From 3810f642d3b28feb62d9eac7d194fdcd3f6790bf Mon Sep 17 00:00:00 2001
From: Lovell Fuller <github@lovell.info>
Date: Tue, 14 Apr 2015 21:31:20 +0100
Subject: [PATCH] Add small cache before convolution for seq access

---
 src/resize.cc | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/resize.cc b/src/resize.cc
index e74d7051..e11b214d 100755
--- a/src/resize.cc
+++ b/src/resize.cc
@@ -459,6 +459,15 @@ class ResizeWorker : public NanAsyncWorker {
             return Error();
           }
           vips_object_local(hook, gaussian);
+          // Sequential input requires a small linecache before use of convolution
+          if (baton->accessMethod == VIPS_ACCESS_SEQUENTIAL) {
+            VipsImage *lineCached;
+            if (vips_linecache(image, &lineCached, "access", VIPS_ACCESS_SEQUENTIAL, "tile_height", 1, "threaded", TRUE, NULL)) {
+              return Error();
+            }
+            vips_object_local(hook, lineCached);
+            image = lineCached;
+          }
           // Apply Gaussian function
           VipsImage *blurred;
           if (vips_convsep(image, &blurred, gaussian, "precision", VIPS_PRECISION_INTEGER, NULL)) {