main.rb

#!/usr/bin/ruby

require 'shellwords'
require 'fileutils'

maxfilesize = 24700000000

Samefilefilter = [
    %r!(?:^|.+/)[^/]+(?=\.[^/.]+$)!,
    %r!(?:^|.+/)[^/]+(?=(?:\.MP4|M01\.XML))!i,
]
path = Dir.glob('**/*').select{|file| File.file?(file)}.sort
flag = Array.new(path.size){false}
pathmss = path.map{|file| Samefilefilter.map{|m| file.match(m)}}
files = []
path.zip(pathmss, 0...path.size) do |file, ms, i|
    next if flag[i]
    files << [file]
    # 本来は path.size だけで良いのだが，流石に O(n^2) のアルゴリズムは遅すぎた
    # 間引きのせいで意図通り動かない場合があるけれども，仕方ないね
    #((i + 1)...[path.size,i + 2].min).each do |j|
    ((i + 1)...path.size).each do |j|
        next if flag[j]
        if ms.lazy.zip(pathmss[j]).any?{|om, cm| om && cm && om[0] == cm[0]}
            files.last << path[j]
            flag[j] = true
        end
    end
end
files = files.flat_map do |fs|
    tmp = []
    fs = fs.map do |f|
        size = File.size(f)
        if size > maxfilesize
            i = 0
            while size > maxfilesize
                tmp << {files: [f + '.part%d' % (i += 1)], size: maxfilesize}
                size -= maxfilesize
            end
            {file: f + '.part%d' % (i += 1), size: size}
        else
            {file: f, size: File.size(f)}
        end
    end
    sumsize = fs.inject(0){|r, i| r + i[:size]}
    if sumsize > maxfilesize
        # まだ実装してない．
        # ここに到達したら初めて実装する．
        raise 0
    end
    tmp << {files: fs.map{|f| f[:file]}, size: sumsize}
end
bag = []
files.each do |file|
    if b = bag.sort_by{|a| a[:size]}.drop_while{|a| a[:size] <= 0}.find{|t| t[:size] >= file[:size]}
        b[:files] << file[:files]
        b[:size] -= file[:size]
    else
        bag << {
            files: [file[:files]],
            size: maxfilesize - file[:size],
        }
    end
end
bag.each_with_index do |b, i|
    puts "No.%<no>d - %<size>.3f GB" % {no: i + 1, size: (maxfilesize - b[:size]) / 1e9}
    b[:files].each do |fs|
        puts " - " + fs.join(" + ")
    end
end
exit unless (dir = ARGV.shift) && !Dir.exist?(dir)
puts "----------------------------------"
puts "copy to #{dir}"
Dir.mkdir(dir)
bag.each_with_index do |v, i|
    path = File.join(dir, 'No.%d' % (i + 1))
    Dir.mkdir(path)
    v[:files].each do |fs|
        fs.each do |f|
            if File.exist?(f)
                newname = File.join(path, f)
                FileUtils.mkdir_p(File.dirname(newname))
                cmd = Shellwords.join(%W|cp -pn --reflink #{f} #{newname}|)
                `#{cmd}`
                cmd = Shellwords.join(%W|touch -r #{f} #{newname}|)
                `#{cmd}`
            elsif (m = f.match(/^(.+)\.part([1-9]\d*)$/)) && File.exist?(m[1])
                realf = m[1]
                partno = m[2].to_i
                newname = File.join(path, f)
                copy_size = File.size(realf) - maxfilesize * (partno - 1)
                if copy_size > maxfilesize
                    copy_size = maxfilesize
                end
                FileUtils.mkdir_p(File.dirname(newname))
                if partno == 1
                    cmd = Shellwords.join(%W|cp -pn --reflink #{realf} #{newname}|)
                    `#{cmd}`
                    File.truncate(newname, copy_size)
                else
                    puts "copy #{realf} to #{newname}: #{copy_size.to_s.gsub(/(\d)(?=(?:\d{3})+(?!\d))/, '\1,')} bytes"
                    IO.copy_stream(realf, newname, copy_size, maxfilesize * (partno - 1))
                end
                cmd = Shellwords.join(%W|touch -r #{realf} #{newname}|)
                `#{cmd}`
            end
        end
    end
end
Dir.glob('**/*').select{|file| Dir.exist?(file) && Dir.entries(file).size == 2}.each{|f| FileUtils.mkdir_p(File.join(dir, 'No.1', f))}