feat: additional startup performance improvements

## Details

Additional changes made with the goal of reducing the startup time of
this plugin. The main idea in this set of changes is to avoid requiring
modules at the top of files until they are actually needed. To
accomplish this we have:

- gone back to storing global information in the `state` module, that
  way we are not calling `setup` in order to provide data to various
  modules that need it, instead they will go back to picking it up from
  `state` fields that are shared, has some drawbacks but overall fine
- for various one off `require` statements (i.e. only used once in a
  given module) inline the `require` statement within the function that
  uses it, particularly helpful with the request `Context` fields and
  running `handlers`

Overall the improvement seems to be around 2x, give or take. Where
previously we were starting up in around 3.0ms, it is now closer to
1.5ms, which is a nice bump.

Most of the remaining time is spent loading the large `settings` module,
and the impact of all the things we do need to load immediately, times
are around 0.5ms and 1.0ms respectively.

Author: MeanderingProgrammer

lua/render-markdown/core/handlers.lua

@@ -1,12 +1,8 @@
 local iter = require('render-markdown.lib.iter')
 local log = require('render-markdown.core.log')
-
----@class render.md.handlers.Config
----@field nested boolean
----@field custom table<string, render.md.Handler>
+local state = require('render-markdown.state')
 
 ---@class render.md.Handlers
----@field private config render.md.handlers.Config
 local M = {}
 
 ---@private
@@ -19,12 +15,6 @@ M.builtin = {
     yaml = require('render-markdown.handler.yaml'),
 }
 
----called from state on setup
----@param config render.md.handlers.Config
-function M.setup(config)
-    M.config = config
-end
-
 ---@param context render.md.request.Context
 ---@param parser vim.treesitter.LanguageTree
 ---@return render.md.Mark[]
@@ -34,8 +24,8 @@ function M.run(context, parser)
         local root = tree:root()
         local language = language_tree:lang()
         if
-            (M.config.custom[language] or M.builtin[language])
-            and (M.config.nested or M.level(language_tree) == 1)
+            (state.custom_handlers[language] or M.builtin[language])
+            and (state.nested or M.level(language_tree) == 1)
             and context.view:overlaps(root)
         then
             local roots = language_roots[language]
@@ -90,7 +80,7 @@ end
 ---@param ctx render.md.handler.Context
 function M.tree(marks, language, ctx)
     log.buf('trace', 'Language', ctx.buf, language)
-    local custom = M.config.custom[language]
+    local custom = state.custom_handlers[language]
     if custom then
         log.buf('trace', 'Handler', ctx.buf, 'custom')
         vim.list_extend(marks, custom.parse(ctx))

lua/render-markdown/core/log.lua

@@ -1,15 +1,12 @@
 local env = require('render-markdown.lib.env')
+local state = require('render-markdown.state')
 
 ---@class render.md.log.Entry
 ---@field date string
 ---@field level string
 ---@field name string
 ---@field message string
 
----@class render.md.log.Config
----@field level render.md.log.Level
----@field runtime boolean
-
 ---@enum (key) render.md.log.Level
 local Level = {
     trace = 0,
@@ -23,20 +20,13 @@ local Level = {
 ---@class render.md.Log
 ---@field private file string
 ---@field private entries render.md.log.Entry[]
----@field private config render.md.log.Config
 local M = {}
 
----called from state on setup
----@param config render.md.log.Config
-function M.setup(config)
+---called from plugin directory
+function M.init()
     -- typically resolves to ~/.local/state/nvim/render-markdown.log
     M.file = vim.fn.stdpath('state') .. '/render-markdown.log'
     M.entries = {}
-    M.config = config
-end
-
----called from plugin directory
-function M.init()
     -- clear the file contents if it is too big
     if env.file_size_mb(M.file) > 5 then
         assert(io.open(M.file, 'w')):close()
@@ -52,7 +42,7 @@ end
 ---@param callback fun()
 ---@return fun()
 function M.runtime(name, callback)
-    if M.config.runtime then
+    if state.log_runtime then
         return function()
             local compat = require('render-markdown.lib.compat')
             local start_time = compat.uv.hrtime()
@@ -122,7 +112,7 @@ end
 ---@param name string
 ---@param ... any
 function M.add(level, name, ...)
-    if M.level(level) < M.level(M.config.level) then
+    if M.level(level) < M.level(state.log_level) then
         return
     end
     local messages = {} ---@type string[]

lua/render-markdown/core/manager.lua

@@ -3,15 +3,7 @@ local log = require('render-markdown.core.log')
 local state = require('render-markdown.state')
 local ui = require('render-markdown.core.ui')
 
