refactor(renderer): rework view renderer (add cache, highlights)

lua/fidget/notification.lua

@@ -1,10 +1,10 @@
 ---@mod fidget.notification Notification subsystem
-local notification          = {}
-notification.model          = require("fidget.notification.model")
-notification.window         = require("fidget.notification.window")
-notification.view           = require("fidget.notification.view")
-local poll                  = require("fidget.poll")
-local logger                = require("fidget.logger")
+local notification  = {}
+notification.model  = require("fidget.notification.model")
+notification.window = require("fidget.notification.window")
+notification.view   = require("fidget.notification.view")
+local poll          = require("fidget.poll")
+local logger        = require("fidget.logger")
 
 --- Used to determine the identity of notification items and groups.
 ---@alias Key any
@@ -21,6 +21,8 @@ local logger                = require("fidget.logger")
 ---@field key           Key|nil       Replace existing notification item of the same key
 ---@field group         Key|nil       Group that this notification item belongs to
 ---@field annote        string|nil    Optional single-line title that accompanies the message
+---@field position      string|nil    Optional text position inside the window
+---@field lang          string|nil    Optional tree-sitter highlight language to use
 ---@field hidden        boolean|nil   Whether this item should be shown
 ---@field ttl           number|nil    How long after a notification item should exist; pass 0 to use default value
 ---@field update_only   boolean|nil   If true, don't create new notification items
@@ -76,6 +78,8 @@ local logger                = require("fidget.logger")
 ---@field content_key   Key         What to deduplicate items by (do not deduplicate if `nil`)
 ---@field message       string      Displayed message for the item
 ---@field annote        string|nil  Optional title that accompanies the message
+---@field position      string|nil  Optional text position inside the window
+---@field lang          string|nil  Optional tree-sitter highlight language to use
 ---@field style         string      Style used to render the annote/title, if any
 ---@field hidden        boolean     Whether this item should be shown
 ---@field expires_at    number      What time this item should be removed; math.huge means never
@@ -86,11 +90,11 @@ local logger                = require("fidget.logger")
 --- A notification element in the notifications history.
 ---
 ---@class HistoryItem : Item
----@field removed       boolean     Whether this item is deleted
----@field group_key     Key         Key of the group this item belongs to
----@field group_name    string|nil  Title of the group this item belongs to
----@field group_icon    string|nil  Icon of the group this item belongs to
----@field last_updated  number      What time this item was last updated, in seconds since Jan 1, 1970
+---@field removed       boolean          Whether this item is deleted
+---@field group_key     Key              Key of the group this item belongs to
+---@field group_name    string|false|nil Title of the group this item belongs to
+---@field group_icon    string|false|nil Icon of the group this item belongs to
+---@field last_updated  number           What time this item was last updated, in seconds since Jan 1, 1970
 
 --- Filter options when querying for notifications history.
 ---
@@ -104,15 +108,30 @@ local logger                = require("fidget.logger")
 ---@field include_active  boolean|nil Include items that have not been removed (default: true)
 
 --- The "model" (abstract state) of notifications.
----@type State
-local state                 = {
+---@class State
+local state         = {
   groups          = {},
+  render          = false,
   view_suppressed = false,
   removed         = {},
   removed_cap     = 128,
   removed_first   = 1,
 }
 
+--- Must be called when the groups table changes
+function state:update()
+  if not self.render then
+    self.render = true
+  end
+end
+
+--- Serves as a lock to prevent unnecessary rendering
+function state:wait()
+  if self.render then
+    self.render = false
+  end
+end
+
 --- Default notification configuration.
 ---
 --- Exposed publicly because it might be useful for users to integrate for when
@@ -156,8 +175,8 @@ notification.default_config = {
 --- Sets a |fidget.notification.Item|'s `content_key`, for deduplication.
 ---
 --- This default implementation sets an item's `content_key` to its `message`,
---- appended with its `annote` (or a null byte if it has no `annote`), a rough
---- "hash" of its contents. You can write your own `update_hook` that "hashes"
+--- appended with its `position` and `annote` (or a null byte if it has no `annote`),
+--- a rough "hash" of its contents. You can write your own `update_hook` that "hashes"
 --- the message differently, e.g., only considering the `message`, or taking the
 --- `data` or style fields into account.
 ---
@@ -181,13 +200,19 @@ notification.default_config = {
 ---
 ---@param item Item
 function notification.set_content_key(item)
-    item.content_key = item.message .. " " .. (item.annote and item.annote or string.char(0))
+  item.content_key = string.format(
+    "%s-%s-%s%s",
+    item.message,
+    item.lang and item.lang or "",
+    item.position and item.position or "",
+    item.annote and item.annote or string.char(0)
+  )
 end
 
