r2912: rename .cl to .lisp

[uffi.git] / examples / compress.lisp

diff --git a/examples/compress.lisp b/examples/compress.lisp
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+++ b/examples/compress.lisp
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+;;;; -*- Mode: Lisp; Syntax: ANSI-Common-Lisp; Base: 10 -*-
+;;;; *************************************************************************
+;;;; FILE IDENTIFICATION
+;;;;
+;;;; Name:          compress.cl
+;;;; Purpose:       UFFI Example file for zlib compression
+;;;; Programmer:    Kevin M. Rosenberg
+;;;; Date Started:  Feb 2002
+;;;;
+;;;; $Id: compress.lisp,v 1.1 2002/09/30 10:02:36 kevin Exp $
+;;;;
+;;;; This file, part of UFFI, is Copyright (c) 2002 by Kevin M. Rosenberg
+;;;;
+;;;; UFFI users are granted the rights to distribute and use this software
+;;;; as governed by the terms of the Lisp Lesser GNU Public License
+;;;; (http://opensource.franz.com/preamble.html), also known as the LLGPL.
+;;;; *************************************************************************
+
+(in-package :cl-user)
+
+(unless (uffi:load-foreign-library
+        (uffi:find-foreign-library
+         "libz"
+         '("/usr/local/lib/" "/usr/lib/" "/zlib/")
+         :types '("so" "a" "dylib"))
+        :module "zlib" 
+        :supporting-libraries '("c"))
+  (warn "Unable to load zlib"))
+
+(uffi:def-function ("compress" c-compress)
+    ((dest (* :unsigned-char))
+     (destlen (* :long))
+     (source :cstring)
+     (source-len :long))
+  :returning :int
+  :module "zlib")
+  
+(defun compress (source)
+  "Returns two values: array of bytes containing the compressed data
+ and the numbe of compressed bytes"
+  (let* ((sourcelen (length source))
+        (destsize (+ 12 (ceiling (* sourcelen 1.01))))
+        (dest (uffi:allocate-foreign-string destsize :unsigned t))
+        (destlen (uffi:allocate-foreign-object :long)))
+    (setf (uffi:deref-pointer destlen :long) destsize)
+    (uffi:with-cstring (source-native source)
+      (let ((result (c-compress dest destlen source-native sourcelen))
+           (newdestlen (uffi:deref-pointer destlen :long)))
+       (unwind-protect
+           (if (zerop result)
+               (values (uffi:convert-from-foreign-string 
+                        dest
+                        :length newdestlen
+                        :null-terminated-p nil)
+                       newdestlen)
+             (error "zlib error, code ~D" result))
+         (progn
+           (uffi:free-foreign-object destlen)
+           (uffi:free-foreign-object dest)))))))
+
+
+#+examples-uffi
+(progn
+  (flet ((print-results (str)
+          (multiple-value-bind (compressed len) (compress str)
+              (format t "~&(compress ~S) => " str)
+              (dotimes (i len)
+                (format t "~X" (char-code (char compressed i))))
+              (format t ",~D" len))))
+    (print-results "")
+    (print-results "test")
+    (print-results "test2")))
+
+;; Results of the above on my system:
+;; (compress "") => 789c300001,8
+;; (compress "test") => 789c2b492d2e1045d1c1,12
+;; (compress "test2") => 789c2b492d2e31206501f3,13