webpack/lib/Compilation.js

Packs CommonJs/AMD modules for the browser. Allows to split your codebase into multiple bundles, which can be loaded on demand. Support loaders to preprocess files, i.e. json, jade, coffee, css, less, ... and your custom stuff.

/*
	MIT License http://www.opensource.org/licenses/mit-license.php
	Author Tobias Koppers @sokra
*/
var async = require("async");

var Tapable = require("tapable");
var Parser = require("./Parser");
var Dependency = require("./Dependency");
var EntryModuleNotFoundError = require("./EntryModuleNotFoundError");
var ModuleNotFoundError = require("./ModuleNotFoundError");
var CriticalDependenciesWarning = require("./CriticalDependenciesWarning");
var Module = require("./Module");
var ArrayMap = require("./ArrayMap");
var Chunk = require("./Chunk");
var Stats = require("./Stats");
var MainTemplate = require("./MainTemplate");
var ChunkTemplate = require("./ChunkTemplate");
var HotUpdateChunkTemplate = require("./HotUpdateChunkTemplate");
var ModuleTemplate = require("./ModuleTemplate");

function Compilation(compiler) {
	Tapable.call(this);
	this.compiler = compiler;
	this.resolvers = compiler.resolvers;
	this.inputFileSystem = compiler.inputFileSystem;

	var options = this.options = compiler.options;
	this.outputOptions = options && options.output;
	this.bail = options && options.bail;
	this.profile = options && options.profile;

	this.mainTemplate = new MainTemplate(this.outputOptions);
	this.chunkTemplate = new ChunkTemplate(this.outputOptions);
	this.hotUpdateChunkTemplate = new HotUpdateChunkTemplate(this.outputOptions);
	this.moduleTemplate = new ModuleTemplate(this.outputOptions);

	this.entries = [];
	this.preparedChunks = [];
	this.chunks = [];
	this.namedChunks = {};
	this.modules = [];
	this._modules = {};
	this.cache = null;
	this.records = null;
	this.nextFreeModuleId = 1;
	this.nextFreeChunkId = 0;
	this.additionalChunkAssets = [];
	this.assets = {};
	this.errors = [];
	this.warnings = [];
	this.children = [];
	this.dependencyFactories = new ArrayMap();
	this.dependencyTemplates = new ArrayMap();
}
module.exports = Compilation;

Compilation.prototype = Object.create(Tapable.prototype);
Compilation.prototype.addModule = function(module, cacheGroup) {
	cacheGroup = cacheGroup || "m";
	var identifier = module.identifier();
	if(this._modules[identifier]) {
		return false;
	}
	if(this.cache && this.cache[cacheGroup + identifier]) {
		var cacheModule = this.cache[cacheGroup + identifier];

		var rebuild = true;
		if(!cacheModule.error && cacheModule.cacheable && this.fileTimestamps && this.contextTimestamps) {
			rebuild = cacheModule.needRebuild(this.fileTimestamps, this.contextTimestamps);
		}

		if(!rebuild) {
			cacheModule.disconnect();
			this._modules[identifier] = cacheModule;
			this.modules.push(cacheModule);
			cacheModule.errors.forEach(function(err) {
				this.errors.push(err);
			}, this);
			cacheModule.warnings.forEach(function(err) {
				this.warnings.push(err);
			}, this);
			return cacheModule;
		} else {
			module.lastId = cacheModule.id;
		}
	}
	this._modules[identifier] = module;
	if(this.cache) {
		this.cache[cacheGroup + identifier] = module;
	}
	this.modules.push(module);
	return true;
};

Compilation.prototype.getModule = function(module) {
	var identifier = module.identifier();
	return this._modules[identifier];
};

Compilation.prototype.findModule = function(identifier) {
	return this._modules[identifier];
};

