amahi/platform

# Amahi Home Server
# Copyright (C) 2007-2013 Amahi
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License v3
# (29 June 2007), as published in the COPYING file.
#
# 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
# file COPYING for more details.
#
# You should have received a copy of the GNU General Public
# License along with this program; if not, write to the Amahi
# team at http://www.amahi.org/ under "Contact Us."


class PartitionUtils
    attr :file
    attr :info

    def initialize
        @file = '/etc/mtab'
        @info = []
        begin
            f = File.open('/etc/mtab')
        rescue
            return @info
        end
        while f.gets
            if ($_.match(/^\/dev/))
                # data = ($_.split)[0..3]
                p = ($_.split)[0..3]
                data = Hash.new
                device = part2device(p[0])
                path = cleanup_path(p[1])
                next if path == "/boot" # C. Ayuso
                data[:device] = device
                (total, free) = disk_stats(path)
                data[:bytes_total] = total
                data[:bytes_free] = free
                data[:path] = path
                @info.push(data)
            end
        end
        f.close
    end

    private

    # return device
    def part2device(part)
        part[/.?[^0-9]*/]
    end

    def cleanup_path(path)
        path.gsub(/\\040/, ' ')
    end

    def disk_stats(path)
        size = 128
        unpack_fmt = 'l_l_l_l_l_l_l_l_l_l_l_l_l_l_l_l_'
        buffer = ' ' * size
        # FIXME!: this is 137 in x86_64!!
        # asm/unistd.h __NR_statfs 99
        begin
            open('|uname -i') do |uname|
                arch = uname.gets
                if (arch =~ /64/)
                    syscall(137, path, buffer)
                else
                    syscall(99, path, buffer)
                end
            end
            type, bsize, blocks, bfree, bavail, files, ffree, namelen =
            buffer.unpack(unpack_fmt).values_at(0, 1, 2, 3, 4, 5, 6, 9)
            # return total bytes, free bytes
            [blocks * bsize, bfree * bsize]
        rescue => e
            Rails.logger.error("******** disk stats error for #{path}: #{e.inspect}")
            [0, 0]
        end
    end

end