Remove MongoDB 3.4 support

* Remove wire version check for including cursor field in aggregate command
* Remove wire version check for retryable reads and writes
* Remove wire version check for use OP_INSERT/UPDATE/DELETE for unacknowledged writes
* Remove dead code that supported OP_INSERT/UPDATE/DELETE
* Simplify CommandMessage to assume OP_QUERY is not used with payloads
 (because it's not only used to send the isMaster command)

JAVA-4299

Author: jyemin

.evergreen/.evg.yml

@@ -1503,10 +1503,6 @@ axes:
         display_name: "3.6"
         variables:
            VERSION: "3.6"
-      - id: "3.4"
-        display_name: "3.4"
-        variables:
-           VERSION: "3.4"
   - id: os
     display_name: OS
     values:
@@ -1689,18 +1685,14 @@ buildvariants:
     - name: "static-analysis"
 
 - matrix_name: "tests-zlib-compression"
-  matrix_spec: { compressor : "zlib", auth: "noauth", ssl: "nossl", jdk: "jdk8",
-                 version: ["3.6", "4.0", "4.2", "4.4", "5.0", "6.0", "latest"],
-                 topology: "standalone", os: "linux" }
+  matrix_spec: { compressor : "zlib", auth: "noauth", ssl: "nossl", jdk: "jdk8", version: "*", topology: "standalone", os: "linux" }
   display_name: "${version} ${compressor} ${topology} ${auth} ${ssl} ${jdk} ${os} "
   tags: ["tests-variant"]
   tasks:
      - name: "test"
 
 - matrix_name: "tests-snappy-compression"
-  matrix_spec: { compressor : "snappy", auth: "noauth", ssl: "nossl", jdk: "jdk8",
-                 version: ["3.4", "3.6", "4.0", "4.2", "4.4", "5.0", "6.0", "latest"],
-                 topology: "standalone", os: "linux" }
+  matrix_spec: { compressor : "snappy", auth: "noauth", ssl: "nossl", jdk: "jdk8", version: "*", topology: "standalone", os: "linux" }
   display_name: "${version} ${compressor} ${topology} ${auth} ${ssl} ${jdk} ${os} "
   tags: ["tests-variant"]
   tasks:
@@ -1715,13 +1707,6 @@ buildvariants:
   tasks:
     - name: "test"
 
-- matrix_name: "tests-jdk8-unsecure"
-  matrix_spec: { auth: "noauth", ssl: "nossl", jdk: "jdk8", version: ["3.4"], topology: "*", os: "linux" }
-  display_name: "${version} ${topology} ${auth} ${ssl} ${jdk} ${os} "
-  tags: ["tests-variant"]
-  tasks:
-     - name: "test"
-
 - matrix_name: "tests-jdk8-unsecure-standalone"
   matrix_spec: { auth: "noauth", ssl: "nossl", jdk: "jdk8", version: ["3.6", "4.0", "4.2", "4.4", "5.0", "6.0", "latest"],
                  topology: "standalone", os: "linux" }

driver-core/src/main/com/mongodb/connection/ServerDescription.java

@@ -52,12 +52,12 @@ public class ServerDescription {
      * The minimum supported driver server version
      * @since 3.8
      */
-    public static final String MIN_DRIVER_SERVER_VERSION = "3.4";
+    public static final String MIN_DRIVER_SERVER_VERSION = "3.6";
     /**
      * The minimum supported driver wire version
      * @since 3.8
      */
-    public static final int MIN_DRIVER_WIRE_VERSION = 5;
+    public static final int MIN_DRIVER_WIRE_VERSION = 6;
     /**
      * The maximum supported driver wire version
      * @since 3.8

driver-core/src/main/com/mongodb/internal/connection/AsyncConnection.java

@@ -16,18 +16,13 @@
 
 package com.mongodb.internal.connection;
 
