Added upsert method

lib/index.js

@@ -1112,6 +1112,103 @@ Index.prototype = {
             json  : doc
         }, callback);
     },
+
+    /**
+    Upsert a document in this index.
+
+    If a document already exists in this index with the specified _type_ and
+    _id_, it will be updated. Otherwise, a new document will be created.
+
+    [ElasticSearch docs](http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/docs-update.html)
+
+    @example
+
+        var blog = client.getIndex('blog');
+
+        blog.upsert('post', {
+            tags   : ['just tagged'],
+            created: Date.now()
+        }
+        ,{ id:'post123' }
+        , function (err, res) {
+            if (err) { throw err; }
+            console.log('Updated a blog post');
+        });
+
+    @method upsert
+    @param {String} type Document type.
+    @param {Object} doc Document data to index.
+    @param {Object} [options] Options.
+      @param {String} [options.consistency="quorum"] Write consistency to use
+          for this indexing operation. Permitted values are "one", "quorum" and
+          "all". See the ElasticSearch docs for details.
+      @param {Boolean} [options.create=false] Only create the document if it
+          doesn't already exist.
+      @param {String} [options.id] Document id. Mandatory.
+      @param {String} [options.parent] Parent document id.
+      @param {Boolean} [options.refresh=false] If `true`, the document will be
+          made searchable immediately after it is indexed.
+      @param {String} [options.replication="sync"] Replication mode for this
+          indexing operation. Maybe be set to "sync" or "async".
+      @param {String} [options.routing] Value that determines what shard this
+          document will be routed to. If not specified, a hash of the document's
+          id will be used.
+      @param {String} [options.timeout="1m"] How long to wait for the primary
+          shard to become available to index this document before aborting. See
+          the ElasticSearch docs for details. This should be a value like "5m"
+          (5 minutes) or "15s" (15 seconds).
+      @param {Number} [options.version] You can use the version parameter to specify that 
+          the document should only be updated if it’s version matches the one specified. 
+          By setting version type to force you can force the new version of the document after 
+          update (use with care! with force there is no guarantee the document didn’t change).
+          Version types external & external_gte are not supported..
+    @param {Function} [callback] Callback function.
+      @param {Error|null} callback.err Error, or `null` on success.
+      @param {Object} callback.res ElasticSearch response data.
+    @see Client.index
+    **/
+    upsert: function (type, doc, options, callback) {
+        var query = [],
+            id, params, url;
+
+        if (typeof options === 'function') {
+            callback = options;
+            options  = {};
+        }
+
+        params = util.merge(options || {});
+
+        if (params.id) {
+            id = params.id;
+            delete params.id;
+        }        
+
+        util.each(params, function (value, name) {
+            if (value === true || value === false) {
+                value = value ? '1' : '0';
+            }
+
+            query.push(encode(name) + '=' + encode(value));
+        });
+
+        url = '/' + encode(this.name) + '/' + encode(type);
+
+        if (id) {
+            url += '/' + encode(id) + '/_update';
+        }
+
+        if (query.length) {
+            url += '?' + query.join('&');
+        }
+
+        this.client._request(url, {
+            method: 'POST',
+            json  : { 
+              doc : doc,
+              doc_as_upsert : true
+            },
+        }, callback);
+    },
 
     // http://www.elasticsearch.org/guide/reference/api/admin-indices-optimize.html
     optimize: function (options) {