feat(lib): implement executeOperationV2

Fixes NODE-1896

lib/collection.js

@@ -46,7 +46,6 @@ const indexes = require('./operations/collection_ops').indexes;
 const indexExists = require('./operations/collection_ops').indexExists;
 const indexInformation = require('./operations/collection_ops').indexInformation;
 const insertMany = require('./operations/collection_ops').insertMany;
-const insertOne = require('./operations/collection_ops').insertOne;
 const isCapped = require('./operations/collection_ops').isCapped;
 const mapReduce = require('./operations/collection_ops').mapReduce;
 const optionsOp = require('./operations/collection_ops').optionsOp;
@@ -61,6 +60,9 @@ const updateDocuments = require('./operations/collection_ops').updateDocuments;
 const updateMany = require('./operations/collection_ops').updateMany;
 const updateOne = require('./operations/collection_ops').updateOne;
 
+const InsertOneOperation = require('./operations/insert_one');
+const executeOperationV2 = require('./operations/execute_operation_v2');
+
 /**
  * @fileOverview The **Collection** class is an internal class that embodies a MongoDB collection
  * allowing for insert/update/remove/find and other command operation on that MongoDB collection.
@@ -460,7 +462,9 @@ Collection.prototype.insertOne = function(doc, options, callback) {
     options.ignoreUndefined = this.s.options.ignoreUndefined;
   }
 
-  return executeOperation(this.s.topology, insertOne, [this, doc, options, callback]);
+  const insertOneOperation = new InsertOneOperation(this, doc, options);
+
+  return executeOperationV2(this.s.topology, insertOneOperation, callback);
 };
 
 /**

lib/operations/execute_operation_v2.js

@@ -0,0 +1,86 @@
+'use strict';
+
+const MongoError = require('mongodb-core').MongoError;
+const Aspect = require('./operation').Aspect;
+const OperationBase = require('./operation').OperationBase;
+
+/**
+ * Executes the given operation with provided arguments.
+ *
+ * This method reduces large amounts of duplication in the entire codebase by providing
+ * a single point for determining whether callbacks or promises should be used. Additionally
+ * it allows for a single point of entry to provide features such as implicit sessions, which
+ * are required by the Driver Sessions specification in the event that a ClientSession is
+ * not provided
+ *
+ * @param {object} topology The topology to execute this operation on
+ * @param {Operation} operation The operation to execute
+ * @param {function} callback The command result callback
+ */
+function executeOperationV2(topology, operation, callback) {
+  if (topology == null) {
+    throw new TypeError('This method requires a valid topology instance');
+  }
+
+  if (!(operation instanceof OperationBase)) {
+    throw new TypeError('This method requires a valid operation instance');
+  }
+
+  const Promise = topology.s.promiseLibrary;
+
+  // The driver sessions spec mandates that we implicitly create sessions for operations
+  // that are not explicitly provided with a session.
+  let session, owner;
+  if (!operation.hasAspect(Aspect.SKIP_SESSION) && topology.hasSessionSupport()) {
+    if (operation.session == null) {
+      owner = Symbol();
+      session = topology.startSession({ owner });
+      operation.session = session;
+    } else if (operation.session.hasEnded) {
+      throw new MongoError('Use of expired sessions is not permitted');
+    }
+  }
+
+  const makeExecuteCallback = (resolve, reject) =>
+    function executeCallback(err, result) {
+      if (session && session.owner === owner) {
+        session.endSession(() => {
+          if (operation.session === session) {
+            operation.clearSession();
+          }
+          if (err) return reject(err);
+          resolve(result);
+        });
+      } else {
+        if (err) return reject(err);
+        resolve(result);
+      }
+    };
+
+  // Execute using callback
+  if (typeof callback === 'function') {
+    const handler = makeExecuteCallback(
+      result => callback(null, result),
+      err => callback(err, null)
+    );
+
+    try {
+      return operation.execute(handler);
+    } catch (e) {
+      handler(e);
+      throw e;
+    }
+  }
+
+  return new Promise(function(resolve, reject) {
+    const handler = makeExecuteCallback(resolve, reject);
+
+    try {
+      return operation.execute(handler);
+    } catch (e) {
+      handler(e);
+    }
+  });
+}
+
+module.exports = executeOperationV2;

