SERVER-24508 BSONElement::ComparatorInterface

1 files changed, 25 insertions, 131 deletions

diff --git a/src/mongo/bson/bsonobj_comparator_interface.h b/src/mongo/bson/bsonobj_comparator_interface.h
index a063f638391..4240f19b3f4 100644
--- a/src/mongo/bson/bsonobj_comparator_interface.h
+++ b/src/mongo/bson/bsonobj_comparator_interface.h
@@ -28,15 +28,8 @@
 
 #pragma once
 
-#include <initializer_list>
-#include <map>
-#include <set>
-#include <unordered_map>
-#include <unordered_set>
-
-#include "mongo/base/disallow_copying.h"
+#include "mongo/bson/bson_comparator_interface_base.h"
 #include "mongo/bson/bsonobj.h"
-#include "mongo/util/assert_util.h"
 
 namespace mongo {
 
@@ -57,152 +50,53 @@ namespace mongo {
  *
  * All methods are thread-safe.
  */
-class BSONObj::ComparatorInterface {
-    MONGO_DISALLOW_COPYING(ComparatorInterface);
-
+class BSONObj::ComparatorInterface : public BSONComparatorInterfaceBase<BSONObj> {
 public:
     /**
-     * Functor compatible for use with ordered STL containers.
-     */
-    class LessThan {
-    public:
-        explicit LessThan(const ComparatorInterface* comparator) : _comparator(comparator) {}
-
-        bool operator()(const BSONObj& lhs, const BSONObj& rhs) const {
-            return _comparator->compare(lhs, rhs) < 0;
-        }
-
-    private:
-        const ComparatorInterface* _comparator;
-    };
-
-    /**
-     * Functor compatible for use with unordered STL containers.
-     */
-    class EqualTo {
-    public:
-        explicit EqualTo(const ComparatorInterface* comparator) : _comparator(comparator) {}
-
-        bool operator()(const BSONObj& lhs, const BSONObj& rhs) const {
-            return _comparator->compare(lhs, rhs) == 0;
-        }
-
-    private:
-        const ComparatorInterface* _comparator;
-    };
-
-    using BSONObjSet = std::set<BSONObj, BSONObj::ComparatorInterface::LessThan>;
-
-    // TODO SERVER-23990: Make the BSONObj hash collation-aware.
-    using BSONObjUnorderedSet =
-        std::unordered_set<BSONObj, BSONObj::Hasher, BSONObj::ComparatorInterface::EqualTo>;
-
-    template <typename T>
-    using BSONObjIndexedMap = std::map<BSONObj, T, BSONObj::ComparatorInterface::LessThan>;
-
-    // TODO SERVER-23990: Make the BSONObj hash collation-aware.
-    template <typename T>
-    using BSONObjIndexedUnorderedMap =
-        std::unordered_map<BSONObj, T, BSONObj::Hasher, BSONObj::ComparatorInterface::EqualTo>;
-
-    virtual ~ComparatorInterface() = default;
-
-    /**
-     * Compares two BSONObj objects. Returns <0, 0, >0 if 'lhs' < 'rhs', 'lhs' == 'rhs', or 'lhs' >
-     * 'rhs' respectively.
+     * Constructs a BSONObjSet whose equivalence classes are given by this comparator. This
+     * comparator must outlive the returned set.
      */
-    virtual int compare(const BSONObj& lhs, const BSONObj& rhs) const = 0;
-
-    /**
-     * Evaluates a deferred comparison object generated by invocation of one of the BSONObj operator
-     * overloads for relops.
-     */
-    bool evaluate(BSONObj::DeferredComparison deferredComparison) const {
-        int cmp = compare(deferredComparison.lhs, deferredComparison.rhs);
-        switch (deferredComparison.type) {
-            case BSONObj::DeferredComparison::Type::kLT:
-                return cmp < 0;
-            case BSONObj::DeferredComparison::Type::kLTE:
-                return cmp <= 0;
-            case BSONObj::DeferredComparison::Type::kEQ:
-                return cmp == 0;
-            case BSONObj::DeferredComparison::Type::kGT:
-                return cmp > 0;
-            case BSONObj::DeferredComparison::Type::kGTE:
-                return cmp >= 0;
-            case BSONObj::DeferredComparison::Type::kNE:
-                return cmp != 0;
-        }
-
-        MONGO_UNREACHABLE;
-    }
-
-    /**
-     * Returns a function object which computes whether one BSONObj is less than another under this
-     * comparator. This comparator must outlive the returned function object.
-     */
-    LessThan makeLessThan() const {
-        return LessThan(this);
-    }
-
-    /**
-     * Returns a function object which computes whether one BSONObj is equal to another under this
-     * comparator. This comparator must outlive the returned function object.
-     */
-    EqualTo makeEqualTo() const {
-        return EqualTo(this);
-    }
-
-    /**
-     * Constructs a BSONObjSet whose ordering is given by this comparator. This comparator must
-     * outlive the returned set.
-     */
-    BSONObjSet makeBSONObjSet(std::initializer_list<BSONObj> init = {}) const {
-        return BSONObjSet(init, LessThan(this));
+    Set makeBSONObjSet(std::initializer_list<BSONObj> init = {}) const {
+        return makeSet(init);
     }
 
