From 9adf5a2cb0f5f3715b1fba354d91d291cac8a0dc Mon Sep 17 00:00:00 2001
From: delphinus <me@delphinus.dev>
Date: Wed, 26 Jul 2023 18:40:28 +0900
Subject: [PATCH] feat: use dynamic finder not to block Neovim

In searching workspace
---
 lua/frecency/finder.lua  | 72 ++++++++++++++++++++++++++++++++++++++++
 lua/frecency/pickers.lua | 22 ++++++++----
 2 files changed, 88 insertions(+), 6 deletions(-)
 create mode 100644 lua/frecency/finder.lua

diff --git a/lua/frecency/finder.lua b/lua/frecency/finder.lua
new file mode 100644
index 00000000..7feb5425
--- /dev/null
+++ b/lua/frecency/finder.lua
@@ -0,0 +1,72 @@
+local finders = require "telescope.finders"
+local log = require "frecency.log"
+
+---@class FrecencyFinder
+---@field config FrecencyFinderConfig
+local Finder = {}
+
+---@class FrecencyFinderConfig
+---@field fs FrecencyFS
+---@field entry_maker FrecencyEntryMaker
+---@field initial_results table[]
+
+---@param config FrecencyFinderConfig
+---@return FrecencyFinder
+Finder.new = function(config)
+  return setmetatable({ config = config }, { __index = Finder })
+end
+
+---@class FrecencyFinderOptions
+---@field need_scandir boolean
+---@field workspace string?
+
+---@param opts FrecencyFinderOptions
+---@return table
+function Finder:start(opts)
+  local entry_maker = self.config.entry_maker:create(opts.workspace)
+  if not opts.need_scandir then
+    return finders.new_table {
+      results = self.config.initial_results,
+      entry_maker = entry_maker,
+    }
+  end
+  log:debug("%s", { finder = opts })
+  return finders.new_dynamic { entry_maker = entry_maker, fn = self:create_fn { path = opts.workspace } }
+end
+
+---@class FrecencyFinderCreateFnOptions
+---@field path string
+
+---@param opts FrecencyFinderCreateFnOptions
+---@return fun(prompt: string?): table[]
+function Finder:create_fn(opts)
+  local it = self.config.fs:scan_dir(opts.path)
+  local is_dead = false
+  local results = vim.deepcopy(self.config.initial_results)
+  local called = 0
+  ---@param prompt string?
+  ---@return table[]
+  return function(prompt)
+    if is_dead then
+      return results
+    end
+    called = called + 1
+    log:debug("called: %d", called)
+    local count = 0
+    while true do
+      local ok, name = pcall(it)
+      if not ok then
+        is_dead = true
+        break
+      end
+      table.insert(results, { path = vim.fs.joinpath(opts.path, name), score = 0 })
+      count = count + 1
+      if count >= 1000 then
+        break
+      end
+    end
+    return results
+  end
+end
+
+return Finder
diff --git a/lua/frecency/pickers.lua b/lua/frecency/pickers.lua
index 1a014f1b..273bec67 100644
--- a/lua/frecency/pickers.lua
+++ b/lua/frecency/pickers.lua
@@ -1,4 +1,5 @@
 local EntryMaker = require "frecency.picker.entry_maker"
+local Finder = require "frecency.finder"
 local log = require "frecency.log"
 local actions = require "telescope.actions"
 local config_values = require("telescope.config").values
@@ -91,12 +92,16 @@ function Picker:start(opts)
     self.results = self:fetch_results(self.workspace)
   end
 
+  local finder = Finder.new({ fs = self.config.fs, entry_maker = self.entry_maker, initial_results = self.results })
+    :start { need_scandir = self.workspace and self.config.show_unindexed and true or false, workspace = self.workspace }
+
   local picker = pickers.new(opts, {
     prompt_title = "Frecency",
-    finder = finders.new_table {
+    --[[ finder = finders.new_table {
       results = self.results,
       entry_maker = self.entry_maker:create(self.workspace),
-    },
+    }, ]]
+    finder = finder,
     previewer = config_values.file_previewer(opts),
     sorter = sorters.get_substr_matcher(),
     on_input_filter_cb = function(prompt)
@@ -203,11 +208,11 @@ function Picker:fetch_results(workspace)
     file.score = self.recency:calculate(file.count, ages)
   end
 
-  if workspace and self.config.show_unindexed then
+  --[[ if workspace and self.config.show_unindexed then
     for name in self.config.fs:scan_dir(workspace) do
       table.insert(files, { path = vim.fs.joinpath(workspace, name), score = 0 })
     end
-  end
+  end ]]
 
   table.sort(files, function(a, b)
     return a.score > b.score
@@ -235,10 +240,15 @@ function Picker:on_input_filter_cb(prompt, cwd)
   log:debug("%s", { workspace = workspace, ["self.workspace"] = self.workspace })
   if self.workspace ~= workspace then
     self.workspace = workspace
-    opts.updated_finder = finders.new_table {
+    --[[ opts.updated_finder = finders.new_table {
       results = self:fetch_results(workspace),
       entry_maker = self.entry_maker:create(workspace),
-    }
+    } ]]
+    opts.updated_finder =
+      Finder.new({ fs = self.config.fs, entry_maker = self.entry_maker, initial_results = self.results }):start {
+        need_scandir = self.workspace and self.config.show_unindexed and true or false,
+        workspace = self.workspace,
+      }
   end
   return opts
 end