----@class render.md.manager.Config
----@field file_types string[]
----@field ignore fun(buf: integer): boolean
----@field change_events string[]
----@field on render.md.on.Config
----@field completions render.md.completions.Config
-
 ---@class render.md.Manager
----@field private config render.md.manager.Config
 local M = {}
 
 ---@private
@@ -21,12 +13,6 @@ M.group = vim.api.nvim_create_augroup('RenderMarkdown', {})
 ---@type integer[]
 M.buffers = {}
 
----called from state on setup
----@param config render.md.manager.Config
-function M.setup(config)
-    M.config = config
-end
-
 ---called from plugin directory
 function M.init()
     -- lazy loading: ignores current buffer as FileType event already executed
@@ -99,13 +85,13 @@ function M.attach(buf)
     end
 
     local config = state.get(buf)
-    M.config.on.attach({ buf = buf })
+    state.on.attach({ buf = buf })
     require('render-markdown.core.ts').init()
-    if M.config.completions.lsp.enabled then
+    if state.completions.lsp.enabled then
         require('render-markdown.integ.lsp').init()
-    elseif M.config.completions.blink.enabled then
+    elseif state.completions.blink.enabled then
         require('render-markdown.integ.blink').init()
-    elseif M.config.completions.coq.enabled then
+    elseif state.completions.coq.enabled then
         require('render-markdown.integ.coq').init()
     else
         require('render-markdown.integ.cmp').init()
@@ -127,7 +113,7 @@ function M.attach(buf)
         events[#events + 1] = 'CursorMovedI'
         events[#events + 1] = 'TextChangedI'
     end
-    local force = M.config.change_events
+    local force = state.change_events
     for _, event in ipairs(force) do
         if not vim.tbl_contains(events, event) then
             events[#events + 1] = event
@@ -173,7 +159,7 @@ function M.should_attach(buf)
     end
 
     local file_type = env.buf.get(buf, 'filetype')
-    local file_types = M.config.file_types
+    local file_types = state.file_types
     if not vim.tbl_contains(file_types, file_type) then
         local reason = ('%s /∈ %s'):format(file_type, vim.inspect(file_types))
         log.attach(buf, 'skip', 'file type', reason)
@@ -188,7 +174,7 @@ function M.should_attach(buf)
         return false
     end
 
-    if M.config.ignore(buf) then
+    if state.ignore(buf) then
         log.attach(buf, 'skip', 'user ignore')
         return false
     end

lua/render-markdown/core/ts.lua

@@ -1,13 +1,7 @@
 local compat = require('render-markdown.lib.compat')
-
----@class render.md.ts.Config
----@field file_types string[]
----@field restart_highlighter boolean
----@field injections table<string, render.md.injection.Config>
----@field patterns table<string, render.md.pattern.Config>
+local state = require('render-markdown.state')
 
 ---@class render.md.Ts
----@field private config render.md.ts.Config
 local M = {}
 
 ---@private
@@ -19,10 +13,8 @@ M.initialized = false
 M.queries = {}
 
 ---called from state on setup
----@param config render.md.ts.Config
-function M.setup(config)
-    M.config = config
-    for _, language in ipairs(M.config.file_types) do
+function M.setup()
+    for _, language in ipairs(state.file_types) do
         M.inject(language)
     end
 end
@@ -33,10 +25,10 @@ function M.init()
         return
     end
     M.initialized = true
-    for _, language in ipairs(M.config.file_types) do
+    for _, language in ipairs(state.file_types) do
         M.disable(language)
     end
-    if M.config.restart_highlighter then
+    if state.restart_highlighter then
         vim.treesitter.stop()
         vim.treesitter.start()
     end
@@ -57,7 +49,7 @@ end
 ---@private
 ---@param language string
 function M.inject(language)
-    local injection = M.config.injections[language]
+    local injection = state.injections[language]
     if not injection or not injection.enabled then
         return
     end
@@ -80,7 +72,7 @@ end
 ---@private
 ---@param language string
 function M.disable(language)
-    local pattern = M.config.patterns[language]
+    local pattern = state.patterns[language]
     if not pattern or not pattern.disable then
         return
     end

lua/render-markdown/core/ui.lua

@@ -1,18 +1,11 @@
 local Context = require('render-markdown.request.context')
-local Decorator = require('render-markdown.lib.decorator')
-local Extmark = require('render-markdown.lib.extmark')
 local compat = require('render-markdown.lib.compat')
 local env = require('render-markdown.lib.env')
-local handlers = require('render-markdown.core.handlers')
 local iter = require('render-markdown.lib.iter')
 local log = require('render-markdown.core.log')
 local state = require('render-markdown.state')
 
