Merge pull request webpack#7165 from webpack/performance/cache-hash

sokra · web-flow · commit 00f77fdb2fef · 2018-05-03T00:47:10.000+02:00
improve NormalModule performance
diff --git a/lib/NormalModule.js b/lib/NormalModule.js
@@ -22,6 +22,7 @@ const ModuleParseError = require("./ModuleParseError");
 const ModuleBuildError = require("./ModuleBuildError");
 const ModuleError = require("./ModuleError");
 const ModuleWarning = require("./ModuleWarning");
+const createHash = require("./util/createHash");
 
 const asString = buf => {
 	if (Buffer.isBuffer(buf)) {
@@ -89,6 +90,7 @@ class NormalModule extends Module {
 		// Info from Build
 		this.error = null;
 		this._source = null;
+		this._buildHash = "";
 		this.buildTimestamp = undefined;
 		this._cachedSource = undefined;
 		this._cachedSourceHash = undefined;
@@ -327,11 +329,23 @@ class NormalModule extends Module {
 		return false;
 	}
 
+	_initBuildHash(compilation) {
+		const hash = createHash(compilation.outputOptions.hashFunction);
+		if (this._source) {
+			hash.update("source");
+			this._source.updateHash(hash);
+		}
+		hash.update("meta");
+		hash.update(JSON.stringify(this.buildMeta));
+		this._buildHash = hash.digest("hex");
+	}
+
 	build(options, compilation, resolver, fs, callback) {
 		this.buildTimestamp = Date.now();
 		this.built = true;
 		this._source = null;
 		this._ast = null;
+		this._buildHash = "";
 		this.error = null;
 		this.errors.length = 0;
 		this.warnings.length = 0;
@@ -349,25 +363,29 @@ class NormalModule extends Module {
 			// if we have an error mark module as failed and exit
 			if (err) {
 				this.markModuleAsErrored(err);
+				this._initBuildHash(compilation);
 				return callback();
 			}
 
 			// check if this module should !not! be parsed.
 			// if so, exit here;
 			const noParseRule = options.module && options.module.noParse;
 			if (this.shouldPreventParsing(noParseRule, this.request)) {
+				this._initBuildHash(compilation);
 				return callback();
 			}
 
 			const handleParseError = e => {
 				const source = this._source.source();
 				const error = new ModuleParseError(this, source, e);
 				this.markModuleAsErrored(error);
+				this._initBuildHash(compilation);
 				return callback();
 			};
 
 			const handleParseResult = result => {
 				this._lastSuccessfulBuildMeta = this.buildMeta;
+				this._initBuildHash(compilation);
 				return callback();
 			};
 
@@ -454,23 +472,8 @@ class NormalModule extends Module {
 		return this._source ? this._source.size() : -1;
 	}
 
-	updateHashWithSource(hash) {
-		if (!this._source) {
-			hash.update("null");
-			return;
-		}
-		hash.update("source");
-		this._source.updateHash(hash);
-	}
-
-	updateHashWithMeta(hash) {
-		hash.update("meta");
-		hash.update(JSON.stringify(this.buildMeta));
-	}
-
 	updateHash(hash) {
-		this.updateHashWithSource(hash);
-		this.updateHashWithMeta(hash);
+		hash.update(this._buildHash);
 		super.updateHash(hash);
 	}
 }
diff --git a/test/NormalModule.unittest.js b/test/NormalModule.unittest.js
@@ -184,38 +184,6 @@ describe("NormalModule", () => {
 		});
 	});
 
-	describe("#updateHashWithSource", () => {
-		let hashSpy;
-		let hash;
-		beforeEach(() => {
-			hashSpy = sinon.spy();
-			hash = {
-				update: hashSpy
-			};
-		});
-		describe("without the module having any source", () => {
-			beforeEach(() => {
-				normalModule._source = null;
-			});
-			it('calls hash function with "null"', () => {
-				normalModule.updateHashWithSource(hash);
-				expect(hashSpy.callCount).toBe(1);
-				expect(hashSpy.args[0][0]).toBe("null");
-			});
-		});
-		describe("without the module having source", () => {
-			let expectedSource = "some source";
-			beforeEach(() => {
-				normalModule._source = new RawSource(expectedSource);
-			});
-			it('calls hash function with "source" and then the actual source of the module', function() {
-				normalModule.updateHashWithSource(hash);
-				expect(hashSpy.callCount).toBe(2);
-				expect(hashSpy.args[0][0]).toBe("source");
-				expect(hashSpy.args[1][0]).toBe(expectedSource);
-			});
-		});
-	});
 	describe("#hasDependencies", () => {
 		it("returns true if has dependencies", () => {
 			normalModule.addDependency(new NullDependency());
diff --git a/test/__snapshots__/StatsTestCases.test.js.snap b/test/__snapshots__/StatsTestCases.test.js.snap
