As the year is coming to an end. I realise i haven’t posted anything this last month. And i have load of things on my mind. But no time. I’ll be heading over to a friends house for the remaining part of this year. So i wish everybody a good and happy 2011. Don’t drink to much and be careful with fireworks.

On a side note: did anybody check out the new php.net layout? i think Hannes and Co are doing a great job!

(to see the new layout go to php.net/my and flip the beta switch at the bottom of the page)

Last weekend was a PFZ meeting. And for this day a few interesting workshops were planned. I mainly was looking forward to the GIT (Git for Subversion Users) talk by Stefan Koopmanschap. And the Dependency Injection presentation by Berry Langerak I didn’t make it too the last one. But learned a lot while doing the GIT workshop with Stefan.

For the last few months i have wanted to take a look at git. But it just never really took the time to sit down and do it. So this opportunity was there at the right time. Although my laptop died halfway through the workshop. I still was able to make it through the whole session together with Joost van Veen. Thanks man. We had a great time. And it was eye opening. Stefan gave a good talk. Helped out where possible. And besides a small Github glitch. It was a successful day.

So successful that i decided to make the switch from Subversion to GIT. Below are some of the steps i took.

The main reasons for me to make the switch

• Distributed structure make it easy to work from any place. connected or not.
• Stashing
• Speed and cleaner folder / file structure
• Real tags

That’s all for now. but this list will grow. I am sure!

Setting up a GIT server

I decided to go for my own GIT server instead of Github. That’s just the way i like it. Full control.

$ aptitude install git-core

Now all we have to do is create a user for git operations. And set the correct permissions.

$ adduser git
$ mkdir /home/git/.ssh
$ chown -R git:git /home/git/.ssh
$ chmod 700 /home/git

If we want to create a new remote repository. We log in on the git server through SSH and setup a new repository like this.

$ ssh git@git.domain.tld
$ mkdir repository.git
$ cd repository.git
$ git –bare init

That’s all. we now have all we need to connect to git remotely and do some work. But now first we need to import the old Subversion repository. I have found two solid methods for getting the job done.

Import a SVN project into GIT with git-svn

First of install git-svn

$ sudo aptitude install git-svn

Before we start the importing. It’s good practice to create an author mapping file. So the SVN commiter names match the GIT ones. This is done by creating a simple text file like so.

$ touch authors.txt
$ echo “m0s = Thijs Lensselink ” > authors.txt

Importing the existing tags and branches is done by adding the –stdlayout switch

$ git svn clone –stdlayout -A authors.txt svn+ssh://user@svnhost/repository repository.git

The problem with this method is that tags and branches are not created properly. I decided to go for the second method down here.

Import a SVN project into GIT with svn2git

For this to work we first need ruby and some gems packages.

$ apt-get install git-svn ruby rubygems
$ gem install svn2git –source http://gemcutter.org

Create the local repository and import the files from SVN

$ mkdir repository.git
$ cd repository.git
$ /var/lib/gems/1.8/bin/svn2git svn+ssh://user@svnhost/repository –authors ../authors.txt

Show the current selected branch

$ git branch
* master

Show all branches. Notice the trunk branch

$ git branch -a
* master
trunk

List all tags

$ git tag -l
v1.0
v2.0

That seemed to work pretty good for almost all projects. Some projects didn’t have the main trunk in SVN. So to import these just add the –rootistrunk switch.

And while this info is still available in my brain at the moment. I will write down some of the workshop material for future reference.

Setup local Development environment

Create directory somewhere that will serve as the local repository. And run init to create the basic git project structure.

$ mkdir [project name]
$ cd [project name]
$ git init

Now we have a fully functional git repository. We can do anything with (add, commit, tag, branch, push, etc.) The first things to do when starting out is setup the user name and email address of the developer using this repository. This is good when looking though the GIT project logs later on. Also handy to set the core editor to the most convenient editor available.