----@class render.md.ui.Config
----@field on render.md.on.Config
-
 ---@class render.md.Ui
----@field private config render.md.ui.Config
 local M = {}
 
 M.ns = vim.api.nvim_create_namespace('render-markdown.nvim')
@@ -22,9 +15,7 @@ M.ns = vim.api.nvim_create_namespace('render-markdown.nvim')
 M.cache = {}
 
 ---called from state on setup
----@param config render.md.ui.Config
-function M.setup(config)
-    M.config = config
+function M.setup()
     -- clear marks and reset cache
     for _, buf in ipairs(vim.api.nvim_list_bufs()) do
         vim.api.nvim_buf_clear_namespace(buf, M.ns, 0, -1)
@@ -37,7 +28,7 @@ end
 function M.get(buf)
     local result = M.cache[buf]
     if not result then
-        result = Decorator.new(buf)
+        result = require('render-markdown.lib.decorator').new(buf)
         M.cache[buf] = result
     end
     return result
@@ -133,7 +124,7 @@ function Updater:clear()
         extmark:hide(M.ns, self.buf)
     end
     vim.api.nvim_buf_clear_namespace(self.buf, M.ns, 0, -1)
-    M.config.on.clear({ buf = self.buf, win = self.win })
+    state.on.clear({ buf = self.buf, win = self.win })
 end
 
 ---@private
@@ -148,7 +139,7 @@ function Updater:render()
             self.decorator:set(extmarks)
             if initial then
                 compat.fix_lsp_window(self.buf, self.win, extmarks)
-                M.config.on.initial({ buf = self.buf, win = self.win })
+                state.on.initial({ buf = self.buf, win = self.win })
             end
             self:display()
         end)
@@ -167,6 +158,8 @@ function Updater:parse(callback)
         if context then
             -- make sure injections are processed
             context.view:parse(parser, function()
+                local Extmark = require('render-markdown.lib.extmark')
+                local handlers = require('render-markdown.core.handlers')
                 local marks = handlers.run(context, parser)
                 callback(iter.list.map(marks, Extmark.new))
             end)
@@ -191,7 +184,7 @@ function Updater:display()
             extmark:show(M.ns, self.buf)
         end
     end
-    M.config.on.render({ buf = self.buf, win = self.win })
+    state.on.render({ buf = self.buf, win = self.win })
 end
 
 ---@private

lua/render-markdown/health.lua

@@ -6,7 +6,7 @@ local state = require('render-markdown.state')
 local M = {}
 
 ---@private
-M.version = '8.8.11'
+M.version = '8.8.12'
 
 function M.check()
     M.start('versions')

lua/render-markdown/integ/blink.lua

@@ -1,23 +1,14 @@
 local source = require('render-markdown.integ.source')
-
----@class render.md.source.blink.Config
----@field file_types string[]
+local state = require('render-markdown.state')
 
 ---@class render.md.blink.Source: blink.cmp.Source
----@field private config render.md.source.blink.Config
 local Source = {}
 Source.__index = Source
 
 ---@private
 ---@type boolean
 Source.initialized = false
 
----called from state on setup
----@param config render.md.source.blink.Config
-function Source.setup(config)
-    Source.config = config
-end
-
 ---called from manager on buffer attach
 function Source.init()
     if Source.initialized then
@@ -33,7 +24,7 @@ function Source.init()
         name = 'RenderMarkdown',
         module = 'render-markdown.integ.blink',
     })
-    for _, file_type in ipairs(Source.config.file_types) do
+    for _, file_type in ipairs(state.file_types) do
         pcall(blink.add_filetype_source, file_type, id)
     end
 end

lua/render-markdown/integ/source.lua

@@ -19,19 +19,9 @@ local children = vim.list_extend(vim.tbl_keys(markers), {
 
 local siblings = { 'paragraph' }
 
----@class render.md.source.Config
----@field completions render.md.completions.Config
-
 ---@class render.md.Source
----@field private config render.md.source.Config
 local M = {}
 
----called from state on setup
----@param config render.md.source.Config
-function M.setup(config)
-    M.config = config
-end
-
 ---@return boolean
 function M.enabled()
     return manager.attached(env.buf.current())
@@ -68,7 +58,7 @@ function M.items(buf, row, col)
 
     local items = {} ---@type lsp.CompletionItem[]
     local config = state.get(buf)
-    local filter = M.config.completions.filter
+    local filter = state.completions.filter
     local prefix = line:sub(before, before) == ' ' and '' or ' '
     if node.type == 'block_quote' then
         local suffix = ''