     /**
      * Constructs a BSONObjUnorderedSet whose equivalence classes are given by this
      * comparator. This comparator must outlive the returned set.
      */
-    BSONObjUnorderedSet makeBSONObjUnorderedSet(std::initializer_list<BSONObj> init = {}) const {
-        // TODO SERVER-23990: Make the BSONObj hash collation-aware.
-        return BSONObjUnorderedSet(init, 0, BSONObj::Hasher(), EqualTo(this));
+    UnorderedSet makeBSONObjUnorderedSet(std::initializer_list<BSONObj> init = {}) const {
+        return makeUnorderedSet(init);
     }
 
     /**
-     * Constructs an ordered map from BSONObj to type T whose ordering is given by this comparator.
-     * This comparator must outlive the returned map.
+     * Constructs an ordered map from BSONObj to type ValueType whose ordering is given by this
+     * comparator.  This comparator must outlive the returned map.
      */
-    template <typename T>
-    BSONObjIndexedMap<T> makeBSONObjIndexedMap(
-        std::initializer_list<std::pair<const BSONObj, T>> init = {}) const {
-        return BSONObjIndexedMap<T>(init, LessThan(this));
+    template <typename ValueType>
+    Map<ValueType> makeBSONObjIndexedMap(
+        std::initializer_list<std::pair<const BSONObj, ValueType>> init = {}) const {
+        return makeMap(init);
     }
 
     /**
-     * Constructs an unordered map from BSONObj to type T whose ordering is given by this
+     * Constructs an unordered map from BSONObj to type ValueType whose ordering is given by this
      * comparator. This comparator must outlive the returned map.
      */
-    template <typename T>
-    BSONObjIndexedUnorderedMap<T> makeBSONObjIndexedUnorderedMap(
-        std::initializer_list<std::pair<const BSONObj, T>> init = {}) const {
-        // TODO SERVER-23990: Make the BSONObj hash collation-aware.
-        return BSONObjIndexedUnorderedMap<T>(init, 0, BSONObj::Hasher(), EqualTo(this));
+    template <typename ValueType>
+    UnorderedMap<ValueType> makeBSONObjIndexedUnorderedMap(
+        std::initializer_list<std::pair<const BSONObj, ValueType>> init = {}) const {
+        return makeUnorderedMap(init);
     }
-
-protected:
-    constexpr ComparatorInterface() = default;
 };
 
-using BSONObjSet = BSONObj::ComparatorInterface::BSONObjSet;
+using BSONObjSet = BSONComparatorInterfaceBase<BSONObj>::Set;
 
-using BSONObjUnorderedSet = BSONObj::ComparatorInterface::BSONObjUnorderedSet;
+using BSONObjUnorderedSet = BSONComparatorInterfaceBase<BSONObj>::UnorderedSet;
 
-template <typename T>
-using BSONObjIndexedMap = BSONObj::ComparatorInterface::BSONObjIndexedMap<T>;
+template <typename ValueType>
+using BSONObjIndexedMap = BSONComparatorInterfaceBase<BSONObj>::Map<ValueType>;
 
-template <typename T>
-using BSONObjIndexedUnorderedMap = BSONObj::ComparatorInterface::BSONObjIndexedUnorderedMap<T>;
+template <typename ValueType>
+using BSONObjIndexedUnorderedMap = BSONComparatorInterfaceBase<BSONObj>::UnorderedMap<ValueType>;
 
 }  // namespace mongo