file-compress.scm

#|
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|#

;; FastLZ based compression for files
;; It allows for very fast compression and decompression but files are about 33% larger than zip.

(define (compress:helper src dst compress?)
  (if (file-exists? src)
    (let* ((filesize (file-info-size (file-info src)))
           (data (let ((content (if filesize (make-u8vector filesize) #f)))
             (if content
               (begin
                 (with-input-from-file src (lambda () (read-subu8vector content 0 filesize)))
                 content
              )
              (u8vector)))))
      (let ((datacomp ((if compress? u8vector-compress u8vector-decompress) data)))
        (with-output-to-file dst (lambda () (write-subu8vector datacomp 0 (u8vector-length datacomp))))
      )
    )))

(define (compress-file src dst)
  (compress:helper src dst #t)
)

(define (decompress-file src dst)
  (compress:helper src dst #f)
)

(define (quick-compress src)
  (compress-file src (string-append src ".flz"))
  (if (file-exists? (string-append src ".flz")) (delete-file src)))

(define (quick-decompress src)
  (decompress-file (string-append src ".flz") src)
  (if (file-exists? src) (delete-file (string-append src ".flz"))))