From 550955df2c34fe4bb3fce42822ecd2a6967e27a4 Mon Sep 17 00:00:00 2001
From: Dhanya Thattil <dhanya.thattil@psi.ch>
Date: Fri, 18 Sep 2026 16:45:45 +0200
Subject: [PATCH] when changing num interfaces, also setting up file writer if
 file write was enabled. added tests inside numinterface (from 2 to 1) to take
 an acquisition and check if the file exists

---
 .../tests/Caller/test-Caller.cpp              | 32 ++++++++++++++++---
 slsReceiverSoftware/src/Implementation.cpp    |  7 ++++
 2 files changed, 34 insertions(+), 5 deletions(-)

diff --git a/slsDetectorSoftware/tests/Caller/test-Caller.cpp b/slsDetectorSoftware/tests/Caller/test-Caller.cpp
index fa7c55d50..0b6d2f3c1 100644
--- a/slsDetectorSoftware/tests/Caller/test-Caller.cpp
+++ b/slsDetectorSoftware/tests/Caller/test-Caller.cpp
@@ -2620,7 +2620,7 @@ TEST_CASE("numinterfaces", "[.detectorintegration]") {
             "inconsistent numinterfaces to test");
         Result<UdpDestination> prev_udp_dest;
         IpAddr prev_src_ip2{};
-        if (prev_val == 2 && det_type != defs::EIGER) {
+        if (prev_val == 2) {
             prev_udp_dest = det.getDestinationUDPList(0);
             prev_src_ip2 = det.getSourceUDPIP2()[0];
         }
@@ -2629,17 +2629,39 @@ TEST_CASE("numinterfaces", "[.detectorintegration]") {
             caller.call("numinterfaces", {"2"}, -1, PUT, oss);
             REQUIRE(oss.str() == "numinterfaces 2\n");
         }
+        // testing file write before and after num interface change
         {
-            std::ostringstream oss;
-            caller.call("numinterfaces", {"1"}, -1, PUT, oss);
-            REQUIRE(oss.str() == "numinterfaces 1\n");
+            auto prev_fwrite =
+                det.getFileWrite().tsquash("inconsistent file write state");
+            det.setFileWrite(true);
+            {
+                std::ostringstream oss;
+                caller.call("numinterfaces", {"1"}, -1, PUT, oss);
+                REQUIRE(oss.str() == "numinterfaces 1\n");
+            }
+            // testing file write after num interface change
+
+            // file write is true
+            REQUIRE(det.getFileWrite().tsquash(
+                        "inconsistent file write state") == true);
+
+            // check if file write actually works
+            auto acq_state = acq::default_acquisition_state();
+            auto file_state = acq::default_file_state();
+            file_state.file_format = defs::BINARY;
+            acq::run(det, acq_state, file_state);
+            std::string fname = acq::get_master_file_name(file_state);
+            REQUIRE(std::filesystem::exists(fname));
+
+            det.setFileWrite(prev_fwrite);
         }
+
         {
             std::ostringstream oss;
             caller.call("numinterfaces", {}, -1, GET, oss);
             REQUIRE(oss.str() == "numinterfaces 1\n");
         }
-        if (prev_val == 2 && det_type != defs::EIGER) {
+        if (prev_val == 2) {
             for (int i = 0; i != det.size(); ++i) {
                 det.setDestinationUDPList({prev_udp_dest[i]}, {i});
             }
diff --git a/slsReceiverSoftware/src/Implementation.cpp b/slsReceiverSoftware/src/Implementation.cpp
index 6a78b764e..60c704578 100644
--- a/slsReceiverSoftware/src/Implementation.cpp
+++ b/slsReceiverSoftware/src/Implementation.cpp
@@ -1164,6 +1164,13 @@ void Implementation::setNumberofUDPInterfaces(const int n) {
 
         // test socket buffer size with current set up
         setUDPSocketBufferSize(0);
+
+        // set up file write if enabled
+        if (fileWriteEnable) {
+            for (const auto &it : dataProcessor)
+                it->SetupFileWriter(fileWriteEnable, fileFormatType,
+                                    &hdf5LibMutex);
+        }
     }
 
     LOG(logINFO) << "Number of Interfaces: " << generalData->numUDPInterfaces;