Compilation.prototype.buildModule = function(module, thisCallback) {
	this.applyPlugins("build-module", module);
	if(module.building) return module.building.push(thisCallback);
	var building = module.building = [thisCallback];
	function callback(err) {
		module.building = undefined;
		building.forEach(function(cb) {
			cb(err);
		});
	}
	module.build(this.options, this, this.resolvers.normal, this.inputFileSystem, function(err) {
		module.errors.forEach(function(err) {
			this.errors.push(err);
		}, this);
		module.warnings.forEach(function(err) {
			this.warnings.push(err);
		}, this);
		if(err) {
			module.error = err;
			this.applyPlugins("failed-module", module);
			return callback(err);
		}
		this.applyPlugins("succeed-module", module);
		return callback();
	}.bind(this));
};

Compilation.prototype.processModuleDependencies = function(module, callback) {
	var dependencies = [];
	function addDependency(dep) {
		for(var i = 0; i < dependencies.length; i++) {
			if(dep.isEqualResource(dependencies[i][0])) {
				return dependencies[i].push(dep);
			}
		}
		dependencies.push([dep]);
	}
	function addDependenciesBlock(block) {
		if(block.dependencies) {
			block.dependencies.forEach(addDependency);
		}
		if(block.blocks) {
			block.blocks.forEach(addDependenciesBlock);
		}
		if(block.variables) {
			block.variables.forEach(function(v) {
				v.dependencies.forEach(addDependency);
			});
		}
	}
	addDependenciesBlock(module);
	this.addModuleDependencies(module, dependencies, this.bail, null, true, callback);
};

Compilation.prototype.addModuleDependencies = function(module, dependencies, bail, cacheGroup, recursive, callback) {
	var factories = [];
	for(var i = 0; i < dependencies.length; i++) {
		var factory = this.dependencyFactories.get(dependencies[i][0].Class);
		if(!factory) {
			return callback(new Error("No module factory availible for dependency type: " + dependencies[i][0].Class.name));
		}
		factories[i] = [factory, dependencies[i]];
	}
	async.forEach(factories, function(item, callback) {
		var dependencies = item[1];
		var criticalDependencies = dependencies.filter(function(d) {
			return !!d.critical;
		});
		if(criticalDependencies.length > 0) {
			this.warnings.push(new CriticalDependenciesWarning(module, criticalDependencies));
		}

		var errorAndCallback = function errorAndCallback(err) {
			err.dependencies = dependencies;
			err.origin = module;
			module.dependenciesErrors.push(err);
			this.errors.push(err);
			if(bail) {
				callback(err);
			} else {
				callback();
			}
		}.bind(this);
		var warningAndCallback = function warningAndCallback(err) {
			err.dependencies = dependencies;
			err.origin = module;
			module.dependenciesWarnings.push(err);
			this.warnings.push(err);
			callback();
		}.bind(this);

		var factory = item[0];
		var start = this.profile && +new Date();
		factory.create(module.context, dependencies[0], function(err, dependantModule) {
			function isOptional() {
				return dependencies.filter(function(d) {
					return !d.optional;
				}).length === 0;
			}
			function errorOrWarningAndCallback(err) {
				if(isOptional()) {
					return warningAndCallback(err);
				} else {
					return errorAndCallback(err);
				}
			}
			if(err) {
				return errorOrWarningAndCallback(new ModuleNotFoundError(module, err));
			}
			if(!dependantModule) {
				return callback();
			}
			if(this.profile) {
				if(!dependantModule.profile) {
					dependantModule.profile = {};
				}
				var afterFactory = +new Date();
				dependantModule.profile.factory = afterFactory - start;
			}

			dependantModule.issuer = module.identifier();
			var newModule = this.addModule(dependantModule, cacheGroup);

			if(!newModule) { // from cache
				dependantModule = this.getModule(dependantModule);

				if(dependantModule.optional) {
					dependantModule.optional = isOptional();
				}

				if(dependantModule.id === 0) {
					return errorOrWarningAndCallback(
						new ModuleNotFoundError(module, new Error("a dependency to an entry point is not allowed"))
					);
				}

				dependencies.forEach(function(dep) {
					dep.module = dependantModule;
					dependantModule.addReason(module, dep);
				});

				if(this.profile) {
					if(!module.profile) {
						module.profile = {};
					}
					var time = +new Date() - start;
					if(!module.profile.dependencies || time > module.profile.dependencies) {
						module.profile.dependencies = time;
					}
				}

