Bugfix #136 - _writev can sometimes be called with too many chunks

Author: jeromew

README.md

@@ -132,6 +132,10 @@ Since this isn't a module with tons of installs and dependent modules I hope we
 
 ## changelog
 
+### version 6.0.3 - published 2022-09-05
+
+- copy-from: fix issue #136 when the _writev mechanism was triggered with a very large number of chunks
+
 ### version 6.0.2 - published 2021-09-13
 
 - copy-from : fix interaction with `pg` optional timeout mechanism

copy-from.js

@@ -40,7 +40,13 @@ class CopyStreamQuery extends Writable {
   }
 
   _writev(chunks, cb) {
-    this.chunks.push(...chunks)
+    // this.chunks.push(...chunks)
+    // => issue #136, RangeError: Maximum call stack size exceeded
+    // Using hybrid approach as advised on https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/apply
+    const QUANTUM = 32768
+    for (let i = 0; i < chunks.length; i += QUANTUM) {
+      this.chunks.push(...chunks.slice(i, Math.min(i + QUANTUM, chunks.length)))
+    }
     if (this._gotCopyInResponse) {
       return this.flush(cb)
     }

test/copy-from.js

@@ -103,7 +103,7 @@ describe('copy-from', () => {
   })
 
   it('correctly handle more heavy scenario', (done) => {
-    const top = 10000
+    const top = 130000
     const chunks = []
     const expected = []
     for (let i = 0; i < top; i++) {
@@ -116,7 +116,7 @@ describe('copy-from', () => {
       assert.equal(stream.rowCount, top, 'should have rowCount ' + top + ' ')
       done()
     })
-  })
+  }).timeout(120000)
 
   it('test client reuse', (done) => {
     const fromClient = getClient()