refactor: reduce size of node positions in url

src/providers/app-state.ts

@@ -1,6 +1,5 @@
 import { Article } from './api-client.js';
-import { Dictionary, Vector2D } from '../types/index.js';
-import * as msgpack from '@msgpack/msgpack';
+import { Dictionary, NodePositions, Vector2D } from '../types/index.js';
 
 /**
  * Manages state for the application. Allows for state to be shared between
@@ -35,7 +34,7 @@ export class AppState {
   /**
    * The node positions for the current graph view.
    */
-  nodePositions?: { [id: string]: Vector2D };
+  nodePositions?: NodePositions;
 
   /**
    * State of keyboard modifiers.
@@ -93,12 +92,7 @@ export class AppState {
     if (this.debug) addParam('debug', 'true');
 
     if (all && this.nodePositions) {
-      const nodePositions: { [id: string]: { x: number; y: number } } = {};
-      for (const [key, value] of Object.entries(this.nodePositions)) {
-        nodePositions[key] = { x: value.x, y: value.y };
-      }
-      const encoded = msgpack.encode(nodePositions);
-      addParam('nodePositions', btoa(String.fromCharCode(...encoded)));
+      addParam('nodePositions', this.nodePositions.toString());
     }
 
     return params.toString();
@@ -122,7 +116,7 @@ export class AppState {
       try {
         state[key] = valueFn(value);
       } catch (e) {
-        console.warn(`Failed to deserialize ${key}: ${e}`);
+        console.warn(`Failed to deserialize ${key}:`, e);
       }
     };
 
@@ -131,18 +125,7 @@ export class AppState {
     trySet('zoomLevel', (value) => Number.parseInt(value, 10));
     trySet('translation', (value) => Vector2D.parse(value));
     trySet('debug', (value) => value === 'true');
-    trySet('nodePositions', (value) => {
-      const decoded = msgpack.decode(
-        Uint8Array.from(atob(value), (c) => c.charCodeAt(0)),
-      );
-      const nodePositions: { [id: string]: Vector2D } = {};
-      for (const [key, value] of Object.entries(
-        decoded as Record<string, { x: number; y: number }>,
-      )) {
-        nodePositions[key] = new Vector2D(value.x, value.y);
-      }
-      return nodePositions;
-    });
+    trySet('nodePositions', (value) => NodePositions.fromString(value));
 
     return state;
   }

src/rendering/node-graph.ts

@@ -7,7 +7,12 @@ import {
   ScopedAppStateManager,
 } from '../providers/index.js';
 import { NodeSelection } from './node-selection.js';
-import { IndexedSet, TwoKeyMap, Vector2D } from '../types/index.js';
+import {
+  IndexedSet,
+  NodePositions,
+  TwoKeyMap,
+  Vector2D,
+} from '../types/index.js';
 import {
   GraphBehaviourManager,
   GraphDebugBehaviour,
@@ -156,11 +161,11 @@ export class NodeGraph {
     });
 
     this.#appStateManager.on('request-node-positions', () => {
-      const nodePositions: { [id: number]: Vector2D } = {};
+      const nodePositions = new NodePositions();
       this.#simulation.nodes().forEach((node) => {
-        nodePositions[node.id] = new Vector2D(
-          Math.round(node.x!),
-          Math.round(node.y!),
+        nodePositions.set(
+          node.id,
+          new Vector2D(Math.round(node.x!), Math.round(node.y!)),
         );
       });
       this.#appStateManager.set('nodePositions', nodePositions);
@@ -252,7 +257,7 @@ export class NodeGraph {
     let missed = false;
 
     for (const node of this.#simulation.nodes()) {
-      const position = nodePositions[node.id];
+      const position = nodePositions.get(node.id);
       if (position) {
         node.x = position.x;
         node.y = position.y;

src/types/index.ts

@@ -1,6 +1,7 @@
 export * from './dictionary.js';
 export * from './indexed-set.js';
 export * from './inflection-tag.js';
+export * from './node-positions.js';
 export * from './graphql-error.js';
 export * from './rect-2d.js';
 export * from './two-key-map.js';

src/types/node-positions.ts

@@ -0,0 +1,41 @@
+import { Vector2D } from './vector-2d.js';
+import { encode, decode } from '@msgpack/msgpack';
+
+/**
+ * Data type for storing node positions.
+ */
+export class NodePositions extends Map<number, Vector2D> {
+  /**
+   * Converts a NodePositions object to a string.
+   */
+  toString(): string {
+    const flatPositions: number[] = [];
+
+    for (const [id, { x, y }] of this) {
+      flatPositions.push(id, x, y);
+    }
+
+    const encoded = encode(flatPositions);
+
+    console.log(JSON.stringify(flatPositions));
+
+    return btoa(String.fromCharCode(...encoded));
+  }
+
+  /**
+   * Converts a string to a NodePositions object.
+   */
+  static fromString(str: string): NodePositions {
+    const decoded = decode(
+      Uint8Array.from(atob(str), (c) => c.charCodeAt(0)),
+    ) as number[];
+
+    const positions = new NodePositions();
+
+    for (let i = 0; i < decoded.length; i += 3) {
+      positions.set(decoded[i], new Vector2D(decoded[i + 1], decoded[i + 2]));
+    }
+
+    return positions;
+  }
+}