lib/operations/insert_one.js

@@ -0,0 +1,94 @@
+'use strict';
+
+const applyRetryableWrites = require('../utils').applyRetryableWrites;
+const applyWriteConcern = require('../utils').applyWriteConcern;
+const handleCallback = require('../utils').handleCallback;
+const MongoError = require('mongodb-core').MongoError;
+const OperationBase = require('./operation').OperationBase;
+const toError = require('../utils').toError;
+
+class InsertOneOperation extends OperationBase {
+  constructor(collection, doc, options) {
+    super(options);
+
+    this.collection = collection;
+    this.doc = doc;
+  }
+
+  execute(callback) {
+    const coll = this.collection;
+    const doc = this.doc;
+    const options = this.options;
+
+    if (Array.isArray(doc)) {
+      return callback(
+        MongoError.create({ message: 'doc parameter must be an object', driver: true })
+      );
+    }
+
+    insertDocuments(coll, [doc], options, (err, r) => {
+      if (callback == null) return;
+      if (err && callback) return callback(err);
+      // Workaround for pre 2.6 servers
+      if (r == null) return callback(null, { result: { ok: 1 } });
+      // Add values to top level to ensure crud spec compatibility
+      r.insertedCount = r.result.n;
+      r.insertedId = doc._id;
+      if (callback) callback(null, r);
+    });
+  }
+}
+
+function insertDocuments(coll, docs, options, callback) {
+  if (typeof options === 'function') (callback = options), (options = {});
+  options = options || {};
+  // Ensure we are operating on an array op docs
+  docs = Array.isArray(docs) ? docs : [docs];
+
+  // Final options for retryable writes and write concern
+  let finalOptions = Object.assign({}, options);
+  finalOptions = applyRetryableWrites(finalOptions, coll.s.db);
+  finalOptions = applyWriteConcern(finalOptions, { db: coll.s.db, collection: coll }, options);
+
+  // If keep going set unordered
+  if (finalOptions.keepGoing === true) finalOptions.ordered = false;
+  finalOptions.serializeFunctions = options.serializeFunctions || coll.s.serializeFunctions;
+
+  docs = prepareDocs(coll, docs, options);
+
+  // File inserts
+  coll.s.topology.insert(coll.s.namespace, docs, finalOptions, (err, result) => {
+    if (callback == null) return;
+    if (err) return handleCallback(callback, err);
+    if (result == null) return handleCallback(callback, null, null);
+    if (result.result.code) return handleCallback(callback, toError(result.result));
+    if (result.result.writeErrors)
+      return handleCallback(callback, toError(result.result.writeErrors[0]));
+    // Add docs to the list
+    result.ops = docs;
+    // Return the results
+    handleCallback(callback, null, result);
+  });
+}
+
+function prepareDocs(coll, docs, options) {
+  const forceServerObjectId =
+    typeof options.forceServerObjectId === 'boolean'
+      ? options.forceServerObjectId
+      : coll.s.db.options.forceServerObjectId;
+
+  // no need to modify the docs if server sets the ObjectId
+  if (forceServerObjectId === true) {
+    return docs;
+  }
+
+  return docs.map(doc => {
+    if (forceServerObjectId !== true && doc._id == null) {
+      doc._id = coll.s.pkFactory.createPk();
+    }
+
+    return doc;
+  });
+}
+
+module.exports = InsertOneOperation;

lib/operations/operation.js

@@ -0,0 +1,56 @@
+'use strict';
+
+const Aspect = {
+  SKIP_SESSION: Symbol('SKIP_SESSION')
+};
+
+/**
+ * This class acts as a parent class for any operation and is responsible for setting this.options,
+ * as well as setting and getting a session.
+ * Additionally, this class implements `hasAspect`, which determines whether an operation has
+ * a specific aspect, including `SKIP_SESSION` and other aspects to encode retryability
+ * and other functionality.
+ */
+class OperationBase {
+  constructor(options) {
+    this.options = options || {};
+  }
+
+  hasAspect(aspect) {
+    if (this.constructor.aspects == null) {
+      return false;
+    }
+    return this.constructor.aspects.has(aspect);
+  }
+
+  set session(session) {
+    Object.assign(this.options, { session });
+  }
+
+  get session() {
+    return this.options.session;
+  }
+
+  clearSession() {
+    delete this.options.session;
+  }
+
+  execute() {
+    throw new TypeError('`execute` must be implemented for OperationBase subclasses');
+  }
+}
+
+function defineAspects(operation, aspects) {
+  aspects = new Set(aspects);
+  Object.defineProperty(operation, 'aspects', {
+    value: aspects,
+    writable: false
+  });
+  return aspects;
+}
+
+module.exports = {
+  Aspect,
+  defineAspects,
+  OperationBase
+};