-import com.mongodb.MongoNamespace;
 import com.mongodb.ReadPreference;
 import com.mongodb.RequestContext;
 import com.mongodb.ServerApi;
-import com.mongodb.WriteConcernResult;
 import com.mongodb.annotations.ThreadSafe;
 import com.mongodb.connection.ConnectionDescription;
 import com.mongodb.internal.async.SingleResultCallback;
 import com.mongodb.internal.binding.ReferenceCounted;
-import com.mongodb.internal.bulk.DeleteRequest;
-import com.mongodb.internal.bulk.InsertRequest;
-import com.mongodb.internal.bulk.UpdateRequest;
 import com.mongodb.internal.session.SessionContext;
 import org.bson.BsonDocument;
 import org.bson.FieldNameValidator;
@@ -55,36 +50,6 @@ public interface AsyncConnection extends ReferenceCounted {
      */
     ConnectionDescription getDescription();
 
-    /**
-     * Insert the documents using the insert wire protocol and apply the write concern asynchronously.
-     * @param namespace    the namespace
-     * @param ordered      whether the writes are ordered
-     * @param insertRequest the insert request
-     * @param callback     the callback to be passed the write result
-     */
-    void insertAsync(MongoNamespace namespace, boolean ordered, InsertRequest insertRequest, RequestContext requestContext,
-                     SingleResultCallback<WriteConcernResult> callback);
-
-    /**
-     * Update the documents using the update wire protocol and apply the write concern asynchronously.
-     * @param namespace    the namespace
-     * @param ordered      whether the writes are ordered
-     * @param updateRequest the update request
-     * @param callback     the callback to be passed the write result
-     */
-    void updateAsync(MongoNamespace namespace, boolean ordered, UpdateRequest updateRequest, RequestContext requestContext,
-                     SingleResultCallback<WriteConcernResult> callback);
-
-    /**
-     * Delete the documents using the delete wire protocol and apply the write concern asynchronously.
-     * @param namespace    the namespace
-     * @param ordered      whether the writes are ordered
-     * @param deleteRequest the delete request
-     * @param callback     the callback to be passed the write result
-     */
-    void deleteAsync(MongoNamespace namespace, boolean ordered, DeleteRequest deleteRequest, RequestContext requestContext,
-                     SingleResultCallback<WriteConcernResult> callback);
-
     /**
      * Execute the command.
      *

driver-core/src/main/com/mongodb/internal/connection/CommandHelper.java

@@ -112,6 +112,7 @@ private static CommandMessage getCommandMessage(final String database, final Bso
                          // Note: server version will be 0.0 at this point when called from InternalConnectionInitializer,
                          // which means OP_MSG will not be used
                         .maxWireVersion(internalConnection.getDescription().getMaxWireVersion())
+                        .serverType(internalConnection.getDescription().getServerType())
                         .build(),
                 clusterConnectionMode, serverApi);
     }

driver-core/src/main/com/mongodb/internal/connection/CommandMessage.java

@@ -22,7 +22,6 @@
 import com.mongodb.ServerApi;
 import com.mongodb.connection.ClusterConnectionMode;
 import com.mongodb.internal.session.SessionContext;
-import com.mongodb.internal.validator.MappedFieldNameValidator;
 import com.mongodb.lang.Nullable;
 import org.bson.BsonArray;
 import org.bson.BsonBinaryWriter;
@@ -31,16 +30,12 @@
 import org.bson.BsonElement;
 import org.bson.BsonInt64;
 import org.bson.BsonString;
-import org.bson.BsonWriter;
 import org.bson.FieldNameValidator;
-import org.bson.codecs.EncoderContext;
 import org.bson.io.BsonOutput;
 
 import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
-import java.util.HashMap;
 import java.util.List;
-import java.util.Map;
 
 import static com.mongodb.ReadPreference.primary;
 import static com.mongodb.ReadPreference.primaryPreferred;
@@ -117,7 +112,7 @@ BsonDocument getCommandDocument(final ByteBufferBsonOutput bsonOutput) {
                 getEncodingMetadata().getFirstDocumentPosition());
         BsonDocument commandBsonDocument;
 
-        if (useOpMsg() && containsPayload()) {
+        if (containsPayload()) {
             commandBsonDocument = byteBufBsonDocument.toBaseBsonDocument();
 
             int payloadStartPosition = getEncodingMetadata().getFirstDocumentPosition()
@@ -131,10 +126,7 @@ BsonDocument getCommandDocument(final ByteBufferBsonOutput bsonOutput) {
             commandBsonDocument = byteBufBsonDocument;
         }
 
