Merge pull request #8 from 2do2go/feature/lazy-hooks

Feature: lazy hooks
2do2go · Feb 9, 2021 · 3481daa · 3481daa
2 parents c0e72b7 + 5dbc27c
commit 3481daa
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Showing 4 changed files with 105 additions and 26 deletions.
diff --git a/lib/embeddedDocument.js b/lib/embeddedDocument.js
@@ -28,11 +28,7 @@ var EmbeddedDocument = function(options) {
 };
 
 EmbeddedDocument.prototype.getUniqGroupId = function() {
-	return [
-		this.collection.collectionName,
-		this.key,
-		utils.stringifyProjection(this.projection)
-	].join('.');
+	return utils.getUniqGroupId(this);
 };
 
 EmbeddedDocument.prototype.getString = function() {
@@ -47,4 +43,12 @@ EmbeddedDocument.prototype.toJSON = function() {
 	return this.identifier;
 };
 
+EmbeddedDocument.prototype.setEmbeddedValue = function(embeddedValue) {
+	if (embeddedValue && embeddedValue[this.key] === this.identifier) {
+		this.embeddedValue = embeddedValue;
+	} else {
+		throw new Error('Invalid embedded value');
+	}
+};
+
 module.exports = EmbeddedDocument;
diff --git a/lib/embedderHooks.js b/lib/embedderHooks.js
@@ -79,6 +79,8 @@ var getFindParamsHash = function(object) {
 			if (!Array.isArray(value) && !utils.isSimpleObject(value)) return;
 
 			if (value instanceof EmbeddedDocument) {
+				if (value.embeddedValue) return;
+
 				var uniqGroupId = value.getUniqGroupId();
 
 				var params = findParamsHash[uniqGroupId];
@@ -149,7 +151,9 @@ var replaceEmbeddedDocuments = function(object, documentsHash) {
 		if (value instanceof EmbeddedDocument) {
 			var uniqGroupId = value.getUniqGroupId();
 
-			var embeddedDocument = documentsHash[uniqGroupId][value.identifier];
+			var embeddedDocument = value.embeddedValue
+				? value.embeddedValue
+				: documentsHash[uniqGroupId][value.identifier];
 
 			if (!embeddedDocument) {
 				throw new Error(

diff --git a/lib/relationHooks.js b/lib/relationHooks.js
@@ -21,14 +21,54 @@ var setupRelationHooks = function(relatedCollection, relation) {
 			});
 	};
 
+	var getEmbeddedDocuments = function(identifiers, callback) {
+		var projectionKeys = Object.keys(relation.projection);
+		if (projectionKeys.length === 1 && relation.projection[relation.key]) {
+			var documents = identifiers.map(function(identifier) {
+				return utils.createObject(relation.key, identifier);
+			});
+			callback(null, documents);
+		} else {
+			var condition = utils.createObject(relation.key, {$in: identifiers});
+			relation.collection.find(condition, relation.projection).toArray(callback);
+		}
+	};
+
+	var getEmbeddedDocumentsHash = function(identifiers, callback) {
+		getEmbeddedDocuments(identifiers, function(err, documents) {
+			if (err) return callback(err);
+
+			var documentsHash = utils.indexBy(documents, relation.key);
+
+			callback(null, documentsHash);
+		});
+	};
+
 	var beforeUpdate = function(params, callback) {
-		if (relation.onUpdate === 'cascade') {
+		var uniqGroupId = utils.getUniqGroupId(relation);
+		params.meta.cascadeUpdateParamsHash = params.meta.cascadeUpdateParamsHash || {};
+
+		if (
+			relation.onUpdate === 'cascade' &&
+			!params.meta.cascadeUpdateParamsHash[uniqGroupId]
+		) {
+			var cascadeUpdateParams = params.meta.cascadeUpdateParamsHash[uniqGroupId] = {};
+
 			getModifiedIdentifiers(params.condition, function(err, identifiers) {
 				if (err) return callback(err);
 
-				params.meta.modifiedIdentifiers = identifiers;
+				cascadeUpdateParams.modifiedIdentifiers = identifiers;
+
+				if (!identifiers.length) return callback();
+
+				// fetch current embedded documents to skip unnecessary updates later
+				getEmbeddedDocumentsHash(identifiers, function(err, documentsHash) {
+					if (err) return callback(err);
+
+					cascadeUpdateParams.originalEmbeddedDocumentsHash = documentsHash;
 
