Merge pull request #2 from narekhovhannisyan/pass-connection-expire

update cache util

Author: narekhovhannisyan

README.md

@@ -10,7 +10,7 @@ All connections are kept in cache and expire after given `connectionExpire` mill
 ## Usage
 
 ### For separate servers.
-```
+```js
 const NodeSSHExtra = require('node-ssh-extra')
 
 NodeSSHExtra({
@@ -29,7 +29,7 @@ NodeSSHExtra({
 
 ### If all servers have the same connection credentials.
 
-```
+```js
 const NodeSSHExtra = require('node-ssh-extra').NodeSSHExtraForSameCredentials({
   privateKey,
   host,
@@ -43,7 +43,8 @@ NodeSSHExtra('mock-domain.com')
     // Do whatever you need to do here.
   })
 
-// And after if you need to do some other thing with new connection just call NodeSSHExtra the same way.
+// And after if you need to do some other thing on the same server, just call NodeSSHExtra the same way.
+// It will reuse the old opened connection if it's not expired, otherwise will create new connection.
 
 NodeSSHExtra('mock-domain.com')
   .then((connection) => {

src/index.js

@@ -1,6 +1,6 @@
 const NodeSSH = require('node-ssh')
 
-const { getFromCacheAsync, storeInCache } = require('./util/cache').SINGLETON
+const { getValueByAsync, store } = require('./util/cache').SINGLETON
 
 /**
  * @typedef {import('./types/ssh').TNodeSSH} TNodeSSH
@@ -14,11 +14,11 @@ const { getFromCacheAsync, storeInCache } = require('./util/cache').SINGLETON
  * @return {Promise.<TNodeSSH>} SSH connection to desired remote.
  */
 const connect = ({ domainOrIP, connectionExpire, ...sshOptions }) =>
-  getFromCacheAsync(domainOrIP).then((connection) => {
+  getValueByAsync(domainOrIP).then((connection) => {
     if (!connection) {
       return new NodeSSH()
         .connect(sshOptions)
-        .then(storeInCache(domainOrIP, connectionExpire))
+        .then(store(domainOrIP, connectionExpire))
     }
 
     return connection

src/types/cache.js

@@ -0,0 +1,10 @@
+/**
+ * @typedef {Object} TCacheMethods
+ * @property {(key: String) => any} getValueBy
+ * @property {(key: String) => Promise.<any>} getValueByAsync
+ * @property {(key: String, expire?: Number) => (value: any) => any} store
+ * @property {() => String[]} getKeys
+ * @property {() => any[]} getKeyValuePairs
+ */
+
+module.exports = {}

src/util/cache.js

@@ -1,14 +1,19 @@
-const storage = {}
+/**
+ * @typedef {import('../types/cache').TCacheMethods} TCacheMethods
+ */
 
 /**
  * Key-value based cache with expire feature.
+ * @returns {TCacheMethods}
  */
 const Cache = () => {
+  const storage = {}
+
   /**
    * Checks if the key is close to expire.
    * @private
    */
-  const timer = setInterval(() => {
+  setInterval(() => {
     const now = Date.now()
     for (const key in storage) {
       const { date, expire } = storage[key]
@@ -24,28 +29,23 @@ const Cache = () => {
    * @param {String} key The key for storing data.
    * @returns {any}
    */
-  const getFromCache = (key) => storage[key] ? storage[key].value : undefined
+  const getValueBy = (key) => storage[key] ? storage[key].value : undefined
 
   /**
    * Stores data with given `key`, `expire` and `value`
    * @param {String} key The key for storing data.
    * @param {Number} [expire] The seconds to expire.
    * @returns {(any) => any}
    */
-  const storeInCache = (key, expire = Infinity) => (value) => {
+  const store = (key, expire = Infinity) => (value) => {
     storage[key] = {}
     storage[key].value = value
     storage[key].date = Date.now()
     storage[key].expire = expire
 
-    return getFromCache(key)
+    return getValueBy(key)
   }
 
-  /**
-   * Stops searching for values to expire.
-   */
-  const stopCache = () => clearInterval(timer)
-
   /**
    * Get stored keys.
    * @returns {String[]}
@@ -54,15 +54,14 @@ const Cache = () => {
 
   /**
    * Gets all key value pairs from cache.
-   * @returns {Array} Array of key value pairs.
+   * @returns {any[]} Array of key value pairs.
    */
-  const getKeyValuePairs = () => getKeys().map((key) => storage[key].value)
+  const getKeyValuePairs = () => getKeys().map((key) => ({ key, value: storage[key].value }))
 
   return {
-    getFromCache,
-    getFromCacheAsync: (key) => Promise.resolve(getFromCache(key)),
-    storeInCache,
-    stopCache,
+    getValueBy,
+    getValueByAsync: (key) => Promise.resolve(getValueBy(key)),
+    store,
     getKeys,
     getKeyValuePairs
   }