fix: Reduce memory leaks (#148)

It is not 100% clear that we've gotten ALL the memory leaks, but it
seems much much much better and doesn't look like it's going to die
immediately or as often anymore :)

8 files changed, 235 insertions, 88 deletions

diff --git a/lua/telescope/_compat.lua b/lua/telescope/_compat.lua
new file mode 100644
index 0000000..3d280ef
--- /dev/null
+++ b/lua/telescope/_compat.lua
@@ -0,0 +1,71 @@
+
+vim.deepcopy = (function()
+  local function _id(v)
+    return v
+  end
+
+  local deepcopy_funcs = {
+    table = function(orig)
+      local copy = {}
+
+      if vim._empty_dict_mt ~= nil and getmetatable(orig) == vim._empty_dict_mt then
+        copy = vim.empty_dict()
+      end
+
+      for k, v in pairs(orig) do
+        copy[vim.deepcopy(k)] = vim.deepcopy(v)
+      end
+
+      if getmetatable(orig) then
+        setmetatable(copy, getmetatable(orig))
+      end
+
+      return copy
+    end,
+    ['function'] = _id or function(orig)
+      local ok, dumped = pcall(string.dump, orig)
+      if not ok then
+        error(debug.traceback(dumped))
+      end
+
+      local cloned = loadstring(dumped)
+      local i = 1
+      while true do
+        local name = debug.getupvalue(orig, i)
+        if not name then
+          break
+        end
+        debug.upvaluejoin(cloned, i, orig, i)
+        i = i + 1
+      end
+      return cloned
+    end,
+    number = _id,
+    string = _id,
+    ['nil'] = _id,
+    boolean = _id,
+  }
+
+  return function(orig)
+    local f = deepcopy_funcs[type(orig)]
+    if f then
+      return f(orig)
+    else
+      error("Cannot deepcopy object of type "..type(orig))
+    end
+  end
+end)()
+
+
+
+table.clear = table.clear or function(t)
+  for k in pairs (t) do
+      t[k] = nil
+  end
+end
+
+table.pop = table.pop or function(t, k)
+  local val = t[k]
+  t[k] = nil
+  return val
+end
diff --git a/lua/telescope/entry_manager.lua b/lua/telescope/entry_manager.lua
index bca4e55..532cca2 100644
--- a/lua/telescope/entry_manager.lua
+++ b/lua/telescope/entry_manager.lua
@@ -71,7 +71,7 @@ function EntryManager:should_save_result(index)
   return index <= self.max_results
 end
 
-function EntryManager:add_entry(score, entry)
+function EntryManager:add_entry(picker, score, entry)
   score = score or 0
 
   if score >= self.worst_acceptable_score then
@@ -82,7 +82,7 @@ function EntryManager:add_entry(score, entry)
     self.info.looped = self.info.looped + 1
 
     if item.score > score then
-      return self:insert(index, {
+      return self:insert(picker, index, {
         score = score,
         entry = entry,
       })
@@ -94,13 +94,13 @@ function EntryManager:add_entry(score, entry)
     end
   end
 
-  return self:insert({
+  return self:insert(picker, {
     score = score,
     entry = entry,
   })
 end
 
-function EntryManager:insert(index, entry)
+function EntryManager:insert(picker, index, entry)
   if entry == nil then
     entry = index
     index = #self.entry_state + 1
@@ -113,7 +113,7 @@ function EntryManager:insert(index, entry)
     self.info.inserted = self.info.inserted + 1 
     next_entry = self.entry_state[index]
 
-    self.set_entry(index, entry.entry)
+    self.set_entry(picker, index, entry.entry)
     self.entry_state[index] = entry
 
     last_score = entry.score
diff --git a/lua/telescope/init.lua b/lua/telescope/init.lua
index d6f0192..52705f2 100644
--- a/lua/telescope/init.lua
+++ b/lua/telescope/init.lua
@@ -1,3 +1,5 @@
+require('telescope._compat')
+
 local telescope = {}
 
