Remove refCount from resolutions as we dont need it explicitly since its tracked by files it references

Author: sheetalkamat

src/compiler/resolutionCache.ts

@@ -181,7 +181,6 @@ export interface ResolutionWithFailedLookupLocations {
     failedLookupLocations?: string[];
     affectingLocations?: string[];
     isInvalidated?: boolean;
-    refCount?: number;
     // Files that have this resolution using
     files?: Set<Path>;
     node10Result?: string;
@@ -1124,30 +1123,25 @@ export function createResolutionCache(
         getResolutionWithResolvedFileName: GetResolutionWithResolvedFileName<T, R>,
         deferWatchingNonRelativeResolution: boolean,
     ) {
-        if (resolution.refCount) {
-            resolution.refCount++;
-            Debug.assertIsDefined(resolution.files);
+        (resolution.files ??= new Set()).add(filePath);
+        if (resolution.files.size !== 1) return;
+
+        if (resolution.globalCacheResolution) resolutionsResolvedWithGlobalCache++;
+        else if (resolution.globalCacheResolution === false) resolutionsResolvedWithoutGlobalCache++;
+
+        if (!deferWatchingNonRelativeResolution || isExternalModuleNameRelative(name)) {
+            watchFailedLookupLocationOfResolution(resolution);
         }
         else {
-            resolution.refCount = 1;
-            if (resolution.globalCacheResolution) resolutionsResolvedWithGlobalCache++;
-            else if (resolution.globalCacheResolution === false) resolutionsResolvedWithoutGlobalCache++;
-            Debug.assert(!resolution.files?.size); // This resolution shouldnt be referenced by any file yet
-            if (!deferWatchingNonRelativeResolution || isExternalModuleNameRelative(name)) {
-                watchFailedLookupLocationOfResolution(resolution);
-            }
-            else {
-                nonRelativeExternalModuleResolutions.add(resolution);
-            }
-            const resolved = getResolutionWithResolvedFileName(resolution);
-            if (resolved && resolved.resolvedFileName) {
-                const key = resolutionHost.toPath(resolved.resolvedFileName);
-                let resolutions = resolvedFileToResolution.get(key);
-                if (!resolutions) resolvedFileToResolution.set(key, resolutions = new Set());
-                resolutions.add(resolution);
-            }
+            nonRelativeExternalModuleResolutions.add(resolution);
+        }
+        const resolved = getResolutionWithResolvedFileName(resolution);
+        if (resolved && resolved.resolvedFileName) {
+            const key = resolutionHost.toPath(resolved.resolvedFileName);
+            let resolutions = resolvedFileToResolution.get(key);
+            if (!resolutions) resolvedFileToResolution.set(key, resolutions = new Set());
+            resolutions.add(resolution);
         }
-        (resolution.files ??= new Set()).add(filePath);
     }
 
     function watchFailedLookupLocation(failedLookupLocation: string, setAtRoot: boolean) {
@@ -1174,7 +1168,7 @@ export function createResolutionCache(
     }
 
     function watchFailedLookupLocationOfResolution(resolution: ResolutionWithFailedLookupLocations) {
-        Debug.assert(!!resolution.refCount);
+        Debug.assert(!!resolution.files?.size);
 
         const { failedLookupLocations, affectingLocations, node10Result } = resolution;
         if (!failedLookupLocations?.length && !affectingLocations?.length && !node10Result) return;
@@ -1195,7 +1189,7 @@ export function createResolutionCache(
     }
 
     function watchAffectingLocationsOfResolution(resolution: ResolutionWithFailedLookupLocations, addToResolutionsWithOnlyAffectingLocations: boolean) {
-        Debug.assert(!!resolution.refCount);
+        Debug.assert(!!resolution.files?.size);
         const { affectingLocations } = resolution;
         if (!affectingLocations?.length) return;
         if (addToResolutionsWithOnlyAffectingLocations) resolutionsWithOnlyAffectingLocations.add(resolution);
@@ -1315,12 +1309,12 @@ export function createResolutionCache(
         syncDirWatcherRemove?: boolean,
     ) {
         Debug.checkDefined(resolution.files).delete(filePath);
-        resolution.refCount!--;
-        if (resolution.refCount) {
-            return;
-        }
+        if (resolution.files!.size) return;
+        resolution.files = undefined;
+
         if (resolution.globalCacheResolution) resolutionsResolvedWithGlobalCache--;
         if (resolution.globalCacheResolution === false) resolutionsResolvedWithoutGlobalCache--;
+
         const resolved = getResolutionWithResolvedFileName(resolution);
         if (resolved && resolved.resolvedFileName) {
             const key = resolutionHost.toPath(resolved.resolvedFileName);

src/harness/incrementalUtils.ts

@@ -294,20 +294,16 @@ export function verifyResolutionCache(
     // Verify ref count
     resolutionToRefs.forEach((info, resolution) => {
         ts.Debug.assert(
-            resolution.refCount === info.length,
-            `${projectName}:: Expected Resolution ref count ${info.length} but got ${resolution.refCount}`,
+            resolution.files?.size === info.length,
+            `${projectName}:: Expected Resolution ref count ${info.length} but got ${resolution.files?.size}`,
             () =>
                 `Expected from:: ${JSON.stringify(info, undefined, " ")}` +
-                `Actual from: ${resolution.refCount}`,
+                `Actual from: ${resolution.files?.size} used from ${resolution.files ? JSON.stringify(ts.arrayFrom(resolution.files), undefined, " ") : "undefined"}`,
         );
         ts.Debug.assert(
             !resolution.isInvalidated,
             `${projectName}:: Resolution should not be invalidated`,
         );
-        ts.Debug.assert(
-            resolutionToExpected.get(resolution)!.refCount === resolution.refCount,
-            `${projectName}:: Expected Resolution ref count ${resolutionToExpected.get(resolution)!.refCount} but got ${resolution.refCount}`,
-        );
         verifySet(resolutionToExpected.get(resolution)!.files, resolution.files, `${projectName}:: Resolution files`);
     });
     verifyMapOfResolutionSet(expected.resolvedFileToResolution, actual.resolvedFileToResolution, `resolvedFileToResolution`);
@@ -330,10 +326,7 @@ export function verifyResolutionCache(
     actual.resolvedTypeReferenceDirectives.forEach((_resolutions, path) => expected.removeResolutionsOfFile(path));
     expected.finishCachingPerDirectoryResolution(/*newProgram*/ undefined, actualProgram);
 
-    resolutionToExpected.forEach(expected => {
-        ts.Debug.assert(!expected.refCount, `${projectName}:: All the resolution should be released`);
-        ts.Debug.assert(!expected.files?.size, `${projectName}:: Shouldnt ref to any files`);
-    });
+    resolutionToExpected.forEach(expected => ts.Debug.assert(!expected.files?.size, `${projectName}:: Shouldnt ref to any files`));
     ts.Debug.assert(expected.resolvedFileToResolution.size === 0, `${projectName}:: resolvedFileToResolution should be released`);
     ts.Debug.assert(expected.resolutionsWithFailedLookups.size === 0, `${projectName}:: resolutionsWithFailedLookups should be released`);
     ts.Debug.assert(expected.resolutionsWithOnlyAffectingLocations.size === 0, `${projectName}:: resolutionsWithOnlyAffectingLocations should be released`);