SERVER-24508 BSONObj::ComparatorInterface

BSONObj instances should now be compared via the comparator
interface's evaluate() method. This preferred over using
BSONObj::woCompare() directly. If the comparison doesn't
require any database semantics (e.g. there is no collation),
there is a global instance of the SimpleBSONObjComparator
which should be used for BSONObj comparisons. If the
comparison requires special semantics, then callers must
instantiate their own comparator object.

8 files changed, 38 insertions, 20 deletions

diff --git a/src/mongo/db/query/collation/collation_index_key_test.cpp b/src/mongo/db/query/collation/collation_index_key_test.cpp
index bcd341c9488..0b92c5d7cae 100644
--- a/src/mongo/db/query/collation/collation_index_key_test.cpp
+++ b/src/mongo/db/query/collation/collation_index_key_test.cpp
@@ -70,7 +70,7 @@ TEST(CollationIndexKeyTest, CollationAwareAppendCorrectlyAppendsElementWithNullC
     BSONObj dataObj = BSON("test" << 1);
     BSONObjBuilder out;
     CollationIndexKey::collationAwareIndexKeyAppend(dataObj.firstElement(), nullptr, &out);
-    ASSERT_EQ(out.obj(), BSON("" << 1));
+    ASSERT_BSONOBJ_EQ(out.obj(), BSON("" << 1));
 }
 
 TEST(CollationIndexKeyTest, CollationAwareAppendReversesStringWithReverseMockCollator) {
@@ -79,9 +79,9 @@ TEST(CollationIndexKeyTest, CollationAwareAppendReversesStringWithReverseMockCol
                            << "string");
     BSONObjBuilder out;
     CollationIndexKey::collationAwareIndexKeyAppend(dataObj.firstElement(), &collator, &out);
-    ASSERT_EQ(out.obj(),
-              BSON(""
-                   << "gnirts"));
+    ASSERT_BSONOBJ_EQ(out.obj(),
+                      BSON(""
+                           << "gnirts"));
 }
 
 TEST(CollationIndexKeyTest, CollationAwareAppendCorrectlySerializesEmptyComparisonKey) {
@@ -96,7 +96,7 @@ TEST(CollationIndexKeyTest, CollationAwareAppendCorrectlySerializesEmptyComparis
 
     BSONObjBuilder out;
     CollationIndexKey::collationAwareIndexKeyAppend(dataObj.firstElement(), &collator, &out);
-    ASSERT_EQ(out.obj(), expectedObj);
+    ASSERT_BSONOBJ_EQ(out.obj(), expectedObj);
 }
 
 TEST(CollationIndexKeyTest, CollationAwareAppendCorrectlySerializesWithEmbeddedNullByte) {
@@ -111,7 +111,7 @@ TEST(CollationIndexKeyTest, CollationAwareAppendCorrectlySerializesWithEmbeddedN
 
     BSONObjBuilder out;
     CollationIndexKey::collationAwareIndexKeyAppend(dataObj.firstElement(), &collator, &out);
-    ASSERT_EQ(out.obj(), expectedObj);
+    ASSERT_BSONOBJ_EQ(out.obj(), expectedObj);
 }
 
 TEST(CollationIndexKeyTest, CollationAwareAppendCorrectlyReversesSimpleEmbeddedObject) {
@@ -123,7 +123,7 @@ TEST(CollationIndexKeyTest, CollationAwareAppendCorrectlyReversesSimpleEmbeddedO
 
     BSONObjBuilder out;
     CollationIndexKey::collationAwareIndexKeyAppend(dataObj.firstElement(), &collator, &out);
-    ASSERT_EQ(out.obj(), expected);
+    ASSERT_BSONOBJ_EQ(out.obj(), expected);
 }
 
 TEST(CollationIndexKeyTest, CollationAwareAppendCorrectlyReversesSimpleEmbeddedArray) {
@@ -135,7 +135,7 @@ TEST(CollationIndexKeyTest, CollationAwareAppendCorrectlyReversesSimpleEmbeddedA
 
     BSONObjBuilder out;
     CollationIndexKey::collationAwareIndexKeyAppend(dataObj.firstElement(), &collator, &out);
-    ASSERT_EQ(out.obj(), expected);
+    ASSERT_BSONOBJ_EQ(out.obj(), expected);
 }
 
 TEST(CollationIndexKeyTest, CollationAwareAppendCorrectlyReversesComplexNesting) {
@@ -151,7 +151,7 @@ TEST(CollationIndexKeyTest, CollationAwareAppendCorrectlyReversesComplexNesting)
 
     BSONObjBuilder out;
     CollationIndexKey::collationAwareIndexKeyAppend(dataObj.firstElement(), &collator, &out);
-    ASSERT_EQ(out.obj(), expected);
+    ASSERT_BSONOBJ_EQ(out.obj(), expected);
 }
 
