From: Judson Lester <nyarly@...>
Date: 2009-11-10T06:31:31+09:00
Subject: Re: [ANN] called_from 0.1.0 released

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I've long wished that caller returned an array of BacktraceLine... likewise
Exception#backtrace.

class BacktraceLine
  attr_reader :line, :file, :method, :arguments
end

Not sure if it's a daydream or an REP...

Judson

On Sun, Nov 8, 2009 at 4:51 PM, Jeremy Kemper <jeremy@bitsweat.net> wrote:

> This is probably the most common usage of Kernel#caller. You've made
> it more useful and much faster -- great extension!
>
> jeremy
>
> On Sun, Nov 8, 2009 at 3:25 PM, makoto kuwata <kwatch@gmail.com> wrote:
> > I releaded called_from 0.1.0.
> > http://github.com/kwatch/called_from
> >
> > Kernel#caller() is very useful, but very slow.
> > 'called_from' solves this problem.
> >
> >
> > About
> > -----
> >
> > 'called_from' provides called_from() global function
> > which gets filename and line number of caller.
> >
> > In short:
> >
> >    require 'called_from'
> >    filename, linenum, function = called_from(1)
> >
> > is equivarent to:
> >
> >    caller(1)[0] =~ /:(\d+)( in `(.*)')?/
> >    filename, linenum, function = $`, $1, $2
> >
> > But called_from() is much faster than caller()[0].
> >
> >
> >
> > Example
> > -------
> >
> >    require 'called_from'
> >
> >    ##
> >    ## report not only what sql is queried but also from where query()
> > is called.
> >    ## (this is very convenient for development and debugging)
> >    ## in such examle, speed of called_from() is very important.
> >    ##
> >    def query(sql)
> >      filename, linenum, function = called_from()
> >      log.debug("#{Time.now}: #{sql} (called from #{filename}:#
> > {linenum})")
> >      return connection.query(sql)
> >    end
> >
> >    ##
> >    ## if cache data is older than template file's timestamp,
> >    ## refresh cache data.
> >    ## it is very important that called_from() is much faster than
> > caller()[0]
> >    ## because speed is necessary for caching.
> >    ##
> >    def cache_helper(cache_key)
> >      ## check template file's timestamp
> >      template_filename, linenum, function = called_from()
> >      timestamp = File.mtime(template_filename)
> >      ## if cache data is newer than template's timestamp, return data
> >      data = @cache.get(cache_key, :timestamp=>timestamp)
> >      return data if data
> >      ## if cache data is older than template's timestamp, refresh it
> >      data = yield()
> >      @cache.set(cache_key, data)
> >      return data
> >    end
> >
> >
> >
> > Benchmark
> > ---------
> >
> > Here is an example result of benchmark on Merb application.
> > This shows that called_from() is more than 30 times faster than caller
> > ()[0].
> >
> >
> >    *** n=100000
> >                                 user     system      total
> > real
> >    caller()[0]              7.920000   0.400000   8.320000
> > (  8.985343)
> >    caller()[0]   (*1)       8.590000   0.420000   9.010000
> > (  9.804065)
> >    called_from()            0.240000   0.010000   0.250000
> > (  0.257151)
> >    called_from() (*2)       0.250000   0.000000   0.250000
> > (  0.268603)
> >
> >
> >    (*1) retrieve filename and line number using pattern match (=~ /:
> > (\d+)/)
> >    (*2) retrieve filename and line number
> >
> >
> >
> > Installation
> > ------------
> >
> >    $ sudo gem install called_from
> >
> > Or
> >
> >    $ tar xzf called_from_X.X.X.tar.gz
> >    $ cd called_from_X.X.X/
> >    $ ruby setup.rb config
> >    $ ruby setup.rb setup
> >    $ sudo ruby setup.rb install
> >
> > Notice: called_from is implemented in both C-extention and pure Ruby.
> > C-extention is available on UNIX-like OS and Ruby 1.8.x.
> >
> >
> > --
> > regards,
> > makoto kuwata
> >
> >
>
>

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