				return callback();
			}

			if(newModule instanceof Module) {
				if(this.profile) {
					newModule.profile = dependantModule.profile;
				}

				newModule.optional = isOptional();
				newModule.issuer = dependantModule.issuer;
				dependantModule = newModule;

				dependencies.forEach(function(dep) {
					dep.module = dependantModule;
					dependantModule.addReason(module, dep);
				});

				if(recursive) {
					return this.processModuleDependencies(dependantModule, callback);
				} else {
					return callback();
				}
			}

			dependantModule.optional = isOptional();

			dependencies.forEach(function(dep) {
				dep.module = dependantModule;
				dependantModule.addReason(module, dep);
			});

			this.buildModule(dependantModule, function(err) {
				if(err) {
					return errorOrWarningAndCallback(err);
				}

				if(this.profile) {
					var afterBuilding = +new Date();
					dependantModule.profile.building = afterBuilding - afterFactory;
				}

				if(recursive) {
					this.processModuleDependencies(dependantModule, callback);
				} else {
					return callback();
				}
			}.bind(this));

		}.bind(this));
	}.bind(this), function(err) {
		if(err) {
			return callback(err);
		}

		return callback();
	});
};

Compilation.prototype._addModuleChain = function process(context, dependency, onModule, callback) {
	var errorAndCallback = this.bail ? function errorAndCallback(err) {
		callback(err);
	} : function errorAndCallback(err) {
		err.dependencies = [dependency];
		this.errors.push(err);
		callback();
	}.bind(this);

	if(typeof dependency !== "object" || dependency === null || !dependency.Class) {
		throw new Error("Parameter 'dependency' must be a Dependency");
	}

	var moduleFactory = this.dependencyFactories.get(dependency.Class);
	if(!moduleFactory) {
		throw new Error("No dependency factory availible for this dependency type: " + dependency.Class.name);
	}

	var start = this.profile && +new Date();
	moduleFactory.create(context, dependency, function(err, module) {
		if(err) {
			return errorAndCallback(new EntryModuleNotFoundError(err));
		}

		if(this.profile) {
			if(!module.profile) {
				module.profile = {};
			}
			var afterFactory = +new Date();
			module.profile.factory = afterFactory - start;
		}

		var result = this.addModule(module);
		if(!result) {
			module = this.getModule(module);

			onModule(module);

			return callback(null, module);
		}

		if(result instanceof Module) {
			if(this.profile) {
				result.profile = module.profile;
			}

			module = result;
		}

		onModule(module);

		if(result instanceof Module) {
			moduleReady.call(this);
		} else {
			this.buildModule(module, function(err) {
				if(err) {
					return errorAndCallback(err);
				}

				if(this.profile) {
					var afterBuilding = +new Date();
					module.profile.building = afterBuilding - afterFactory;
				}

				moduleReady.call(this);
			}.bind(this));
		}

		function moduleReady() {
			this.processModuleDependencies(module, function(err) {
				if(err) {
					return callback(err);
				}

				return callback(null, module);
			}.bind(this));
		}
	}.bind(this));
};

Compilation.prototype.addEntry = function process(context, entry, name, callback) {
	this._addModuleChain(context, entry, function(module) {

		entry.module = module;
		this.entries.push(module);
		module.id = 0;

	}.bind(this), function(err, module) {
		if(err) {
			return callback(err);
		}

		if(module) {
			if(module.reasons.length > 0) {
				return callback(new Error("module cannot be added as entry point, because its already in the bundle"));
			}
			this.preparedChunks.push({
				name: name,
				module: module
			});
		}
		return callback();
	}.bind(this));
};

Compilation.prototype.prefetch = function process(context, dependency, callback) {
	this._addModuleChain(context, dependency, function(module) {

		module.prefetched = true;

	}, callback);
};

