Working decoder on byte level

1 files changed, 29 insertions, 0 deletions

diff --git a/file.lisp b/file.lisp
new file mode 100644
index 0000000..642c5ab
--- /dev/null
+++ b/file.lisp
@@ -0,0 +1,29 @@
+(in-package #:lempel)
+
+(defun compress-file (input-path output-path)
+  (let ((file (str:read-file input-path)))
+    (with-open-file (output output-path
+                            :direction :output
+                            :if-does-not-exist :create
+                            :if-exists :supersede
+                            :element-type '(unsigned-byte 8))
+      (write-sequence (prefix-encode (compress file) #xAE) output)))
+  t)
+
+(defun decompress-file (input-path output-path)
+  (let ((file (read-file input-path)))
+    (with-open-file (output output-path
+                            :direction :output
+                            :if-does-not-exist :create
+                            :if-exists :supersede
+                            :element-type :default)
+      (write-sequence (prefix-decode file #xAE) output)))
+  t)
+
+(declaim (ftype (function (string) (array (unsigned-byte 8))) read-file))
+(defun read-file (path)
+  (with-open-file (file path :element-type '(unsigned-byte 8))
+    (let* ((size (file-length file))
+           (buf (make-array size :element-type '(unsigned-byte 8))))
+      (read-sequence buf file)
+      buf)))