fix: session refactoring with Saad & Allan

api/package-lock.json

@@ -10,6 +10,7 @@
       "dependencies": {
         "@sasjs/utils": "^2.33.1",
         "bcryptjs": "^2.4.3",
+        "cors": "^2.8.5",
         "express": "^4.17.1",
         "joi": "^17.4.2",
         "jsonwebtoken": "^8.5.1",
@@ -3904,6 +3905,18 @@
       "resolved": "https://registry.npmjs.org/core-util-is/-/core-util-is-1.0.2.tgz",
       "integrity": "sha1-tf1UIgqivFq1eqtxQMlAdUUDwac="
     },
+    "node_modules/cors": {
+      "version": "2.8.5",
+      "resolved": "https://registry.npmjs.org/cors/-/cors-2.8.5.tgz",
+      "integrity": "sha512-KIHbLJqu73RGr/hnbrO9uBeixNGuvSQjul/jdFvS/KFSIH1hWVd1ng7zOHx+YrEfInLG7q4n6GHQ9cDtxv/P6g==",
+      "dependencies": {
+        "object-assign": "^4",
+        "vary": "^1"
+      },
+      "engines": {
+        "node": ">= 0.10"
+      }
+    },
     "node_modules/cosmiconfig": {
       "version": "7.0.0",
       "resolved": "https://registry.npmjs.org/cosmiconfig/-/cosmiconfig-7.0.0.tgz",
@@ -18036,6 +18049,15 @@
       "resolved": "https://registry.npmjs.org/core-util-is/-/core-util-is-1.0.2.tgz",
       "integrity": "sha1-tf1UIgqivFq1eqtxQMlAdUUDwac="
     },
+    "cors": {
+      "version": "2.8.5",
+      "resolved": "https://registry.npmjs.org/cors/-/cors-2.8.5.tgz",
+      "integrity": "sha512-KIHbLJqu73RGr/hnbrO9uBeixNGuvSQjul/jdFvS/KFSIH1hWVd1ng7zOHx+YrEfInLG7q4n6GHQ9cDtxv/P6g==",
+      "requires": {
+        "object-assign": "^4",
+        "vary": "^1"
+      }
+    },
     "cosmiconfig": {
       "version": "7.0.0",
       "resolved": "https://registry.npmjs.org/cosmiconfig/-/cosmiconfig-7.0.0.tgz",

api/package.json

@@ -43,6 +43,7 @@
   "dependencies": {
     "@sasjs/utils": "^2.33.1",
     "bcryptjs": "^2.4.3",
+    "cors": "^2.8.5",
     "express": "^4.17.1",
     "joi": "^17.4.2",
     "jsonwebtoken": "^8.5.1",

api/public/swagger.yaml

@@ -981,7 +981,7 @@ paths:
                         application/json:
                             schema:
                                 type: string
-            description: "Trigger a SAS program using it's location in the _program parameter.\nEnable debugging using the _debug parameter.\nAdditional URL parameters are turned into SAS macro variables.\nAny files provided are placed into the session and\ncorresponding _WEBIN_XXX variables are created."
+            description: "Trigger a SAS program using it's location in the _program parameter.\r\nEnable debugging using the _debug parameter.\r\nAdditional URL parameters are turned into SAS macro variables.\r\nAny files provided are placed into the session and\r\ncorresponding _WEBIN_XXX variables are created."
             summary: 'Execute Stored Program, return raw content'
             tags:
                 - STP
@@ -1005,7 +1005,7 @@ paths:
                         application/json:
                             schema:
                                 $ref: '#/components/schemas/ExecuteReturnJsonResponse'
-            description: "Trigger a SAS program using it's location in the _program parameter.\nEnable debugging using the _debug parameter.\nAdditional URL parameters are turned into SAS macro variables.\nAny files provided are placed into the session and\ncorresponding _WEBIN_XXX variables are created."
+            description: "Trigger a SAS program using it's location in the _program parameter.\r\nEnable debugging using the _debug parameter.\r\nAdditional URL parameters are turned into SAS macro variables.\r\nAny files provided are placed into the session and\r\ncorresponding _WEBIN_XXX variables are created."
             summary: 'Execute Stored Program, return JSON'
             tags:
                 - STP

api/src/app.ts

@@ -2,7 +2,6 @@ import path from 'path'
 import express from 'express'
 import morgan from 'morgan'
 import dotenv from 'dotenv'
-
 import webRouter from './routes/web'
 import apiRouter from './routes/api'
 import { getWebBuildFolderPath } from './utils'
@@ -10,6 +9,9 @@ import { connectDB } from './routes/api/auth'
 
 const app = express()
 
+const cors=require('cors')
+app.use(cors())
+
 app.use(express.json({ limit: '50mb' }))
 app.use(morgan('tiny'))
 app.use(express.static(path.join(__dirname, '../public')))

api/src/controllers/internal/Execution.ts

@@ -2,13 +2,10 @@ import path from 'path'
 import fs from 'fs'
 import { getSessionController } from './'
 import { readFile, fileExists, createFile } from '@sasjs/utils'
-import { configuration } from '../../../package.json'
-import { promisify } from 'util'
-import { execFile } from 'child_process'
 import { PreProgramVars, Session, TreeNode } from '../../types'
 import { generateFileUploadSasCode, getTmpFilesFolderPath } from '../../utils'
-
+export const delay = (ms: number) =>
-const execFilePromise = promisify(execFile)
+new Promise((resolve) => setTimeout(resolve, ms))
 
 export class ExecutionController {
   async execute(
@@ -76,25 +73,25 @@ ${program}`
       }
     }
 
