From 72d707b0d0f36baadca8b5c3958e2c1080f1cdec Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?V=C3=ADt=20Str=C3=A1dal?= <vit.stradal@gooddata.com>
Date: Wed, 9 Oct 2024 12:16:02 +0200
Subject: [PATCH] reduce allocating big zeroes ndarray in mapflex - #501

---
 IO/FlexRaw/FlexRaw.pm | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/IO/FlexRaw/FlexRaw.pm b/IO/FlexRaw/FlexRaw.pm
index 4d9edf94d..169c9b49f 100644
--- a/IO/FlexRaw/FlexRaw.pm
+++ b/IO/FlexRaw/FlexRaw.pm
@@ -598,9 +598,7 @@ sub mapflex {
     } else {
       barf "Bad typename '$type' in mapflex" if !defined $flextypes{$type};
       $type = $flextypes{$type};
-      my $si = 1;
-      $si *= $_ for ref $hdr->{Dims} ? @{$hdr->{Dims}} : $hdr->{Dims};
-      $size += $si * PDL::Core::howbig ($type);
+      $size += _data_size_in_bytes($type, $hdr->{Dims});
     }
   }
   # $s now contains estimated size of data in header --
@@ -671,6 +669,13 @@ sub mapflex {
   wantarray ? @out : $out[0];
 }
 
+sub _data_size_in_bytes {
+  my ($type, $dims) = @_;
+  my $si = 1;
+  $si *= $_ for ref $dims ? @$dims : $dims;
+  $si * PDL::Core::howbig($type);
+}
+
 =head2 writeflex
 
 =for ref