From 6ffa3c24b3b46d3ce789bae799b17d1a369dec3f Mon Sep 17 00:00:00 2001
From: TJ DeVries <devries.timothyj@gmail.com>
Date: Tue, 15 Sep 2020 14:15:55 -0400
Subject: [PATCH] feat: improve (?) performance of default sorter

---
 lua/telescope/sorters.lua                | 14 +++--
 lua/tests/manual/profile_for_sorters.lua | 71 ++++++++++++++++++++++++
 2 files changed, 79 insertions(+), 6 deletions(-)
 create mode 100644 lua/tests/manual/profile_for_sorters.lua

diff --git a/lua/telescope/sorters.lua b/lua/telescope/sorters.lua
index 9e17cf2..dd7cf4f 100644
--- a/lua/telescope/sorters.lua
+++ b/lua/telescope/sorters.lua
@@ -77,26 +77,28 @@ sorters.get_fuzzy_file = function(opts)
   opts = opts or {}
 
   local ngram_len = opts.ngram_len or 2
-  local os_sep = '/'
+  local os_sep = util.get_separator()
+  local match_string = '[^' .. os_sep .. ']*$'
 
   local cached_tails = setmetatable({}, {
     __index = function(t, k)
-      local tail_split = vim.split(k, os_sep)
-      local tail = tail_split[#tail_split]
+      local tail = string.match(k, match_string)
 
       rawset(t, k, tail)
       return tail
     end,
   })
 
+  -- TODO: Consider either a faster way of getting these
+  --        OR we really should just cache them longer
+  --        OR we need a different way of keeping track of uppercase letters.
   local cached_uppers = setmetatable({}, {
     __index = function(t, k)
       local obj = {}
       for i = 1, #k do
-        local s = k:sub(i, i)
-        local s_byte = s:byte()
+        local s_byte = k:byte(i, i)
         if s_byte <= 90 and s_byte >= 65 then
-          obj[s] = true
+          obj[s_byte] = true
         end
       end
 
diff --git a/lua/tests/manual/profile_for_sorters.lua b/lua/tests/manual/profile_for_sorters.lua
new file mode 100644
index 0000000..b5c7cd4
--- /dev/null
+++ b/lua/tests/manual/profile_for_sorters.lua
@@ -0,0 +1,71 @@
+-- TODO: Add a ladder test.
+--          1, 2, 4, 8, 16, 32 attempts
+
+RELOAD('plenary')
+-- RELOAD('telescope')
+
+local profiler = require('plenary.profile.lua_profiler')
+local Job = require('plenary.job')
+
+BIG_LIST = nil
+BIG_LIST = BIG_LIST or Job:new { command = 'fdfind', cwd = '~/build/' }:sync()
+print(#BIG_LIST)
+
+local do_profile = true
+local sorter_to_test = require('telescope.sorters').get_fuzzy_file()
+
+local strings_to_test = { "", "ev", "eval.c", "neovim/eval.c" }
+
+if do_profile then
+  profiler.start()
+end
+
+local first_results = setmetatable({}, {
+  __index = function(t, k)
+    local obj = {}
+    rawset(t, k, obj)
+    return obj
+  end
+})
+
+local second_results = {}
+
+local do_iterations = function(num)
+  local start
+  for _, prompt in ipairs(strings_to_test) do
+    start = vim.fn.reltime()
+
+    for _ = 1, num do
+      for _, v in ipairs(BIG_LIST) do
+        sorter_to_test:score(prompt, v)
+      end
+    end
+    -- print("First  Time: ", vim.fn.reltimestr(vim.fn.reltime(start)), num, prompt)
+    table.insert(first_results[prompt], vim.fn.reltimestr(vim.fn.reltime(start)))
+
+    start = vim.fn.reltime()
+    for _ = 1, num do
+      for _, v in ipairs(BIG_LIST) do
+        sorter_to_test:score(prompt, v)
+      end
+    end
+
+    -- print("Second Time: ", vim.fn.reltimestr(vim.fn.reltime(start)), num, prompt)
+    table.insert(second_results, vim.fn.reltimestr(vim.fn.reltime(start)))
+  end
+end
+
+do_iterations(1)
+-- do_iterations(2)
+-- do_iterations(4)
+-- do_iterations(8)
+-- do_iterations(16)
+-- do_iterations(32)
+
+print(vim.inspect(first_results))
+
+if do_profile then
+  profiler.stop()
+  profiler.report('/home/tj/tmp/profiler_score.txt')
+end
+