$ git config –global user.name “Thijs Lensselink”
$ git config –global user.email “email@lenss.nl”
$ git config –global core.editor vi

The repository exists out of a origin and a master branch at this moment. The origin refers to the current repository location. And the master refers to the current repository state. Like HEAD in CVS and SVN. Let’s add a file for testing.

$ touch index.php
$ git add index.php (or add *)
$ git commit -m “Commit something”

Working on a local repository is nice. but we want to save it on a server of course. For this we need to set a repository location. We can do this in two ways. We can overwrite the origin or add a new location. Let’s try the first one.

$ git remote add origin git@git.domain.tld:repository.git

Setting up the remote git repository and push the changes

All changes to this repository are made locally so far. Let’s try and push them to the git server. The only problem here is. I haven’t found a way to create repositories remotely. So we have to log in to the server here and create the repository.

$ ssh git@git.domain.tld
$ mkdir repository.git
$ cd repository.git
$ git –bare init
$ exit

Back on the client side we can now do a push an see what happens.

$ git push origin master
Counting objects: 3, done.
Writing objects: 100% (3/3), 232 bytes, done.
Total 3 (delta 0), reused 0 (delta 0)
To git@192.168.178.24:foo.git
* [new branch] master -> master

if you get this error:

error: src refspec master does not match any.

This means there is no master branch yet. This happens when the repository was created with the –bare switch. You have to commit a change first before you can push anything to the remote repository server.

That’s all. We now have a working GIT server and local repository. All that is left is to do some serious development work. On the other hand, before i forget. i will use this space to rehash Stefan’s workshop for future reference.

Tagging

Let start by looking at the way git creates tags. First of there are two types of tags lightweight and annotated. The lightweight version is nothing more then a pointer to a specific commit. It’s like a branch that doesn’t change. Annotated tags are a bit different then their lightweight version. And for sure different from the tags in Subversion. A tags in git contains the following data

• checksum
• tagger name
• email + date
• tag message
• GPG signed

Creating an annotated tag for version 1 looks something like this

$ git tag -a v1.0 -m “Creating a tag”

Dispaly a certain tag

$ git show v1.0

I haven’t had time to look into working with signing of tags. So maybe i will add an entry about that later on.

Branching

A repository can have multiple branches. And switching between branches is a since in git. Branching is much like
it is in Subversion.

Create a new branch from master called foo

$ git branch foo master

Display all branches available. The current branch is highlighted by the * sign

$ git branch
* master
foo

Changing branches in git is a piece of cake.

$ git checkout foo
Switched to branch ‘foo’

There is not much more to branching.

diff, merge and delete branches

When adding a new feature to an existing code base. It’s good practice to create a branch before you start editing. And after everything is done and the change is stable. The branch can be merged back into the master.

First let’s check if there is a difference between the newly created branch and the master.

$ git diff foo master
diff –git a/touch.foo b/touch.foo
deleted file mode 100644
index 257cc56..0000000
— a/touch.foo
+++ /dev/null
@@ -1 +0,0 @@
-foo

Some changes have been found so let’s merge them in the master branch

$ git checkout master
$ git merge foo master (or git pull foo master)
Already up-to-date with 12d2f9cebaf71a580b021a8eeddc38f267b69e53
Trying simple merge with 4d3dff7e0d2a26302a5884e763fd7a48f5ab4437
Merge made by octopus.
touch.foo | 1 +
1 files changed, 1 insertions(+), 0 deletions(-)
create mode 100644 touch.foo

with git pull it is possible to import branches from other repositories

When done with the changes. And everything is pushed to the remote git server, we can remove the ‘foo’ branch

$ git branch -d foo
Deleted branch foo (was d9a8c76).

That’s all for branching right now.

Stashing

One of my personal favorite the stash command. Imagine working on a project. And somebody asks you to make a small change. In subversion i needed to do a new checkout and work on that. This can be quite slow and cumbersome. In git this is solved elegantly by using the stash command.

$ git stash
Saved working directory and index state “WIP on master: 648f347… foo”
(To restore them type “git stash apply”)
HEAD is now at 648f347 foo

This saves a copy of the working state and let’s you do changes on a fresh base. After your done get back to your work by doing

$ git stash pop (or apply)

With pop you push the stash back to the master. With apply the changes will first be applied to the master before restoring the work state.