-        if (commandBsonDocument.containsKey("$query")) {
-            commandBsonDocument = commandBsonDocument.getDocument("$query");
-        }
-        return commandBsonDocument;
+       return commandBsonDocument;
     }
 
     boolean containsPayload() {
@@ -160,7 +152,7 @@ protected EncodingMetadata encodeMessageBodyWithMetadata(final BsonOutput bsonOu
             bsonOutput.writeByte(0);    // payload type
             commandStartPosition = bsonOutput.getPosition();
 
-            addDocument(getCommandToEncode(), bsonOutput, commandFieldNameValidator, getExtraElements(sessionContext));
+            addDocument(command, bsonOutput, commandFieldNameValidator, getExtraElements(sessionContext));
 
             if (payload != null) {
                 bsonOutput.writeByte(1);          // payload type
@@ -177,48 +169,24 @@ protected EncodingMetadata encodeMessageBodyWithMetadata(final BsonOutput bsonOu
             // Write the flag bits
             bsonOutput.writeInt32(flagPosition, getOpMsgFlagBits());
         } else {
-            bsonOutput.writeInt32(getOpQueryFlagBits());
+            bsonOutput.writeInt32(0);
             bsonOutput.writeCString(namespace.getFullName());
             bsonOutput.writeInt32(0);
             bsonOutput.writeInt32(-1);
 
             commandStartPosition = bsonOutput.getPosition();
 
-            if (payload == null) {
-                List<BsonElement> elements = null;
-                if (serverApi != null) {
-                    elements = new ArrayList<>(3);
-                    addServerApiElements(elements);
-                }
-                addDocument(getCommandToEncode(), bsonOutput, commandFieldNameValidator, elements);
-            } else {
-                // We're not concerned with adding ServerApi elements here.  The only reason we do it for OP_QUERY-based commands is that
-                // OP_QUERY is always used for the handshake, and we have to pass ServerApi elements in the handshake.  Other than that,
-                // all servers that support ServerApi also support OP_MSG, so this code path should never be hit.
-                addDocumentWithPayload(bsonOutput, messageStartPosition);
+            List<BsonElement> elements = null;
+            if (serverApi != null) {
+                elements = new ArrayList<>(3);
+                addServerApiElements(elements);
             }
+            addDocument(command, bsonOutput, commandFieldNameValidator, elements);
         }
         return new EncodingMetadata(commandStartPosition);
     }
 
-    private FieldNameValidator getPayloadArrayFieldNameValidator() {
-        Map<String, FieldNameValidator> rootMap = new HashMap<String, FieldNameValidator>();
-        rootMap.put(payload.getPayloadName(), payloadFieldNameValidator);
-        return new MappedFieldNameValidator(commandFieldNameValidator, rootMap);
-    }
-
-    private void addDocumentWithPayload(final BsonOutput bsonOutput, final int messageStartPosition) {
-        BsonBinaryWriter bsonBinaryWriter = new BsonBinaryWriter(bsonOutput, getPayloadArrayFieldNameValidator());
-        BsonWriter bsonWriter = new SplittablePayloadBsonWriter(bsonBinaryWriter, bsonOutput, messageStartPosition, getSettings(), payload);
-        BsonDocument commandToEncode = getCommandToEncode();
-        getCodec(commandToEncode).encode(bsonWriter, commandToEncode, EncoderContext.builder().build());
-    }
-
     private int getOpMsgFlagBits() {
-        return getOpMsgResponseExpectedFlagBit();
-    }
-
-    private int getOpMsgResponseExpectedFlagBit() {
         int flagBits = 0;
         if (!requireOpMsgResponse()) {
             flagBits = 1 << 1;
@@ -237,22 +205,6 @@ private boolean requireOpMsgResponse() {
         }
     }
 
