P2P application in 15 lines of Python posted on slashdot

Discussion in 'Ruby' started by slonik AZ, Dec 15, 2004.

  1. slonik AZ

    slonik AZ Guest

    Hi Everybody,
    slashdot published an article on someone's
    15 lines long Peer-2-Peer application
    http://developers.slashdot.org/article.pl?sid=04/12/15/1953227

    Another person followed up with a 9 line equivalent Perl code.

    I wonder what an equivalent Ruby program would look like?

    I do not care whether it 15 or 25 lines. Python program is not very readable.
    Can Ruby variant be concise, yet more clear?

    --Leo--
     
    slonik AZ, Dec 15, 2004
    #1
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  2. I was going to post the same message :)
    Good rubyists unite! (I'm not good :( ). Let's write a short more
    understandable program!
     
    Giovanni Intini, Dec 15, 2004
    #2
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  3. Actually, someone answered with a web server written in only 3 lines of codes.
    More info here: http://tinyurl.com/6lxpa
     
    Purple Meteor, Dec 16, 2004
    #3
  4. LOL. The Python example used quite a few core libraries, so I think
    a one-line instantiation of WebBRICK would suffice for a web server
    example :)

    Seriously, these golf competitions don't do much for me. Show me
    formatted code that applies some interesting algorithms instead.
    That's how you spar with other languages!
     
    Michael DeHaan, Dec 16, 2004
    #4
  5. Michael DeHaan ha scritto:
    ruby -rwebrick -e 'WEBrick::HTTPServer.new:)DocumentRoot=>".").start'
    but it is a oneliner in python too ;)

    def qs(l)
    return [] if (x,*xs=*l).empty?
    less, more = xs.partition{|y| y < x}
    qs(less) + [x] + qs(more)
    end

    algoritm suggestions are welcome :)
     
    gabriele renzi, Dec 16, 2004
    #5
  6. How about

    def qs(l)
    l.sort!
    end

    ;-),
    nikolai
     
    Nikolai Weibull, Dec 16, 2004
    #6
  7. I did this 9.5 hours ago. Compared to the python one it is not
    vulnerable to File stealing attacks (a client can request a file
    .../foobar and ~/foobar from the python server and will get it back
    AFAIK) and 6 lines long. It is however vulnerable to the DRb style
    ..instance_eval exploits. I will fix this shortly, but I might have to
    use 7 lines then.

    # Server: ruby p2p.rb password server server-uri merge-servers
    # Sample: ruby p2p.rb foobar server druby://localhost:1337 druby://foo.bar:1337
    # Client: ruby p2p.rb password client server-uri download-pattern
    # Sample: ruby p2p.rb foobar client druby://localhost:1337 *.rb
    require'drb';F,D,C,P,M,U,*O=File,Class,Dir,*ARGV;def s(p)F.split(p[/[^|].*/])[-1
    ]end;def c(u);DRbObject.new((),u)end;def x(u)[P,u].hash;end;M=="client"&&c(U).f(
    x(U)).each{|n|p,c=x(n),c(n);(c.f(p,O[0],0).map{|f|s f}-D["*"]).each{|f|F.open(f,
    "w"){|o|o<<c.f(p,f,1)}}}||(DRb.start_service U,C.new{def f(c,a=[],t=2)c==x(U)&&(
    t==0&&D[s(a)]||t==1&&F.read(s(a))||p(a))end;def y()(p(U)+p).each{|u|c(u).f(x(u),
    p(U))rescue()};self;end;private;def p(x=[]);O.push(*x).uniq!;O;end}.new.y;sleep)
     
    Florian Gross, Dec 16, 2004
    #7
  8. I hope sort is not implemented as quicksort ;)

    Regards,

    Brian
     
    Brian Schröder, Dec 16, 2004
    #8
  9. array.c:

    static VALUE
    sort_internal(ary)
    VALUE ary;
    {
    qsort(RARRAY(ary)->ptr, RARRAY(ary)->len, sizeof(VALUE),
    rb_block_given_p()?sort_1:sort_2);
    return ary;
    }

    rb_ary_sort_bang(ary)
    VALUE ary;
    {
    rb_ary_modify(ary);
    if (RARRAY(ary)->len > 1) {
    FL_SET(ary, ARY_TMPLOCK); /* prohibit modification during sort */
    rb_ensure(sort_internal, ary, sort_unlock, ary);
    }
    return ary;
    }

    Just hope your systems qsort() is any good,
    nikolai
     
    Nikolai Weibull, Dec 16, 2004
    #9
  10. slonik AZ

    ts Guest

    N> Just hope your systems qsort() is any good,

    uln% grep qsort util.h
    void ruby_qsort _((void*, const int, const int, int (*)(), void*));
    #define qsort(b,n,s,c,d) ruby_qsort(b,n,s,c,d)
    uln%


    Guy Decoux
     
    ts, Dec 16, 2004
    #10
  11. Here we go. Thanks to Mauricio Fernández for helping out with cutting
    off a few important characters!


