Cache /v1/perspectives

api/v1/helpers/verbs/doFind.js

@@ -15,6 +15,8 @@ const u = require('./utils');
 const fu = require('./findUtils');
 const COUNT_HEADER_NAME = require('../../constants').COUNT_HEADER_NAME;
 const httpStatus = require('../../constants').httpStatus;
+const redisCache = require('../../../../cache/redisCache').client;
+const SECS_IN_MIN = 60;
 
 /**
  * Finds all matching records but only returns a subset of the results for
@@ -32,19 +34,25 @@ const httpStatus = require('../../constants').httpStatus;
  *  find command
  */
 function doFindAndCountAll(reqResNext, props, opts) {
-  u.getScopedModel(props, opts.attributes).findAndCountAll(opts)
-  .then((o) => {
-    reqResNext.res.set(COUNT_HEADER_NAME, o.count);
-    const retval = o.rows.map((row) => {
-      if (props.modelName === 'Lens') {
-        delete row.dataValues.library;
-      }
+  return new Promise((resolve, reject) => {
+    u.getScopedModel(props, opts.attributes).findAndCountAll(opts)
+    .then((o) => {
+      reqResNext.res.set(COUNT_HEADER_NAME, o.count);
+      const retval = o.rows.map((row) => {
+        if (props.modelName === 'Lens') {
+          delete row.dataValues.library;
+        }
 
-      return u.responsify(row, props, reqResNext.req.method);
-    });
-    reqResNext.res.status(httpStatus.OK).json(retval);
-  })
-  .catch((err) => u.handleError(reqResNext.next, err, props.modelName));
+        return u.responsify(row, props, reqResNext.req.method);
+      });
+      resolve(retval);
+      // reqResNext.res.status(httpStatus.OK).json(retval);
+    })
+    .catch((err) => reject(err));
+  });
+
+
+  // .catch((err) => u.handleError(reqResNext.next, err, props.modelName));
 } // doFindAndCountAll
 
 /**
@@ -67,43 +75,48 @@ function doFindAll(reqResNext, props, opts) {
     opts.where.tags.$contains = [];
   }
 
-  u.getScopedModel(props, opts.attributes).findAll(opts)
-  .then((o) => {
-    reqResNext.res.set(COUNT_HEADER_NAME, o.length);
-    let retval = o.map((row) => {
-      if (props.modelName === 'Lens') {
-        delete row.dataValues.library;
-      }
+  return new Promise((resolve, reject) => {
+    u.getScopedModel(props, opts.attributes).findAll(opts)
+    .then((o) => {
+      reqResNext.res.set(COUNT_HEADER_NAME, o.length);
+      let retval = o.map((row) => {
+        if (props.modelName === 'Lens') {
+          delete row.dataValues.library;
+        }
 
-      return u.responsify(row, props, reqResNext.req.method);
-    });
+        return u.responsify(row, props, reqResNext.req.method);
+      });
 
-    const { tags } = reqResNext.req.swagger.params;
-    if (tags && tags.value && tags.value.length) {
-      retval = fu.filterArrFromArr(retval, tags.value);
-    }
-
-    reqResNext.res.status(httpStatus.OK).json(retval);
-  })
-  .catch((err) => u.handleError(reqResNext.next, err, props.modelName));
+      const { tags } = reqResNext.req.swagger.params;
+      if (tags && tags.value && tags.value.length) {
+        retval = fu.filterArrFromArr(retval, tags.value);
+      }
+      resolve(retval);
+      // reqResNext.res.status(httpStatus.OK).json(retval);
+    })
+    .catch((err) => reject(err));
+  });
+  // .catch((err) => u.handleError(reqResNext.next, err, props.modelName));
 } // doFindAll
 
 /**
  * Finds all matching records. This function is just a wrapper around
  * doFindAll or doFindAndCountAll, depending upon whether we need to paginate
- * the results.
+ * the results. If cacheKey is provided, we cache the response.
  *
- * @param {IncomingMessage} req - The request object
- * @param {ServerResponse} res - The response object
- * @param {Function} next - The next middleware function in the stack
+ * @param {Object} reqResNext - The object containing the request object, the
+ *  response object and the next middleware function in the stack
  * @param {Object} props - The helpers/nouns module for the given DB model
+ * @param {Object} opts - The "options" object to pass into the Sequelize
+ * find command
+ * @param {Object} cacheKey - Optional cache key used to cache the response in
+ * redis
  */
-module.exports = function doFind(req, res, next, props) {
-  const opts = fu.options(req.swagger.params, props);
+function doFindResponse(reqResNext, props, opts, cacheKey) {
   if (opts.limit || opts.offset) {
-    res.links({
-      prev: req.originalUrl,
-      next: fu.getNextUrl(req.originalUrl, opts.limit, opts.offset),
+    reqResNext.res.links({
+      prev: reqResNext.req.originalUrl,
+      next: fu.getNextUrl(reqResNext.req.originalUrl, opts.limit, opts.offset),
     });
   }
 
@@ -112,9 +125,52 @@ module.exports = function doFind(req, res, next, props) {
    * we're not doing a "limit" query, just to findAll, avoiding the extra
    * "SELECT count(*)... " database call.
    */
+  let doFindPromise;
   if (opts.limit) {
-    doFindAndCountAll({ req, res, next }, props, opts);
+    doFindPromise = doFindAndCountAll(reqResNext, props, opts);
+  } else {
+    doFindPromise = doFindAll(reqResNext, props, opts);
+  }
+
+  doFindPromise.then((retval) => {
+    reqResNext.res.status(httpStatus.OK).json(retval);
+
+    if (cacheKey) {
+      // cache the object by cacheKey. Store the key-value pair in cache
+      // with an expiry of 1 minute (60s)
+      const strObj = JSON.stringify(retval);
+      redisCache.setex(cacheKey, SECS_IN_MIN, strObj);
+    }
+  })
+  .catch((err) => u.handleError(reqResNext.next, err, props.modelName));
+}
+
+/**
+ * Finds all matching records. Get result from cache if present, else, get
+ * results from db and store in cache, if caching is enabled.
+ *
+ * @param {IncomingMessage} req - The request object
+ * @param {ServerResponse} res - The response object
+ * @param {Function} next - The next middleware function in the stack
+ * @param {Object} props - The helpers/nouns module for the given DB model
+ */
+module.exports = function doFind(req, res, next, props) {
+  const opts = fu.options(req.swagger.params, props);
+
+  if (props.cacheEnabled) {
+    const cacheKey = JSON.stringify(opts);
+
+    redisCache.get(cacheKey, (cacheErr, reply) => {
+      if (cacheErr || !reply) {
+        // if err or no reply, get resuls from db and set redis cache
+        doFindResponse({ req, res, next }, props, opts, cacheKey);
+      } else {
+        // get from cache
+        const dbObj = JSON.parse(reply);
+        res.status(httpStatus.OK).json(dbObj);
+      }
+    });
   } else {
-    doFindAll({ req, res, next }, props, opts);
+    doFindResponse({ req, res, next }, props, opts);
   }
 }; // exports