From ac26483e8df89eae3bbc62d656e8aa0747e30b8a Mon Sep 17 00:00:00 2001
From: Gustavo Baratto <gbaratto@demonware.net>
Date: Fri, 16 Oct 2015 18:39:17 -0700
Subject: [PATCH] add capability to also remove prefixes

---
 README.md      |  8 ++++++++
 lib/datadog.js | 11 ++++++++---
 2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/README.md b/README.md
index 4055342..2cf25dd 100644
--- a/README.md
+++ b/README.md
@@ -12,6 +12,14 @@ A plugin to connect etsy's statsD to Datadog
 ```js
 datadogApiKey: "your_api_key" // You can get it from this page: https://app.datadoghq.com/account/settings#api
 datadogPrefix: "your_prefix" // Your metrics will be prefixed by this prefix
+datadogRemovePrefix: 2 // Number of period delimited prefixes to remove. If you use this option with *datadogPrefix* remove will happen prior to addition.
+```
+### Example:
+
+If the metric name is called **"hosts.foo.bar.count"**, it will be rewritten to **"application.bar.count"**:
+```
+datadogRemovePrefix: 2
+datadogPrefix: "application"
 ```
 
 ## How to enable
diff --git a/lib/datadog.js b/lib/datadog.js
index 1dc6179..bae194c 100644
--- a/lib/datadog.js
+++ b/lib/datadog.js
@@ -25,6 +25,7 @@ var datadogApiHost;
 var datadogApiKey;
 var datadogStats = {};
 var datadogPrefix;
+var datadogRemovePrefix;
 
 var Datadog = function(api_key, options) {
     options = options || {};
@@ -182,11 +183,14 @@ var flush_stats = function datadog_post_stats(ts, metrics) {
 };
 
 var get_prefix = function datadog_get_prefix(key) {
+    var new_key = key;
+    if (datadogRemovePrefix !== undefined) {
+        new_key = key.split(".").slice(datadogRemovePrefix).join('.');
+    }
     if (datadogPrefix !== undefined) {
-        return [datadogPrefix, key].join('.');
-    } else {
-        return key;
+        new_key = [datadogPrefix, new_key].join('.');
     }
+    return new_key;
 }
 
 var backend_status = function datadog_status(writeCb) {
@@ -205,6 +209,7 @@ exports.init = function datadog_init(startup_time, config, events, log) {
    datadogApiKey = config.datadogApiKey;
    datadogApiHost = config.datadogApiHost;
    datadogPrefix = config.datadogPrefix;
+   datadogRemovePrefix = config.datadogRemovePrefix;
 
    if (!datadogApiHost) {
       datadogApiHost = 'https://app.datadoghq.com';