--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/servlib/bundling/SDNV.h	Thu Apr 21 14:57:45 2011 +0100
@@ -0,0 +1,125 @@
+/*
+ *    Copyright 2005-2006 Intel Corporation
+ * 
+ *    Licensed under the Apache License, Version 2.0 (the "License");
+ *    you may not use this file except in compliance with the License.
+ *    You may obtain a copy of the License at
+ * 
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ *    Unless required by applicable law or agreed to in writing, software
+ *    distributed under the License is distributed on an "AS IS" BASIS,
+ *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *    See the License for the specific language governing permissions and
+ *    limitations under the License.
+ */
+
+#ifndef _SDNV_H_
+#define _SDNV_H_
+
+#include <oasys/compat/inttypes.h>
+
+#ifdef __cplusplus
+
+namespace dtn {
+
+/**
+ * Class to handle parsing and formatting of self describing numeric
+ * values (SDNVs).
+ *
+ * The basic idea is to enable a compact byte representation of
+ * numeric values that may widely vary in size. This encoding is based
+ * on the ASN.1 specification for encoding Object Identifier Arcs.
+ *
+ * Conceptually, the integer value to be encoded is split into 7-bit
+ * segments. These are encoded into the output byte stream, such that
+ * the high order bit in each byte is set to one for all bytes except
+ * the last one.
+ *
+ * Note that this implementation only handles values up to 64-bits in
+ * length (since the conversion is between a u_int64_t and the encoded
+ * byte sequence).
+ */
+class SDNV {
+public:
+    /**
+     * The maximum length for this SDNV implementation is 10 bytes,
+     * since the maximum value is 64 bits wide.
+     */
+    static const size_t MAX_LENGTH = 10;
+    
+    /**
+     * Return the number of bytes needed to encode the given value.
+     */
+    static size_t encoding_len(u_int64_t val);
+    
+    /**
+     * Convert the given 64-bit integer into an SDNV.
+     *
+     * @return The number of bytes used, or -1 on error.
+     */
+    static int encode(u_int64_t val, u_char* bp, size_t len);
+    
+    /**
+     * Convert an SDNV pointed to by bp into a unsigned 64-bit
+     * integer.
+     *
+     * @return The number of bytes of bp consumed, or -1 on error.
+     */
+    static int decode(const u_char* bp, size_t len, u_int64_t* val);
+
+    /**
+     * Convert an SDNV pointed to by bp into a unsigned 32-bit
+     * integer. Checks for overflow in the SDNV.
+     *
+     * @return The number of bytes of bp consumed, or -1 on error.
+     */
+    static int decode(const u_char* bp, size_t len, u_int32_t* val)
+    {
+        u_int64_t lval;
+        int ret = decode(bp, len, &lval);
+        
+        if (lval > 0xffffffffLL) {
+            return -1;
+        }
+
+        *val = (u_int32_t)lval;
+        
+        return ret;
+    }
+
+    /// @{
+    /// Variants of encode/decode that take a char* for the buffer
+    /// instead of a u_char*
+    ///
+    /// XXX/demmer all this crap should be replaced with a byte_t for
+    /// consistency
+    ///
+    static int encode(u_int64_t val, char* bp, size_t len)
+    {
+        return encode(val, (u_char*)bp, len);
+    }
+    
+    static int decode(char* bp, size_t len, u_int64_t* val)
+    {
+        return decode((u_char*)bp, len, val);
+    }
+    
+    static int decode(char* bp, size_t len, u_int32_t* val)
+    {
+        return decode((u_char*)bp, len, val);
+    }
+    /// @}
+
+    /**
+     * Return the number of bytes which comprise the given value.
+     * Assumes that bp points to a valid encoded SDNV.
+     */
+    static size_t len(const u_char* bp);
+};
+
+} // namespace dtn
+
+#endif /* __cplusplus */
+
+#endif /* _SDNV_H_ */