(api) Add query parameter 'dc' for specifying the max number of results per domain

code/services-application/api-service/java/nu/marginalia/api/ApiSearchOperator.java

@@ -30,10 +30,11 @@ public class ApiSearchOperator {
 
     public ApiSearchResults query(String query,
                                   int count,
+                                  int domainCount,
                                   int index,
                                   NsfwFilterTier filterTier)
     {
-        var rsp = queryClient.search(createParams(query, count, index, filterTier));
+        var rsp = queryClient.search(createParams(query, count, domainCount, index, filterTier));
 
         return new ApiSearchResults("RESTRICTED", query,
                 rsp.results()
@@ -44,13 +45,13 @@ public class ApiSearchOperator {
                 .collect(Collectors.toList()));
     }
 
-    private QueryParams createParams(String query, int count, int index, NsfwFilterTier filterTirer) {
+    private QueryParams createParams(String query, int count, int domainCount, int index, NsfwFilterTier filterTirer) {
         SearchSetIdentifier searchSet = selectSearchSet(index);
 
         return new QueryParams(
                 query,
                 RpcQueryLimits.newBuilder()
-                        .setResultsByDomain(2)
+                        .setResultsByDomain(Math.clamp(domainCount, 1, 100))
                         .setResultsTotal(Math.min(100, count))
                         .setTimeoutMs(150)
                         .setFetchSize(8192)

code/services-application/api-service/java/nu/marginalia/api/ApiService.java

@@ -119,6 +119,7 @@ public class ApiService extends SparkService {
         }
 
         int count = intParam(request, "count", 20);
+        int domainCount = intParam(request, "dc", 2);
         int index = intParam(request, "index", 3);
         int nsfw = intParam(request, "nsfw", 1);
 
@@ -137,7 +138,7 @@ public class ApiService extends SparkService {
                 .labels(license.key)
                 .time(() ->
                         searchOperator
-                        .query(query, count, index, nsfwFilterTier)
+                        .query(query, count, domainCount, index, nsfwFilterTier)
                         .withLicense(license.getLicense())
                 );
     }