From 3436648add766bea162e46b3f160402701f973f1 Mon Sep 17 00:00:00 2001
From: Thomas Hobson <git@hexf.me>
Date: Sat, 17 Jul 2021 00:22:55 +1200
Subject: [PATCH] api: signaling process via ws

---
 api/src/api/v2.js | 48 +++++++++++++++++++++++++++++++----------------
 api/src/job.js    | 16 ++++++++++++----
 2 files changed, 44 insertions(+), 20 deletions(-)

diff --git a/api/src/api/v2.js b/api/src/api/v2.js
index 487b10b..76bab08 100644
--- a/api/src/api/v2.js
+++ b/api/src/api/v2.js
@@ -9,6 +9,8 @@ const { Job } = require('../job');
 const package = require('../package');
 const logger = require('logplease').create('api/v2');
 
+const SIGNALS = ["SIGABRT","SIGALRM","SIGBUS","SIGCHLD","SIGCLD","SIGCONT","SIGEMT","SIGFPE","SIGHUP","SIGILL","SIGINFO","SIGINT","SIGIO","SIGIOT","SIGKILL","SIGLOST","SIGPIPE","SIGPOLL","SIGPROF","SIGPWR","SIGQUIT","SIGSEGV","SIGSTKFLT","SIGSTOP","SIGTSTP","SIGSYS","SIGTERM","SIGTRAP","SIGTTIN","SIGTTOU","SIGUNUSED","SIGURG","SIGUSR1","SIGUSR2","SIGVTALRM","SIGXCPU","SIGXFSZ","SIGWINCH"]
+// ref: https://man7.org/linux/man-pages/man7/signal.7.html
 
 function get_job(body){
     const {
@@ -148,27 +150,28 @@ router.ws('/connect', async (ws, req) => {
         try{
             const msg = JSON.parse(data);
 
-            if(msg.type === "init"){
-                if(job === null){
-                    const job = await get_job(msg);
+            switch(msg.type){
+                case "init":
+                    if(job === null){
+                        job = await get_job(msg);
 
-                    await job.prime();
+                        await job.prime();
 
-                    ws.send(JSON.stringify({
-                        type: "runtime",
-                        language: job.runtime.language,
-                        version: job.runtime.version.raw
-                    }))
+                        ws.send(JSON.stringify({
+                            type: "runtime",
+                            language: job.runtime.language,
+                            version: job.runtime.version.raw
+                        }))
 
-                    await job.execute_interactive(eventBus);
+                        await job.execute_interactive(eventBus);
 
-                    ws.close(4999, "Job Completed");
+                        ws.close(4999, "Job Completed");
 
-                }else{
-                    ws.close(4000, "Already Initialized");
-                }
-
-            }else if(msg.type === "data"){
+                    }else{
+                        ws.close(4000, "Already Initialized");
+                    }
+                    break;
+            case "data":
                 if(job !== null){
                     if(msg.stream === "stdin"){
                         eventBus.emit("stdin", msg.data)
@@ -178,7 +181,20 @@ router.ws('/connect', async (ws, req) => {
                 }else{
                     ws.close(4003, "Not yet initialized")
                 }
+                break;
+            case "signal":
+                if(job !== null){
+                    if(SIGNALS.includes(msg.signal)){
+                        eventBus.emit("signal", msg.signal)
+                    }else{
+                        ws.close(4005, "Invalid signal")
+                    }
+                }else{
+                    ws.close(4003, "Not yet initialized")
+                }
+                break;
             }
+            
         }catch(error){
             ws.send(JSON.stringify({type: "error", message: error.message}))
             ws.close(4002, "Notified Error")
diff --git a/api/src/job.js b/api/src/job.js
index 8001a76..d213bbc 100644
--- a/api/src/job.js
+++ b/api/src/job.js
@@ -110,7 +110,13 @@ class Job {
                 eventBus.on("stdin", (data) => {
                     proc.stdin.write(data);
                 })
+
+                eventBus.on("kill", (signal) => {
+                    proc.kill(signal)
+                })
             }
+            
+            
 
             const kill_timeout = set_timeout(
                 _ => proc.kill('SIGKILL'),
@@ -118,20 +124,22 @@ class Job {
             );
 
             proc.stderr.on('data', data => {
-                if (stderr.length > config.output_max_size) {
+                if(eventBus !== null) {
+                    eventBus.emit("stderr", data);
+                } else if (stderr.length > config.output_max_size) {
                     proc.kill('SIGKILL');
                 } else {
-                    if(eventBus !== null) eventBus.emit("stderr", data);
                     stderr += data;
                     output += data;
                 }
             });
 
             proc.stdout.on('data', data => {
-                if (stdout.length > config.output_max_size) {
+                if(eventBus !== null){
+                    eventBus.emit("stdout", data);
+                } else if (stdout.length > config.output_max_size) {
                     proc.kill('SIGKILL');
                 } else {
-                    if(eventBus !== null) eventBus.emit("stdout", data);
                     stdout += data;
                     output += data;
                 }