1 files changed, 105 insertions, 0 deletions
diff --git a/config-model/src/main/java/com/yahoo/searchdefinition/parser/InheritanceResolver.java b/config-model/src/main/java/com/yahoo/searchdefinition/parser/InheritanceResolver.java
new file mode 100644
index 00000000000..488464ccd1f
--- /dev/null
+++ b/config-model/src/main/java/com/yahoo/searchdefinition/parser/InheritanceResolver.java
@@ -0,0 +1,105 @@
+// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.searchdefinition.parser;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Class resolving some inheritance relationships.
+ *
+ * @author arnej27959
+ **/
+public class InheritanceResolver {
+
+    private final Map<String, ParsedSchema> parsedSchemas;
+    private final Map<String, ParsedDocument> parsedDocs = new HashMap<>();
+
+    public InheritanceResolver(Map<String, ParsedSchema> parsedSchemas) {
+        this.parsedSchemas = parsedSchemas;
+    }
+
+    private void inheritanceCycleCheck(ParsedSchema schema, List<String> seen) {
+        String name = schema.name();
+        if (seen.contains(name)) {
+            seen.add(name);
+            throw new IllegalArgumentException("Inheritance cycle for schemas: " +
+                                               String.join(" -> ", seen));
+        }
+        seen.add(name);
+        for (ParsedSchema parent : schema.getResolvedInherits()) {
+            inheritanceCycleCheck(parent, seen);
+        }
+        seen.remove(name);
+    }
+
+    private void resolveSchemaInheritance() {
+        for (ParsedSchema schema : parsedSchemas.values()) {
+            for (String inherit : schema.getInherited()) {
+                var parent = parsedSchemas.get(inherit);
+                if (parent == null) {
+                    throw new IllegalArgumentException("schema " + schema.name() + " inherits from unavailable schema " + inherit);
+                }
+                schema.resolveInherit(inherit, parent);
+            }
+        }
+    }
+
+    private void checkSchemaCycles() {
+        List<String> seen = new ArrayList<>();
+        for (ParsedSchema schema : parsedSchemas.values()) {
+            inheritanceCycleCheck(schema, seen);
+        }
+    }
+
+    private void resolveDocumentInheritance() {
+        for (ParsedSchema schema : parsedSchemas.values()) {
+            if (! schema.hasDocument()) {
+                // TODO: is schema without a document even valid?
+                continue;
+            }
+            ParsedDocument doc = schema.getDocument();
+            var old = parsedDocs.put(doc.name(), doc);
+            assert(old == null);
+        }
+        for (ParsedDocument doc : parsedDocs.values()) {
+            for (String inherit : doc.getInherited()) {
+                var parentDoc = parsedDocs.get(inherit);
+                if (parentDoc == null) {
+                    throw new IllegalArgumentException("document " + doc.name() + " inherits from unavailable document " + inherit);
+                }
+                doc.resolveInherit(inherit, parentDoc);
+            }
+        }
+    }
+
+    private void inheritanceCycleCheck(ParsedDocument document, List<String> seen) {
+        String name = document.name();
+        if (seen.contains(name)) {
+            seen.add(name);
+            throw new IllegalArgumentException("Inheritance cycle for documents: " +
+                                               String.join(" -> ", seen));
+        }
+        seen.add(name);
+        for (ParsedDocument parent : document.getResolvedInherits()) {
+            inheritanceCycleCheck(parent, seen);
+        }
+        seen.remove(name);
+    }
+
+    private void checkDocumentCycles() {
+        List<String> seen = new ArrayList<>();
+        for (ParsedDocument doc : parsedDocs.values()) {
+            inheritanceCycleCheck(doc, seen);
+        }
+    }
+
+    public void resolveInheritance() {
+        resolveSchemaInheritance();
+        resolveDocumentInheritance();
+        checkSchemaCycles();
+        checkDocumentCycles();
+    }
+
+}