-				callback();
+					callback();
+				});
 			});
 		} else {
 			callback();
@@ -39,36 +79,50 @@ var setupRelationHooks = function(relatedCollection, relation) {
 	relation.collection.on('beforeUpdateMany', beforeUpdate);
 
 	var afterUpdate = function(params, callback) {
-		var identifiers = params.meta.modifiedIdentifiers || [];
+		var uniqGroupId = utils.getUniqGroupId(relation);
+		var cascadeUpdateParams = params.meta.cascadeUpdateParamsHash[uniqGroupId] || {};
+		var identifiers = cascadeUpdateParams.modifiedIdentifiers || [];
+		var originalDocumentsHash = cascadeUpdateParams.originalEmbeddedDocumentsHash || {};
 
 		if (!identifiers.length) return callback();
 
 		if (relation.onUpdate === 'cascade') {
-			// in cascade mode we need to update each updated identifier
-			var funcs = identifiers.map(function(identifier) {
-				return function(callback) {
-					var projectionKeys = Object.keys(relation.projection);
-					if (projectionKeys.length === 1 && relation.projection[relation.key]) {
-						callback();
-					} else {
+			getEmbeddedDocumentsHash(identifiers, function(err, newDocumentsHash) {
+				if (err) return callback(err);
+
+				// in cascade mode we need to update each updated identifier
+				var funcs = identifiers.map(function(identifier) {
+					return function(callback) {
+						var originalDocument = originalDocumentsHash[identifier];
+						var newDocument = newDocumentsHash[identifier];
+						if (
+							originalDocument && newDocument &&
+							utils.isDeepStrictEqual(originalDocument, newDocument)
+						) {
+							return callback();
+						}
+
 						var condition = utils.createObject(
 							relation.paths.identifier,
 							identifier
 						);
 
+						var embeddedDocument = relation.embedder(identifier);
+
+						if (newDocument) {
+							embeddedDocument.setEmbeddedValue(newDocument);
+						}
+
 						var modifier = {
-							$set: utils.createObject(
-								relation.paths.modifier,
-								relation.embedder(identifier)
-							)
+							$set: utils.createObject(relation.paths.modifier, embeddedDocument)
 						};
 
 						relatedCollection.updateMany(condition, modifier, callback);
-					}
-				};
-			});
+					};
+				});
 
-			utils.asyncParallel(funcs, callback);
+				utils.asyncParallel(funcs, callback);
+			});
 		} else {
 			callback();
 		}

diff --git a/lib/utils.js b/lib/utils.js
@@ -1,5 +1,8 @@
 'use strict';
 
+var util = require('util');
+var defaults = require('./defaults');
+
 var isObject = exports.isObject = function(obj) {
 	var type = typeof obj;
 	return type === 'function' || type === 'object' && !!obj;
@@ -47,6 +50,12 @@ exports.deepSet = function(object, field, value) {
 	return object;
 };
 
+exports.isDeepStrictEqual = function(val1, val2) {
+	return util.isDeepStrictEqual
+		? util.isDeepStrictEqual(val1, val2)
+		: JSON.stringify(val1) === JSON.stringify(val2);
+};
+
 exports.isModifier = function(modifier) {
 	var keys = Object.keys(modifier);
 	return keys.length && (/^\$/).test(keys[0]);
@@ -99,7 +108,7 @@ exports.asyncParallel = function(funcs, callback, context) {
 	});
 };
 
-exports.stringifyProjection = function(projection) {
+var stringifyProjection = exports.stringifyProjection = function(projection) {
 	var parts = [];
 
 	Object.keys(projection).sort().forEach(function(key) {
@@ -118,3 +127,11 @@ exports.stringifyProjection = function(projection) {
 
 	return '{' + parts.join(',') + '}';
 };
+
+exports.getUniqGroupId = function(relation) {
+	return [
+		relation.collection.collectionName,
+		relation.key || defaults.key,
+		stringifyProjection(relation.projection || defaults.projection)
+	].join('.');
+};