3.7 File Boxes

(require web-server/lang/file-box)

As mentioned earlier, it is dangerous to rely on the store in Web Language servlets, due to the deployment scenarios available to them. "lang/file-box.ss" provides a simple API to replace boxes in a safe way.

(file-box? v) → boolean?

v : any/c

Checks if v is a file-box.

(file-box p v) → file-box?

p : path?

v : serializable?

Creates a file-box that is stored at p, with the default contents of v.

(file-unbox fb) → serializable?

fb : file-box?

Returns the value inside fb

(file-box-set? fb) → boolean?

fb : file-box?

Returns #t if fb contains a value.

(file-box-set! fb v) → void

fb : file-box?

v : serializable?

Saves v in the file represented by fb.

Warning:If you plan on using a load-balancer, make sure your file-boxes are on a shared medium.