1 ;;;; -*- Mode: Lisp; Syntax: ANSI-Common-Lisp; Base: 10 -*-
2 ;;;; *************************************************************************
3 ;;;; FILE IDENTIFICATION
6 ;;;; Purpose: UFFI Example file for zlib compression
7 ;;;; Programmer: Kevin M. Rosenberg
8 ;;;; Date Started: Feb 2002
10 ;;;; This file, part of UFFI, is Copyright (c) 2002-2010 by Kevin M. Rosenberg
12 ;;;; *************************************************************************
16 (eval-when (:load-toplevel :execute)
17 (unless (uffi:load-foreign-library
19 (uffi:find-foreign-library
21 '("/usr/local/lib/" "/usr/lib/" "/zlib/")
24 (uffi:find-foreign-library "z"
25 `(,(pathname-directory *load-pathname*)))
27 :supporting-libraries '("c"))
28 (warn "Unable to load zlib")))
30 (uffi:def-function ("compress" c-compress)
31 ((dest (* :unsigned-char))
38 (defun compress (source)
39 "Returns two values: array of bytes containing the compressed data
40 and the numbe of compressed bytes"
41 (let* ((sourcelen (length source))
42 (destsize (+ 12 (ceiling (* sourcelen 1.01))))
43 (dest (uffi:allocate-foreign-string destsize :unsigned t))
44 (destlen (uffi:allocate-foreign-object :long)))
45 (setf (uffi:deref-pointer destlen :long) destsize)
46 (uffi:with-cstring (source-native source)
47 (let ((result (c-compress dest destlen source-native sourcelen))
48 (newdestlen (uffi:deref-pointer destlen :long)))
51 (values (uffi:convert-from-foreign-string
54 :null-terminated-p nil)
56 (error "zlib error, code ~D" result))
58 (uffi:free-foreign-object destlen)
59 (uffi:free-foreign-object dest)))))))
61 (uffi:def-function ("uncompress" c-uncompress)
62 ((dest (* :unsigned-char))
69 (defun uncompress (source)
70 (let* ((sourcelen (length source))
71 (destsize 200000) ;adjust as needed
72 (dest (uffi:allocate-foreign-string destsize :unsigned t))
73 (destlen (uffi:allocate-foreign-object :long)))
74 (setf (uffi:deref-pointer destlen :long) destsize)
75 (uffi:with-cstring (source-native source)
76 (let ((result (c-uncompress dest destlen source-native sourcelen))
77 (newdestlen (uffi:deref-pointer destlen :long)))
80 (uffi:convert-from-foreign-string
83 :null-terminated-p nil)
84 (error "zlib error, code ~D" result))
86 (uffi:free-foreign-object destlen)
87 (uffi:free-foreign-object dest)))))))
91 (flet ((print-results (str)
92 (multiple-value-bind (compressed len) (compress str)
93 (let ((*print-length* nil))
94 (format t "~&(compress ~S) => " str)
95 (format t "~S~%" (map 'list #'char-code compressed))))))
97 (print-results "test")
98 (print-results "test2")))
102 (flet ((test-compress (str)
103 (multiple-value-bind (compressed len) (compress str)
104 (multiple-value-bind (uncompressed len2) (uncompress compressed)
105 (util.test:test str uncompressed :test #'string=
106 :fail-info "Error uncompressing a compressed string")))))
108 (test-compress "test")
109 (test-compress "test2")))
111 ;; Results of the above on my system:
112 ;; (compress "") => 789c300001,8
113 ;; (compress "test") => 789c2b492d2e1045d1c1,12
114 ;; (compress "test2") => 789c2b492d2e31206501f3,13