From 6f46b520452f3b1b1cc81aac10799f32bda767d2 Mon Sep 17 00:00:00 2001
From: Dorian Niemiec <dorian.niemiec@svrjs.org>
Date: Wed, 21 Feb 2024 22:47:07 +0100
Subject: [PATCH] Fix GreenRhombus cutting off the final part of response

---
 index.js | 39 ++++++++++++++++++++++++++++-----------
 1 file changed, 28 insertions(+), 11 deletions(-)

diff --git a/index.js b/index.js
index ffdd86a..b51bebc 100644
--- a/index.js
+++ b/index.js
@@ -250,31 +250,48 @@ function createFastCGIHandler(options) {
     }
   });
 
+  var stdoutPushEvent = new EventEmitter();
+
   function stdoutPush(data) {
-    var toResume = (stdoutBuffer.length == 0);
     if(data === null) {
       stdoutToEnd = true;
     } else {
       stdoutBuffer = Buffer.concat([stdoutBuffer, Buffer.from(data)]);
     }
-    if(toResume) emulatedStdout.resume();
+    stdoutPushEvent.emit("ready");
+    emulatedStdout.resume();
+  }
+
+  function stdoutRead(n, callback) {
+    if(stdoutBuffer.length == 0 && stdoutToEnd) {
+      callback(Buffer.alloc(0));
+    } else if(n != 0) {
+      var handler = function() {
+        if(n > stdoutBuffer.length && !stdoutToEnd) {
+          stdoutPushEvent.once("ready", handler);
+          fs.writeFileSync("/tmp/fai", "");
+        } else {
+          var bytesToPush = Math.min(stdoutBuffer.length, n);
+          var bufferToPush = stdoutBuffer.subarray(0, bytesToPush);
+          stdoutBuffer = stdoutBuffer.subarray(bytesToPush);
+          callback(bufferToPush);
+        }
+      };
+      handler();
+    }
   }
 
   var stdoutBuffer = Buffer.alloc(0);
   var stdoutToEnd = false;
   var emulatedStdout = new stream.Readable({
     read: function (n) {
-      if(stdoutBuffer.length == 0 && stdoutToEnd) {
-        this.push(null);
-      } else if (stdoutBuffer.length != 0 && n != 0) {
-        var bytesToPush = Math.min(stdoutBuffer.length, n);
-        var bufferToPush = stdoutBuffer.subarray(0, bytesToPush);
-        stdoutBuffer = stdoutBuffer.subarray(bytesToPush);
-        this.push(bufferToPush);
-      }
+      var s = this;
+      stdoutRead(n, function(buffer) {
+        s.push(buffer.length > 0 ? buffer : null);
+      });
     }
   });
-  emulatedStdout.pause();
+  emulatedStdout.pause(); //Reduce backpressure
 
   var emulatedStderr = new stream.Readable({
     read: function () {}