doc: config: Improve comments, logging, exceptions

src/config.cc

@@ -21,12 +21,14 @@ uint32_t ConfigMap::Get<uint32_t>(const std::string &k) {
   ValueType value = at(k);
   try {
     return value.asUInt();
-  } catch (std::exception &e) {
-    LOG(DEBUG) << "Value '" << value.asString() << "' not natively convertible to uint32";
+  } catch (std::exception &e1) {
+    const auto str_val = value.asString();
+    LOG(DEBUG) << "Key: " << k << "| Value '" << str_val << "' | Exception: " << e1.what();
+    LOG(DEBUG) << "Recovering by converting to uint32_t";
     try {
-      return static_cast<uint32_t>(std::stoul(value.asString()));
-    } catch (std::exception &e) {
-      LOG(ERROR) << "Configuration error with key: '" << k << "'";
+      return static_cast<uint32_t>(std::stoul(str_val));
+    } catch (std::exception &e2) {
+      LOG(ERROR) << "Conversion of '" << str_val << "' failed with exception: " << e2.what();
       throw;
     }
   }
@@ -37,12 +39,14 @@ uint64_t ConfigMap::Get<uint64_t>(const std::string &k) {
   ValueType value = at(k);
   try {
     return value.asUInt64();
-  } catch (std::exception &e) {
-    LOG(DEBUG) << "Value '" << value.asString() << "' not natively convertible to uint64";
+  } catch (std::exception &e1) {
+    const auto str_val = value.asString();
+    LOG(DEBUG) << "Key: " << k << "| Value '" << str_val << "' | Exception: " << e1.what();
+    LOG(DEBUG) << "Recovering by converting to uint64_t";
     try {
-      return static_cast<uint64_t>(std::stoul(value.asString()));
-    } catch (std::exception &e) {
-      LOG(ERROR) << "Configuration error with key: '" << k << "'";
+      return static_cast<uint64_t>(std::stoul(str_val));
+    } catch (std::exception &e2) {
+      LOG(ERROR) << "Conversion of '" << str_val << "' failed with exception: " << e2.what();
       throw;
     }
   }
@@ -53,12 +57,14 @@ int ConfigMap::Get<int>(const std::string &k) {
   ValueType value = at(k);
   try {
     return value.asInt();
-  } catch (std::exception &e) {
-    LOG(DEBUG) << "Value '" << value.asString() << "' not natively convertible to integer";
+  } catch (std::exception &e1) {
+    const auto str_val = value.asString();
+    LOG(DEBUG) << "Key: " << k << "| Value '" << str_val << "' | Exception: " << e1.what();
+    LOG(DEBUG) << "Recovering by converting to int";
     try {
-      return std::stoi(value.asString());
-    } catch (std::exception &e) {
-      LOG(ERROR) << "Configuration error with key: '" << k << "'";
+      return static_cast<int>(std::stoul(str_val));
+    } catch (std::exception &e2) {
+      LOG(ERROR) << "Conversion of '" << str_val << "' failed with exception: " << e2.what();
       throw;
     }
   }

src/config.h

@@ -146,22 +146,24 @@ class Config {
   }
 
   inline uint32_t GetSourceID(ProcessorType processor) const {
+    // Source ID is only used to fill the output CMSSW FRD event header, which is currently
+    // supported for the GMT and Calo processors.
     switch (processor) {
       case ProcessorType::GMT:
         return 1;
       case ProcessorType::CALO:
         return 2;
       default:
-        if (support_cmssw_headers_) {
-          LOG(ERROR)
-              << "PROCESSOR_TYPE INCOMPATIBLE WITH CMSSW HEADER OUTPUT OPTION, PLEASE DISABLE "
-                 "CMSSW HEADERS OR CHANGE PROCESSOR_TYPE, EXITING";
-          throw std::invalid_argument(
-              "ERROR: PROCESSOR_TYPE INCOMPATIBLE WITH CMSSW HEADER OUTPUT OPTION, PLEASE DISABLE "
-              "CMSSW HEADERS OR CHANGE PROCESSOR_TYPE");
-        } else {
-          LOG(WARNING) << "Undefined source ID has been requested: returning 0.";
+        if (!support_cmssw_headers_) {
+          LOG(WARNING)
+              << "Specified `processor_type` has no pre-defined source ID. Using `source_id`=0.";
           return 0;
+        } else {
+          const char msg_incompatible[] =
+              "Specified `processor_type` incompatible with CMSSW header-enabled outputs. Disable "
+              "`cmsswHeaders` or change `processor_type` to one of {GMT, CALO}.";
+          LOG(ERROR) << msg_incompatible;
+          throw std::invalid_argument(msg_incompatible);
         }
     }
   }