 --[[
diff --git a/lua/telescope/make_entry.lua b/lua/telescope/make_entry.lua
index 8c598cd..bca2aa1 100644
--- a/lua/telescope/make_entry.lua
+++ b/lua/telescope/make_entry.lua
@@ -14,8 +14,8 @@ make_entry.types = {
 
 local transform_devicons
 if has_devicons then
-  transform_devicons = function(filename, display, opts)
-    if opts.disable_devicons or not filename then
+  transform_devicons = function(filename, display, disable_devicons)
+    if disable_devicons or not filename then
       return display
     end
 
@@ -43,17 +43,20 @@ function make_entry.gen_from_string()
 end
 
 function make_entry.gen_from_file(opts)
+  -- local opts = vim.deepcopy(init_opts or {})
   opts = opts or {}
 
   local cwd = vim.fn.expand(opts.cwd or vim.fn.getcwd())
+  local disable_devicons = opts.disable_devicons
+  local shorten_path = opts.shorten_path
 
   local make_display = function(line)
     local display = line
-    if opts.shorten_path then
+    if shorten_path then
       display = utils.path_shorten(line)
     end
 
-    display = transform_devicons(line, display, opts)
+    display = transform_devicons(line, display, disable_devicons)
 
     return display
   end
diff --git a/lua/telescope/pickers.lua b/lua/telescope/pickers.lua
index aa18db6..d05bd42 100644
--- a/lua/telescope/pickers.lua
+++ b/lua/telescope/pickers.lua
@@ -1,6 +1,8 @@
 local a = vim.api
 local popup = require('popup')
 
+require('telescope')
+
 local actions = require('telescope.actions')
 local config = require('telescope.config')
 local debounce = require('telescope.debounce')
@@ -17,9 +19,16 @@ local get_default = utils.get_default
 
 -- TODO: Make this work with deep extend I think.
 local extend = function(opts, defaults)
-  local result = opts or {}
+  local result = {}
+
+  for k, v in pairs(opts or {}) do
+    assert(type(k) == 'string', "Should be string, opts")
+    result[k] = v
+  end
+
   for k, v in pairs(defaults or {}) do
     if result[k] == nil then
+      assert(type(k) == 'string', "Should be string, defaults")
       result[k] = v
     end
   end
@@ -33,12 +42,6 @@ local ns_telescope_prompt = a.nvim_create_namespace('telescope_prompt')
 
 local pickers = {}
 
--- Picker takes a function (`get_window_options`) that returns the configurations required for three windows:
---  prompt
---  results
---  preview
-
-
 -- TODO: Add overscroll option for results buffer
 
 --- Picker is the main UI that shows up to interact w/ your results.
@@ -105,7 +108,7 @@ function Picker:new(opts)
     },
 
     preview_cutoff = get_default(opts.preview_cutoff, config.values.preview_cutoff),
-  }, Picker)
+  }, self)
 end
 
 function Picker:_get_initial_window_options(prompt_title)
@@ -205,11 +208,11 @@ function Picker:clear_extra_rows(results_bufnr)
     pcall(vim.api.nvim_buf_set_lines, results_bufnr, 0, worst_line, false, empty_lines)
   end
 
-  log.debug("Clearing:", worst_line)
+  log.trace("Clearing:", worst_line)
 end
 
 function Picker:highlight_displayed_rows(results_bufnr, prompt)
-  if not self.sorter.highlighter then
+  if not self.sorter or not self.sorter.highlighter then
     return
   end
 
@@ -268,8 +271,8 @@ function Picker:find()
   self:reset_selection()
 
   local prompt_string = assert(self.prompt, "Prompt is required.")
-  local finder = assert(self.finder, "Finder is required to do picking")
-  local sorter = self.sorter
+
+  assert(self.finder, "Finder is required to do picking")
 
   self.original_win_id = a.nvim_get_current_win()
 
@@ -288,6 +291,7 @@ function Picker:find()
 
   local results_win, results_opts = popup.create('', popup_opts.results)
   local results_bufnr = a.nvim_win_get_buf(results_win)
+  self.results_bufnr = results_bufnr
 
   -- TODO: Should probably always show all the line for results win, so should implement a resize for the windows
   a.nvim_win_set_option(results_win, 'wrap', false)
@@ -375,53 +379,9 @@ function Picker:find()
     -- vim.api.nvim_buf_set_virtual_text(prompt_bufnr, 0, 1, { {"hello", "Error"} }, {})
 
