Include audio mapping in the digest used to distinguish different

[dcpomatic.git] / src / lib / md5_digester.cc

diff --git a/src/lib/md5_digester.cc b/src/lib/md5_digester.cc
new file mode 100644 (file)
index 0000000..1244209
--- /dev/null
+++ b/src/lib/md5_digester.cc
@@ -0,0 +1,63 @@
+/*
+    Copyright (C) 2014 Carl Hetherington <cth@carlh.net>
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+#include <iomanip>
+#include <sstream>
+#include <openssl/md5.h>
+#include "md5_digester.h"
+
+using std::string;
+using std::stringstream;
+using std::hex;
+using std::setfill;
+using std::setw;
+
+MD5Digester::MD5Digester ()
+{
+       MD5_Init (&_context);
+}
+
+MD5Digester::~MD5Digester ()
+{
+       get ();
+}
+
+void
+MD5Digester::add (void const * data, size_t size)
+{
+       MD5_Update (&_context, data, size);
+}
+
+string
+MD5Digester::get () const
+{
+       if (!_digest) {
+               unsigned char digest[MD5_DIGEST_LENGTH];
+               MD5_Final (digest, &_context);
+               
+               stringstream s;
+               for (int i = 0; i < MD5_DIGEST_LENGTH; ++i) {
+                       s << hex << setfill('0') << setw(2) << ((int) digest[i]);
+               }
+               
+               _digest = s.str ();
+       }
+       
+       return _digest.get ();
+}