 ---@options notification [[
 ---@protected
 --- Notification options
-notification.options        = {
+notification.options = {
   --- How frequently to update and render notifications
   ---
   --- Measured in Hertz (frames per second).
@@ -317,9 +342,7 @@ end
 ---
 ---@return boolean closed_successfully Whether the window closed successfully.
 function notification.close()
-  return notification.window.guard(function()
-    notification.window.close()
-  end)
+  return notification.window.guard(notification.window.close)
 end
 
 --- Clear active notifications.
@@ -355,30 +378,38 @@ function notification.reset()
   notification.clear()
   notification.clear_history()
   notification.poller:reset_error() -- Clear error if previously encountered one
+  notification.poller:release()     -- Release timer resources
 end
 
+---@private
+local _guard = notification.window.guard
+
 --- The poller for the notification subsystem.
 ---@protected
 notification.poller = poll.Poller {
   name = "notification",
   poll = function(self)
     notification.model.tick(self:now(), state)
 
-    -- TODO: if not modified, don't re-render
-    local lines, width = notification.view.render(self:now(), state.groups)
+    local message = notification.view.render(self:now(), state)
 
-    if #lines > 0 then
+    if message and #message.lines > 0 and state.render then
       if state.view_suppressed then
         return true
       end
 
-      notification.window.guard(function()
-        notification.window.set_lines(lines, width)
-      end)
+      _guard(notification.window.set_lines, message)
+
+      state:wait()
+
       return true
     else
       if state.view_suppressed then
         return false
+      else
+        if not state.render then
+          return true
+        end
       end
 
       -- If we could not close the window, keep polling, i.e., keep trying to close the window.
@@ -459,7 +490,7 @@ end
 ---
 ---@return Key[] keys
 function notification.group_keys()
-  return vim.tbl_map(function(group) return group.key end, state.groups)
+  return vim.iter(state.groups):map(function(group) return group.key end):totable()
 end
 
 return notification

lua/fidget/notification/model.lua

@@ -15,9 +15,58 @@ local M      = {}
 local logger = require("fidget.logger")
 local poll   = require("fidget.poll")
 
+--- Cache used during rendering of notifications.
+---
+---@alias CItem NotificationLine[]|nil
+---                                    width          count
+---@alias CacheItem { [1]: CItem, [2]: integer, [3]: integer }
+---                                                   icon
+---@alias CacheHdr  { [1]: CItem, [2]: integer, [3]: string }
+---@alias CacheSep  { [1]: CItem, [2]: integer }
+---
+---@class Cache
+---@field group_header table<Display, CacheHdr>
+---@field group_sep    CacheSep
+---@field render_item  table<Item|any, CacheItem>
+---@field render_width integer
+---@field window       integer
+local cache  = {}
+M.cache      = cache
+
+--- Deletes objects from the cache.
+---
+---@param item Item|Group
+---@param last boolean?
+local function del_cached(item, last)
+  ---@type Group
+  if item.config and item.key and item.key ~= "default" then
+    -- Free up non-default headers (including lsp)
+    cache.group_header[item.config.name] = nil
+  end
+  if last then
+    if cache.render_item and next(cache.render_item) ~= nil then
+      -- At the last notification, free up remaining cached items
+      for k, _ in pairs(cache.render_item) do
+        cache.render_item[k] = nil
+      end
+    end
+    return
+  end
+  ---@type Item
+  local key = item.content_key or item
+  if cache.render_item
+      and cache.render_item[key]
+      and cache.render_item[key][3] == 1
+  then
+    -- We do not use this item anymore (ttl reached)
+    cache.render_item[key] = nil
+  end
+end
+
 --- The abstract state of the notifications subsystem.
 ---@class State
 ---@field groups          Group[]         active notification groups
+---@field render          boolean         whether the notification should be rendered
 ---@field view_suppressed boolean         whether the notification window is suppressed
 ---@field removed         HistoryItem[]   ring buffer of removed notifications, kept around for history
 ---@field removed_cap     number          capacity of removed ring buffer
@@ -32,7 +81,7 @@ local poll   = require("fidget.poll")
 ---@class HistoryExtra
 ---@field removed   boolean
 ---@field group_key Key
----@field group_name string|nil
+---@field group_name string|false|nil
 ---@field group_icon string|nil
 
