api: add getStats() function

doc/api/http_api.md

@@ -65,7 +65,7 @@ Portal submits content into new blog post
 ## Usage
 
 ### API version
-The latest version is `1.2.13`
+The latest version is `1.2.14`
 
 The current version can be queried via /api.
 
@@ -634,3 +634,14 @@ lists all pads on this epl instance
 
 *Example returns:*
  * `{code: 0, message:"ok", data: {padIDs: ["testPad", "thePadsOfTheOthers"]}}`
+
+### Global
+
+#### getStats()
+ *  API >= 1.2.14
+
+get stats of the etherpad instance
+
+*Example returns*
+ * `{"code":0,"message":"ok","data":{"totalPads":3,"totalSessions": 2,"totalActivePads": 1}}`
+

src/node/db/API.js

@@ -837,6 +837,37 @@ exports.createDiffHTML = async function(padID, startRev, endRev) {
   return { html, authors };
 }
 
+/**********************/
+/** GLOBAL FUNCTIONS **/
+/**********************/
+
+/**
+ getStats() returns an json object with some instance stats
+
+ Example returns:
+
+ {"code":0,"message":"ok","data":{"totalPads":3,"totalSessions": 2,"totalActivePads": 1}}
+ {"code":4,"message":"no or wrong API Key","data":null}
+ */
+
+exports.getStats = async function() {
+  const sessionKeys = Object.keys(padMessageHandler.sessioninfos);
+
+  const activePads = new Set();
+
+  sessionKeys
+    .map(k => padMessageHandler.sessioninfos[k])
+    .forEach(o => activePads.add(o.padId));
+
+  const { padIDs } = await padManager.listAllPads();
+
+  return {
+    totalPads: padIDs.length,
+    totalSessions: sessionKeys.length,
+    totalActivePads: activePads.size,
+  }
+}
+
 /******************************/
 /** INTERNAL HELPER FUNCTIONS */
 /******************************/

src/node/handler/APIHandler.js

@@ -137,8 +137,13 @@ version["1.2.13"] = Object.assign({}, version["1.2.12"],
   }
 );
 
+version["1.2.14"] = Object.assign({}, version["1.2.13"],
+  { "getStats"                : []
+  }
+);
+
 // set the latest available API version here
-exports.latestApiVersion = '1.2.13';
+exports.latestApiVersion = '1.2.14';
 
 // exports the versions so it can be used by the new Swagger endpoint
 exports.version = version;