 }  // namespace
diff --git a/src/mongo/db/query/collation/collation_spec_test.cpp b/src/mongo/db/query/collation/collation_spec_test.cpp
index cd8553c7305..29ab7f99473 100644
--- a/src/mongo/db/query/collation/collation_spec_test.cpp
+++ b/src/mongo/db/query/collation/collation_spec_test.cpp
@@ -203,7 +203,7 @@ TEST(CollationSpecTest, ToBSONCorrectlySerializesDefaults) {
                                << "version"
                                << "myVersion");
 
-    ASSERT_EQ(expectedObj, collationSpec.toBSON());
+    ASSERT_BSONOBJ_EQ(expectedObj, collationSpec.toBSON());
 }
 
 TEST(CollationSpecTest, ToBSONCorrectlySerializesCaseFirstUpper) {
@@ -233,7 +233,7 @@ TEST(CollationSpecTest, ToBSONCorrectlySerializesCaseFirstUpper) {
                                << "version"
                                << "myVersion");
 
-    ASSERT_EQ(expectedObj, collationSpec.toBSON());
+    ASSERT_BSONOBJ_EQ(expectedObj, collationSpec.toBSON());
 }
 
 TEST(CollationSpecTest, ToBSONCorrectlySerializesCaseFirstLower) {
@@ -263,7 +263,7 @@ TEST(CollationSpecTest, ToBSONCorrectlySerializesCaseFirstLower) {
                                << "version"
                                << "myVersion");
 
-    ASSERT_EQ(expectedObj, collationSpec.toBSON());
+    ASSERT_BSONOBJ_EQ(expectedObj, collationSpec.toBSON());
 }
 
 TEST(CollationSpecTest, ToBSONCorrectlySerializesPrimaryStrength) {
@@ -293,7 +293,7 @@ TEST(CollationSpecTest, ToBSONCorrectlySerializesPrimaryStrength) {
                                << "version"
                                << "myVersion");
 
-    ASSERT_EQ(expectedObj, collationSpec.toBSON());
+    ASSERT_BSONOBJ_EQ(expectedObj, collationSpec.toBSON());
 }
 
 TEST(CollationSpecTest, ToBSONCorrectlySerializesSecondaryStrength) {
@@ -323,7 +323,7 @@ TEST(CollationSpecTest, ToBSONCorrectlySerializesSecondaryStrength) {
                                << "version"
                                << "myVersion");
 
-    ASSERT_EQ(expectedObj, collationSpec.toBSON());
+    ASSERT_BSONOBJ_EQ(expectedObj, collationSpec.toBSON());
 }
 
 TEST(CollationSpecTest, ToBSONCorrectlySerializesQuaternaryStrength) {
@@ -353,7 +353,7 @@ TEST(CollationSpecTest, ToBSONCorrectlySerializesQuaternaryStrength) {
                                << "version"
                                << "myVersion");
 
-    ASSERT_EQ(expectedObj, collationSpec.toBSON());
+    ASSERT_BSONOBJ_EQ(expectedObj, collationSpec.toBSON());
 }
 
 TEST(CollationSpecTest, ToBSONCorrectlySerializesIdenticalStrength) {
@@ -383,7 +383,7 @@ TEST(CollationSpecTest, ToBSONCorrectlySerializesIdenticalStrength) {
                                << "version"
                                << "myVersion");
 
-    ASSERT_EQ(expectedObj, collationSpec.toBSON());
+    ASSERT_BSONOBJ_EQ(expectedObj, collationSpec.toBSON());
 }
 
 TEST(CollationSpecTest, ToBSONCorrectlySerializesAlternateShifted) {
@@ -413,7 +413,7 @@ TEST(CollationSpecTest, ToBSONCorrectlySerializesAlternateShifted) {
                                << "version"
                                << "myVersion");
 
-    ASSERT_EQ(expectedObj, collationSpec.toBSON());
+    ASSERT_BSONOBJ_EQ(expectedObj, collationSpec.toBSON());
 }
 
 TEST(CollationSpecTest, ToBSONCorrectlySerializesMaxVariableSpace) {
@@ -443,7 +443,7 @@ TEST(CollationSpecTest, ToBSONCorrectlySerializesMaxVariableSpace) {
                                << "version"
                                << "myVersion");
 
-    ASSERT_EQ(expectedObj, collationSpec.toBSON());
+    ASSERT_BSONOBJ_EQ(expectedObj, collationSpec.toBSON());
 }
 
 }  // namespace
diff --git a/src/mongo/db/query/collation/collator_factory_mock.cpp b/src/mongo/db/query/collation/collator_factory_mock.cpp
index ac606847131..13784517d1d 100644
--- a/src/mongo/db/query/collation/collator_factory_mock.cpp
+++ b/src/mongo/db/query/collation/collator_factory_mock.cpp
@@ -33,6 +33,7 @@
 #include "mongo/base/status_with.h"
 #include "mongo/bson/bsonobj.h"
 #include "mongo/bson/bsonobjbuilder.h"
+#include "mongo/bson/simple_bsonobj_comparator.h"
 #include "mongo/db/query/collation/collator_interface_mock.h"
 #include "mongo/stdx/memory.h"
 
