Generate an APC prefix based on __FILE__

[trsteel88]

Closes #654

[toaotc]

i don't believe this is a good idea. If you have many symfony2 installations on the server, you will have conflicts because same hash would be created for files with same content.

so 👎

[stof]

it does not create the hash based on the content of the file, but based on the path of the file

[toaotc]

@stof yes - you're right. I could swear I saw a file_get_contents(). So it seems to be 👍 to me.

edit: but a line comment for what happens there would be nice

[fabpot]

@trsteel88 Can you revert the comment and tweak it to explain what's going on here?

[stof]

I'm 👍 for this change if we add the comment back (tweaking it a bit of course)

[pyrech]

I wonder if the hash could not be added in the file during the composer install rather than calculated every time? sha1 is not quiet expensive but could be worth it in a prod environnement.

[trsteel88]

I am away on holiday at the moment so would not be able to make the change
for a few weeks.

[fabpot]

Thank you @trsteel88.

[fabpot]

I've re-added the comment in 2df0e6f