Resolve environments using cache if cache has complete info (microsoft#17474)

Kartik Raj · web-flow · commit 688213e97c3d · 2021-09-21T10:40:38.000-07:00
* If environments in cache have complete info, use it regardless of whether there is a refresh going on

* News entry

* Update comment
diff --git a/news/1 Enhancements/17474.md b/news/1 Enhancements/17474.md
@@ -0,0 +1 @@
+Resolve environments using cache if cache has complete env info.
diff --git a/src/client/pythonEnvironments/base/locators/composite/envsCollectionCache.ts b/src/client/pythonEnvironments/base/locators/composite/envsCollectionCache.ts
@@ -36,10 +36,10 @@ export interface IEnvsCollectionCache {
     addEnv(env: PythonEnvInfo): void;
 
     /**
-     * Return cached environment information for a given interpreter path if it exists,
-     * otherwise return `undefined`.
+     * Return cached environment information for a given interpreter path if it exists and
+     * has complete info, otherwise return `undefined`.
      */
-    getEnv(path: string): PythonEnvInfo | undefined;
+    getCompleteInfo(path: string): PythonEnvInfo | undefined;
 
     /**
      * Writes the content of the in-memory cache to persistent storage.
@@ -53,6 +53,8 @@ export interface IEnvsCollectionCache {
     validateCache(): Promise<void>;
 }
 
+type PythonEnvCompleteInfo = { hasCompleteInfo?: boolean } & PythonEnvInfo;
+
 interface IPersistentStorage {
     load(): Promise<PythonEnvInfo[] | undefined>;
     store(envs: PythonEnvInfo[]): Promise<void>;
@@ -63,7 +65,7 @@ interface IPersistentStorage {
  */
 export class PythonEnvInfoCache extends PythonEnvsWatcher<PythonEnvCollectionChangedEvent>
     implements IEnvsCollectionCache {
-    private envs: PythonEnvInfo[] = [];
+    private envs: PythonEnvCompleteInfo[] = [];
 
     constructor(private readonly persistentStorage: IPersistentStorage) {
         super();
@@ -103,8 +105,9 @@ export class PythonEnvInfoCache extends PythonEnvsWatcher<PythonEnvCollectionCha
         }
     }
 
-    public getEnv(executablePath: string): PythonEnvInfo | undefined {
-        return this.envs.find((e) => areSameEnv(e, executablePath));
+    public getCompleteInfo(executablePath: string): PythonEnvInfo | undefined {
+        const env = this.envs.find((e) => areSameEnv(e, executablePath));
+        return env?.hasCompleteInfo ? env : undefined;
     }
 
     public async clearAndReloadFromStorage(): Promise<void> {
@@ -114,6 +117,9 @@ export class PythonEnvInfoCache extends PythonEnvsWatcher<PythonEnvCollectionCha
     public async flush(): Promise<void> {
         if (this.envs.length) {
             traceInfo('Environments added to cache', JSON.stringify(this.envs));
+            this.envs.forEach((e) => {
+                e.hasCompleteInfo = true;
+            });
             await this.persistentStorage.store(this.envs);
         }
     }
diff --git a/src/client/pythonEnvironments/base/locators/composite/envsCollectionService.ts b/src/client/pythonEnvironments/base/locators/composite/envsCollectionService.ts
@@ -54,10 +54,11 @@ export class EnvsCollectionService extends PythonEnvsWatcher<PythonEnvCollection
     }
 
     public async resolveEnv(executablePath: string): Promise<PythonEnvInfo | undefined> {
-        const cachedEnv = this.cache.getEnv(executablePath);
-        // Envs in cache may have incomplete info when a refresh is happening, so
-        // do not rely on cache in those cases.
-        if (cachedEnv && this.refreshPromises.size === 0) {
+        // Note cache may have incomplete info when a refresh is happening.
+        // This API is supposed to return complete info by definition, so
+        // only use cache if it has complete info on an environment.
+        const cachedEnv = this.cache.getCompleteInfo(executablePath);
+        if (cachedEnv) {
             return cachedEnv;
         }
         const resolved = await this.locator.resolveEnv(executablePath);

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1 @@`
	`1`	`+Resolve environments using cache if cache has complete env info.`