Adding threading for when not running against PouchDB.

packages/server/package.json

@@ -74,6 +74,7 @@
     "tar-fs": "^2.1.0",
     "uuid": "^3.3.2",
     "validate.js": "^0.13.1",
+    "worker-farm": "^1.7.0",
     "yargs": "^13.2.4",
     "zlib": "^1.0.5"
   },

packages/server/src/workflows/index.js

@@ -1,67 +1,31 @@
-const mustache = require("mustache")
-const actions = require("./actions")
-const logic = require("./logic")
 const triggers = require("./triggers")
+const workerFarm = require("worker-farm")
+const CouchDB = require("../db/client")
+const singleThread = require("./thread")
 
-/**
- * The workflow orchestrator is a class responsible for executing workflows.
- * It relies on the strategy pattern, which allows composable behaviour to be
- * passed into its execute() function. This allows custom execution behaviour based
- * on where the orchestrator is run.
- *
- */
-class Orchestrator {
-  constructor(workflow) {
-    this._context = {}
-    this._workflow = workflow
-  }
+let workers = workerFarm(require.resolve("./thread"))
 
-  async getStep(type, stepId) {
-    let step = null
-    if (type === "ACTION") {
-      step = await actions.getAction(stepId)
-    } else if (type === "LOGIC") {
-      step = logic.getLogic(stepId)
-    }
-    if (step == null) {
-      throw `Cannot find workflow step by name ${stepId}`
-    }
-    return step
-  }
-
-  async execute(context) {
-    let workflow = this._workflow
-    if (!workflow.live) {
-      return
-    }
-    for (let block of workflow.definition.steps) {
-      let step = await this.getStep(block.type, block.stepId)
-      let args = { ...block.args }
-      // bind the workflow action args to the workflow context, if required
-      for (let arg of Object.keys(args)) {
-        const argValue = args[arg]
-        // We don't want to render mustache templates on non-strings
-        if (typeof argValue !== "string") continue
-
-        args[arg] = mustache.render(argValue, { context: this._context })
+function runWorker(job) {
+  return new Promise((resolve, reject) => {
+    workers(job, err => {
+      if (err) {
+        reject(err)
+      } else {
+        resolve()
       }
-      const response = await step({
-        args,
-        context,
-      })
-
-      this._context = {
-        ...this._context,
-        [block.id]: response,
-      }
-    }
-  }
-}
-
-module.exports.init = function() {
-  triggers.workflowQueue.process(async job => {
-    // Create orchestrator for each individual workflow (their own context)
-    const workflowOrchestrator = new Orchestrator(job.data.workflow)
-    await workflowOrchestrator.execute(job.data.event)
+    })
+  })
+}
+
+/**
+ * This module is built purely to kick off the worker farm and manage the inputs/outputs
+ */
+module.exports.init = function() {
+  triggers.workflowQueue.process(async job => {
+    if (CouchDB.preferredAdapters != null && CouchDB.preferredAdapters[0] !== "leveldb") {
+      await runWorker(job)
+    } else {
+      await singleThread(job)
+    }
   })
 }

packages/server/src/workflows/thread.js

@@ -0,0 +1,67 @@
+const mustache = require("mustache")
+const actions = require("./actions")
+const logic = require("./logic")
+
+/**
+ * The workflow orchestrator is a class responsible for executing workflows.
+ * It handles the context of the workflow and makes sure each step gets the correct
+ * inputs and handles any outputs.
+ */
+class Orchestrator {
+  constructor(workflow) {
+    this._context = {}
+    this._workflow = workflow
+  }
+
+  async getStep(type, stepId) {
+    let step = null
+    if (type === "ACTION") {
+      step = await actions.getAction(stepId)
+    } else if (type === "LOGIC") {
+      step = logic.getLogic(stepId)
+    }
+    if (step == null) {
+      throw `Cannot find workflow step by name ${stepId}`
+    }
+    return step
+  }
+
+  async execute(context) {
+    let workflow = this._workflow
+    for (let block of workflow.definition.steps) {
+      let step = await this.getStep(block.type, block.stepId)
+      let args = { ...block.args }
+      // bind the workflow action args to the workflow context, if required
+      for (let arg of Object.keys(args)) {
+        const argValue = args[arg]
+        // We don't want to render mustache templates on non-strings
+        if (typeof argValue !== "string") continue
+
+        args[arg] = mustache.render(argValue, { context: this._context })
+      }
+      const response = await step({
+        args,
+        context,
+      })
+
+      this._context = {
+        ...this._context,
+        [block.id]: response,
+      }
+    }
+  }
+}
+
+module.exports = async (job, cb = null) => {
+  try {
+    const workflowOrchestrator = new Orchestrator(job.data.workflow)
+    await workflowOrchestrator.execute(job.data.event)
+    if (cb) {
+      cb()
+    }
+  } catch (err) {
+    if (cb) {
+      cb(err)
+    }
+  }
+}

packages/server/src/workflows/triggers.js

@@ -13,6 +13,9 @@ async function queueRelevantWorkflows(event, eventType) {
 
   const workflows = workflowsToTrigger.rows.map(wf => wf.doc)
   for (let workflow of workflows) {
+    if (!workflow.live) {
+      continue
+    }
     workflowQueue.add({ workflow, event })
   }
 }

packages/server/yarn.lock

@@ -1912,7 +1912,7 @@ env-paths@^2.2.0:
   version "2.2.0"
   resolved "https://registry.yarnpkg.com/env-paths/-/env-paths-2.2.0.tgz#cdca557dc009152917d6166e2febe1f039685e43"
 
-errno@~0.1.1:
+errno@~0.1.1, errno@~0.1.7:
   version "0.1.7"
   resolved "https://registry.yarnpkg.com/errno/-/errno-0.1.7.tgz#4684d71779ad39af177e3f007996f7c67c852618"
   dependencies:
@@ -6238,6 +6238,13 @@ word-wrap@~1.2.3:
   version "1.2.3"
   resolved "https://registry.yarnpkg.com/word-wrap/-/word-wrap-1.2.3.tgz#610636f6b1f703891bd34771ccb17fb93b47079c"
 
+worker-farm@^1.7.0:
+  version "1.7.0"
+  resolved "https://registry.yarnpkg.com/worker-farm/-/worker-farm-1.7.0.tgz#26a94c5391bbca926152002f69b84a4bf772e5a8"
+  integrity sha512-rvw3QTZc8lAxyVrqcSGVm5yP/IJ2UcB3U0graE3LCFoZ0Yn2x4EoVSqJKdB/T5M+FLcRPjz4TDacRf3OCfNUzw==
+  dependencies:
+    errno "~0.1.7"
+
 wrap-ansi@^5.1.0:
   version "5.1.0"
   resolved "https://registry.yarnpkg.com/wrap-ansi/-/wrap-ansi-5.1.0.tgz#1fd1f67235d5b6d0fee781056001bfb694c03b09"