 --- Get the notification group indexed by group_key; create one if none exists.
@@ -49,8 +98,8 @@ local function get_group(configs, groups, group_key)
     end
   end
 
-  -- Group not found; create it and insert it into list of active groups.
-
+  --- Group not found; create it and insert it into list of active groups.
+  ---
   ---@type Group
   local group = {
     key = group_key,
@@ -69,6 +118,15 @@ end
 ---@param item  Item
 local function add_removed(state, now, group, item)
   if not item.skip_history then
+    -- Skip duplicates unless we have no items deduplication
+    if group.config.update_hook and #state.removed > 0 then
+      if state.removed[state.removed_first - 1].content_key
+          and state.removed[state.removed_first - 1].content_key == item.content_key
+      then
+        return
+      end
+    end
+
     local group_name = group.config.name
     if type(group_name) == "function" then
       group_name = group_name(now, group.items)
@@ -80,7 +138,7 @@ local function add_removed(state, now, group, item)
     end
 
     ---@cast item HistoryItem
-    item.last_updated = poll.unix_time(now)
+    item.last_updated = poll.unix_time()
     item.removed = true
     item.group_key = group.key
     item.group_name = group_name
@@ -99,7 +157,7 @@ end
 local function item_to_history(item, extra)
   ---@type HistoryItem
   item = vim.tbl_extend("force", item, extra)
-  item.last_updated = poll.unix_time(item.last_updated)
+  item.last_updated = poll.unix_time()
   return item
 end
 
@@ -190,9 +248,9 @@ end
 ---@return            number expiry_time
 local function compute_expiry(now, ttl, default_ttl)
   if not ttl or ttl == 0 then
-    return now + (default_ttl or 3)
+    return now + ((default_ttl or 3) * 10 ^ 9)
   else
-    return now + ttl
+    return now + (ttl * 10 ^ 9)
   end
 end
 
@@ -237,6 +295,8 @@ function M.update(now, configs, state, msg, level, opts)
       group_key = group_key,
       message = msg,
       annote = opts.annote or annote_from_level(group.config, level),
+      position = opts.position or nil,
+      lang = opts.lang or nil,
       style = style_from_level(group.config, level) or group.config.annote_style or "Question",
       hidden = opts.hidden or false,
       expires_at = compute_expiry(now, opts.ttl, group.config.ttl),
@@ -254,6 +314,8 @@ function M.update(now, configs, state, msg, level, opts)
     item.message = msg or item.message
     item.style = style_from_level(group.config, level) or item.style
     item.annote = opts.annote or annote_from_level(group.config, level) or item.annote
+    item.position = opts.position or item.position
+    item.lang = opts.lang or item.lang
     item.hidden = opts.hidden or item.hidden
     item.expires_at = opts.ttl and compute_expiry(now, opts.ttl, group.config.ttl) or item.expires_at
     item.skip_history = opts.skip_history or item.skip_history
@@ -271,6 +333,7 @@ function M.update(now, configs, state, msg, level, opts)
       return (a.config.priority or 50) - (b.config.priority or 50)
     end)
   end
+  state:update()
 end
 
 --- Remove an item from a particular group.
@@ -337,23 +400,26 @@ end
 ---@param now number timestamp of current frame.
 ---@param state  State
 function M.tick(now, state)
-  local new_groups = {}
-  for _, group in ipairs(state.groups) do
-    local new_items = {}
-    for _, item in ipairs(group.items) do
-      if item.expires_at > now then
-        table.insert(new_items, item)
-      else
-        add_removed(state, now, group, item)
-      end
-    end
-    if #group.items > 0 then
-      group.items = new_items
-      table.insert(new_groups, group)
+  for i = #state.groups, 1, -1 do
+    local group = state.groups[i]
+    -- Dereference unused items on the last notification
+    if #group.items == 0 then
+      del_cached(group, true)
+      table.remove(state.groups, i)
+      state:update()
     else
+      for j = #group.items, 1, -1 do
+        local item = group.items[j]
+
+        if item.expires_at <= now then
+          del_cached(item)
+          add_removed(state, now, group, item)
+          table.remove(group.items, j)
+          state:update()
+        end
+      end
     end
   end
-  state.groups = new_groups
 end
 
 --- Generate a notifications history according to the provided filter.