avoid creating recursive chunk references

sokra · sokra · commit cc705ec609a2 · 2017-06-09T16:06:52.000+02:00
parent-child-dependencies are more optimized
diff --git a/lib/Compilation.js b/lib/Compilation.js
@@ -830,7 +830,11 @@ class Compilation extends Tapable {
 		}
 	}
 
-	processDependenciesBlockForChunk(block, chunk) {
+	processDependenciesBlockForChunk(module, chunk) {
+		let block = module;
+		const initialChunk = chunk;
+		const chunkDependencies = new Map(); // Map<Chunk, Array<{Module, Chunk}>>
+
 		const iteratorBlock = b => {
 			let c;
 			if(!b.chunks) {
@@ -840,9 +844,17 @@ class Compilation extends Tapable {
 			} else {
 				c = b.chunks[0];
 			}
-			chunk.addChunk(c);
-			c.addParent(chunk);
-			queue.push([b, c]);
+			let deps = chunkDependencies.get(chunk);
+			if(!deps) chunkDependencies.set(chunk, deps = []);
+			deps.push({
+				chunk: c,
+				module
+			});
+			queue.push({
+				block: b,
+				module: null,
+				chunk: c
+			});
 		};
 
 		const iteratorDependency = d => {
@@ -854,18 +866,25 @@ class Compilation extends Tapable {
 			}
 			if(chunk.addModule(d.module)) {
 				d.module.addChunk(chunk);
-				queue.push([d.module, chunk]);
+				queue.push({
+					block: d.module,
+					module: d.module,
+					chunk
+				});
 			}
 		};
 
-		const queue = [
-			[block, chunk]
-		];
+		const queue = [{
+			block,
+			module,
+			chunk
+		}];
 
 		while(queue.length) {
 			const queueItem = queue.pop();
-			block = queueItem[0];
-			chunk = queueItem[1];
+			block = queueItem.block;
+			module = queueItem.module;
+			chunk = queueItem.chunk;
 
 			if(block.variables) {
 				iterationBlockVariable(block.variables, iteratorDependency);
@@ -879,6 +898,45 @@ class Compilation extends Tapable {
 				iterationOfArrayCallback(block.blocks, iteratorBlock);
 			}
 		}
+
+		chunk = initialChunk;
+		let chunks = new Set();
+		const queue2 = [{
+			chunk,
+			chunks
+		}];
+
+		while(queue2.length) {
+			const queueItem = queue2.pop();
+			chunk = queueItem.chunk;
+			chunks = queueItem.chunks;
+
+			const deps = chunkDependencies.get(chunk);
+			if(!deps) continue;
+
+			const depsFiltered = deps.filter(dep => {
+				if(chunks.has(dep.chunk)) return false;
+				for(const chunk of chunks) {
+					if(chunk.containsModule(dep.module))
+						return false;
+				}
+				return true;
+			});
+
+			for(let i = 0; i < depsFiltered.length; i++) {
+				const dep = depsFiltered[i];
+				const depChunk = dep.chunk;
+				chunk.addChunk(depChunk);
+				depChunk.addParent(chunk);
+
+				const newChunks = depsFiltered.length > 1 ? new Set(chunks) : chunks;
+				newChunks.add(chunk);
+				queue2.push({
+					chunk: depChunk,
+					chunks: newChunks
+				});
+			}
+		}
 	}
 
 	removeChunkFromDependencies(block, chunk) {
