vim-patch:8.1.1439: ga_grow(): 1.5x growth rate #10699

Problem:    Json_encode() is very slow for large results.
Solution:   In the growarray use a growth of at least 50%. (Ken Takata,
            closes vim/vim#4461)
https://github.com/vim/vim/commit/c47ed44be76a520ded90913099771999c8a79eeb

1 files changed, 8 insertions, 0 deletions

diff --git a/src/nvim/garray.c b/src/nvim/garray.c
index 74fd9d89cb..1cfc2b6176 100644
--- a/src/nvim/garray.c
+++ b/src/nvim/garray.c
@@ -89,6 +89,14 @@ void ga_grow(garray_T *gap, int n)
   if (n < gap->ga_growsize) {
     n = gap->ga_growsize;
   }
+
+  // A linear growth is very inefficient when the array grows big.  This
+  // is a compromise between allocating memory that won't be used and too
+  // many copy operations. A factor of 1.5 seems reasonable.
+  if (n < gap->ga_len / 2) {
+    n = gap->ga_len / 2;
+  }
+
   int new_maxlen = gap->ga_len + n;
 
   size_t new_size = (size_t)gap->ga_itemsize * (size_t)new_maxlen;