCL_CURRENT | MCL_FUTURE
        )
        if result != 0:
            print('WARNING: cannot lock all memory')
        else:
            pass
    else:
        pass


mlockall()

t0 = time()

def psi_path_to_metrics(psi_path):

    with open(psi_path) as f:
        psi_list = f.readlines()
    # print(psi_list)
    some_list, full_list = psi_list[0].split(' '), psi_list[1].split(' ')
    #print(some_list, full_list)
    some_avg10 = some_list[1].split('=')[1]
    some_avg60 = some_list[2].split('=')[1]
    some_avg300 = some_list[3].split('=')[1]

    full_avg10 = full_list[1].split('=')[1]
    full_avg60 = full_list[2].split('=')[1]
    full_avg300 = full_list[3].split('=')[1]

    return (some_avg10, some_avg60, some_avg300,
            full_avg10, full_avg60, full_avg300)



def cgroup2_root():
    """
    """
    with open('/proc/mounts') as f:
        for line in f:
            if ' cgroup2 ' in line:
            # if line.startswith('cgroup2 '):
                return line[7:].rpartition(' cgroup2 ')[0].strip()


def get_psi_mem_files(cgroup2_path):
    """
    """

    path_list = []

    for root, dirs, files in os.walk(cgroup2_path):
        for file in files:
            path = os.path.join(root, file)
            if path.endswith('/memory.pressure'):
                path_list.append(path)

    return path_list


def psi_path_to_cgroup2(path):
    """
    """
    return path.partition(i)[2][:-16]


i = cgroup2_root()

print('cgroup2 root dir:', i)
if i is not None:
    y = get_psi_mem_files(i)
    for path in y:
        pass # print(psi_path_to_cgroup2(path))

path_list = get_psi_mem_files(i)

print('      avg10  avg60 avg300         avg10  avg60 avg300  cgroup2')

print('      -----  ----- ------         -----  ----- ------  ---------')

(some_avg10, some_avg60, some_avg300, full_avg10, full_avg60, full_avg300) = psi_path_to_metrics('/proc/pressure/memory')
print('some {} {} {} | full {} {} {}  {}'.format(
    some_avg10.rjust(6),
    some_avg60.rjust(6),
    some_avg300.rjust(6),
    full_avg10.rjust(6),
    full_avg60.rjust(6),
    full_avg300.rjust(6), '[SYSTEM]'))


for psi_path in path_list:
    (some_avg10, some_avg60, some_avg300,
     full_avg10, full_avg60, full_avg300) = psi_path_to_metrics(psi_path)

    print('some {} {} {} | full {} {} {}  {}'.format(
        some_avg10.rjust(6),
        some_avg60.rjust(6),
        some_avg300.rjust(6),
        full_avg10.rjust(6),
        full_avg60.rjust(6),
        full_avg300.rjust(6), psi_path_to_cgroup2(psi_path)))


print(time() - t0)