improve Compilation.processDependenciesBlocksForChunkGroups performance

sokra · sokra · commit 1c0d4f77b0bd · 2018-05-01T10:54:00.000+02:00
prepare references for modules
diff --git a/lib/Compilation.js b/lib/Compilation.js
@@ -1168,6 +1168,61 @@ class Compilation extends Tapable {
 		const chunkDependencies = new Map(); // Map<Chunk, Array<{Module, Chunk}>>
 		const allCreatedChunkGroups = new Set();
 
+		// PREPARE
+		const blockInfoMap = new Map();
+
+		const iteratorDependency = d => {
+			// We skip Dependencies without Reference
+			const ref = d.getReference();
+			if (!ref) {
+				return;
+			}
+			// We skip Dependencies without Module pointer
+			const refModule = ref.module;
+			if (!refModule) {
+				return;
+			}
+			// We skip weak Dependencies
+			if (ref.weak) {
+				return;
+			}
+
+			blockInfoModules.add(refModule);
+		};
+
+		const iteratorBlockPrepare = b => {
+			blockInfoBlocks.push(b);
+			blockQueue.push(b);
+		};
+
+		let block, blockQueue, blockInfoModules, blockInfoBlocks;
+		for (const module of this.modules) {
+			blockQueue = [module];
+			while (blockQueue.length > 0) {
+				block = blockQueue.pop();
+				blockInfoModules = new Set();
+				blockInfoBlocks = [];
+
+				if (block.variables) {
+					iterationBlockVariable(block.variables, iteratorDependency);
+				}
+
+				if (block.dependencies) {
+					iterationOfArrayCallback(block.dependencies, iteratorDependency);
+				}
+
+				if (block.blocks) {
+					iterationOfArrayCallback(block.blocks, iteratorBlockPrepare);
+				}
+
+				const blockInfo = {
+					modules: blockInfoModules,
+					blocks: blockInfoBlocks
+				};
+				blockInfoMap.set(block, blockInfo);
+			}
+		}
+
 		// PART ONE
 
 		const blockChunkGroups = new Map();
@@ -1180,7 +1235,7 @@ class Compilation extends Tapable {
 			chunkGroup
 		}));
 
-		let module, block, chunk, chunkGroup;
+		let module, chunk, chunkGroup;
 
 		// For each async Block in graph
 		const iteratorBlock = b => {
@@ -1227,36 +1282,6 @@ class Compilation extends Tapable {
 			});
 		};
 
-		// For each Dependency in the graph
-		const iteratorDependency = d => {
-			// We skip Dependencies without Reference
-			const ref = d.getReference();
-			if (!ref) {
-				return;
-			}
-			// We skip Dependencies without Module pointer
-			const refModule = ref.module;
-			if (!refModule) {
-				return;
-			}
-			// We skip weak Dependencies
-			if (ref.weak) {
-				return;
-			}
-			// We connect Module and Chunk when not already done
-			if (chunk.addModule(refModule)) {
-				refModule.addChunk(chunk);
-
-				// And enqueue the Module for traversal
-				queue.push({
-					block: refModule,
-					module: refModule,
-					chunk,
-					chunkGroup
-				});
-			}
-		};
-
 		// Iterative traversal of the Module graph
 		// Recursive would be simpler to write but could result in Stack Overflows
 		while (queue.length) {
@@ -1266,18 +1291,27 @@ class Compilation extends Tapable {
 			chunk = queueItem.chunk;
 			chunkGroup = queueItem.chunkGroup;
 
-			// Traverse all variables, Dependencies and Blocks
-			if (block.variables) {
-				iterationBlockVariable(block.variables, iteratorDependency);
-			}
-
-			if (block.dependencies) {
-				iterationOfArrayCallback(block.dependencies, iteratorDependency);
+			// get prepared block info
+			const blockInfo = blockInfoMap.get(block);
+
+			// Traverse all referenced modules
+			for (const refModule of blockInfo.modules) {
+				// We connect Module and Chunk when not already done
+				if (chunk.addModule(refModule)) {
+					refModule.addChunk(chunk);
+
+					// And enqueue the Module for traversal
+					queue.push({
+						block: refModule,
+						module: refModule,
+						chunk,
+						chunkGroup
+					});
+				}
 			}
 
-			if (block.blocks) {
-				iterationOfArrayCallback(block.blocks, iteratorBlock);
-			}
+			// Traverse all Blocks
+			iterationOfArrayCallback(blockInfo.blocks, iteratorBlock);
 		}
 
 		// PART TWO
