Re: [PHP4BETA] proposed fopen_wrappers generalization / patch v.2

Andi Gutmans wrote:
> 
> It definitely sounds good but can you describe it in a bit more detail? :)
> 

Well, i'll try to remember the steps i took so far:

1) the function doing fopen wrapping was one big ugly piece
   containing code for simple fopen, for HTTP and FTP protocol 
   initiation on sockets and the PHP special cases for
stdin/stdout/stderr
   all in one

   i devided this one in a master function figuring out url type
   with plain old fopen as fallback and one function for each
   of the URL types 'http:', 'ftp:' and 'php:'

   no problem so far 

2) i added support for local 'file:/path' URLs by just stripping of
   the 'file:' prefix for local files and generating a warning
   if 'file://hostname/path' was used

   still no problem, although i temporarily borke it later on

3) experimental stage: here i built a simple array of structs that
   mapped URL type names against pointers to handler functions,
   initialized it staticly and changed the if/else if/else cascade
   into a comparison loop over this array

   after refreshing my knowledge about how to declare function pointers
   and pointers to function pointers this was looking very good

4) doing the right thing: after proof of concept in step 3) i converted
   the static array into "HashTable fopen_url_wrappers_hash;",
   added the following functions:
     - int        php_init_fopen_wrappers(void); 
     - int        php_shutdown_fopen_wrappers(void); 
     - PHPAPI int php_register_url_wrapper(char *protocol, FILE *
(*wrapper)(...));
     - PHPAPI int php_unregister_url_wrapper(char *protocol);
   and called the init & shutdown functions in the appropriate places in
   main.c
  
   php_init_fopen_wrappers() will register the default handlers 
   for ftp:, http: and php:

   extension modules may register additional handlers using the
register/unregister 
   pair of function

   a simple dummy module will register itself for 'test:' URLs and will
treat them
   like 'file:' URLs by just trying an fopen() on the supplied path

   thats what is there as of now



I didn't do a checkin yet as i am not sure about the follwing issues:

- Did i really get those HashTable functions right?

- Where is the best place for the init/shutdown functions?
  Currently they are in php_module_startup/shutdown
  immediately before php_startup_internal_extensions() /
  after php_config_ini_shutdown()?

- What should happen if two modules try to register a wrapper for
  the same URL type ?


i have tried it so far with linux and solaris, cgi and apxs, 
'test:'-module staticly linked in, without problems


now this is almost as long as the patch itself ... :)


--
Hartmut Holzgraefe         [email protected]           http://www.six.de