-    private int getOpQueryFlagBits() {
-        return getOpQuerySecondaryOkFlagBit();
-    }
-
-    private int getOpQuerySecondaryOkFlagBit() {
-        if (isSecondaryOk()) {
-            return 1 << 2;
-        } else {
-            return 0;
-        }
-    }
-
-    private boolean isSecondaryOk() {
-        return (readPreference != null && readPreference.isSecondaryOk()) || isDirectConnectionToReplicaSetMember();
-    }
-
     private boolean isDirectConnectionToReplicaSetMember() {
         return clusterConnectionMode == SINGLE
                 && getSettings().getServerType() != SHARD_ROUTER
@@ -263,16 +215,8 @@ private boolean useOpMsg() {
         return getOpCode().equals(OpCode.OP_MSG);
     }
 
-    private BsonDocument getCommandToEncode() {
-        BsonDocument commandToEncode = command;
-        if (!useOpMsg() && readPreference != null && !readPreference.equals(primary())) {
-            commandToEncode = new BsonDocument("$query", command).append("$readPreference", readPreference.toDocument());
-        }
-        return commandToEncode;
-    }
-
     private List<BsonElement> getExtraElements(final SessionContext sessionContext) {
-        List<BsonElement> extraElements = new ArrayList<BsonElement>();
+        List<BsonElement> extraElements = new ArrayList<>();
         extraElements.add(new BsonElement("$db", new BsonString(new MongoNamespace(getCollectionName()).getDatabaseName())));
         if (sessionContext.getClusterTime() != null) {
             extraElements.add(new BsonElement("$clusterTime", sessionContext.getClusterTime()));
@@ -345,5 +289,4 @@ private static OpCode getOpCode(final MessageSettings settings, final ClusterCon
     private static boolean isServerVersionAtLeastThreeDotSix(final MessageSettings settings) {
         return settings.getMaxWireVersion() >= THREE_DOT_SIX_WIRE_VERSION;
     }
-
 }

driver-core/src/main/com/mongodb/internal/connection/Connection.java

@@ -16,17 +16,12 @@
 
 package com.mongodb.internal.connection;
 
-import com.mongodb.MongoNamespace;
 import com.mongodb.ReadPreference;
 import com.mongodb.RequestContext;
 import com.mongodb.ServerApi;
-import com.mongodb.WriteConcernResult;
 import com.mongodb.annotations.ThreadSafe;
 import com.mongodb.connection.ConnectionDescription;
 import com.mongodb.internal.binding.ReferenceCounted;
-import com.mongodb.internal.bulk.DeleteRequest;
-import com.mongodb.internal.bulk.InsertRequest;
-import com.mongodb.internal.bulk.UpdateRequest;
 import com.mongodb.internal.session.SessionContext;
 import org.bson.BsonDocument;
 import org.bson.FieldNameValidator;
@@ -55,39 +50,6 @@ public interface Connection extends ReferenceCounted {
      */
     ConnectionDescription getDescription();
 
-    /**
-     * Insert the documents using the insert wire protocol and apply the write concern.
-     *
-     * @param namespace    the namespace
-     * @param ordered      whether the writes are ordered
-     * @param insertRequest the insert request
-     * @param requestContext the request context
-     * @return the write concern result
-     */
-    WriteConcernResult insert(MongoNamespace namespace, boolean ordered, InsertRequest insertRequest, RequestContext requestContext);
-
-    /**
-     * Update the documents using the update wire protocol and apply the write concern.
-     *
-     * @param namespace    the namespace
-     * @param ordered      whether the writes are ordered
-     * @param updateRequest the update request
-     * @param requestContext the request context
-     * @return the write concern result
-     */
-    WriteConcernResult update(MongoNamespace namespace, boolean ordered, UpdateRequest updateRequest, RequestContext requestContext);
-
-    /**
-     * Delete the documents using the delete wire protocol and apply the write concern.
-     *
-     * @param namespace    the namespace
-     * @param ordered      whether the writes are ordered
-     * @param deleteRequest the delete request
-     * @param requestContext the request context
-     * @return the write concern result
-     */
-    WriteConcernResult delete(MongoNamespace namespace, boolean ordered, DeleteRequest deleteRequest, RequestContext requestContext);
-
     /**
      * Execute the command.
      *