Merge pull request #904 from pfalcon/moduzlib

Module "uzlib" - based on similarly named library

1 files changed, 101 insertions, 0 deletions

diff --git a/extmod/uzlib/tinfzlib.c b/extmod/uzlib/tinfzlib.c
new file mode 100644
index 000000000..dbacc1d9d
--- /dev/null
+++ b/extmod/uzlib/tinfzlib.c
@@ -0,0 +1,101 @@
+/*
+ * tinfzlib  -  tiny zlib decompressor
+ *
+ * Copyright (c) 2003 by Joergen Ibsen / Jibz
+ * All Rights Reserved
+ *
+ * http://www.ibsensoftware.com/
+ *
+ * This software is provided 'as-is', without any express
+ * or implied warranty.  In no event will the authors be
+ * held liable for any damages arising from the use of
+ * this software.
+ *
+ * Permission is granted to anyone to use this software
+ * for any purpose, including commercial applications,
+ * and to alter it and redistribute it freely, subject to
+ * the following restrictions:
+ *
+ * 1. The origin of this software must not be
+ *    misrepresented; you must not claim that you
+ *    wrote the original software. If you use this
+ *    software in a product, an acknowledgment in
+ *    the product documentation would be appreciated
+ *    but is not required.
+ *
+ * 2. Altered source versions must be plainly marked
+ *    as such, and must not be misrepresented as
+ *    being the original software.
+ *
+ * 3. This notice may not be removed or altered from
+ *    any source distribution.
+ */
+
+#include "tinf.h"
+
+int tinf_zlib_uncompress(void *dest, unsigned int *destLen,
+                         const void *source, unsigned int sourceLen)
+{
+   TINF_DATA d;
+   int res;
+
+   /* initialise data */
+   d.source = (const unsigned char *)source;
+
+   d.destStart = (unsigned char *)dest;
+   d.destRemaining = *destLen;
+
+   res = tinf_zlib_uncompress_dyn(&d, sourceLen);
+
+   *destLen = d.dest - d.destStart;
+
+   return res;
+}
+
+int tinf_zlib_uncompress_dyn(TINF_DATA *d, unsigned int sourceLen)
+{
+   unsigned int a32;
+   int res;
+   unsigned char cmf, flg;
+
+   /* -- get header bytes -- */
+
+   cmf = d->source[0];
+   flg = d->source[1];
+
+   /* -- check format -- */
+
+   /* check checksum */
+   if ((256*cmf + flg) % 31) return TINF_DATA_ERROR;
+
+   /* check method is deflate */
+   if ((cmf & 0x0f) != 8) return TINF_DATA_ERROR;
+
+   /* check window size is valid */
+   if ((cmf >> 4) > 7) return TINF_DATA_ERROR;
+
+   /* check there is no preset dictionary */
+   if (flg & 0x20) return TINF_DATA_ERROR;
+
+   /* -- get adler32 checksum -- */
+
+   a32 =           d->source[sourceLen - 4];
+   a32 = 256*a32 + d->source[sourceLen - 3];
+   a32 = 256*a32 + d->source[sourceLen - 2];
+   a32 = 256*a32 + d->source[sourceLen - 1];
+
+   d->source += 2;
+
+   /* -- inflate -- */
+
+   res = tinf_uncompress_dyn(d);
+
+   if (res != TINF_OK) return res;
+
+   /* -- check adler32 checksum -- */
+
+   if (a32 != tinf_adler32(d->destStart, d->dest - d->destStart)) return TINF_DATA_ERROR;
+
+   return TINF_OK;
+}
+