@@ -40,7 +41,8 @@ namespace mongo {
 
 StatusWith<std::unique_ptr<CollatorInterface>> CollatorFactoryMock::makeFromBSON(
     const BSONObj& spec) {
-    if (spec == BSON(CollationSpec::kLocaleField << CollationSpec::kSimpleBinaryComparison)) {
+    if (SimpleBSONObjComparator::kInstance.evaluate(
+            spec == BSON(CollationSpec::kLocaleField << CollationSpec::kSimpleBinaryComparison))) {
         return {nullptr};
     }
     auto collator =
diff --git a/src/mongo/db/query/collation/collator_interface.h b/src/mongo/db/query/collation/collator_interface.h
index 76f236c7413..7d44a4c63ed 100644
--- a/src/mongo/db/query/collation/collator_interface.h
+++ b/src/mongo/db/query/collation/collator_interface.h
@@ -34,6 +34,7 @@
 #include "mongo/base/disallow_copying.h"
 #include "mongo/base/string_data.h"
 #include "mongo/base/string_data_comparator_interface.h"
+#include "mongo/bson/bsonobj_comparator_interface.h"
 #include "mongo/db/query/collation/collation_spec.h"
 
 namespace mongo {
@@ -46,7 +47,8 @@ namespace mongo {
  *
  * Does not throw exceptions.
  */
-class CollatorInterface : public StringData::ComparatorInterface {
+class CollatorInterface : public StringData::ComparatorInterface,
+                          public BSONObj::ComparatorInterface {
     MONGO_DISALLOW_COPYING(CollatorInterface);
 
 public:
@@ -100,6 +102,8 @@ public:
      */
     virtual int compare(StringData left, StringData right) const = 0;
 
+    virtual int compare(const BSONObj& left, const BSONObj& right) const = 0;
+
     /**
      * Hashes the string such that strings which are equal under this collation also have equal
      * hashes.
diff --git a/src/mongo/db/query/collation/collator_interface_icu.cpp b/src/mongo/db/query/collation/collator_interface_icu.cpp
index 12498d12712..1040591fef5 100644
--- a/src/mongo/db/query/collation/collator_interface_icu.cpp
+++ b/src/mongo/db/query/collation/collator_interface_icu.cpp
@@ -71,6 +71,10 @@ int CollatorInterfaceICU::compare(StringData left, StringData right) const {
     MONGO_UNREACHABLE;
 }
 
+int CollatorInterfaceICU::compare(const BSONObj& left, const BSONObj& right) const {
+    return left.woCompare(right, BSONObj(), true, this);
+}
+
 CollatorInterface::ComparisonKey CollatorInterfaceICU::getComparisonKey(
     StringData stringData) const {
     // A StringPiece is ICU's StringData. They are logically the same abstraction.
diff --git a/src/mongo/db/query/collation/collator_interface_icu.h b/src/mongo/db/query/collation/collator_interface_icu.h
index 9bb83824891..c35cc898c37 100644
--- a/src/mongo/db/query/collation/collator_interface_icu.h
+++ b/src/mongo/db/query/collation/collator_interface_icu.h
@@ -50,6 +50,8 @@ public:
 
     int compare(StringData left, StringData right) const final;
 
+    int compare(const BSONObj& left, const BSONObj& right) const final;
+
     ComparisonKey getComparisonKey(StringData stringData) const final;
 
 private:
diff --git a/src/mongo/db/query/collation/collator_interface_mock.cpp b/src/mongo/db/query/collation/collator_interface_mock.cpp
index 638427bcd99..74fc7a26f4f 100644
--- a/src/mongo/db/query/collation/collator_interface_mock.cpp
+++ b/src/mongo/db/query/collation/collator_interface_mock.cpp
@@ -92,6 +92,10 @@ int CollatorInterfaceMock::compare(StringData left, StringData right) const {
     MONGO_UNREACHABLE;
 }
 
+int CollatorInterfaceMock::compare(const BSONObj& left, const BSONObj& right) const {
+    return left.woCompare(right, BSONObj(), true, this);
+}
+
 CollatorInterface::ComparisonKey CollatorInterfaceMock::getComparisonKey(
     StringData stringData) const {
     switch (_mockType) {
diff --git a/src/mongo/db/query/collation/collator_interface_mock.h b/src/mongo/db/query/collation/collator_interface_mock.h
index 8ef8d63fb83..6ab8a3d072b 100644
--- a/src/mongo/db/query/collation/collator_interface_mock.h
+++ b/src/mongo/db/query/collation/collator_interface_mock.h
@@ -65,6 +65,8 @@ public:
 
     int compare(StringData left, StringData right) const final;
 
+    int compare(const BSONObj& left, const BSONObj& right) const final;
+
     ComparisonKey getComparisonKey(StringData stringData) const final;
 
 private: