7.0.1 fix det server version (#702)

* check server version before initial checks, catch old server version exception, get old server version as 64 bit and print it along with exception

RELEASE.txt

@@ -20,7 +20,7 @@ This document describes the differences between v7.0.1 and v7.0.0
 =================
 
 
-    Receiver:
+    Receiver
     --------
 
 
@@ -35,6 +35,22 @@ This document describes the differences between v7.0.1 and v7.0.0
 
 
 
+    Client
+    ------
+
+
+    *   Detector Server Version from previous Releases
+        Hostname command would hang with 7.0.0 client if the detector server
+        was from a previous release (eg. 6.1.2). In this case, the user cannot
+        get the detector server version.
+
+        Fixed that the hostname command will throw an exception about 
+        incompatible server with its version in the message. Now, the user can 
+        get the version number without having to telnet or ssh to the detector.
+        With this info, one can then update to matching client for that server
+        and start the detector updation process.
+
+
 2  On-board Detector Server Compatibility
 ==========================================
 

slsDetectorSoftware/src/Module.cpp

@@ -73,8 +73,8 @@ void Module::setHostname(const std::string &hostname,
     auto client = DetectorSocket(shm()->hostname, shm()->controlPort);
     client.close();
     try {
-        initialDetectorServerChecks();
         checkDetectorVersionCompatibility();
+        initialDetectorServerChecks();
         LOG(logINFO) << "Module Version Compatibility - Success";
     } catch (const RuntimeError &e) {
         if (!initialChecks) {
@@ -93,9 +93,28 @@ int64_t Module::getFirmwareVersion() const {
 }
 
 std::string Module::getControlServerLongVersion() const {
-    char retval[MAX_STR_LENGTH]{};
-    sendToDetector(F_GET_SERVER_VERSION, nullptr, retval);
-    return retval;
+    try {
+        char retval[MAX_STR_LENGTH]{};
+        sendToDetector(F_GET_SERVER_VERSION, nullptr, retval);
+        return retval;
+    }
+    // throw with old server version (sends 8 bytes)
+    catch (RuntimeError &e) {
+        std::string emsg = std::string(e.what());
+        if (emsg.find(F_GET_SERVER_VERSION) && emsg.find("8 bytes")) {
+            throwDeprecatedServerVersion();
+        }
+        throw;
+    }
+}
+
+void Module::throwDeprecatedServerVersion() const {
+    uint64_t res = sendToDetectorStop<int64_t>(F_GET_SERVER_VERSION);
+    std::cout << std::endl;
+    std::ostringstream os;
+    os << "Detector Server (Control) version (0x" << std::hex << res
+       << ") is incompatible with this client. Please update detector server!";
+    throw RuntimeError(os.str());
 }
 
 std::string Module::getStopServerLongVersion() const {

slsDetectorSoftware/src/Module.h

@@ -92,6 +92,7 @@ class Module : public virtual slsDetectorDefs {
     int64_t getFirmwareVersion() const;
     std::string getControlServerLongVersion() const;
     std::string getStopServerLongVersion() const;
+    void throwDeprecatedServerVersion() const;
     std::string getDetectorServerVersion() const;
     std::string getHardwareVersion() const;
     std::string getKernelVersion() const;