Compilation.prototype.rebuildModule = function(module, thisCallback) {
	if(module.variables.length || module.blocks.length)
		throw new Error("Cannot rebuild a complex module with variables or blocks");
	if(module.rebuilding) {
		return module.rebuilding.push(thisCallback);
	}
	var rebuilding = module.rebuilding = [thisCallback];
	function callback(err) {
		module.rebuilding = undefined;
		rebuilding.forEach(function(cb) {
			cb(err);
		});
	}
	var deps = module.dependencies.slice();
	this.buildModule(module, function(err) {
		if(err) return callback(err);

		this.processModuleDependencies(module, function(err) {
			if(err) return callback(err);
			deps.forEach(function(d) {
				if(d.module && d.module.removeReason(module, d)) {
					module.chunks.forEach(function(chunk) {
						if(!d.module.hasReasonForChunk(chunk)) {
							if(d.module.removeChunk(chunk)) {
								this.removeChunkFromDependencies(d.module, chunk);
							}
						}
					}, this);
				}
			}, this);
			callback();
		}.bind(this));

	}.bind(this));
};

Compilation.prototype.seal = function seal(callback) {
	this.applyPlugins("seal");
	this.preparedChunks.forEach(function(preparedChunk) {
		var module = preparedChunk.module;
		var chunk = this.addChunk(preparedChunk.name, module);
		chunk.initial = chunk.entry = true;
		chunk.addModule(module);
		module.addChunk(chunk);
		this.processDependenciesBlockForChunk(module, chunk);
	}, this);
	this.applyPlugins("optimize");

	this.applyPlugins("optimize-modules", this.modules);
	this.applyPlugins("after-optimize-modules", this.modules);

	this.applyPlugins("optimize-chunks", this.chunks);
	this.applyPlugins("after-optimize-chunks", this.chunks);

	this.applyPluginsAsync("optimize-tree", this.chunks, this.modules, function(err) {
		if(err) {
			return callback(err);
		}

		var shouldRecord = this.applyPluginsBailResult("should-record") !== false;

		this.applyPlugins("revive-modules", this.modules, this.records);
		this.applyPlugins("optimize-module-order", this.modules);
		this.applyModuleIds();
		this.applyPlugins("optimize-module-ids", this.modules);
		this.applyPlugins("after-optimize-module-ids", this.modules);
		if(shouldRecord)
			this.applyPlugins("record-modules", this.modules, this.records);

		this.applyPlugins("revive-chunks", this.chunks, this.records);
		this.applyPlugins("optimize-chunk-order", this.chunks);
		this.applyChunkIds();
		this.applyPlugins("optimize-chunk-ids", this.chunks);
		this.applyPlugins("after-optimize-chunk-ids", this.chunks);
		if(shouldRecord)
			this.applyPlugins("record-chunks", this.chunks, this.records);

		this.sortItems();
		this.applyPlugins("before-hash");
		this.createHash();
		this.applyPlugins("after-hash");
		this.applyPlugins("before-chunk-assets");
		this.createChunkAssets();
		this.applyPlugins("additional-chunk-assets", this.chunks);
		this.summarizeDependencies();
		if(shouldRecord)
			this.applyPlugins("record", this, this.records);

		this.applyPluginsAsync("additional-assets", function(err) {
			if(err) {
				return callback(err);
			}
			this.applyPluginsAsync("optimize-chunk-assets", this.chunks, function(err) {
				if(err) {
					return callback(err);
				}
				this.applyPlugins("after-optimize-chunk-assets", this.chunks);
				this.applyPluginsAsync("optimize-assets", this.assets, function(err) {
					if(err) {
						return callback(err);
					}
					this.applyPlugins("after-optimize-assets", this.assets);
					return callback();
				}.bind(this));
			}.bind(this));
		}.bind(this));
	}.bind(this));
};

Compilation.prototype.addChunk = function addChunk(name, module, loc) {
	var chunk;
	if(name) {
		if(Object.prototype.hasOwnProperty.call(this.namedChunks, name)) {
			chunk = this.namedChunks[name];
			if(module) {
				chunk.addOrigin(module, loc);
			}
			return chunk;
		}
	}
	chunk = new Chunk(name, module, loc);
	this.chunks.push(chunk);
	if(name) {
		this.namedChunks[name] = chunk;
	}
	return chunk;
};

