fix(server/database streams): remove event listener on batch completion (#3938)

packages/preview-service/src/server/routes/api.ts

@@ -36,12 +36,18 @@ const apiRouterFactory = () => {
         streamId: req.params.streamId,
         objectIds: getObjectsRequestBody.objects
       })
+
       // https://knexjs.org/faq/recipes.html#manually-closing-streams
       // https://github.com/knex/knex/issues/2324
-      res.on('close', () => {
+      const responseCloseHandler = () => {
         dbStream.end()
         dbStream.destroy()
+      }
+
+      dbStream.on('close', () => {
+        res.removeListener('close', responseCloseHandler)
       })
+      res.on('close', responseCloseHandler)
 
       const speckleObjStream = new SpeckleObjectsStream(isSimpleTextRequested(req))
 

packages/preview-service/src/server/routes/objects.ts

@@ -41,12 +41,18 @@ const objectsRouterFactory = () => {
         streamId: req.params.streamId,
         objectId: req.params.objectId
       })
+
       // https://knexjs.org/faq/recipes.html#manually-closing-streams
       // https://github.com/knex/knex/issues/2324
-      res.on('close', () => {
+      const responseCloseHandler = () => {
         dbStream.end()
         dbStream.destroy()
+      }
+
+      dbStream.on('close', () => {
+        res.removeListener('close', responseCloseHandler)
       })
+      res.on('close', responseCloseHandler)
 
       const speckleObjStream = new SpeckleObjectsStream(isSimpleTextRequested(req))
       const gzipStream = zlib.createGzip()

packages/server/modules/core/rest/diffDownload.ts

@@ -94,12 +94,18 @@ export default (app: Application) => {
           streamId: req.params.streamId,
           objectIds: childrenChunk
         })
+
         // https://knexjs.org/faq/recipes.html#manually-closing-streams
         // https://github.com/knex/knex/issues/2324
-        res.on('close', () => {
+        const responseCloseHandler = () => {
           dbStream.end()
           dbStream.destroy()
+        }
+
+        dbStream.on('close', () => {
+          res.removeListener('close', responseCloseHandler)
         })
+        res.on('close', responseCloseHandler)
 
         await new Promise((resolve, reject) => {
           dbStream.once('end', resolve)

packages/server/modules/core/rest/download.ts

@@ -63,12 +63,19 @@ export default (app: express.Express) => {
       streamId: req.params.streamId,
       objectId: req.params.objectId
     })
+
     // https://knexjs.org/faq/recipes.html#manually-closing-streams
     // https://github.com/knex/knex/issues/2324
-    res.on('close', () => {
+    const responseCloseHandler = () => {
       dbStream.end()
       dbStream.destroy()
+    }
+
+    dbStream.on('close', () => {
+      res.removeListener('close', responseCloseHandler)
     })
+    res.on('close', responseCloseHandler)
+
     const speckleObjStream = new SpeckleObjectsStream(simpleText)
     const gzipStream = zlib.createGzip()