meowbb/fs.rkt

98 lines
3.5 KiB
Racket

#!/usr/bin/env racket
#lang racket/base
(require racket/file racket/format racket/match racket/string racket/system
ffi/unsafe)
(provide (struct-out user) (struct-out post)
list-users get-posts dfs-modtime sorted-level
hash-ref*
*post-index*)
(define *pub-path*
(let ([hostname (file->string "/etc/hostname")])
(if (string=? (string-trim hostname) "lgbt")
(build-path "/pub")
(let ([uid ((get-ffi-obj "getuid" (ffi-lib "libc" '("6" "7")) (_fun -> _int)))])
(displayln "using remote mount")
(system "gio mount sftp://unix.lgbt/pub")
(build-path "/run/user/" (~a uid) "gvfs/sftp:host=unix.lgbt/pub")))))
;; pseudo-node name to represent the index post at a tree level
;; starts with a slash because you can't put those in filenames :3
(define *post-index* "/index")
;; data definitions
(struct user [name description path] #:transparent)
(struct post [forum path timestamp author content] #:transparent)
;; gets a hash of username to user struct
(define (list-users)
(define users (directory-list *pub-path*))
(for/hash ([u (in-list users)])
(define un (path->string u))
(displayln un)
(define base (build-path *pub-path* u "forum"))
(define desc-path (build-path base "description.txt"))
(define desc (if (file-exists? desc-path)
(file->string desc-path)
"<unknown description>"))
(values un (user un desc base))))
;; given the (list-users) hash, fetches and organizes every post into a rose tree, with leaf nodes
;; being tagged with *post-index* representing a list of posts at that level (multiple users could
;; make the same title of post)
(define (get-posts users)
(define (valid-txt? path)
(and (not (equal? path (build-path "description.txt")))
(file-exists? path)
(regexp-match? #rx"\\.txt$" path)))
(define posts (make-hash))
(define (insert-tree! fullpath p [ctx posts])
(match fullpath
['()
(hash-update! ctx *post-index* (lambda (r) (cons p r)) '())]
[(list fst rst ...)
(insert-tree! rst p (hash-ref! ctx fst make-hash))]))
(for ([(un u) (in-hash users)] #:when (directory-exists? (user-path u)))
(displayln un)
(define base (user-path u))
(parameterize ([current-directory base])
(for ([item (in-directory)] #:when (valid-txt? item))
(displayln item)
(define timestamp (file-or-directory-modify-seconds item))
(define parts (map path->string (explode-path (path-replace-extension item #""))))
;; we require that posts are at least 2 levels deep (forum name, post title)
(match parts
[(list forum post-path ...)
(define p (post forum post-path timestamp un (file->string item)))
(insert-tree! parts p)]
[_ (displayln "invalid path")]))))
posts)
(define (dfs-modtime start [path '()] [modtimes (make-hash)])
(define newest
(for/fold ([newest 0]) ([(k v) (in-hash start)])
(cond
[(equal? k *post-index*)
(apply max newest (map post-timestamp v))]
[else
(max newest (dfs-modtime v (cons k path) modtimes))])))
(hash-set! modtimes (reverse path) newest)
newest)
(define (hash-ref* h k)
(match k
['() h]
[(cons f r) (hash-ref* (hash-ref h f) r)]))
(define (sorted-level posts modtimes path)
(define level-posts
(for/list ([(k v) (in-hash (hash-ref* posts path))])
(cons k v)))
(map cdr
(sort level-posts >
#:key (λ (p) (hash-ref modtimes (append path (list (car p))))))))