Forum: Ruby Localmemcache-0.2.1: The beauty of memcached. For local data. Blazingly fast.

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Sven C. Koehler (Guest)
on 2009-04-05 22:55
(Received via mailing list)
Hi,

this release addresses some bugs that people were experiencing and
brings
speed improvements.

===

Localmemcache that aims to provide an interface similar to memcached but
for
accessing local data instead of remote data.  It's based on mmap()'ed
shared memory for maximum speed.

* http://localmemcache.rubyforge.org/

===

Changes for 0.2.1:
  * Fixed a bug that prevented setting values in the hashtable
  * Accessing a closed memory cache does no longer result in a crash

  * Speed improvements: On my machine localmemcache is now only about
20%
  slower than Ruby's hash (0.2.0 was about 40% slower)
  * OS X is now officially not supported as it lacks sem_timedwait and
  sem_getvalue (You still can force a build but it won't be able to
  recover from crashes.)
  * The environment variable LMC_NAMESPACES_ROOT_PATH can now be used to
  override the default, which is /var/tmp/localmemcache


EXAMPLE
=======

require 'localmemcache'
$lm = LocalMemCache.new :namespace => "viewcounters"
$lm[:foo] = 1
$lm[:foo]
$lm.delete(:foo)

INSTALL
=======

# gem install localmemcache

(In case rubyforge has not yet updated the mirrors, fetch the 0.2.1 gem
from here: http://github.com/sck/localmemcache/downloads and then do
# gem install localmemcache-0.2.1.gem )

CONTACT
=======

Please contact me with bugs, suggestions and patches at: schween + snafu
# de

LINKS
=====

Localmemcache: http://localmemcache.rubyforge.org/
Rubyforge project: http://localmemcache.rubyforge.org/

Source code is hosted on github: http://github.com/sck/localmemcache/

Best,

Sven C. Koehler

4e25d2a677e6723f706d47da4dfd68cd  localmemcache-0.2.1.gem
1658b6d660d64dbf57642789f49875e7  localmemcache-0.2.1.tar.gz
Iñaki Baz C. (Guest)
on 2009-04-05 23:33
(Received via mailing list)
El Domingo 05 Abril 2009, Sven C. Koehler
escribió:> Hi,
>
> this release addresses some bugs that people were experiencing and brings
> speed improvements.

Hi, I'm trying to install it in my 64 bits Ubuntu host with Ruby1.9.1
installed from sources in /usr/local.

This is the error output I get after doing "gem install localmemcache":


/usr/local/bin/ruby1.9 extconf.rb install localmemcache
checking for main() in -lrt... *** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of
necessary libraries and/or headers.  Check the mkmf.log file for more
details.  You may need configuration options.

Provided configuration options:
        --with-opt-dir
        --without-opt-dir
        --with-opt-include
        --without-opt-include=${opt-dir}/include
        --with-opt-lib
        --without-opt-lib=${opt-dir}/lib
        --with-make-prog
        --without-make-prog
        --srcdir=.
        --curdir
        --ruby=/usr/local/bin/ruby1.9
        --with-rtlib
        --without-rtlib
/usr/local/lib/ruby1.9/1.9.1/mkmf.rb:362:in `try_do': The complier
failed to
generate an executable file. (RuntimeError)
You have to install development tools first.
        from /usr/local/lib/ruby1.9/1.9.1/mkmf.rb:415:in `try_link0'
        from /usr/local/lib/ruby1.9/1.9.1/mkmf.rb:419:in `try_link'
        from /usr/local/lib/ruby1.9/1.9.1/mkmf.rb:527:in `try_func'
        from /usr/local/lib/ruby1.9/1.9.1/mkmf.rb:723:in `block in
have_library'
        from /usr/local/lib/ruby1.9/1.9.1/mkmf.rb:668:in `block in
checking_for'
        from /usr/local/lib/ruby1.9/1.9.1/mkmf.rb:274:in `block (2
levels) in
postpone'
        from /usr/local/lib/ruby1.9/1.9.1/mkmf.rb:248:in `open'
        from /usr/local/lib/ruby1.9/1.9.1/mkmf.rb:274:in `block in
postpone'
        from /usr/local/lib/ruby1.9/1.9.1/mkmf.rb:248:in `open'
        from /usr/local/lib/ruby1.9/1.9.1/mkmf.rb:270:in `postpone'
        from /usr/local/lib/ruby1.9/1.9.1/mkmf.rb:667:in `checking_for'
        from /usr/local/lib/ruby1.9/1.9.1/mkmf.rb:718:in `have_library'
        from extconf.rb:13:in `<main>'


mkmf.log is empty. What could I check?
Thanks.
Iñaki Baz C. (Guest)
on 2009-04-05 23:50
(Received via mailing list)
El Domingo 05 Abril 2009, Sven C. Koehler
escribió:> Hi,
>
> this release addresses some bugs that people were experiencing and brings
> speed improvements.

Now I've installed it in Ruby1.8 with no problem but I think there is
something wrong in the Gem.

Basically if I do:

--------------
~# irb1.8
irb> require "localmemcache"
LoadError: no such file to load -- localmemcache
        from (irb):5:in `require'
        from (irb):5
--------------

It makes sense since there is no "lib/localmemcache.rb" in the
localmemcache
gem directory.