    #!/usr/bin/ruby
    # Server: ruby p2p.rb password server server-uri merge-servers
    # Sample: ruby p2p.rb foobar server druby://localhost:1337 druby://foo.bar:1337
    # Client: ruby p2p.rb password client server-uri download-pattern
    # Sample: ruby p2p.rb foobar client druby://localhost:1337 *.rb
    require'drb';F,D,P,M,U,*O=File,Dir,*ARGV;def s(p)F.basename p[/\w.*/]end;def c u
    DRbObject.new((),u)end;def x(u);[P,u].hash;end;M["c"]?c(U).f(x(U)).map{|n|p=x(n)
    c=c(n);(c.f(p,O[0],0).map{|f|s f}-D["*"]).map{|f|open(f,"w")<<c.f(p,f,1)}}:(DRb.
    start_service U,Class.new{def p(z=O)O.push(*z).uniq!;O;end;new.methods.map{|m|m[
    /_[_t]/]||private(m)};def f(c,a=[],t=2)c==x(U)&&(t==0?D[s(a)]:t==1?F.read(s(a)):
    p(a))end;def y;(p(U)+p).map{|u|c(u).f(x(u),p(U))rescue()};self;end}.new.y;sleep)
     
    Florian Gross, Dec 16, 2004
    #11
  12. Then hope Ruby's implementation of qsort is any good ;-),
    nikolai
     
    Nikolai Weibull, Dec 16, 2004
    #12
  13. So just out of interest, what kind of sort is ruby using?
    (I could dig the sources, but I hope it will be an easy question for someone to
    answer without spending too much time.)

    Regards,

    Brian
     
    Brian Schröder, Dec 16, 2004
    #13
  14. I am saddened that they failed to mention ducks. Ducks, or, more
    particularly, images of ducks, are the only legitimate payload in
    peer-to-peer networks these days. And, notice how I summarized this
    point in less than 15 lines of text. Christmas miracles abound, folks.

    _why
     
    why the lucky stiff, Dec 16, 2004
    #14
  15. Seems to be your standard memory-swap optimized quicksort, using its own
    stack (i.e. no recursion), much like the one in glibc,
    nikolai
     
    Nikolai Weibull, Dec 16, 2004
    #15
  16. Nice use of drb.

    I wonder how long the same program would be in ruby if it implemented
    the "tinyp2p" protocol instead of using drb. ;)

    -dave
     
    David G. Andersen, Dec 16, 2004
    #16
  17. _why

    No matter how much you might be off topic, I always enjoy reading your
    posts. Another miracle lurking in the dark, there.

    yours,
    kaspar
     
    Kaspar Schiess, Dec 17, 2004
    #17
  18. Another new version, binary files can be transfered to and from Win32,
    you can run servers from behind Routers and you can list all the files
    on the specified network sorted by node and file name before downloading
    them. Still six lines.

    #!/usr/bin/ruby
    # Server: ruby p2p.rb password server public-uri private-uri merge-servers
    # Sample: ruby p2p.rb foobar server druby://123.123.123.123:1337
    # druby://:1337 druby://foo.bar:1337
    # Client: ruby p2p.rb password client server-uri download-pattern [list-only]
    # Sample: ruby p2p.rb foobar client druby://localhost:1337 *.rb
    ################################################################################
    require'drb';F=File;P,M,U,V,*O=ARGV;def c(u)DRbObject.new((),u)end;def x(u);[P,u
    ].hash;end;def s(p);F.basename p[/[^|]+/];end;M["s"]?(DRb.start_service V,Class.
    new{def p(z=O)O.push(*z).uniq;end;new.methods.map{|m|m[/_[_t]/]||private(m)};def
    y;(p(U)+p).map{|u|u!=U&&c(u).f(x(u),p(U))};self;end;def f(c,a=[],t=2)x(U)==c&&t<
    1?Dir[s(a)]:t<2?[*open(s(a),"rb")]:p(a)end}.new.y;sleep):c(U).f(x(U)).map{|n|c(n
    ).f(x(n),V,0).map{|f|s f}.sort.map{|f|O[0]?p(f):eek:pen(f,"wb")<<c(n).f(x(n),f,1)}}
     
    Florian Gross, Dec 17, 2004
    #18
  19. slonik AZ

    thanhvn.info Guest

    thanhvn.info, Sep 10, 2012
    #19
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