Compilation.prototype.processDependenciesBlockForChunk = function processDependenciesBlockForChunk(block, chunk) {
	block.blocks.forEach(function(b) {
		var c;
		if(!b.chunk) {
			c = this.addChunk(b.chunkName, b.module, b.loc);
			b.chunk = c;
			c.addBlock(b);
		} else {
			c = b.chunk;
		}
		chunk.addChunk(c);
		c.addParent(chunk);
		this.processDependenciesBlockForChunk(b, c);
	}, this);
	function iteratorDependency(d) {
		if(!d.module) {
			return;
		}
		if(d.module.error) {
			d.module = null;
			return;
		}
		if(chunk.addModule(d.module)) {
			d.module.addChunk(chunk);
			this.processDependenciesBlockForChunk(d.module, chunk);
		}
	}
	block.dependencies.forEach(iteratorDependency, this);
	block.variables.forEach(function(v) {
		v.dependencies.forEach(iteratorDependency, this);
	}, this);
};

Compilation.prototype.removeChunkFromDependencies = function removeChunkFromDependencies(block, chunk) {
	block.blocks.forEach(function(b) {
		var c = b.chunk;
		chunk.removeChunk(c);
		c.removeParent(chunk);
		this.removeChunkFromDependencies(b, c);
	}, this);
	function iteratorDependency(d) {
		if(!d.module) {
			return;
		}
		if(!d.module.hasReasonForChunk(chunk)) {
			if(d.module.removeChunk(chunk)) {
				this.removeChunkFromDependencies(d.module, chunk);
			}
		}
	}
	block.dependencies.forEach(iteratorDependency, this);
	block.variables.forEach(function(v) {
		v.dependencies.forEach(iteratorDependency, this);
	}, this);

};

Compilation.prototype.applyModuleIds = function applyModuleIds() {
	this.modules.forEach(function(module) {
		if(module.id === null) {
			module.id = this.nextFreeModuleId++;
		}
	}, this);
};

Compilation.prototype.applyChunkIds = function applyChunkIds() {
	this.chunks.forEach(function(chunk) {
		if(chunk.id === null) {
			chunk.id = this.nextFreeChunkId++;
		}
		if(!chunk.ids) {
			chunk.ids = [chunk.id];
		}
	}, this);
};

Compilation.prototype.sortItems = function sortItems() {
	function byId(a, b) {
		return a.id - b.id;
	}
	this.chunks.sort(byId);
	this.modules.sort(byId);
	this.modules.forEach(function(module) {
		module.chunks.sort(byId);
		module.reasons.sort(function(a, b) {
			return byId(a.module, b.module)
		});
	});
	this.chunks.forEach(function(chunk) {
		chunk.modules.sort(byId);
	});
};

Compilation.prototype.summarizeDependencies = function summarizeDependencies() {
	function filterDups(array) {
		var newArray = [];
		for(var i = 0; i < array.length; i++) {
			if(i === 0 || array[i-1] !== array[i])
				newArray.push(array[i]);
		}
		return newArray;
	}
	this.fileDependencies = [];
	this.contextDependencies = [];
	this.children.forEach(function(child) {
		this.fileDependencies = this.fileDependencies.concat(child.fileDependencies);
		this.contextDependencies = this.contextDependencies.concat(child.contextDependencies);
	}.bind(this));
	this.modules.forEach(function(module) {
		if(module.fileDependencies) {
			module.fileDependencies.forEach(function(item) {
				this.fileDependencies.push(item);
			}, this);
		}
		if(module.contextDependencies) {
			module.contextDependencies.forEach(function(item) {
				this.contextDependencies.push(item);
			}, this);
		}
	}, this);
	this.fileDependencies.sort();
	this.fileDependencies = filterDups(this.fileDependencies);
	this.contextDependencies.sort();
	this.contextDependencies = filterDups(this.contextDependencies);
};