     -- TODO: Entry manager should have a "bulk" setter. This can prevent a lot of redraws from display
-    local entry_adder = function(index, entry)
-      local row = self:get_row(index)
-
-      -- If it's less than 0, then we don't need to show it at all.
-      if row < 0 then
-        log.debug("ON_ENTRY: Weird row", row)
-        return
-      end
-
-      local display
-      if type(entry.display) == 'function' then
-        self:_increment("display_fn")
-        display = entry:display()
-      elseif type(entry.display) == 'string' then
-        display = entry.display
-      else
-        log.info("Weird entry", entry)
-        return
-      end
-
-      -- This is the two spaces to manage the '> ' stuff.
-      -- Maybe someday we can use extmarks or floaty text or something to draw this and not insert here.
-      -- until then, insert two spaces
-      display = '  ' .. display
-
-      self:_increment("displayed")
-
-      -- TODO: Don't need to schedule this if we schedule the adder.
-      vim.schedule(function()
-        if not vim.api.nvim_buf_is_valid(results_bufnr) then
-          log.debug("ON_ENTRY: Invalid buffer")
-          return
-        end
-
-
-        local set_ok = pcall(vim.api.nvim_buf_set_lines, results_bufnr, row, row + 1, false, {display})
-
-        -- This pretty much only fails when people leave newlines in their results.
-        --  So we'll clean it up for them if it fails.
-        if not set_ok and display:find("\n") then
-          display = display:gsub("\n", " | ")
-          vim.api.nvim_buf_set_lines(results_bufnr, row, row + 1, false, {display})
-        end
-      end)
-    end
 
-    self.manager = EntryManager:new(self.max_results, entry_adder, self.stats)
+    self.manager = EntryManager:new(self.max_results, self.entry_adder)
+    -- self.manager = EntryManager:new(self.max_results, self.entry_adder, self.stats)
 
     local process_result = function(entry)
       self:_increment("processed")
@@ -439,8 +399,8 @@ function Picker:find()
       log.trace("Processing result... ", entry)
 
       local sort_ok, sort_score = nil, 0
-      if sorter then
-        sort_ok, sort_score = self:_track("_sort_time", pcall, sorter.score, sorter, prompt, entry)
+      if self.sorter then
+        sort_ok, sort_score = self:_track("_sort_time", pcall, self.sorter.score, self.sorter, prompt, entry)
 
         if not sort_ok then
           log.warn("Sorting failed with:", prompt, entry, sort_score)
@@ -454,7 +414,7 @@ function Picker:find()
         end
       end
 
-      self:_track("_add_time", self.manager.add_entry, self.manager, sort_score, entry)
+      self:_track("_add_time", self.manager.add_entry, self.manager, self, sort_score, entry)
 
       debounced_status()
     end
@@ -485,7 +445,6 @@ function Picker:find()
       self:clear_extra_rows(results_bufnr)
       self:highlight_displayed_rows(results_bufnr, prompt)
 
-
       -- TODO: Cleanup.
       self.stats._done = vim.loop.hrtime()
       self.stats.time = (self.stats._done - self.stats._start) / 1e9
@@ -504,7 +463,7 @@ function Picker:find()
     end
 
     local ok, msg = pcall(function()
-      return finder(prompt, process_result, vim.schedule_wrap(process_complete))
+      self.finder(prompt, process_result, vim.schedule_wrap(process_complete))
     end)
 
     if not ok then
@@ -518,10 +477,20 @@ function Picker:find()
   -- Register attach
   vim.api.nvim_buf_attach(prompt_bufnr, false, {
     on_lines = on_lines,
-    on_detach = function(...) print("DETACH:", ...) end,
+    on_detach = vim.schedule_wrap(function()
+      on_lines = nil
+
+      -- TODO: Can we add a "cleanup" / "teardown" function that completely removes these.
+      self.finder = nil
+      self.previewer = nil
+      self.sorter = nil
+      self.manager = nil
+
+      -- TODO: Should we actually do this?
+      collectgarbage(); collectgarbage()
+    end),
   })
 