-    const code = path.join(session.path, 'code.sas')
+    const codePath = path.join(session.path, 'code.sas')
-    if (!(await fileExists(code))) {
+    
-      await createFile(code, program)
+    // Creating this file in a RUNNING session will break out
+    // the autoexec loop and actually execute the program
+    // but - given it will take several milliseconds to create
+    // (which can mean SAS trying to run a partial program, or
+    // failing due to file lock) we first create the file THEN
+    // we rename it.
+    await createFile(codePath + '.bkp', program)
+    fs.renameSync(codePath + '.bkp',codePath)
+
+    // we now need to poll the session array 
+    while (
+      !session.completed
+    ) { 
+      await delay(50)
     }
 
-    let additionalArgs: string[] = []
-    if (autoExec) additionalArgs = ['-AUTOEXEC', autoExec]
 
-    const sasLoc = process.sasLoc ?? configuration.sasPath
-    const { stdout, stderr } = await execFilePromise(sasLoc, [
-      '-SYSIN',
-      code,
-      '-LOG',
-      log,
-      '-WORK',
-      session.path,
-      ...additionalArgs,
-      process.platform === 'win32' ? '-nosplash' : ''
-    ]).catch((err) => ({ stderr: err, stdout: '' }))
 
     if (await fileExists(log)) log = await readFile(log)
     else log = ''
@@ -107,7 +104,7 @@ ${program}`
     )
 
     let jsonResult
-    if ((debug && vars[debug] >= 131) || stderr) {
+    if ((debug && vars[debug] >= 131)) {
       webout = `<html><body>
 ${webout}
 <div style="text-align:left">

api/src/controllers/internal/Session.ts

@@ -1,4 +1,7 @@
 import { Session } from '../../types'
+import { configuration } from '../../../package.json'
+import { promisify } from 'util'
+import { execFile } from 'child_process'
 import { getTmpSessionsFolderPath, generateUniqueFileName } from '../../utils'
 import {
   deleteFolder,
@@ -9,6 +12,9 @@ import {
 } from '@sasjs/utils'
 import path from 'path'
 import { ExecutionController } from './Execution'
+import { date } from 'joi'
+
+const execFilePromise = promisify(execFile)
 
 export class SessionController {
   private sessions: Session[] = []
@@ -34,7 +40,8 @@ export class SessionController {
     const sessionId = generateUniqueFileName(generateTimestamp())
     const sessionFolder = path.join(getTmpSessionsFolderPath(), sessionId)
 
-    const autoExecContent = `data _null_;
+    const autoExecContent = `
+  data _null_;
     /* remove the dummy SYSIN */
     length fname $8;
     rc=filename(fname,getoption('SYSIN') );
@@ -45,12 +52,14 @@ export class SessionController {
     do until ( fileexist(getoption('SYSIN')) or slept>(60*15) );
       slept=slept+sleep(0.01,1);
     end;
+    stop;
   run;
-  EOL`
+`
-
+    // the autoexec file is executed on SAS startup
     const autoExec = path.join(sessionFolder, 'autoexec.sas')
     await createFile(autoExec, autoExecContent)
 
+    // a dummy SYSIN code.sas file is necessary to start SAS
     await createFile(path.join(sessionFolder, 'code.sas'), '')
 
     const creationTimeStamp = sessionId.split('-').pop() as string
@@ -65,17 +74,49 @@ export class SessionController {
         1000
       ).toString(),
       path: sessionFolder,
-      inUse: false
+      inUse: false,
+      completed: false
     }
 
+    // we do not want to leave sessions running forever 
+    // we clean them up after a predefined period, if unused
     this.scheduleSessionDestroy(session)
 
-    this.executionController
+    // create empty code.sas as SAS will not start without a SYSIN
-      .execute('', undefined, autoExec, session)
+    const codePath = path.join(session.path, 'code.sas')
-      .catch(() => {})
+    await createFile(codePath, '')
 
+
+    // this.executionController
+    //   .execute('', undefined, autoExec, session)
+    //   .catch((err) => {console.log(err)})
+    
+
+    // trigger SAS but don't wait for completion - we need to 
+    // update the session array to say that it is currently running
+    // however we also need a promise so that we can update the
+    // session array to say that it has (eventually) finished.
+    const sasLoc = process.sasLoc ?? configuration.sasPath
+    execFilePromise(sasLoc, [
+      '-SYSIN',
+      codePath,
+      '-LOG',
+      path.join(session.path, 'log.log'),
+      '-WORK',
+      session.path,
+      '-AUTOEXEC', 
+      path.join(session.path, 'autoexec.sas'),
+      process.platform === 'win32' ? '-nosplash' : ''
+    ]).then(() => {
+      session.completed=true
+      console.log('session completed', session)
+    }).catch((err) => {})
+
+    // we have a triggered session - add to array
     this.sessions.push(session)
 
+    // SAS has been triggered but we can't use it until 
+    // the autoexec deletes the code.sas file
     await this.waitForSession(session)
 
     return session
@@ -85,8 +126,6 @@ export class SessionController {
     if (await fileExists(path.join(session.path, 'code.sas'))) {
       while (await fileExists(path.join(session.path, 'code.sas'))) {}
 
-      await deleteFile(path.join(session.path, 'log.log'))
-
       session.ready = true
 
       return Promise.resolve(session)
@@ -98,8 +137,10 @@ export class SessionController {
   }
 
   public async deleteSession(session: Session) {
+    // remove the temporary files, to avoid buildup
     await deleteFolder(session.path)
 
+    // remove the session from the session array
     if (session.ready) {
       this.sessions = this.sessions.filter(
         (sess: Session) => sess.id !== session.id

api/src/types/Session.ts

@@ -5,4 +5,5 @@ export interface Session {
   deathTimeStamp: string
   path: string
   inUse: boolean
+  completed?: boolean
 }