Compilation.prototype.createHash = function createHash() {
	var outputOptions = this.outputOptions;
	var hashFunction = outputOptions.hashFunction;
	var hashDigest = outputOptions.hashDigest;
	var hashDigestLength = outputOptions.hashDigestLength;
	var hash = require("crypto").createHash(hashFunction);
	this.mainTemplate.updateHash(hash);
	this.chunkTemplate.updateHash(hash);
	this.moduleTemplate.updateHash(hash);
	var i, chunk;
	for(i = 0; i < this.chunks.length; i++) {
		var chunk = this.chunks[i];
		var chunkHash = require("crypto").createHash(hashFunction);
		chunk.updateHash(chunkHash);
		this.chunkTemplate.updateHash(chunkHash);
		chunk.hash = chunkHash.digest(hashDigest);
		hash.update(chunk.hash);
		chunk.renderedHash = chunk.hash.substr(0, hashDigestLength);
	}
	this.fullHash = hash.digest(hashDigest);
	this.hash = this.fullHash.substr(0, hashDigestLength);
};

Compilation.prototype.modifyHash = function modifyHash(update) {
	var outputOptions = this.outputOptions;
	var hashFunction = outputOptions.hashFunction;
	var hashDigest = outputOptions.hashDigest;
	var hashDigestLength = outputOptions.hashDigestLength;
	var hash = require("crypto").createHash(hashFunction);
	hash.update(this.fullHash);
	hash.update(update);
	this.fullHash = hash.digest(hashDigest);
	this.hash = this.fullHash.substr(0, hashDigestLength);
};

Compilation.prototype.createChunkAssets = function createChunkAssets() {
	var outputOptions = this.outputOptions;
	var filename = outputOptions.filename || "bundle.js";
	var chunkFilename = outputOptions.chunkFilename || "[id]." + filename;
	var namedChunkFilename = outputOptions.namedChunkFilename || null;
	for(var i = 0; i < this.modules.length; i++) {
		var module = this.modules[i];
		if(module.assets) {
			Object.keys(module.assets).forEach(function(name) {
				var file = this.getPath(name);
				this.assets[file] = module.assets[name];
				this.applyPlugins("module-asset", module, file);
			}, this);
		}
	}
	for(var i = 0; i < this.chunks.length; i++) {
		var chunk = this.chunks[i];
		chunk.files = [];
		var chunkHash = chunk.hash;
		var source;
		var file;
		var filenameTemplate = chunk.filenameTemplate ?	chunk.filenameTemplate :
			chunk.initial ? filename :
			chunkFilename;
		var usedHash = !chunk.entry || (this.mainTemplate.useChunkHash && this.mainTemplate.useChunkHash(chunk)) ? chunkHash : this.fullHash;
		if(this.cache && this.cache["c" + chunk.id] && this.cache["c" + chunk.id].hash === usedHash) {
			source = this.cache["c" + chunk.id].source;
		} else {
			if(chunk.entry) {
				source = this.mainTemplate.render(this.hash, chunk, this.moduleTemplate, this.dependencyTemplates);
			} else {
				source = this.chunkTemplate.render(chunk, this.moduleTemplate, this.dependencyTemplates);
			}
			if(this.cache) {
				this.cache["c" + chunk.id] = {
					hash: usedHash,
					source: source
				}
			}
		}
		this.assets[
			file = this.getPath(filenameTemplate, {
				chunk: chunk
			})
		] = source;
		chunk.files.push(file);
		this.applyPlugins("chunk-asset", chunk, file);
		if(chunk.id !== 0 && namedChunkFilename && chunk.name) {
			this.assets[
				file = this.getPath(namedChunkFilename, {
					chunk: chunk
				})
			] = source;
			chunk.files.push(file);
			this.applyPlugins("chunk-asset", chunk, file);
		}
	}
};

Compilation.prototype.getPath = function (filename, data) {
	data = data || {};
	data.hash = data.hash || this.hash;
	return this.mainTemplate.applyPluginsWaterfall("asset-path", filename, data);
};

Compilation.prototype.getStats = function() {
	return new Stats(this);
};

Compilation.prototype.createChildCompiler = function(name, outputOptions) {
	return this.compiler.createChildCompiler(this, name, outputOptions);
};