Re: [PATCH 01/13] libfshelp: use a hash table in get-identity.c

[Samuel Thibault]

Justus Winter, le Mon 09 Dec 2013 15:16:29 +0100, a écrit :
> Currently fshelp_get_identity uses ports_class_iterate to de-duplicate
> the identity ports. Use a hash table instead.

Ack.

> * libfshelp/get-identity.c (struct idspec): Remove field fileno.
> (struct idspec): Add field id_hashloc.
> (id_clean): New function.
> (id_initialize): Use id_clean as cleanup function for idclass.
> (fshelp_get_identity): Use a hash table to de-duplicate the identity
> ports.
> ---
>  libfshelp/get-identity.c |   66 
> ++++++++++++++++++++++++----------------------
>  1 file changed, 35 insertions(+), 31 deletions(-)
> 
> diff --git a/libfshelp/get-identity.c b/libfshelp/get-identity.c
> index 946b7e8..2dbd254 100644
> --- a/libfshelp/get-identity.c
> +++ b/libfshelp/get-identity.c
> @@ -21,6 +21,8 @@
>  
>  #include <fshelp.h>
>  #include <hurd/ports.h>
> +#include <hurd/ihash.h>
> +#include <stddef.h>
>  #include <assert.h>
>  
>  static struct port_class *idclass = 0;
> @@ -29,14 +31,26 @@ static pthread_mutex_t idlock = PTHREAD_MUTEX_INITIALIZER;
>  struct idspec
>  {
>    struct port_info pi;
> -  ino_t fileno;
> +  hurd_ihash_locp_t id_hashloc;
>  };
>  
> +static struct hurd_ihash idhash
> +  = HURD_IHASH_INITIALIZER (offsetof (struct idspec, id_hashloc));
> +
> +static void
> +id_clean (void *cookie)
> +{
> +  struct idspec *i = cookie;
> +  pthread_mutex_lock (&idlock);
> +  hurd_ihash_locp_remove (&idhash, i->id_hashloc);
> +  pthread_mutex_unlock (&idlock);
> +}
> +
>  static void
>  id_initialize ()
>  {
>    assert (!idclass);
> -  idclass = ports_create_class (0, 0);
> +  idclass = ports_create_class (id_clean, NULL);
>  }
>  
>  error_t
> @@ -47,42 +61,32 @@ fshelp_get_identity (struct port_bucket *bucket,
>    struct idspec *i;
>    error_t err = 0;
>  
> -  error_t check_port (void *arg)
> -    {
> -      struct idspec *i = arg;
> -      if (i->fileno == fileno)
> -     {
> -       *pt = ports_get_right (i);
> -       return 1;
> -     }
> -      else
> -     return 0;
> -    }
> -
>    pthread_mutex_lock (&idlock);
>    if (!idclass)
>      id_initialize ();
>  
> -  *pt = MACH_PORT_NULL;
> -
> -  ports_class_iterate (idclass, check_port);
> -
> -  if (*pt != MACH_PORT_NULL)
> +  i = hurd_ihash_find (&idhash, (hurd_ihash_key_t) fileno);
> +  if (i == NULL)
>      {
> -      pthread_mutex_unlock (&idlock);
> -      return 0;
> +      err = ports_create_port (idclass, bucket, sizeof (struct idspec), &i);
> +      if (err)
> +        goto lose;
> +      err = hurd_ihash_add (&idhash, (hurd_ihash_key_t) fileno, i);
> +      if (err)
> +        goto lose_port;
> +
> +      *pt = ports_get_right (i);
> +      ports_port_deref (i);
>      }
> +  else
> +    *pt = ports_get_right (i);
>  
> -  err = ports_create_port (idclass, bucket, sizeof (struct idspec), &i);
> -  if (err)
> -    {
> -      pthread_mutex_unlock (&idlock);
> -      return err;
> -    }
> -  i->fileno = fileno;
> +  /* Success!  */
> +  goto lose;
>  
> -  *pt = ports_get_right (i);
> -  ports_port_deref (i);
> + lose_port:
> +  ports_destroy_right (i);
> + lose:
>    pthread_mutex_unlock (&idlock);
> -  return 0;
> +  return err;
>  }
> -- 
> 1.7.10.4
> 

-- 
Samuel
 J'ai un gros problème: j'ai cet exercice à rendre demain lundi, mais ma
 TI 89 ne sait pas le faire...
 Est-ce que quelqu'un pourrait m'aider??
 -+- OD In Guide du Neuneu Usenet : Comment ça ! Il faut réfléchir ?-+-