Add doc.getStats for debugging purpose (#920)

Co-authored-by: raararaara <[email protected]>

packages/sdk/public/index.html

@@ -328,6 +328,8 @@ <h4 class="title">
           const doc = new yorkie.Document('codemirror', {
             enableDevtools: true,
           });
+          window.doc = doc;
+
           doc.subscribe('connection', new Network(statusHolder).statusListener);
           doc.subscribe('presence', (event) => {
             if (event.type === 'presence-changed') return;

packages/sdk/src/document/crdt/root.ts

@@ -39,6 +39,26 @@ interface CRDTElementPair {
   parent?: CRDTContainer;
 }
 
+/**
+ * `RootStats` is a structure that represents the statistics of the root object.
+ */
+export interface RootStats {
+  /**
+   * `elements` is the number of elements in the root object.
+   */
+  elements?: number;
+
+  /**
+   * `gcElements` is the number of elements that can be garbage collected.
+   */
+  gcElements?: number;
+
+  /**
+   * `gcPairs` is the number of garbage collection pairs.
+   */
+  gcPairs?: number;
+}
+
 /**
  * `CRDTRoot` is a structure that represents the root. It has a hash table of
  * all elements to find a specific element when applying remote changes
@@ -308,4 +328,16 @@ export class CRDTRoot {
   public toSortedJSON(): string {
     return this.rootObject.toSortedJSON();
   }
+
+  /**
+   * `getStats` returns the current statistics of the root object.
+   * This includes counts of various types of elements and structural information.
+   */
+  public getStats(): RootStats {
+    return {
+      elements: this.getElementMapSize(),
+      gcPairs: this.gcPairMap.size,
+      gcElements: this.getGarbageElementSetSize(),
+    };
+  }
 }

packages/sdk/src/document/document.ts

@@ -42,7 +42,7 @@ import {
 import { ChangeContext } from '@yorkie-js-sdk/src/document/change/context';
 import { converter } from '@yorkie-js-sdk/src/api/converter';
 import { ChangePack } from '@yorkie-js-sdk/src/document/change/change_pack';
-import { CRDTRoot } from '@yorkie-js-sdk/src/document/crdt/root';
+import { CRDTRoot, RootStats } from '@yorkie-js-sdk/src/document/crdt/root';
 import { CRDTObject } from '@yorkie-js-sdk/src/document/crdt/object';
 import {
   createJSON,
@@ -1388,6 +1388,13 @@ export class Document<T, P extends Indexable = Indexable> {
     return this.root.toSortedJSON();
   }
 
+  /**
+   * `getStats` returns the statistics of this document.
+   */
+  public getStats(): RootStats {
+    return this.root.getStats();
+  }
+
   /**
    * `toJSForTest` returns value with meta data for testing.
    */

packages/sdk/src/util/splay_tree.ts

@@ -211,7 +211,7 @@ export class SplayTree<V> {
         `out of index range: pos: ${pos} > node.length: ${node.getLength()}`,
       );
     }
-    this.splayNode(node)
+    this.splayNode(node);
     return [node, pos];
   }
 
@@ -226,7 +226,7 @@ export class SplayTree<V> {
       return -1;
     }
 
-    this.splayNode(node)
+    this.splayNode(node);
     return this.root!.getLeftWeight();
   }