chore: refactor main code base into smaller parts

lib/reconnect.js

@@ -0,0 +1,134 @@
+'use strict'
+
+const debug = require('./debug')
+var lazyConnect = function (client) {
+  lazyConnect = require('./connect')
+  lazyConnect(client)
+}
+const noop = () => {}
+
+/**
+ * @description Try connecting to a server again
+ *
+ * @param {RedisClient} client
+ * @param {Error} [error]
+ */
+function retryConnection (client, error) {
+  debug('Retrying connection...')
+
+  const reconnectParams = {
+    delay: client.retryDelay,
+    attempt: client.attempts,
+    error,
+    totalRetryTime: client.retryTotaltime,
+    timesConnected: client.timesConnected
+  }
+  client.emit('reconnecting', reconnectParams)
+
+  client.retryTotaltime += client.retryDelay
+  client.attempts += 1
+  lazyConnect(client)
+  client.retryTimer = null
+}
+
+/**
+ * @description The connection is lost. Retry if requested
+ *
+ * @param {RedisClient} client
+ * @param {string} why
+ * @param {Error} [error]
+ */
+function reconnect (client, why, error) {
+  // If a retry is already in progress, just let that happen
+  if (client.retryTimer) {
+    return
+  }
+  // TODO: Always return an error?
+  error = error || null
+
+  debug('Redis connection is gone from %s event.', why)
+  client.connected = false
+  client.ready = false
+  // Deactivate cork to work with the offline queue
+  client.cork = noop
+  client.uncork = noop
+  client.pipeline = false
+  client.pubSubMode = 0
+
+  // since we are collapsing end and close, users don't expect to be called twice
+  if (!client.emittedEnd) {
+    client.emit('end')
+    client.emittedEnd = true
+  }
+
+  if (why === 'timeout') {
+    var message = 'Redis connection in broken state: connection timeout exceeded.'
+    const err = new Error(message)
+    // TODO: Find better error codes...
+    err.code = 'CONNECTION_BROKEN'
+    client.flushAndError({
+      message: message,
+      code: 'CONNECTION_BROKEN'
+    })
+    client.emit('error', err)
+    client.end(false)
+    return
+  }
+
+  // If client is a requested shutdown, then don't retry
+  if (client.closing) {
+    debug('Connection ended by quit / end command, not retrying.')
+    client.flushAndError({
+      message: 'Stream connection ended and command aborted.',
+      code: 'NR_CLOSED'
+    }, {
+      error
+    })
+    return
+  }
+
+  client.retryDelay = client.retryStrategy({
+    attempt: client.attempts,
+    error,
+    totalRetryTime: client.retryTotaltime,
+    timesConnected: client.timesConnected
+  })
+  if (typeof client.retryDelay !== 'number') {
+    // Pass individual error through
+    if (client.retryDelay instanceof Error) {
+      error = client.retryDelay
+    }
+    client.flushAndError({
+      message: 'Stream connection ended and command aborted.',
+      code: 'NR_CLOSED'
+    }, {
+      error
+    })
+    // TODO: Check if client is so smart
+    if (error) {
+      client.emit('error', error)
+    }
+    client.end(false)
+    return
+  }
+
+  // Retry commands after a reconnect instead of throwing an error. Use this with caution
+  if (client.options.retryUnfulfilledCommands) {
+    client.offlineQueue.unshift.apply(client.offlineQueue, client.commandQueue.toArray())
+    client.commandQueue.clear()
+  } else if (client.commandQueue.length !== 0) {
+    client.flushAndError({
+      message: 'Redis connection lost and command aborted.',
+      code: 'UNCERTAIN_STATE'
+    }, {
+      error,
+      queues: ['commandQueue']
+    })
+  }
+
+  debug('Retry connection in %s ms', client.retryDelay)
+
+  client.retryTimer = setTimeout((client, error) => retryConnection(client, error), client.retryDelay, client, error)
+}
+
+module.exports = reconnect