Improve cache-reporting when entry already exists

src/cache-base.ts

@@ -130,16 +130,13 @@ export class GradleStateCache {
     restoreKeys:[${cacheKey.restoreKeys}]`
         )
 
-        const cacheResult = await restoreCache(this.getCachePath(), cacheKey.key, cacheKey.restoreKeys)
-        entryListener.markRequested(cacheKey.key, cacheKey.restoreKeys)
-
+        const cacheResult = await restoreCache(this.getCachePath(), cacheKey.key, cacheKey.restoreKeys, entryListener)
         if (!cacheResult) {
             core.info(`${this.cacheDescription} cache not found. Will initialize empty.`)
             return
         }
 
         core.saveState(this.cacheResultStateKey, cacheResult.key)
-        entryListener.markRestored(cacheResult.key, cacheResult.size)
 
         core.info(`Restored ${this.cacheDescription} from cache key: ${cacheResult.key}`)
 
@@ -186,11 +183,8 @@ export class GradleStateCache {
 
         core.info(`Caching ${this.cacheDescription} with cache key: ${cacheKeyFromRestore}`)
         const cachePath = this.getCachePath()
-        const savedEntry = await saveCache(cachePath, cacheKeyFromRestore)
-
-        if (savedEntry) {
-            listener.entry(this.cacheDescription).markSaved(savedEntry.key, savedEntry.size)
-        }
+        const entryListener = listener.entry(this.cacheDescription)
+        await saveCache(cachePath, cacheKeyFromRestore, entryListener)
 
         return
     }

src/cache-extract-entries.ts

@@ -118,12 +118,9 @@ abstract class AbstractEntryExtractor {
         pattern: string,
         listener: CacheEntryListener
     ): Promise<ExtractedCacheEntry> {
-        listener.markRequested(cacheKey)
-
-        const restoredEntry = await restoreCache([pattern], cacheKey)
+        const restoredEntry = await restoreCache([pattern], cacheKey, [], listener)
         if (restoredEntry) {
             core.info(`Restored ${artifactType} with key ${cacheKey} to ${pattern}`)
-            listener.markRestored(restoredEntry.key, restoredEntry.size)
             return new ExtractedCacheEntry(artifactType, pattern, cacheKey)
         } else {
             core.info(`Did not restore ${artifactType} with key ${cacheKey} to ${pattern}`)
@@ -217,10 +214,7 @@ abstract class AbstractEntryExtractor {
             cacheDebug(`No change to previously restored ${artifactType}. Not saving.`)
         } else {
             core.info(`Caching ${artifactType} with path '${pattern}' and cache key: ${cacheKey}`)
-            const savedEntry = await saveCache([pattern], cacheKey)
-            if (savedEntry !== undefined) {
-                entryListener.markSaved(savedEntry.key, savedEntry.size)
-            }
+            await saveCache([pattern], cacheKey, entryListener)
         }
 
         for (const file of matchingFiles) {

src/cache-reporting.ts

@@ -76,6 +76,12 @@ export class CacheEntryListener {
         this.savedSize = size
         return this
     }
+
+    markAlreadyExists(key: string): CacheEntryListener {
+        this.savedKey = key
+        this.savedSize = 0
+        return this
+    }
 }
 
 export function logCachingReport(listener: CacheListener): void {
@@ -112,12 +118,18 @@ function getSum(
     cacheEntries: CacheEntryListener[],
     predicate: (value: CacheEntryListener) => number | undefined
 ): string {
+    if (cacheEntries.length === 0) {
+        return '0'
+    }
     return formatSize(cacheEntries.map(e => predicate(e) ?? 0).reduce((p, v) => p + v, 0))
 }
 
 function formatSize(bytes: number | undefined): string {
-    if (bytes === undefined || bytes === 0) {
+    if (bytes === undefined) {
         return ''
     }
+    if (bytes === 0) {
+        return '0 (Entry already exists)'
+    }
     return `${Math.round(bytes / (1024 * 1024))} MB (${bytes} B)`
 }

src/cache-utils.ts

@@ -4,6 +4,8 @@ import * as crypto from 'crypto'
 import * as path from 'path'
 import * as fs from 'fs'
 
+import {CacheEntryListener} from './cache-reporting'
+
 const JOB_CONTEXT_PARAMETER = 'workflow-job-context'
 const CACHE_DISABLED_PARAMETER = 'cache-disabled'
 const CACHE_READONLY_PARAMETER = 'cache-read-only'
@@ -49,23 +51,32 @@ export function hashStrings(values: string[]): string {
 export async function restoreCache(
     cachePath: string[],
     cacheKey: string,
-    cacheRestoreKeys: string[] = []
+    cacheRestoreKeys: string[],
+    listener: CacheEntryListener
 ): Promise<cache.CacheEntry | undefined> {
+    listener.markRequested(cacheKey, cacheRestoreKeys)
     try {
-        return await cache.restoreCache(cachePath, cacheKey, cacheRestoreKeys)
+        const restoredEntry = await cache.restoreCache(cachePath, cacheKey, cacheRestoreKeys)
+        if (restoredEntry !== undefined) {
+            listener.markRestored(restoredEntry.key, restoredEntry.size)
+        }
+        return restoredEntry
     } catch (error) {
         handleCacheFailure(error, `Failed to restore ${cacheKey}`)
         return undefined
     }
 }
 
-export async function saveCache(cachePath: string[], cacheKey: string): Promise<cache.CacheEntry | undefined> {
+export async function saveCache(cachePath: string[], cacheKey: string, listener: CacheEntryListener): Promise<void> {
     try {
-        return await cache.saveCache(cachePath, cacheKey)
+        const savedEntry = await cache.saveCache(cachePath, cacheKey)
+        listener.markSaved(savedEntry.key, savedEntry.size)
     } catch (error) {
+        if (error instanceof cache.ReserveCacheError) {
+            listener.markAlreadyExists(cacheKey)
+        }
         handleCacheFailure(error, `Failed to save cache entry ${cacheKey}`)
     }
-    return undefined
 }
 
 export function cacheDebug(message: string): void {