Merge pull request #379 from sasjs/issue-378

Issue 378

Author: YuryShkoda

.vscode/settings.json

@@ -1,5 +1,3 @@
 {
-  "cSpell.words": [
-    "autoexec"
-  ]
+  "cSpell.words": ["autoexec", "initialising"]
 }

api/public/swagger.yaml

@@ -113,8 +113,8 @@ components:
             properties:
                 sessionId:
                     type: string
-                    description: "The SessionId is the name of the temporary folder used to store the outputs.\nFor SAS, this would be the SASWORK folder. Can be used to poll job status.\nThis session ID should be used to poll job status."
-                    example: '{ sessionId: ''20241028074744-54132-1730101664824'' }'
+                    description: "`sessionId` is the ID of the session and the name of the temporary folder\nused to store code outputs.<br><br>\nFor SAS, this would be the location of the SASWORK folder.<br><br>\n`sessionId` can be used to poll session state using the\nGET /SASjsApi/session/{sessionId}/state endpoint."
+                    example: 20241028074744-54132-1730101664824
             required:
                 - sessionId
             type: object
@@ -585,6 +585,14 @@ components:
                 - needsToUpdatePassword
             type: object
             additionalProperties: false
+        SessionState:
+            enum:
+                - initialising
+                - pending
+                - running
+                - completed
+                - failed
+            type: string
         ExecutePostRequestPayload:
             properties:
                 _program:
@@ -597,8 +605,8 @@ components:
             properties:
                 sessionId:
                     type: string
-                    description: "The SessionId is the name of the temporary folder used to store the outputs.\nFor SAS, this would be the SASWORK folder. Can be used to poll program status.\nThis session ID should be used to poll program status."
-                    example: '{ sessionId: ''20241028074744-54132-1730101664824'' }'
+                    description: "`sessionId` is the ID of the session and the name of the temporary folder\nused to store program outputs.<br><br>\nFor SAS, this would be the location of the SASWORK folder.<br><br>\n`sessionId` can be used to poll session state using the\nGET /SASjsApi/session/{sessionId}/state endpoint."
+                    example: 20241028074744-54132-1730101664824
             required:
                 - sessionId
             type: object
@@ -1841,6 +1849,30 @@ paths:
                 -
                     bearerAuth: []
             parameters: []
+    '/SASjsApi/session/{sessionId}/state':
+        get:
+            operationId: SessionState
+            responses:
+                '200':
+                    description: Ok
+                    content:
+                        application/json:
+                            schema:
+                                $ref: '#/components/schemas/SessionState'
+            description: "The polling endpoint is currently implemented for single-server deployments only.<br>\nLoad balanced / grid topologies will be supported in a future release.<br>\nIf your site requires this, please reach out to SASjs Support."
+            summary: 'Get session state (initialising, pending, running, completed, failed).'
+            tags:
+                - Session
+            security:
+                -
+                    bearerAuth: []
+            parameters:
+                -
+                    in: path
+                    name: sessionId
+                    required: true
+                    schema:
+                        type: string
     /SASjsApi/stp/execute:
         get:
             operationId: ExecuteGetRequest

api/src/controllers/code.ts

@@ -42,10 +42,12 @@ interface TriggerCodePayload {
 
 interface TriggerCodeResponse {
   /**
-   * The SessionId is the name of the temporary folder used to store the outputs.
-   * For SAS, this would be the SASWORK folder. Can be used to poll job status.
-   * This session ID should be used to poll job status.
-   * @example "{ sessionId: '20241028074744-54132-1730101664824' }"
+   * `sessionId` is the ID of the session and the name of the temporary folder
+   * used to store code outputs.<br><br>
+   * For SAS, this would be the location of the SASWORK folder.<br><br>
+   * `sessionId` can be used to poll session state using the
+   * GET /SASjsApi/session/{sessionId}/state endpoint.
+   * @example "20241028074744-54132-1730101664824"
    */
   sessionId: string
 }

api/src/controllers/internal/Execution.ts

@@ -2,7 +2,7 @@ import path from 'path'
 import fs from 'fs'
 import { getSessionController, processProgram } from './'
 import { readFile, fileExists, createFile, readFileBinary } from '@sasjs/utils'
-import { PreProgramVars, Session, TreeNode } from '../../types'
+import { PreProgramVars, Session, TreeNode, SessionState } from '../../types'
 import {
   extractHeaders,
   getFilesFolder,
@@ -75,8 +75,7 @@ export class ExecutionController {
 
     const session =
       sessionByFileUpload ?? (await sessionController.getSession())
-    session.inUse = true
-    session.consumed = true
+    session.state = SessionState.running
 
     const logPath = path.join(session.path, 'log.log')
     const headersPath = path.join(session.path, 'stpsrv_header.txt')
@@ -121,7 +120,7 @@ export class ExecutionController {
       : ''
 
