[Mesa-dev] [PATCH 3/7] glsl: Add initial functions to implement an on-disk cache

[Tapani Pälli]

Hi;

On 02/04/2015 11:52 PM, Carl Worth wrote:
> From: Kristian Høgsberg <krh at bitplanet.net>
>
> This code provides for an on-disk cache of objects. Objects are stored
> and retrieved (in ~/.cache/mesa) via names that are arbitrary 20-byte
> sequences, (intended to be SHA-1 hashes of something identifying for
> the content).
>
> The cache is limited to a maximum number of entries (1024 in this
> patch), and uses random replacement. These attributes are managed via

What would you think about changing this to use some defined maximum 
size (in MB)? I think for the user size is what matters and it could be 
a configurable option, number of items seems a bit vague and hard to 
predict (?)

8<

> +uint8_t *
> +cache_get(struct program_cache *cache, cache_key key, size_t *size)
> +{
> +   int fd, ret, len;
> +   struct stat sb;
> +   char filename[256], *data;
> +
> +   if (size)
> +      *size = 0;
> +
> +   if (!cache_has(cache, key))
> +      return NULL;
> +
> +   get_cache_file(cache, filename, sizeof filename, key);
> +
> +   fd = open(filename, O_RDONLY | O_CLOEXEC);
> +   if (fd == -1)
> +      return NULL;
> +
> +   if (fstat(fd, &sb) == -1) {
> +      close(fd);
> +      return NULL;
> +   }
> +
> +   data = (char *) malloc(sb.st_size);
> +   if (data == NULL) {
> +      close(fd);
> +      return NULL;
> +   }

Will there be some further verification here if the file contents are 
what is expected or is this done in higher level where cache is called?

// Tapani