Replaced simple cache with lru cache for chart data

Author: Brian Vaughn

package.json

@@ -24,6 +24,7 @@
     "jest": "22.1.4",
     "json-loader": "0.5.4",
     "log-update": "^2.0.0",
+    "lru-cache": "^4.1.3",
     "memoize-one": "^3.1.1",
     "node-libs-browser": "0.5.3",
     "nullthrows": "^1.0.0",

plugins/Profiler/ProfilerStore.js

@@ -16,6 +16,7 @@ import type {ChartType, Interaction, RootProfilerData, Snapshot} from './Profile
 const {List} = require('immutable');
 const {EventEmitter} = require('events');
 const {get, set} = require('../../utils/storage');
+const LRU = require('lru-cache');
 
 const LOCAL_STORAGE_CHART_TYPE_KEY = 'profiler:selectedChartType';
 const LOCAL_STORAGE_COMMIT_THRESHOLD = 'profiler:commitThreshold';
@@ -26,7 +27,7 @@ class ProfilerStore extends EventEmitter {
   _bridge: Bridge;
   _mainStore: Object;
 
-  cachedData = {};
+  cachedData = LRU(50); // Evict items from the cache after this number
   commitThreshold: number = ((get(LOCAL_STORAGE_COMMIT_THRESHOLD, 0): any): number);
   hideCommitsBelowThreshold: boolean = ((get(LOCAL_STORAGE_HIDE_COMMITS_BELOW_THRESHOLD, false): any): boolean);
   isRecording: boolean = false;
@@ -54,26 +55,26 @@ class ProfilerStore extends EventEmitter {
   }
 
   cacheDataForSnapshot(snapshotIndex: number, snapshotRootID: string, key: string, data: any): void {
-    this.cachedData[`${snapshotIndex}-${snapshotRootID}-${key}`] = data;
+    this.cachedData.set(`${snapshotIndex}-${snapshotRootID}-${key}`, data);
   }
 
   cacheInteractionData(rootID: string, data: any): void {
-    this.cachedData[`${rootID}-interactions`] = data;
+    this.cachedData.set(`${rootID}-interactions`, data);
   }
 
   clearSnapshots = () => {
-    this.cachedData = {};
+    this.cachedData.reset();
     this.processedInteractions = {};
     this.rootsToProfilerData = new Map();
     this.emit('profilerData', this.rootsToProfilerData);
   };
 
   getCachedDataForSnapshot(snapshotIndex: number, snapshotRootID: string, key: string): any {
-    return this.cachedData[`${snapshotIndex}-${snapshotRootID}-${key}`] || null;
+    return this.cachedData.get(`${snapshotIndex}-${snapshotRootID}-${key}`) || null;
   }
 
   getCachedInteractionData(rootID: string): any {
-    return this.cachedData[`${rootID}-interactions`] || null;
+    return this.cachedData.get(`${rootID}-interactions`) || null;
   }
 
   processInteraction(interaction: Interaction): Interaction {

yarn.lock

@@ -4769,6 +4769,13 @@ lru-cache@^4.0.0, lru-cache@^4.0.1:
     pseudomap "^1.0.1"
     yallist "^2.0.0"
 
+lru-cache@^4.1.3:
+  version "4.1.3"
+  resolved "https://registry.yarnpkg.com/lru-cache/-/lru-cache-4.1.3.tgz#a1175cf3496dfc8436c156c334b4955992bce69c"
+  dependencies:
+    pseudomap "^1.0.2"
+    yallist "^2.1.2"
+
 make-dir@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/make-dir/-/make-dir-1.0.0.tgz#97a011751e91dd87cfadef58832ebb04936de978"
@@ -5580,7 +5587,7 @@ prr@~0.0.0:
   version "0.0.0"
   resolved "https://registry.yarnpkg.com/prr/-/prr-0.0.0.tgz#1a84b85908325501411853d0081ee3fa86e2926a"
 
-pseudomap@^1.0.1:
+pseudomap@^1.0.1, pseudomap@^1.0.2:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/pseudomap/-/pseudomap-1.0.2.tgz#f052a28da70e618917ef0a8ac34c1ae5a68286b3"
 
@@ -7334,6 +7341,10 @@ yallist@^2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/yallist/-/yallist-2.0.0.tgz#306c543835f09ee1a4cb23b7bce9ab341c91cdd4"
 
+yallist@^2.1.2:
+  version "2.1.2"
+  resolved "https://registry.yarnpkg.com/yallist/-/yallist-2.1.2.tgz#1c11f9218f076089a47dd512f93c6699a6a81d52"
+
 yargs-parser@^4.2.0:
   version "4.2.1"
   resolved "https://registry.yarnpkg.com/yargs-parser/-/yargs-parser-4.2.1.tgz#29cceac0dc4f03c6c87b4a9f217dd18c9f74871c"