From d4d03e620e9a6c04adda4c65450fa55a76aa2c45 Mon Sep 17 00:00:00 2001
From: vdiez <diez@outlook.com>
Date: Tue, 2 Mar 2021 10:41:08 +0100
Subject: [PATCH] implement stream backpressure

---
 lib/api/createReadStream.js | 41 +++++++++++++++++++++++--------------
 1 file changed, 26 insertions(+), 15 deletions(-)

diff --git a/lib/api/createReadStream.js b/lib/api/createReadStream.js
index 1fb46ac..fb010fe 100644
--- a/lib/api/createReadStream.js
+++ b/lib/api/createReadStream.js
@@ -45,21 +45,10 @@ module.exports = function createReadStream(path, options, cb) {
         });
       };
     }
-    var running = false;
-    stream._read = function(size) {
-      if (running) {
-        return;
-      }
 
-      if (offset >= end) {
-        return shouldClose
-          ? close(function() {
-              stream.push(null);
-            })
-          : stream.push(null);
-      }
+    var running = false;
 
-      running = true;
+    function read(size) {
       request(
         'read',
         {
@@ -69,15 +58,37 @@ module.exports = function createReadStream(path, options, cb) {
         },
         connection,
         function(err, content) {
-          running = false;
           if (err != null) {
             return process.nextTick(stream.emit.bind(stream, 'error', err));
           }
 
           offset += content.length;
-          stream.push(content);
+          if (stream.push(content)) {
+            if (end - offset === 0) {
+              running = false;
+              stream.push(null);
+            } else read(size);
+          } else {
+            running = false;
+          }
         }
       );
+    }
+    stream._read = function(size) {
+      if (running) {
+        return;
+      }
+
+      if (offset >= end) {
+        return shouldClose
+          ? close(function() {
+              stream.push(null);
+            })
+          : stream.push(null);
+      } else {
+        running = true;
+        read(size);
+      }
     };
     cb(null, stream);
   }