     // it should be deleted by scheduleSessionDestroy
-    session.inUse = false
+    session.state = SessionState.completed
 
     const resultParts = []
 
@@ -145,7 +144,9 @@ export class ExecutionController {
     return {
       httpHeaders,
       result:
-        isDebugOn(vars) || session.crashed ? resultParts.join(`\n`) : webout
+        isDebugOn(vars) || session.failureReason
+          ? resultParts.join(`\n`)
+          : webout
     }
   }
 

api/src/controllers/internal/FileUploadController.ts

@@ -2,11 +2,8 @@ import { Request, RequestHandler } from 'express'
 import multer from 'multer'
 import { uuidv4 } from '@sasjs/utils'
 import { getSessionController } from '.'
-import {
-  executeProgramRawValidation,
-  getRunTimeAndFilePath,
-  RunTimeType
-} from '../../utils'
+import { executeProgramRawValidation, getRunTimeAndFilePath } from '../../utils'
+import { SessionState } from '../../types'
 
 export class FileUploadController {
   private storage = multer.diskStorage({
@@ -56,9 +53,8 @@ export class FileUploadController {
     }
 
     const session = await sessionController.getSession()
-    // marking consumed true, so that it's not available
-    // as readySession for any other request
-    session.consumed = true
+    // change session state to 'running', so that it's not available for any other request
+    session.state = SessionState.running
 
     req.sasjsSession = session
 

api/src/controllers/internal/Session.ts

@@ -1,5 +1,5 @@
 import path from 'path'
-import { Session } from '../../types'
+import { Session, SessionState } from '../../types'
 import { promisify } from 'util'
 import { execFile } from 'child_process'
 import {
@@ -23,7 +23,9 @@ export class SessionController {
   protected sessions: Session[] = []
 
   protected getReadySessions = (): Session[] =>
-    this.sessions.filter((sess: Session) => sess.ready && !sess.consumed)
+    this.sessions.filter(
+      (session: Session) => session.state === SessionState.pending
+    )
 
   protected async createSession(): Promise<Session> {
     const sessionId = generateUniqueFileName(generateTimestamp())
@@ -39,19 +41,18 @@ export class SessionController {
 
     const session: Session = {
       id: sessionId,
-      ready: true,
-      inUse: true,
-      consumed: false,
-      completed: false,
+      state: SessionState.pending,
       creationTimeStamp,
       deathTimeStamp,
       path: sessionFolder
     }
 
     const headersPath = path.join(session.path, 'stpsrv_header.txt')
+
     await createFile(headersPath, 'content-type: text/html; charset=utf-8')
 
     this.sessions.push(session)
+
     return session
   }
 
@@ -66,6 +67,10 @@ export class SessionController {
 
     return session
   }
+
+  public getSessionById(id: string) {
+    return this.sessions.find((session) => session.id === id)
+  }
 }
 
 export class SASSessionController extends SessionController {
@@ -83,10 +88,7 @@ export class SASSessionController extends SessionController {
 
     const session: Session = {
       id: sessionId,
-      ready: false,
-      inUse: false,
-      consumed: false,
-      completed: false,
+      state: SessionState.initialising,
       creationTimeStamp,
       deathTimeStamp,
       path: sessionFolder
@@ -144,13 +146,20 @@ ${autoExecContent}`
       process.sasLoc!.endsWith('sas.exe') ? session.path : ''
     ])
       .then(() => {
-        session.completed = true
+        session.state = SessionState.completed
+
         process.logger.info('session completed', session)
       })
       .catch((err) => {
-        session.completed = true
-        session.crashed = err.toString()
-        process.logger.error('session crashed', session.id, session.crashed)
+        session.state = SessionState.failed
+
+        session.failureReason = err.toString()
+
+        process.logger.error(
+          'session crashed',
+          session.id,
+          session.failureReason
+        )
       })
 
     // we have a triggered session - add to array
@@ -167,15 +176,19 @@ ${autoExecContent}`
     const codeFilePath = path.join(session.path, 'code.sas')
 
