Fixed #182 added named query cacher

Author: theodorDiaconu

lib/namedQuery/README.md

@@ -0,0 +1,44 @@
+import {Meteor} from 'meteor/meteor';
+import cloneDeep from 'lodash.cloneDeep';
+
+const DEFAULT_TTL = 60000;
+
+/**
+ * This is a very basic in-memory result caching functionality
+ */
+export default class MemoryResultCacher {
+    constructor(config = {}) {
+        this.store = {};
+        this.config = config;
+    }
+
+    get(cacheId, {
+        query,
+        countCursor,
+    }) {
+        const cacheData = this.store[cacheId];
+        if (cacheData !== undefined) {
+            return cloneDeep(cacheData);
+        }
+
+        let data;
+        if (query) {
+            data = query.fetch();
+        } else {
+            data = countCursor.count();
+        }
+
+        this.set(cacheId, data);
+
+        return data;
+    }
+
+    set(cacheId, data) {
+        const ttl = this.config.ttl || DEFAULT_TTL;
+        this.store[cacheId] = cloneDeep(data);
+
+        Meteor.setTimeout(() => {
+            delete this.store[cacheId];
+        }, ttl)
+    }
+}

lib/namedQuery/cache/MemoryResultCacher.js

@@ -0,0 +1,5 @@
+import {EJSON} from 'meteor/ejson';
+
+export default function(queryName, params) {
+    return `${queryName}::${EJSON.stringify(params)}`;
+}

lib/namedQuery/cache/generateQueryId.js

@@ -24,11 +24,15 @@ export default class NamedQueryBase {
     }
 
     clone(newParams) {
-        return new this.constructor(
+        let clone = new this.constructor(
             this.queryName,
             this.collection,
             deepClone(this.body),
             _.extend({}, deepClone(this.params), newParams)
         );
+
+        clone.cacher = this.cacher;
+
+        return clone;
     }
 }

lib/namedQuery/namedQuery.base.js

@@ -1,6 +1,8 @@
 import prepareForProcess from '../query/lib/prepareForProcess.js';
 import Base from './namedQuery.base';
 import deepClone from 'lodash.cloneDeep';
+import MemoryResultCacher from './cache/MemoryResultCacher';
+import generateQueryId from './cache/generateQueryId';
 
 export default class extends Base {
     /**
@@ -13,6 +15,11 @@ export default class extends Base {
             deepClone(this.params)
         );
 
+        if (this.cacher) {
+            const cacheId = generateQueryId(this.queryName, this.params);
+            return this.cacher.get(cacheId, {query});
+        }
+
         return query.fetch();
     }
 
@@ -30,7 +37,15 @@ export default class extends Base {
      * @returns {any}
      */
     getCount() {
-        return this.getCursorForCounting().count();
+        const countCursor = this.getCursorForCounting();
+
+        if (this.cacher) {
+            const cacheId = 'count::' + generateQueryId(this.queryName, this.params);
+
+            return this.cacher.get(cacheId, {countCursor});
+        }
+
+        return countCursor.count();
     }
 
     /**
@@ -42,4 +57,15 @@ export default class extends Base {
 
         return this.collection.find(body.$filters || {}, {fields: {_id: 1}});
     }
+
+    /**
+     * @param cacher
+     */
+    cacheResults(cacher) {
+        if (!cacher) {
+            cacher = new MemoryResultCacher();
+        }
+
+        this.cacher = cacher;
+    }
 }

lib/namedQuery/namedQuery.server.js

@@ -1,4 +1,4 @@
-import { createQuery } from 'meteor/cultofcoders:grapher';
+import { createQuery, MemoryResultCacher } from 'meteor/cultofcoders:grapher';
 import postListExposure from './queries/postListExposure.js';
 
 const postList = createQuery('postList', {
@@ -16,6 +16,7 @@ const postList = createQuery('postList', {
     }
 });
 
+
 export { postList };
 export { postListExposure };
 
@@ -28,3 +29,15 @@ postListExposure.expose({
         }
     }
 });
+
+const postListCached = createQuery('postListCached', {
+    posts: {
+        title: 1,
+    }
+});
+
+export {postListCached};
+
+postListCached.cacheResults(new MemoryResultCacher({
+    ttl: 400,
+}));

lib/namedQuery/testing/bootstrap/server.js

@@ -1,6 +1,7 @@
-import { postList } from './bootstrap/server.js';
+import { postList, postListCached } from './bootstrap/server.js';
 import { createQuery } from 'meteor/cultofcoders:grapher';
 
+
 describe('Named Query', function () {
     it('Should return the proper values', function () {
         const createdQuery = createQuery({
@@ -42,5 +43,31 @@ describe('Named Query', function () {
             assert.isObject(post.author);
             assert.isObject(post.group);
         })
-    })
-});
+    });
+
+    it('Should properly cache the values', function (done) {
+        const posts = postListCached.fetch();
+        const postsCount = postListCached.getCount();
+
+        const Posts = Mongo.Collection.get('posts');
+        const postId = Posts.insert({title: 'Hello Cacher!'});
+
+        assert.equal(posts.length, postListCached.fetch().length);
+        assert.equal(postsCount, postListCached.getCount());
+
+        Meteor.setTimeout(function () {
+            const newPosts = postListCached.fetch();
+            const newCount = postListCached.getCount();
+
+            Posts.remove(postId);
+
+            assert.isArray(newPosts);
+            assert.isNumber(newCount);
+
+            assert.equal(posts.length + 1, newPosts.length);
+            assert.equal(postsCount + 1, newCount);
+
+            done();
+        }, 500)
+    });
+});

lib/namedQuery/testing/server.test.js

@@ -21,4 +21,8 @@ export {
     default as getDocumentationObject
 } from './lib/documentor/index.js';
 
+export {
+    default as MemoryResultCacher
+} from './lib/namedQuery/cache/MemoryResultCacher';
+
 export { Types } from './lib/constants';