Working with other repositories

Clone a repository from a remote GIT server

$ git clone git@git.domain.tld:repository.git ./project2

Clone a local GIT repository

$ git clone ./project ./project2

Now it could be possible a friend or a remote community member without write access made a few changes to his / her remote repository. And wants them on the global remote GIT server. This can be done by pulling the code.

First add the new repository location

$ git remote add friend git://githubaddress

And then fetch the remote changes

$ git fetch friend

This only fetches the changes. but does not apply them to the master. Apply them

$ git pull friend master

updating remote repository

$ git push friend master

That’s all i can remember right now.

As i was trying to get ready to convert my SVN repository into a GIT repository. I noticed one of my DNS slave servers wasn’t responding. A look at the log files showed something was wrong.

The master server showed:

[1289693117] nsd[6899]: error: query tsig unknown key/algorithm

While the slave displayed the following message

[883615032] nsd[6624]: error: xfrd: zone [ domain ] received error code REFUSED from [ ip address ]

After an hour of searching Google and not hitting any useful result. I rebooted the machine. And was presented by forced hard disk check. The damn thing seemed to be out of sync. And when rebooted. The date was off by a few centuries.

So after resetting the date and restarting NSD. The problem was resolved.

$ date -s ’14 NOV 2010 01:37:00′
$ /usr/sbin/nsdc update > /dev/nul 2>%1
$ /usr/sbin/nsdc patch > /dev/nul 2>%1
$ /usr/sbin/nsdc rebuild > /dev/nul 2>%1
$ /usr/sbin/nsdc reload > /dev/nul 2>%1
$ /usr/sbin/nsdc notify > /dev/nul 2>%1

Last week i toyed with mod_pagespeed a bit. But just couldn’t get the hang of it. So the last two days permitted me to play some more with this great Apache module. Only this time i choose to build from source and ignore the binaries for a while.

For me the main problem was. As soon as i enabled the module. It was active for all sites running on this server. And that should not be a problem. But some of these sites are WordPress monsters. That are ready to take any server down with a bit of high load.

So after a bit of trail and error. I figured out i could just disable mod_pagespeed globally by altering the main config file. After Apache reloaded mod_pagespeed was not active for the running sites.

in /etc/apache2/mods-available/pagespeed.conf make sure ModPagespeed is set to ‘off’

ModPagespeed off

So now i can simply enable settings i need on a per vhost basis. For this site end some other sites i used the following config section in my vhost.

# MOD-pagespeed

SetOutputFilter MOD_PAGESPEED_OUTPUT_FILTER
ModPagespeed on

ModPagespeedUrlPrefix “http://lenss.nl”

ModPagespeedFileCachePath “/var/mod_pagespeed/cache/”
ModPagespeedGeneratedFilePrefix “/var/mod_pagespeed/files/”

#ModPagespeedRewriteLevel CoreFilters
ModPagespeedRewriteLevel PassThrough

ModPagespeedEnableFilters add_head
ModPagespeedEnableFilters collapse_whitespace
ModPagespeedEnableFilters elide_attributes
ModPagespeedEnableFilters remove_comments
ModPagespeedEnableFilters rewrite_css
ModPagespeedEnableFilters rewrite_javascript
ModPagespeedEnableFilters move_css_to_head

First of we enable mod_pagespeed of course. And then we set the current domain for this instance. After that we set the file paths for the altered and cached files. And we use ‘PassThrough’ instead of ‘CoreFilters’. So we can decide our self’s what filters we will be using.

This had a much better result then my previous attempts. The server was still happily serving pages. And the load was OK. So let’s check the sites if mod_pagespeed is actually running.

