hooks: update sample signal descriptors in hook_list_process()

lib/hook_list.cpp

@@ -24,6 +24,7 @@
 #include <villas/hook.hpp>
 #include <villas/hook_list.hpp>
 #include <villas/list.h>
+#include <villas/sample.h>
 #include <villas/log.h>
 
 using namespace villas;
@@ -129,6 +130,8 @@ skip_add:
 		h->prepare(sigs);
 
 		sigs = h->getSignals();
+
+		signal_list_dump(sigs);
 	}
 }
 
@@ -146,6 +149,7 @@ int hook_list_process(vlist *hs, sample *smps[], unsigned cnt)
 			Hook *h = (Hook *) vlist_at(hs, i);
 
 			auto ret = h->process(smp);
+			smp->signals = h->getSignals();
 			switch (ret) {
 				case Hook::Reason::ERROR:
 					return -1;

lib/hooks/average.cpp

@@ -172,7 +172,6 @@ public:
 			return Reason::ERROR;
 
 		sample_data_insert(smp, (union signal_data *) &avg, offset, 1);
-		smp->signals = &signals;
 
 		return Reason::OK;
 	}

lib/hooks/cast.cpp

@@ -161,9 +161,6 @@ public:
 
 		signal_data_cast(&smp->data[signal_index], orig_sig, new_sig);
 
-		/* Replace signal descriptors of sample */
-		smp->signals = &signals;
-
 		return Reason::OK;
 	}
 };

lib/hooks/dp.cpp

@@ -318,8 +318,6 @@ public:
 			sample_data_insert(smp, (union signal_data *) coeffs, offset, fharmonics_len);
 		}
 
-		smp->signals = &signals;
-
 		time += timestep;
 		steps++;