add auto batching entries (#102)

docs/API.md

@@ -40,7 +40,6 @@ Type: `String` or `{ client_email: String, private_key: String }` *(optional)*
 Full path to the JSON file containing the Google Service Credentials,
 you can also use an object parameter with the client_email and the private_key instead of the path. Defaults to the GOOGLE_APPLICATION_CREDENTIALS environment variable. At least one has to be available.
 
-
 #### projectId
 
 Type: `String` *(required)*
@@ -72,6 +71,10 @@ Type: Boolean *(optional)*
 
 Set the gRPC fallback option for the Google Stackdriver API.
 
+## Batching
+
+Log entries will automatically be batched by the Google cloud logging library that's being used internally using a *fire and forget* meganism.
+
 ## Prefixing messages
 
 Prefixing message is supported via a `prefix` property from the log data:
@@ -89,4 +92,4 @@ Will send the following JSON payload to Stackdriver:
   "message": "[foo] Info message"
   // ...
 }
-```
+```

src/stackdriver.js

@@ -42,6 +42,8 @@ function _getKey (log, data, k, keys) {
   return undefined
 }
 
+function _noop () {}
+
 module.exports.parseJsonStream = function () {
   return split2(_jsonParser)
 }
@@ -108,7 +110,8 @@ module.exports.toStackdriverStream = function (options = {}) {
     objectMode: true,
     write (chunk, encoding, callback) {
       const entry = log.entry(chunk.meta, chunk.data)
-      log[chunk.meta.severity](entry, callback)
+      log[chunk.meta.severity](entry, _noop)
+      callback()
     }
   })
   return writableStream