# --*-- encoding: utf-8 -*-
import argparse
import os
import struct

class HostEntry(object):

    def __init__(self, logical_offset, physical_offset, length, pid):
        self.logical_offset = logical_offset
        self.physical_offset = physical_offset
        self.length = length
        self.pid = pid

    def __str__(self):
        delimter = ', '
        s = ''
        s += 'logical_offset: ' + str(self.logical_offset) + delimter
        s += 'physical_offset: ' + str(self.physical_offset) + delimter
        s += 'length: ' + str(self.length) + delimter
        s += 'pid: ' + str(self.pid) + '\n'
        return s

    def __repr__(self):
        return str(self)


def parse(fn):
    ret = []
    ENTRY_SIZE = 48
    LOGICAL = 0
    PHYSICAL = 8
    LENGTH = 16
    PID = 40
    with open(fn, 'rb') as inp:
        bs = inp.read()
        for i in range(len(bs)/48):
            offset = i * ENTRY_SIZE
            logical_offset = struct.unpack("<LL", bs[offset+LOGICAL:offset+LOGICAL+8])[0]
            physical_offset = struct.unpack("<LL", bs[offset+PHYSICAL:offset+PHYSICAL+8])[0]
            length = struct.unpack("<LL", bs[offset+LENGTH:offset+LENGTH+8])[0]
            pid = struct.unpack("<L", bs[offset+PID:offset+PID+4])[0]
            ret.append(HostEntry(logical_offset, physical_offset, length, pid))

    # return sorted(ret, key=lambda x: x.pid)
    return sorted(ret, key=lambda x: x.logical_offset)


def main(dirpath):
    idxs = []
    for dirpath, dirnames, filenames in os.walk(dirpath):
        for filename in filenames:
            if 'index' in filename:
                idxs.extend(parse(dirpath+'/'+filename))
        break

    print idxs



if __name__ == '__main__':
    parser = argparse.ArgumentParser(description="Parse the index file of PLFS container")
    parser.add_argument('-i', type=str, default='/home/deng/fs/backend/poc/hostdir.26', help='输入文件夹')
    args = parser.parse_args()
    dirpath = args.i
    main(dirpath)