couchbase-promises

Couchbase Promises

Overview

Just like the Couchbase Node.js SDK, but with the addition of *Async() methods that return A+ Promises for all methods that contain a Node.js callback parameter. This module functions as a drop-in replacement for the couchbase module.

The current version supports Couchbase Node.js SDK version 2.2.1.

Promises are created using the Bluebird Promises library. If you absolutely must use native ECMAScript Promises, then have a look at couchbase-es-promises. I highly recommend avoiding couchbase-es-promises, as Bluebird is compatible with native promises, and offers an order of magnitude more performance.

General Usage

Usage is almost exactly the same as the native SDK, but with the added ability to use Promises instead of callbacks.

A user repository module with a simple lookup...

const couchbase = require('couchbase-promises');
const cluster = new couchbase.Cluster('couchbase://127.0.0.1');
const bucket = cluster.openBucket();

const UserNotFoundError = () => {
  Error.call(this);
  Error.captureStackTrace(this, UserNotFoundError);
  this.message = "User not found.";
}

module.exports = {
  UserNotFoundError: UserNotFoundError,
  getUserAsync: function(userId) {
    return bucket.getAsync(userId)
      .then(function(result) {
        return {
          user: result.value,
          meta: {
            etag: result.cas
          }
        };
      }).catch(couchbase.Error, function(e) {
        if (e.code === couchbase.errors.keyNotFound)
          throw new UserNotFoundError();

        throw e;
      });
  }
};

Additional Functionality

The the couchbase module only provides batch operation support for key lookups (via Bucket.prototype.getMulti()). The couchbase-promises module provides a few extra methods on the Bucket class for performing batch operations.

Bucket.prototype.insertMultiAsync(docs, options)

Inserts multiple documents into the bucket. This method will create individual insert operations for each document, and parallelize their execution with Promisea.all().

Returns: a Promise that resolves with a Summary object. This Promise will always be fulfilled. Any errors that occur will be specified in the resolved Summary.

Parameters

• docs: a Map or an object where each property name is the key of the document to insert.
• options: an optional object to pass to the native insert() method.

Bucket.prototype.removeMultiAsyc(keys, options)

Removes multiple documents in the bucket. This method will create individual remove operations for each key, and parallelize their execution with Promisea.all().

Returns: a Promise that resolves with a Summary object. This Promise will always be fulfilled. Any errors that occur will be specified in the resolved Summary.

Parameters

• keys: a Set or an Array of keys to remove.
• options: an optional object to pass to the native remove() method.

Summary Class

Contains a summary of a bulk operation. Keys include:

• hasErrors: a Boolean value indicating whether or not any items failed in the bulk operation.
• keys: an array of keys that were used in the bulk operations.
• results: an object with properties for key used in the bulk operation.
  • success: a Boolean value indicating whether or not the the individual operation succeeded.
  • err: the error returned from Couchbase if the operation was not successful.
  • result: the result object returned from Couchbase.

Changelog

2.1.0

• Bug Fixes

  • Fixing bug where callback parameter is not getting set correctly.

• New Features

  • Adding method Bucket.prototype.insertMultiAsync().
  • Adding method Bucket.prototype.removeMultiAsync().

• Technical Debt

  • Updating couchbase to the latest version (2.2.1).