Problem: Duplicated code

Solution: set_curve_key method in options_t struct with little
improvement in switch-case block

src/options.cpp

@@ -90,6 +90,35 @@ zmq::options_t::options_t () :
 #endif
 }
 
+int zmq::options_t::set_curve_key(uint8_t * destination,  const void * optval_, size_t optvallen_)
+{
+    char * optval = (char *) optval_;
+    switch (optvallen_) {
+
+        case CURVE_KEYSIZE:
+            memcpy (destination, optval_, optvallen_);
+            mechanism = ZMQ_CURVE;
+            return 0;
+
+        case CURVE_KEYSIZE_Z85:
+            char z85_key [CURVE_KEYSIZE_Z85 + 1];
+            memcpy (z85_key, optval, optvallen_);
+            z85_key [optvallen_] = 0;
+            optval = z85_key;
+        //Intentionall fallthrough
+        case CURVE_KEYSIZE_Z85 + 1:
+            if (zmq_z85_decode (destination, optval)) {
+                mechanism = ZMQ_CURVE;
+                return 0;
+            }
+            break;
+
+        default:
+            break;
+    }
+    return -1;
+}
+
 int zmq::options_t::setsockopt (int option_, const void *optval_,
     size_t optvallen_)
 {
@@ -418,87 +447,19 @@ int zmq::options_t::setsockopt (int option_, const void *optval_,
             break;
 
         case ZMQ_CURVE_PUBLICKEY:
-            //  TODO: refactor repeated code for these three options
-            //  into set_curve_key (destination, optval, optlen) method
-            //  ==> set_curve_key (curve_public_key, optval_, optvallen_);
-            if (optvallen_ == CURVE_KEYSIZE) {
-                memcpy (curve_public_key, optval_, CURVE_KEYSIZE);
-                mechanism = ZMQ_CURVE;
+            if(0 == set_curve_key(curve_public_key, optval_, optvallen_))
                 return 0;
-            }
-            else
-            if (optvallen_ == CURVE_KEYSIZE_Z85 + 1) {
-                if (zmq_z85_decode (curve_public_key, (char *) optval_)) {
-                    mechanism = ZMQ_CURVE;
-                    return 0;
-                }
-            }
-            else
-            //  Deprecated, not symmetrical with zmq_getsockopt
-            if (optvallen_ == CURVE_KEYSIZE_Z85) {
-                char z85_key [CURVE_KEYSIZE_Z85 + 1];
-                memcpy (z85_key, (char *) optval_, CURVE_KEYSIZE_Z85);
-                z85_key [CURVE_KEYSIZE_Z85] = 0;
-                if (zmq_z85_decode (curve_public_key, z85_key)) {
-                    mechanism = ZMQ_CURVE;
-                    return 0;
-                }
-            }
             break;
 
         case ZMQ_CURVE_SECRETKEY:
-            if (optvallen_ == CURVE_KEYSIZE) {
-                memcpy (curve_secret_key, optval_, CURVE_KEYSIZE);
-                mechanism = ZMQ_CURVE;
+            if(0 == set_curve_key(curve_secret_key, optval_, optvallen_))
                 return 0;
-            }
-            else
-            if (optvallen_ == CURVE_KEYSIZE_Z85 + 1) {
-                if (zmq_z85_decode (curve_secret_key, (char *) optval_)) {
-                    mechanism = ZMQ_CURVE;
-                    return 0;
-                }
-            }
-            else
-            //  Deprecated, not symmetrical with zmq_getsockopt
-            if (optvallen_ == CURVE_KEYSIZE_Z85) {
-                char z85_key [CURVE_KEYSIZE_Z85 + 1];
-                memcpy (z85_key, (char *) optval_, CURVE_KEYSIZE_Z85);
-                z85_key [CURVE_KEYSIZE_Z85] = 0;
-                if (zmq_z85_decode (curve_secret_key, z85_key)) {
-                    mechanism = ZMQ_CURVE;
-                    return 0;
-                }
-            }
             break;
 
         case ZMQ_CURVE_SERVERKEY:
-            if (optvallen_ == CURVE_KEYSIZE) {
-                memcpy (curve_server_key, optval_, CURVE_KEYSIZE);
-                mechanism = ZMQ_CURVE;
+            if(0 == set_curve_key(curve_server_key, optval_, optvallen_))
                 as_server = 0;
                 return 0;
-            }
-            else
-            if (optvallen_ == CURVE_KEYSIZE_Z85 + 1) {
-                if (zmq_z85_decode (curve_server_key, (char *) optval_)) {
-                    mechanism = ZMQ_CURVE;
-                    as_server = 0;
-                    return 0;
-                }
-            }
-            else
-            //  Deprecated, not symmetrical with zmq_getsockopt
-            if (optvallen_ == CURVE_KEYSIZE_Z85) {
-                char z85_key [CURVE_KEYSIZE_Z85 + 1];
-                memcpy (z85_key, (char *) optval_, CURVE_KEYSIZE_Z85);
-                z85_key [CURVE_KEYSIZE_Z85] = 0;
-                if (zmq_z85_decode (curve_server_key, z85_key)) {
-                    mechanism = ZMQ_CURVE;
-                    as_server = 0;
-                    return 0;
-                }
-            }
             break;
 #endif
 

src/options.hpp

@@ -56,6 +56,8 @@ namespace zmq
     {
         options_t ();
 
+        int set_curve_key(uint8_t * destination, const void * optval_, size_t optvallen_);
+
         int setsockopt (int option_, const void *optval_, size_t optvallen_);
         int getsockopt (int option_, void *optval_, size_t *optvallen_) const;