$ wget -O /dev/null –server-response http://lenss.nl 2>&1| grep -i ‘X-Mod-Pagespeed’
X-Mod-Pagespeed: 0.9.0.0-172

Well that looks good. So now it’s time to do some testing. And this leaves me with a bit of a pickle. As i don’t have the required wget v 1.12 (i have a small patch for wget v1.11). Besides that i have some other problems running the tests

TEST: 404s are served and properly recorded.
wget -O /dev/null http://lenss.nl/mod_pagespeed/ic.a.bad.css 2>&1| grep -q ’404 Not Found’
wget -q -O – –save-headers http://localhost:80/mod_pagespeed_statistics | grep -q ‘resource_404_count: 1′
FAIL.

This fails because the statistics page requested is not available because this site uses rewrites. And i haven’t found a way to go around this yet besides disabling them in .htaccess with mod_rewrite. So shortly disabling this made it possible to run the biggest part of the test suite without problems.

resource_fetches: 2
total_page_load_ms: 0
page_load_count: 0
cache_extensions: 0
not_cacheable: 0
css_file_count_reduction: 0
css_filter_files_minified: 13
css_filter_minified_bytes_saved: 5082
css_filter_parse_failures: 0
css_elements: 0
image_inline: 0
image_rewrite_saved_bytes: 0
image_rewrites: 0
javascript_blocks_minified: 15
javascript_bytes_saved: 380
javascript_minification_failures: 0
javascript_total_blocks: 15
resource_url_domain_rejections: 0
url_trims: 0
url_trim_saved_bytes: 0
resource_404_count: 2
slurp_404_count: 0
serf_fetch_request_count: 0
serf_fetch_bytes_count: 0
serf_fetch_time_duration_ms: 0
serf_fetch_cancel_count: 0

It fails on the image compression part and that’s fine. Because i will leave that for later. So let’s run the site through the pagespeed browser extension with mod_pagespeed disabled:

load time without : 2.193
firebug/pagespeed score : 68

Now the same thing but with mod_pagespeed enabled:

Load time with : 1.284
firebug/pagespeed score : 90

That looks pretty good. And the other sites i have tested preform way better with the mod_pagespeed module enabled.

I still have some Javascript issues. Some things need further inspection because i have seen error like these coming along:

Permission denied for to call method Location.toString on .

Besides that. This morning my site was down due to Apache spitting segfaults. I disabled the ‘rewrite_javascript’ filter for now. And it seems to run a bit more stable.

[Thu Nov 11 07:38:24 2010] [notice] child pid 23608 exit signal Segmentation fault (11)

So besides it being a beta i am pretty impressed by the current state of this module. And after running it for a couple of weeks the statistics are pretty impressive.

Manuel Lemos also wrote a nice article about mod_pagespeed which is worth reading.

Today Rasmus posted on twitter that he just compiled PHP v 1.0.8. And it actually worked. Is that great? :) He was in need of this for his upcoming talk this week in Paris. But i couldn’t resist and try to compile this ancient piece of work ;)

$ wget http://museum.php.net/php1/php-108.tar.gz
$ tar xfvz php-108.tar.gz
$ cd php

If you need to change any config setting do it now. And hit make!

$ vi config.h
$ make

This creates a few .cgi files. So it actually does still build

phpf.cgi
phpl.cgi
phplmon.cgi
phplview.cgi

Let’s copy that to my cgi-bin and run it through Apache.

I cam across this page today and it made me laugh :) With thanks to the GNU jokes archive.

How the way people code “Hello World” varies depending on their age and job:

High School/Jr. High

10 PRINT "HELLO WORLD"
 20 END

First year in College

program Hello(input, output)
begin
writeln(‘Hello World’)
end.

