Introduce ConfigOrigin.CALCULATED (#9371)

* Use origin CALCULATED for merged methods

* fix javadoc for ConfigOrigin.CALCULATED

* apply github suggestions

Author: mtoffl01

internal-api/src/main/java/datadog/trace/api/ConfigOrigin.java

@@ -19,6 +19,8 @@ public enum ConfigOrigin {
   DD_CONFIG("dd_config"),
   /** set for cases where it is difficult/not possible to determine the source of a config. */
   UNKNOWN("unknown"),
+  /** set when the config is calculated from multiple configs */
+  CALCULATED("calculated"),
   /** set when the user has not set any configuration for the key (defaults to a value) */
   DEFAULT("default");
 

internal-api/src/main/java/datadog/trace/bootstrap/config/provider/ConfigProvider.java

@@ -255,7 +255,12 @@ public Map<String, String> getMergedMap(String key, String... aliases) {
       String value = sources[i].get(key, aliases);
       Map<String, String> parsedMap = ConfigConverter.parseMap(value, key);
       if (!parsedMap.isEmpty()) {
-        origin = sources[i].origin();
+        if (origin != ConfigOrigin.DEFAULT) {
+          // if we already have a non-default origin, the value is calculated from multiple sources
+          origin = ConfigOrigin.CALCULATED;
+        } else {
+          origin = sources[i].origin();
+        }
       }
       merged.putAll(parsedMap);
     }
@@ -277,7 +282,12 @@ public Map<String, String> getMergedTagsMap(String key, String... aliases) {
       Map<String, String> parsedMap =
           ConfigConverter.parseTraceTagsMap(value, ':', Arrays.asList(',', ' '));
       if (!parsedMap.isEmpty()) {
-        origin = sources[i].origin();
+        if (origin != ConfigOrigin.DEFAULT) {
+          // if we already have a non-default origin, the value is calculated from multiple sources
+          origin = ConfigOrigin.CALCULATED;
+        } else {
+          origin = sources[i].origin();
+        }
       }
       merged.putAll(parsedMap);
     }
@@ -298,7 +308,12 @@ public Map<String, String> getOrderedMap(String key) {
       String value = sources[i].get(key);
       Map<String, String> parsedMap = ConfigConverter.parseOrderedMap(value, key);
       if (!parsedMap.isEmpty()) {
-        origin = sources[i].origin();
+        if (origin != ConfigOrigin.DEFAULT) {
+          // if we already have a non-default origin, the value is calculated from multiple sources
+          origin = ConfigOrigin.CALCULATED;
+        } else {
+          origin = sources[i].origin();
+        }
       }
       merged.putAll(parsedMap);
     }
@@ -322,7 +337,13 @@ public Map<String, String> getMergedMapWithOptionalMappings(
         Map<String, String> parsedMap =
             ConfigConverter.parseMapWithOptionalMappings(value, key, defaultPrefix, lowercaseKeys);
         if (!parsedMap.isEmpty()) {
-          origin = sources[i].origin();
+          if (origin != ConfigOrigin.DEFAULT) {
+            // if we already have a non-default origin, the value is calculated from multiple
+            // sources
+            origin = ConfigOrigin.CALCULATED;
+          } else {
+            origin = sources[i].origin();
+          }
         }
         merged.putAll(parsedMap);
       }

internal-api/src/test/groovy/datadog/trace/api/ConfigCollectorTest.groovy

@@ -64,22 +64,26 @@ class ConfigCollectorTest extends DDSpecification {
 
   def "should collect merged data from multiple sources"() {
     setup:
-    injectEnvConfig(Strings.toEnvVar(configKey), configValue1)
-    injectSysConfig(configKey, configValue2)
+    injectEnvConfig(Strings.toEnvVar(configKey), envValue)
+    if (jvmValue != null) {
+      injectSysConfig(configKey, jvmValue)
+    }
 
     expect:
     def setting = ConfigCollector.get().collect().get(configKey)
     setting.stringValue() == expectedValue
-    setting.origin == ConfigOrigin.JVM_PROP
+    setting.origin == expectedOrigin
 
     where:
-    configKey                                                 | configValue1                                   | configValue2              | expectedValue
+    configKey                                                 | envValue                                       | jvmValue                  | expectedValue                                                          | expectedOrigin
     // ConfigProvider.getMergedMap
-    TracerConfig.TRACE_PEER_SERVICE_MAPPING                   | "service1:best_service,userService:my_service" | "service2:backup_service" | "service2:backup_service,service1:best_service,userService:my_service"
+    TracerConfig.TRACE_PEER_SERVICE_MAPPING                   | "service1:best_service,userService:my_service" | "service2:backup_service" | "service2:backup_service,service1:best_service,userService:my_service" | ConfigOrigin.CALCULATED
     // ConfigProvider.getOrderedMap
-    TracerConfig.TRACE_HTTP_SERVER_PATH_RESOURCE_NAME_MAPPING | "/asdf/*:/test,/b:some"                        | "/a:prop"                 | "/asdf/*:/test,/b:some,/a:prop"
+    TracerConfig.TRACE_HTTP_SERVER_PATH_RESOURCE_NAME_MAPPING | "/asdf/*:/test,/b:some"                        | "/a:prop"                 | "/asdf/*:/test,/b:some,/a:prop"                                        | ConfigOrigin.CALCULATED
     // ConfigProvider.getMergedMapWithOptionalMappings
-    TracerConfig.HEADER_TAGS                                  | "j:ten"                                        | "e:five,b:six"            | "e:five,j:ten,b:six"
+    TracerConfig.HEADER_TAGS                                  | "j:ten"                                        | "e:five,b:six"            | "e:five,j:ten,b:six"                                                   | ConfigOrigin.CALCULATED
+    // ConfigProvider.getMergedMap, but only one source
+    TracerConfig.TRACE_PEER_SERVICE_MAPPING                   | "service1:best_service,userService:my_service" | null                      | "service1:best_service,userService:my_service"                         | ConfigOrigin.ENV
   }
 
   def "default not-null config settings are collected"() {