-
   -- TODO: Use WinLeave as well?
   local on_buf_leave = string.format(
     [[  autocmd BufLeave <buffer> ++nested ++once :silent lua require('telescope.pickers').on_close_prompt(%s)]],
@@ -536,7 +505,7 @@ function Picker:find()
 
   local preview_border_win = preview_opts and preview_opts.border and preview_opts.border.win_id
 
-  state.set_status(prompt_bufnr, {
+  state.set_status(prompt_bufnr, setmetatable({
     prompt_bufnr = prompt_bufnr,
     prompt_win = prompt_win,
     prompt_border_win = prompt_border_win,
@@ -549,9 +518,7 @@ function Picker:find()
     preview_win = preview_win,
     preview_border_win = preview_border_win,
     picker = self,
-    previewer = self.previewer,
-    finder = finder,
-  })
+  }, { __mode = 'kv' }))
 
   mappings.apply_keymap(prompt_bufnr, self.attach_mappings, config.values.default_mappings)
 
@@ -571,7 +538,7 @@ function Picker:hide_preview()
 end
 
 
-function Picker:close_windows(status)
+function Picker.close_windows(status)
   local prompt_win = status.prompt_win
   local results_win = status.results_win
   local preview_win = status.preview_win
@@ -702,7 +669,7 @@ function Picker:set_selection(row)
         local old_display = '  ' .. old_selection:sub(3)
         a.nvim_buf_set_lines(results_bufnr, self._selection_row, self._selection_row + 1, false, {old_display})
 
-        if prompt and self.sorter.highlighter then
+        if prompt and self.sorter and self.sorter.highlighter then
           self:highlight_one_row(results_bufnr, prompt, old_display, self._selection_row)
         end
       end
@@ -739,7 +706,7 @@ function Picker:set_selection(row)
 
     self:display_multi_select(results_bufnr)
 
-    if prompt and self.sorter.highlighter then
+    if prompt and self.sorter and self.sorter.highlighter then
       self:highlight_one_row(results_bufnr, prompt, display, row)
     end
   end)
@@ -767,6 +734,54 @@ function Picker:set_selection(row)
   end
 end
 
+
+function Picker:entry_adder(index, entry)
+  local row = self:get_row(index)
+
+  -- If it's less than 0, then we don't need to show it at all.
+  if row < 0 then
+    log.debug("ON_ENTRY: Weird row", row)
+    return
+  end
+
+  local display
+  if type(entry.display) == 'function' then
+    self:_increment("display_fn")
+    display = entry:display()
+  elseif type(entry.display) == 'string' then
+    display = entry.display
+  else
+    log.info("Weird entry", entry)
+    return
+  end
+
+  -- This is the two spaces to manage the '> ' stuff.
+  -- Maybe someday we can use extmarks or floaty text or something to draw this and not insert here.
+  -- until then, insert two spaces
+  display = '  ' .. display
+
+  self:_increment("displayed")
+
+  -- TODO: Don't need to schedule this if we schedule the adder.
+  vim.schedule(function()
+    if not vim.api.nvim_buf_is_valid(self.results_bufnr) then
+      log.debug("ON_ENTRY: Invalid buffer")
+      return
+    end
+
+
+    local set_ok = pcall(vim.api.nvim_buf_set_lines, self.results_bufnr, row, row + 1, false, {display})
+
+    -- This pretty much only fails when people leave newlines in their results.
+    --  So we'll clean it up for them if it fails.
+    if not set_ok and display:find("\n") then
+      display = display:gsub("\n", " | ")
+      vim.api.nvim_buf_set_lines(self.results_bufnr, row, row + 1, false, {display})
+    end
+  end)
+end
+
+
 function Picker:_reset_track()
   self.stats.processed = 0
   self.stats.displayed = 0
@@ -819,14 +834,14 @@ end
 
 function Picker:close_existing_pickers()
   for _, prompt_bufnr in ipairs(state.get_existing_prompts()) do
+    log.debug("Prompt bufnr was left open:", prompt_bufnr)
     pcall(actions.close, prompt_bufnr)
   end
 end
 
 
 pickers.new = function(opts, defaults)
-  opts = extend(opts, defaults)
-  return Picker:new(opts)
+  return Picker:new(extend(opts, defaults))
 end
 
 function pickers.on_close_prompt(prompt_bufnr)
@@ -840,7 +855,7 @@ function pickers.on_close_prompt(prompt_bufnr)
   -- TODO: This is an attempt to clear all the memory stuff we may have left.
   -- vim.api.nvim_buf_detach(prompt_bufnr)
 