Senior year in College

(defun hello
(print
(cons ‘Hello (list ‘World))))

New professional

#include <stdio.h>

 void main(void)
 {
  char *message[] = {"Hello ", "World"};
  int i;
  for(i = 0; i < 2; ++i)
  printf("%s", message[i]);
  printf("\n");
 }

Seasoned professional

#include <iostream.h>
 #include <string.h>
 class string
 {
  private:
   int size;
   char *ptr;
  public:
   string() : size(0), ptr(new char('\0')) {}
   string(const string &s) : size(s.size)
   {
     ptr = new char[size + 1];
     strcpy(ptr, s.ptr);
   }
   ~string()
   {
     delete [] ptr;
   }
   friend ostream &operator <<(ostream &, const string &);
   string &operator=(const char *);
 };

 ostream &operator<<(ostream &stream, const string &s)
 {
   return(stream << s.ptr);
 }
 string &string::operator=(const char *chrs)
 {
   if (this != &chrs)
   {
     delete [] ptr;
     size = strlen(chrs);
     ptr = new char[size + 1];
     strcpy(ptr, chrs);
   }
   return(*this);
 }
 int main()
 {
   string str;
   str = "Hello World";
   cout << str << endl;
   return(0);
 }

System Administrator

#include <stdio.h>
 #include <stdlib.h>
 main()
 {
  char *tmp;
  int i=0;
  /* on y va bourin */
  tmp=(char *)malloc(1024*sizeof(char));
  while (tmp[i]="Hello Wolrd"[i++]);
  /* Ooopps y'a une infusion ! */
  i=(int)tmp[8];
  tmp[8]=tmp[9];
  tmp[9]=(char)i;
  printf("%s\n",tmp);
 }

Apprentice Hacker

#!/usr/local/bin/perl
 $msg="Hello, world.\n";
 if ($#ARGV >= 0) {
     while(defined($arg=shift(@ARGV))) {
	 $outfilename = $arg;
	 open(FILE, ">" . $outfilename) || die "Can't write $arg: $!\n";
	 print (FILE $msg);
	 close(FILE) || die "Can't close $arg: $!\n";
     }
 } else {
     print ($msg);
 }
 1;

Experienced Hacker

 #include <stdio.h>
 #include <string.h>
 #define S "Hello, World\n"
 main(){exit(printf(S) == strlen(S) ? 0 : 1);}

Seasoned Hacker

 % cc -o a.out ~/src/misc/hw/hw.c
 % a.out
 Hello, world.

Guru Hacker

% cat
Hello, world.

New Manager (do you remember?)

 10 PRINT "HELLO WORLD"
 20 END

Middle Manager

 mail -s "Hello, world." bob@b12
 Bob, could you please write me a program that prints "Hello, world."?
 I need it by tomorrow.
 ^D

Senior Manager

 % zmail jim
 I need a "Hello, world." program by this afternoon.

Chief Executive

% letter
 letter: Command not found.
 % mail
 To: ^X ^F ^C
 % help mail
 help: Command not found.
 % damn!
 !: Event unrecognized
 % logout

Research Scientist

PROGRAM HELLO
PRINT *, 'Hello World'
END

Older research Scientist

WRITE (6, 100)
100 FORMAT (1H ,11HHELLO WORLD)
CALL EXIT
END

After purchasing a new batch of the friendly blue guys. Damien Seguy was so friendly to send me an early Christmas present :)

I have some small versions left by the way. So if you are one of those people looking. Drop me a line or leave a comment.

Ok so i had nothing todo for a few minutes and found a link to this page. I am never really into this stuff. But it looked funny and i had nothing to do. So i walked through the questions… and the result :)

Supreme Nerd. Apply for a professorship at MIT now!!!.

Another nerdy thing i picked up was that Ilia Alshanetsky’s scalar type hints patch has been merged with the PHP trunk. Great stuff. Have been waiting for this for a while.

This long Easter weekend gave me some time to create a new theme for this blog. So after a day of work this is the result. I was a bit tired of the dark unreadable format. At the moment i am still tweaking here and there but it looks fine!

Have been working hard this week on kremermakelaars.nl. And managed to finish it right before the end of this year. The old website was one of those left overs from the early 90′s. The only thing missing was a spinning @ sign. But i think i managed to give it a nice visual boost. For the back-end i created s nice CMS to manage all objects and page content. The whole thing is build with ZF, Mysql, and some javascript libraries.

The customer is happy. I’m happy. Now it’s time for some fun!

So that’s all for 2009. I wish everybody a good and happy new year.