     // TODO: don't wait forever
-    while ((await fileExists(codeFilePath)) && !session.crashed) {}
+    while (
+      (await fileExists(codeFilePath)) &&
+      session.state !== SessionState.failed
+    ) {}
 
-    if (session.crashed)
+    if (session.state === SessionState.failed) {
       process.logger.error(
         'session crashed! while waiting to be ready',
-        session.crashed
+        session.failureReason
       )
-
-    session.ready = true
+    } else {
+      session.state = SessionState.pending
+    }
   }
 
   private async deleteSession(session: Session) {
@@ -191,7 +204,7 @@ ${autoExecContent}`
   private scheduleSessionDestroy(session: Session) {
     setTimeout(
       async () => {
-        if (session.inUse) {
+        if (session.state === SessionState.running) {
           // adding 10 more minutes
           const newDeathTimeStamp =
             parseInt(session.deathTimeStamp) + 10 * 60 * 1000
@@ -202,7 +215,7 @@ ${autoExecContent}`
           const { expiresAfterMins } = session
 
           // delay session destroy if expiresAfterMins present
-          if (expiresAfterMins && !expiresAfterMins.used) {
+          if (expiresAfterMins && session.state !== SessionState.completed) {
             // calculate session death time using expiresAfterMins
             const newDeathTimeStamp =
               parseInt(session.deathTimeStamp) +

api/src/controllers/internal/processProgram.ts

@@ -3,7 +3,7 @@ import { WriteStream, createWriteStream } from 'fs'
 import { execFile } from 'child_process'
 import { once } from 'stream'
 import { createFile, moveFile } from '@sasjs/utils'
-import { PreProgramVars, Session } from '../../types'
+import { PreProgramVars, Session, SessionState } from '../../types'
 import { RunTimeType } from '../../utils'
 import {
   ExecutionVars,
@@ -49,7 +49,7 @@ export const processProgram = async (
     await moveFile(codePath + '.bkp', codePath)
 
     // we now need to poll the session status
-    while (!session.completed) {
+    while (session.state !== SessionState.completed) {
       await delay(50)
     }
   } else {
@@ -114,13 +114,20 @@ export const processProgram = async (
 
     await execFilePromise(executablePath, [codePath], writeStream)
       .then(() => {
-        session.completed = true
+        session.state = SessionState.completed
+
         process.logger.info('session completed', session)
       })
       .catch((err) => {
-        session.completed = true
-        session.crashed = err.toString()
-        process.logger.error('session crashed', session.id, session.crashed)
+        session.state = SessionState.failed
+
+        session.failureReason = err.toString()
+
+        process.logger.error(
+          'session crashed',
+          session.id,
+          session.failureReason
+        )
       })
 
     // copy the code file to log and end write stream

api/src/controllers/session.ts

@@ -1,6 +1,8 @@
 import express from 'express'
 import { Request, Security, Route, Tags, Example, Get } from 'tsoa'
 import { UserResponse } from './user'
+import { getSessionController } from './internal'
+import { SessionState } from '../types'
 
 interface SessionResponse extends UserResponse {
   needsToUpdatePassword: boolean
@@ -26,6 +28,18 @@ export class SessionController {
   ): Promise<SessionResponse> {
     return session(request)
   }
+
+  /**
+   * The polling endpoint is currently implemented for single-server deployments only.<br>
+   * Load balanced / grid topologies will be supported in a future release.<br>
+   * If your site requires this, please reach out to SASjs Support.
+   * @summary Get session state (initialising, pending, running, completed, failed).
+   * @example completed
+   */
+  @Get('/:sessionId/state')
+  public async sessionState(sessionId: string): Promise<SessionState> {
+    return sessionState(sessionId)
+  }
 }
 
 const session = (req: express.Request) => ({
@@ -35,3 +49,23 @@ const session = (req: express.Request) => ({
   isAdmin: req.user!.isAdmin,
   needsToUpdatePassword: req.user!.needsToUpdatePassword
 })
+
+const sessionState = (sessionId: string): SessionState => {
+  for (let runTime of process.runTimes) {
+    // get session controller for each available runTime
+    const sessionController = getSessionController(runTime)
+
+    // get session by sessionId
+    const session = sessionController.getSessionById(sessionId)
+
+    // return session state if session was found
+    if (session) {
+      return session.state
+    }
+  }
+
+  throw {
+    code: 404,
+    message: `Session with ID '${sessionId}' was not found.`
+  }
+}