From 9c5a1b12ef3223b95281ed6b92c019ce7f7a4302 Mon Sep 17 00:00:00 2001
From: Ryan Yin <xiaoyin_c@qq.com>
Date: Sat, 12 Aug 2023 22:35:06 +0800
Subject: [PATCH] feat: neovim - fix performance issue of telescope preview

---
 .../desktop/neovim/astronvim_user/init.lua    | 46 +++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/home/base/desktop/neovim/astronvim_user/init.lua b/home/base/desktop/neovim/astronvim_user/init.lua
index 1f163b7b..e8090150 100644
--- a/home/base/desktop/neovim/astronvim_user/init.lua
+++ b/home/base/desktop/neovim/astronvim_user/init.lua
@@ -271,6 +271,52 @@ return {
             })
         end
     },
+
+    {
+      'nvim-telescope/telescope.nvim', branch = '0.1.x',
+      dependencies = { 'nvim-lua/plenary.nvim' },
+      init = function()
+        -- 1. Disable highlighting for certain filetypes
+        -- 2. Ignore files larger than a certain filesize
+        local previewers = require("telescope.previewers")
+
+        local _bad = { ".*%.csv", ".*%.min.js" } -- Put all filetypes that slow you down in this array
+        local filesize_threshold = 300 * 1024 -- 300KB
+        local bad_files = function(filepath)
+          for _, v in ipairs(_bad) do
+            if filepath:match(v) then
+              return false
+            end
+          end
+          return true
+        end
+
+        local new_maker = function(filepath, bufnr, opts)
+          opts = opts or {}
+          if opts.use_ft_detect == nil then opts.use_ft_detect = true end
+
+          -- 1. Check if the file is in the bad_files array, and if so, don't highlight it
+          opts.use_ft_detect = opts.use_ft_detect == false and false or bad_files(filepath)
+
+          -- 2. Check the file size, and ignore it if it's too big(preview nothing).
+          filepath = vim.fn.expand(filepath)
+          vim.loop.fs_stat(filepath, function(_, stat)
+            if not stat then return end
+            if stat.size > filesize_threshold then
+              return
+            else
+              previewers.buffer_previewer_maker(filepath, bufnr, opts)
+            end
+          end)
+        end
+
+        require("telescope").setup {
+          defaults = {
+            buffer_previewer_maker = new_maker,
+          }
+        }
+      end,
+    }
   },
 
   -- Configure require("lazy").setup() options