Change types of exec and extra_args to binary

When config is created, it accepts binaries that are converted to list
and kept in config record. This causes issues in the code that uses this
project as a dependency. There is a different type for exec and extra_args
outside and inside the config record.

src/aeminer_pow_cuckoo.erl

@@ -58,11 +58,11 @@
 -type instance()          :: aeminer_pow:instance()
                            | undefined.
 
--type exec()              :: string().
+-type exec()              :: binary().
 
 -type exec_group()        :: binary().
 
--type extra_args()        :: string().
+-type extra_args()        :: binary().
 
 -type hex_enc_header()    :: boolean().
 
@@ -120,9 +120,9 @@
 config(Exec, ExecGroup, ExtraArgs, HexEncHdr, Repeats, EdgeBits, Instances) when
       ?IS_CONFIG(Exec, ExecGroup, ExtraArgs, HexEncHdr, Repeats, EdgeBits, Instances) ->
     #config{
-       exec           = binary_to_list(Exec),
+       exec           = Exec,
        exec_group     = ExecGroup,
-       extra_args     = binary_to_list(ExtraArgs),
+       extra_args     = ExtraArgs,
        hex_enc_header = HexEncHdr,
        repeats        = Repeats,
        edge_bits      = EdgeBits,
@@ -204,17 +204,20 @@ verify(Data, Nonce, Soln, Target, EdgeBits) when
 %% Internal functions.
 
 generate_int(Hash, Nonce, Target,
-             #config{exec = Exec, extra_args = ExtraArgs0,
+             #config{exec = Exec0, extra_args = ExtraArgs0,
                      hex_enc_header = HexEncHdr} = Config, Instance) ->
-    ExtraArgs   = case is_miner_instance_addressation_enabled(Config) of
-                      true  -> ExtraArgs0 ++ " -d " ++ integer_to_list(Instance);
-                      false -> ExtraArgs0
-                  end,
-    EncodedHash = case HexEncHdr of
-                      true  -> hex_string(Hash);
-                      false -> Hash
-                  end,
+    ExtraArgs =
+        case is_miner_instance_addressation_enabled(Config) of
+            true  -> binary_to_list(ExtraArgs0) ++ " -d " ++ integer_to_list(Instance);
+            false -> binary_to_list(ExtraArgs0)
+        end,
+    EncodedHash =
+        case HexEncHdr of
+            true  -> hex_string(Hash);
+            false -> Hash
+        end,
     ExecBinDir  = exec_bin_dir(Config),
+    Exec = binary_to_list(Exec0),
     generate_int(EncodedHash, Nonce, Target, ExecBinDir, Exec, ExtraArgs, Config).
 
 generate_int(Hash, Nonce, Target, MinerBinDir, MinerBin, MinerExtraArgs,