-  picker:close_windows(status)
+  picker.close_windows(status)
 end
 
 pickers._Picker = Picker
diff --git a/lua/telescope/sorters.lua b/lua/telescope/sorters.lua
index bc68fc1..d77baa5 100644
--- a/lua/telescope/sorters.lua
+++ b/lua/telescope/sorters.lua
@@ -54,7 +54,7 @@ end
 sorters.Sorter = Sorter
 
 TelescopeCachedTails = TelescopeCachedTails or nil
-do
+if not TelescopeCachedTails then
   local os_sep = util.get_separator()
   local match_string = '[^' .. os_sep .. ']*$'
   TelescopeCachedTails = setmetatable({}, {
diff --git a/lua/tests/manual/newline_tables.lua b/lua/tests/manual/newline_tables.lua
index 314d49d..2212da9 100644
--- a/lua/tests/manual/newline_tables.lua
+++ b/lua/tests/manual/newline_tables.lua
@@ -1,15 +1,23 @@
-require('plenary.reload').reload_module('telescope')
+-- require('plenary.reload').reload_module('telescope')
 
 local finders = require('telescope.finders')
 local pickers = require('telescope.pickers')
 local sorters = require('telescope.sorters')
+local previewers = require('telescope.previewers')
 
-local my_list = {'a', 'b', 'c'}
+local my_list = {
+  'lua/telescope/WIP.lua',
+  'lua/telescope/actions.lua',
+  'lua/telescope/builtin.lua',
+}
 
-pickers.new({
+local opts = {}
+
+pickers.new(opts, {
   prompt    = 'Telescope Builtin',
   finder    = finders.new_table {
     results = my_list,
   },
   sorter    = sorters.get_generic_fuzzy_sorter(),
+  previewer = previewers.cat.new(opts),
 }):find()
diff --git a/lua/tests/manual/reference_tracker.lua b/lua/tests/manual/reference_tracker.lua
new file mode 100644
index 0000000..dc90671
--- /dev/null
+++ b/lua/tests/manual/reference_tracker.lua
@@ -0,0 +1,48 @@
+
+-- local actions = require('telescope.actions')
+-- local utils = require('telescope.utils')
+require('telescope')
+local finders = require('telescope.finders')
+local make_entry = require('telescope.make_entry')
+local previewers = require('telescope.previewers')
+local pickers = require('telescope.pickers')
+local sorters = require('telescope.sorters')
+
+local log = require('telescope.log')
+
+local real_opts = setmetatable({}, { __mode = 'v' })
+local opts = setmetatable({}, { 
+  __index = function(t, k) log.debug("accessing:", k); return real_opts[k] end,
+  __newindex = function(t, k, v) log.debug("setting:", k, v); real_opts[k] = v end
+})
+
+opts.entry_maker = opts.entry_maker or make_entry.gen_from_file()
+if opts.cwd then
+  opts.cwd = vim.fn.expand(opts.cwd)
+end
+
+-- local get_finder_opts = function(opts)
+--   local t = {}
+--   t.entry_maker = table.pop(opts, 'entry_maker')
+--   return t
+-- end
+
+-- local finder_opts = get_finder_opts(opts)
+-- assert(not opts.entry_maker)
+
+local picker_config = {
+  prompt    = 'Git File',
+  finder    = finders.new_oneshot_job(
+    { "git", "ls-files", "-o", "--exclude-standard", "-c" }
+    , opts
+  ),
+  -- previewer = previewers.cat.new(opts),
+  -- sorter    = sorters.get_fuzzy_file(opts),
+  -- sorter    = sorters.get_fuzzy_file(),
+}
+
+log.debug("Done with config")
+
+local x = pickers.new(picker_config)
+x:find()
+x = nil