#110 early tags prototype

lib/ExpressRedisCache/add.js

@@ -59,6 +59,10 @@ function add(name, body, options, callback) {
           +entry.expire
         );
         self.emit("message", message);
+
+        if (options.tag) {
+          self.emit("message", `SADD ${prefix}:${options.tag} "${redisKey}"`);
+        }
         callback(null, name, entry, res);
       });
     } else {

lib/ExpressRedisCache/delTag.js

@@ -0,0 +1,63 @@
+import util from "util";
+import async from "async";
+
+/**  Delete cache entries by tag
+ *
+ *  @method ExpressRedisCache.delTag
+ *  @description Delete entries by tag
+ *  @return null
+ *  @arg {String} name - The tag name
+ *  @arg {Function} callback
+ */
+
+function delTag(name, callback) {
+  let self = this;
+
+  if (typeof name !== "string") {
+    return this.emit(
+      "error",
+      new Error("ExpressRedisCache.delTag: missing first argument String")
+    );
+  }
+
+  if (typeof callback !== "function") {
+    return this.emit(
+      "error",
+      new Error("ExpressRedisCache.delTag: missing second argument Function")
+    );
+  }
+
+  /** Get prefix */
+
+  let prefix = self.prefix.match(/:$/)
+    ? self.prefix.replace(/:$/, "")
+    : self.prefix;
+
+  /** Tell Redis to delete hash */
+
+  let redisKey = `${prefix}:${name}`;
+
+  self.client.smembers(redisKey, (err, deletions) => {
+    deletions.push(redisKey);
+    async.each(
+      deletions,
+
+      (key, callback) => {
+        self.client.del(key, () => {
+          self.emit("message", util.format("DEL %s", key));
+          callback();
+        });
+      },
+
+      error => {
+        if (error) {
+          throw error;
+        }
+
+        callback(null, deletions.length);
+      }
+    );
+  });
+}
+
+export default delTag;

lib/ExpressRedisCache/route.js

@@ -83,6 +83,12 @@ function route() {
       name = res.express_redis_cache_name;
     }
 
+    // If a tag has been explicitly attached to `res` then use it as tag
+
+    if (res.express_redis_cache_tag) {
+      tag = res.express_redis_cache_tag;
+    }
+
     // If route() was called with a string as its first argument, use this string as name
 
     if (typeof options[0] === "string") {
@@ -104,7 +110,17 @@ function route() {
      *  @type Number
      *  @default this.expire
      */
+
     let expire = self.expire;
+
+    /** The object representing the tag for the cache key
+     *
+     *  @type String
+     *  @default this.tag
+     */
+
+    let tag = self.tag;
+
     if (typeof options[0] === "object") {
       if (
         typeof options[0].expire === "number" ||
@@ -113,6 +129,10 @@ function route() {
       ) {
         expire = options[0].expire;
       }
+
+      if (typeof options[0].tag === "string") {
+        tag = options[0].tag;
+      }
     }
 
     if (typeof options[0] === "number") {
@@ -181,7 +201,8 @@ function route() {
             body,
             {
               type: this._headers["content-type"],
-              expire: expirationPolicy(req, res)
+              expire: expirationPolicy(req, res),
+              tag
             },
             function (name, cache) {}); // eslint-disable-line
 

lib/index.js

@@ -3,6 +3,7 @@ import redis from "redis";
 import Get from "./ExpressRedisCache/get";
 import Add from "./ExpressRedisCache/add";
 import Del from "./ExpressRedisCache/del";
+import DelTag from "./ExpressRedisCache/delTag";
 import Route from "./ExpressRedisCache/route";
 import Size from "./ExpressRedisCache/size";
 import { config } from "../package.json";
@@ -140,6 +141,16 @@ export default class ExpressRedisCache extends EventEmitter {
 
     this.del = Del;
 
+    /**  js-comment
+     *
+     *  @method
+     *  @description This is a method
+     *  @return void{Object}
+     *  @arg {Object} arg - About arg
+     */
+
+    this.delTag = DelTag;
+
     /**  js-comment
      *
      *  @method

test/delTag.js

@@ -0,0 +1,37 @@
+import should from "should";
+import async from "async";
+import ERC from "../dist";
+
+let prefix = process.env.EX_RE_CA_PREFIX || "erct:";
+let host = process.env.EX_RE_CA_HOST || "localhost";
+let port = process.env.EX_RE_CA_PORT || 6379;
+
+const cache = new ERC({
+  prefix: prefix,
+  host: host,
+  port: port
+});
+
+describe("delTag", () => {
+  before(done => {
+    cache.add(
+      "tag-to-del",
+      "-",
+      {
+        tag: "testtag"
+      },
+      done
+    );
+  });
+
+  it("should be a function", () => {
+    cache.delTag.should.be.a.Function;
+  });
+
+  it("should callback", done => {
+    cache.delTag("testtag", ($error, $deletions) => {
+      debugger;
+      done();
+    });
+  });
+});