The only way to load it is by doing:

-------------
~# cd /usr/lib/ruby/gems/1.8/gems/localmemcache-0.2.1/src/ruby-binding/
~# irb1.8
irb> require "localmemcache"
true
-------------

I understand that, for a normal Gem to work properly, it must create a
"gen_name.rb" in "GEMS_DIR/gen_name/lib/" (this is how all the rest of
Gems
are installed), but localmemcache doesn't create a "lib" directory.

Regards.
David M. (Guest)
on 2009-04-06 04:27
(Received via mailing list)
On Sunday 05 April 2009 14:48:28 Iñaki Baz C. wrote:
> ~# irb1.8
> irb> require "localmemcache"

1.9 has gems loaded by default. 1.8 doesn't. Try:

require 'rubygems'
require 'localmemcache'
Sven C. Koehler (Guest)
on 2009-04-06 04:28
(Received via mailing list)
On Sun, Apr 05, 2009 at 09:48:26PM +0200, Iñaki Baz C. wrote:
>         from (irb):5
I just checked it with my ubuntu machine and it's fine for me.  Most
likely you didn't load rubygems properly:

| sck@u:~/$ sudo gem install localmemcache
| Building native extensions.  This could take a while...
| Successfully installed localmemcache-0.2.1
| 1 gem installed
| sck@u:~$ irb -rubygems
| irb(main):001:0> require 'localmemcache'
| => true
| irb(main):003:0> $:
| => ["/var/lib/gems/1.8/gems/localmemcache-0.2.1/bin", 
"/var/lib/gems/1.8/gems/localmemcache-0.2.1/src/ruby-binding", 
"/usr/local/lib/site_ruby/1.8", "/usr/local/lib/site_ruby/1.8/i486-linux", 
"/usr/local/lib/site_ruby/1.8/i386-linux", "/usr/local/lib/site_ruby", 
"/usr/lib/ruby/vendor_ruby/1.8", "/usr/lib/ruby/vendor_ruby/1.8/i486-linux", 
"/usr/lib/ruby/vendor_ruby", "/usr/lib/ruby/1.8", "/usr/lib/ruby/1.8/i486-linux", 
"/usr/lib/ruby/1.8/i386-linux", "."]

-S.
-
Iñaki Baz C. (Guest)
on 2009-04-06 04:34
(Received via mailing list)
El Lunes 06 Abril 2009, David M.
escribió:> On Sunday 05 April 2009 14:48:28 Iñaki Baz C. wrote:
> > ~# irb1.8
> > irb> require "localmemcache"
>
> 1.9 has gems loaded by default. 1.8 doesn't. Try:
>
> require 'rubygems'
> require 'localmemcache'

Sure you are right. Thanks for pointing it out.
Iñaki Baz C. (Guest)
on 2009-04-06 04:36
(Received via mailing list)
El Lunes 06 Abril 2009, Sven C. Koehler
escribió:> I just checked it with my ubuntu machine and it's fine for me.  Most
> likely you didn't load rubygems properly:

Yes, sorry, I forgot to load rubygems in 1.8.

But there is still the issue with Ruby 1.9.1. It's a different issue.

Thanks.
Sven C. Koehler (Guest)
on 2009-04-06 05:48
(Received via mailing list)
On Mon, Apr 06, 2009 at 09:30:12AM +0900, Iñaki Baz C. wrote:
> But there is still the issue with Ruby 1.9.1. It's a different issue.

Ok, I just released localmemcache-0.2.2 which should fix the problems
with Ruby 1.9.

| sck@u:~$ sudo gem install localmemcache
| Building native extensions.  This could take a while...
| Successfully installed localmemcache-0.2.2
| 1 gem installed
| sck@u:~$ irb
| irb(main):001:0> require 'localmemcache'
| => true
| irb(main):002:0> $:
| => ["/var/lib/gems/1.9.0/gems/localmemcache-0.2.2/src/ruby-binding", 
"/var/lib/gems/1.9.0/gems/localmemcache-0.2.2/bin", "/usr/local/lib/site_ruby/1.9.0", 
"/usr/local/lib/site_ruby/1.9.0/i486-linux", "/usr/local/lib/site_ruby/1.9/i386-linux", 
"/usr/local/lib/site_ruby", "/usr/lib/ruby/vendor_ruby/1.9.0", 
"/usr/lib/ruby/vendor_ruby/1.9.0/i486-linux", "/usr/lib/ruby/vendor_ruby", 
"/usr/lib/ruby/1.9.0", "/usr/lib/ruby/1.9.0/i486-linux", "/usr/lib/ruby/1.9/i386-linux", 
"."]


-S.
Iñaki Baz C. (Guest)
on 2009-04-06 12:38
(Received via mailing list)
2009/4/6 Sven C. Koehler <removed_email_address@domain.invalid>:
> On Mon, Apr 06, 2009 at 09:30:12AM +0900, Iñaki Baz C. wrote:
>> But there is still the issue with Ruby 1.9.1. It's a different issue.
>
> Ok, I just released localmemcache-0.2.2 which should fix the problems
> with Ruby 1.9.

Thanks, it works!

Just a question: Every data I save in localmemcache is converted to
String:

irb> lm[:aaa]=true
true
irb> lm[:bbb]=123
123
irb> lm[:aaa]
"true"
irb> lm[:bbb]
"123"

About the performance, even if localmemcache is just 20% slower than
Ruby Hash, I wonder which is the real performance taking into account
that all the returned values are String, so instead of:

  if @do_action

I must do:

  if $lm[:do_action] == "true"


However, really thanks for this great utility. It allows for example
running  4 different processes of a Ruby programm in a quad-core CPU
sharing local memory :)
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