Speed up FileSystemBlobStore.load by not storing invalidation keys

This was unneeded because we can simply compute the cache key by
concatenating the v8 version and the file's contents.

src/file-system-blob-store.js

@@ -14,14 +14,12 @@ class FileSystemBlobStore {
   constructor (directory) {
     this.blobFilename = path.join(directory, 'BLOB')
     this.blobMapFilename = path.join(directory, 'MAP')
-    this.invalidationKeysFilename = path.join(directory, 'INVKEYS')
     this.lockFilename = path.join(directory, 'LOCK')
     this.reset()
   }
 
   reset () {
     this.inMemoryBlobs = new Map()
-    this.invalidationKeys = {}
     this.storedBlob = new Buffer(0)
     this.storedBlobMap = {}
     this.usedKeys = new Set()
@@ -34,14 +32,10 @@ class FileSystemBlobStore {
     if (!fs.existsSync(this.blobFilename)) {
       return
     }
-    if (!fs.existsSync(this.invalidationKeysFilename)) {
-      return
-    }
 
     try {
       this.storedBlob = fs.readFileSync(this.blobFilename)
       this.storedBlobMap = JSON.parse(fs.readFileSync(this.blobMapFilename))
-      this.invalidationKeys = JSON.parse(fs.readFileSync(this.invalidationKeysFilename))
     } catch (e) {
       this.reset()
     }
@@ -51,7 +45,6 @@ class FileSystemBlobStore {
     let dump = this.getDump()
     let blobToStore = Buffer.concat(dump[0])
     let mapToStore = JSON.stringify(dump[1])
-    let invalidationKeysToStore = JSON.stringify(this.invalidationKeys)
 
     let acquiredLock = false
     try {
@@ -60,7 +53,6 @@ class FileSystemBlobStore {
 
       fs.writeFileSync(this.blobFilename, blobToStore)
       fs.writeFileSync(this.blobMapFilename, mapToStore)
-      fs.writeFileSync(this.invalidationKeysFilename, invalidationKeysToStore)
     } catch (error) {
       // Swallow the exception silently only if we fail to acquire the lock.
       if (error.code !== 'EEXIST') {
@@ -73,22 +65,19 @@ class FileSystemBlobStore {
     }
   }
 
-  has (key, invalidationKey) {
-    let containsKey = this.inMemoryBlobs.has(key) || this.storedBlobMap.hasOwnProperty(key)
-    let isValid = this.invalidationKeys[key] === invalidationKey
-    return containsKey && isValid
+  has (key) {
+    return this.inMemoryBlobs.has(key) || this.storedBlobMap.hasOwnProperty(key)
   }
 
-  get (key, invalidationKey) {
-    if (this.has(key, invalidationKey)) {
+  get (key) {
+    if (this.has(key)) {
       this.usedKeys.add(key)
       return this.getFromMemory(key) || this.getFromStorage(key)
     }
   }
 
-  set (key, invalidationKey, buffer) {
+  set (key, buffer) {
     this.usedKeys.add(key)
-    this.invalidationKeys[key] = invalidationKey
     return this.inMemoryBlobs.set(key, buffer)
   }
 

src/native-compile-cache.js

@@ -60,11 +60,10 @@ class NativeCompileCache {
       // create wrapper function
       let wrapper = Module.wrap(content)
 
-      let cacheKey = filename
-      let invalidationKey = computeHash(wrapper + self.v8Version)
+      let cacheKey = computeHash(wrapper + self.v8Version)
       let compiledWrapper = null
-      if (self.cacheStore.has(cacheKey, invalidationKey)) {
-        let buffer = self.cacheStore.get(cacheKey, invalidationKey)
+      if (self.cacheStore.has(cacheKey)) {
+        let buffer = self.cacheStore.get(cacheKey)
         let compilationResult = cachedVm.runInThisContextCached(wrapper, filename, buffer)
         compiledWrapper = compilationResult.result
         if (compilationResult.wasRejected) {
@@ -79,7 +78,7 @@ class NativeCompileCache {
           throw err
         }
         if (compilationResult.cacheBuffer) {
-          self.cacheStore.set(cacheKey, invalidationKey, compilationResult.cacheBuffer)
+          self.cacheStore.set(cacheKey, compilationResult.cacheBuffer)
         }
         compiledWrapper = compilationResult.result
       }