Make sure the entries in the set are unique.

Make both a less and equal operator so std::unique can be used to.
Add and interface so that whole sets can be tested effectively if they are subsets.

6 files changed, 31 insertions, 12 deletions

diff --git a/document/src/tests/fieldsettest.cpp b/document/src/tests/fieldsettest.cpp
index 8a01c53c278..29581ff4549 100644
--- a/document/src/tests/fieldsettest.cpp
+++ b/document/src/tests/fieldsettest.cpp
@@ -275,9 +275,10 @@ TEST(FieldCollectionTest, testHash ) {
     const DocumentTypeRepo& repo = testDocMan.getTypeRepo();
     const DocumentType & type = *repo.getDocumentType("testdoctype1");
     EXPECT_EQ(0ul, FieldCollection(type, Field::Set::Builder().build()).hash());
-    EXPECT_EQ(0x548599858c77ef83ul, FieldCollection(type, Field::Set::Builder().insert(&type.getField("headerval")).build()).hash());
-    EXPECT_EQ(0x4a7ff2406d36a9b0ul, FieldCollection(type, Field::Set::Builder().insert(&type.getField("headerval")).insert(&type.getField("hstringval")).build()).hash());
-    EXPECT_EQ(0x1e0918531b19734ul, FieldCollection(type, Field::Set::Builder().insert(&type.getField("hstringval")).build()).hash());
+    EXPECT_EQ(0x548599858c77ef83ul, FieldCollection(type, Field::Set::Builder().add(&type.getField("headerval")).build()).hash());
+    EXPECT_EQ(0x4a7ff2406d36a9b0ul, FieldCollection(type, Field::Set::Builder().add(&type.getField("headerval")).add(
+            &type.getField("hstringval")).build()).hash());
+    EXPECT_EQ(0x1e0918531b19734ul, FieldCollection(type, Field::Set::Builder().add(&type.getField("hstringval")).build()).hash());
 }
 
 } // document
diff --git a/document/src/vespa/document/base/field.cpp b/document/src/vespa/document/base/field.cpp
index 7f1a598cd76..fb814fc5f17 100644
--- a/document/src/vespa/document/base/field.cpp
+++ b/document/src/vespa/document/base/field.cpp
@@ -14,15 +14,25 @@ namespace document {
 Field::Set::Set(std::vector<CPtr> fields)
     : _fields(std::move(fields))
 {
-    std::sort(_fields.begin(), _fields.end(), Field::FieldPtrComparator());
+    std::sort(_fields.begin(), _fields.end(), Field::FieldPtrLess());
+    _fields.erase(std::unique(_fields.begin(), _fields.end(), Field::FieldPtrEqual()), _fields.end());
 }
 
 bool
 Field::Set::contains(const Field & field) const {
-    return std::binary_search(_fields.begin(), _fields.end(), &field, Field::FieldPtrComparator());
+    return std::binary_search(_fields.begin(), _fields.end(), &field, Field::FieldPtrLess());
 }
 
-Field::Field() : Field("", 0, *DataType::INT) { }
+bool
+Field::Set::contains(const Set & fields) const {
+    return std::includes(_fields.begin(), _fields.end(),
+                         fields._fields.begin(), fields._fields.end(),
+                         Field::FieldPtrLess());
+}
+
+Field::Field()
+    : Field("", 0, *DataType::INT)
+{ }
 
 Field::Field(vespalib::stringref name, int fieldId, const DataType& dataType)
     : FieldBase(name),
diff --git a/document/src/vespa/document/base/field.h b/document/src/vespa/document/base/field.h
index cf876903dfa..7580b2b692f 100644
--- a/document/src/vespa/document/base/field.h
+++ b/document/src/vespa/document/base/field.h
@@ -32,27 +32,35 @@ public:
     using SP = std::shared_ptr<Field>;
     using CPtr = const Field *;
 
-    struct FieldPtrComparator {
+    struct FieldPtrLess {
         bool operator()(CPtr f1, CPtr f2) const {
             return (*f1 < *f2);
         }
     };
 
+    struct FieldPtrEqual {
+        bool operator()(CPtr f1, CPtr f2) const {
+            return (*f1 == *f2);
+        }
+    };
+
     class Set {
     public:
         class Builder {
         public:
             Builder & reserve(size_t sz) { _vector.reserve(sz); return *this; }
-            Builder & insert(CPtr field) { _vector.emplace_back(field); return *this; }
+            Builder & add(CPtr field) { _vector.push_back(field); return *this; }
             Set build() { return Set(std::move(_vector)); }
         private:
             std::vector<CPtr> _vector;
         };
         bool contains(const Field & field) const;
+        bool contains(const Set & field) const;
         size_t size() const { return _fields.size(); }
         bool empty() const { return _fields.empty(); }
         const CPtr * begin() const { return &_fields[0]; }
         const CPtr * end() const { return begin() + _fields.size(); }
+        static Set emptySet() { return Builder().build(); }
     private:
         explicit Set(std::vector<CPtr> fields);
         std::vector<CPtr> _fields;
diff --git a/document/src/vespa/document/datatype/structdatatype.cpp b/document/src/vespa/document/datatype/structdatatype.cpp
index 11af020c465..c0c63ddb37f 100644
--- a/document/src/vespa/document/datatype/structdatatype.cpp
+++ b/document/src/vespa/document/datatype/structdatatype.cpp
@@ -167,7 +167,7 @@ StructDataType::getFieldSet() const
     Field::Set::Builder builder;
     builder.reserve(_idFieldMap.size());
     for (const auto & entry : _idFieldMap) {
-        builder.insert(entry.second.get());
+        builder.add(entry.second.get());
     }
     return builder.build();
 }
diff --git a/document/src/vespa/document/fieldset/fieldsetrepo.cpp b/document/src/vespa/document/fieldset/fieldsetrepo.cpp
index 5cc3e548d82..33cbf6185c4 100644
--- a/document/src/vespa/document/fieldset/fieldsetrepo.cpp
+++ b/document/src/vespa/document/fieldset/fieldsetrepo.cpp
@@ -49,10 +49,10 @@ parseFieldCollection(const DocumentTypeRepo& repo,
         const DocumentType::FieldSet * fs = type.getFieldSet(token);
         if (fs) {
             for (const auto & fieldName : fs->getFields()) {
-                builder.insert(&type.getField(fieldName));
+                builder.add(&type.getField(fieldName));
             }
         } else {
-            builder.insert(&type.getField(token));
+            builder.add(&type.getField(token));
         }
     }
     return std::make_unique<FieldCollection>(type, builder.build());
diff --git a/document/src/vespa/document/fieldset/fieldsets.cpp b/document/src/vespa/document/fieldset/fieldsets.cpp
index 115ad37343d..317c1743bb5 100644
--- a/document/src/vespa/document/fieldset/fieldsets.cpp
+++ b/document/src/vespa/document/fieldset/fieldsets.cpp
@@ -42,7 +42,7 @@ FieldCollection::contains(const FieldSet& fields) const
             return _set.contains(static_cast<const Field &>(fields));
         case Type::SET: {
             const auto & coll = static_cast<const FieldCollection&>(fields);
-            return std::includes(_set.begin(), _set.end(), coll.getFields().begin(), coll.getFields().end(), Field::FieldPtrComparator());
+            return _set.contains(coll.getFields());
         }
         case Type::NONE:
         case Type::DOCID: