perf: add cache for indent

Author: shellRaining

lua/hlchunk/mods/indent/init.lua

@@ -11,6 +11,7 @@ local fn = vim.fn
 local ROWS_INDENT_RETCODE = indentHelper.ROWS_INDENT_RETCODE
 
 ---@class IndentMetaInfo : MetaInfo
+---@field cache table<number, number>
 
 local constructor = function(self, conf, meta)
     local default_meta = {
@@ -20,6 +21,7 @@ local constructor = function(self, conf, meta)
         ns_id = api.nvim_create_namespace("indent"),
         shiftwidth = fn.shiftwidth(),
         leftcol = fn.winsaveview().leftcol,
+        cache = {},
     }
 
     BaseMod.init(self, conf, meta)
@@ -35,7 +37,7 @@ end
 ---@overload fun(conf?: UserIndentConf, meta?: MetaInfo): IndentMod
 local IndentMod = class(BaseMod, constructor)
 
-function IndentMod:renderLine(bufnr, index, blankLen)
+function IndentMod:renderLine(bufnr, lnum, blankLen)
     local row_opts = {
         virt_text_pos = "overlay",
         hl_mode = "combine",
@@ -58,14 +60,30 @@ function IndentMod:renderLine(bufnr, index, blankLen)
         --         return
         --     end
         -- end
-        api.nvim_buf_set_extmark(bufnr, self.meta.ns_id, index - 1, 0, row_opts)
+        api.nvim_buf_set_extmark(bufnr, self.meta.ns_id, lnum, 0, row_opts)
     end
 end
 
 function IndentMod:render(range)
     self:clear(range)
 
-    local retcode, rows_indent = indentHelper.get_rows_indent(range, {
+    -- narrow the range that should get indent
+    local non_cached_start = range.start
+    local non_cached_finish = range.finish
+    for i = range.start, range.finish do
+        if not self.meta.cache[i] then
+            non_cached_start = i
+            break
+        end
+    end
+    for i = non_cached_start, range.finish do
+        if self.meta.cache[i] then
+            non_cached_finish = i - 1
+            break
+        end
+    end
+
+    local retcode, rows_indent = indentHelper.get_rows_indent(Scope(range.bufnr, non_cached_start, non_cached_finish), {
         use_treesitter = self.conf.use_treesitter,
         virt_indent = true,
     })
@@ -75,9 +93,11 @@ function IndentMod:render(range)
         end
         return
     end
-
-    for index, _ in pairs(rows_indent) do
-        self:renderLine(range.bufnr, index, rows_indent[index])
+    for lnum, indent in pairs(rows_indent) do
+        self.meta.cache[lnum] = indent
+    end
+    for lnum = range.start, range.finish do
+        self:renderLine(range.bufnr, lnum, self.meta.cache[lnum])
     end
 end
 
@@ -116,7 +136,10 @@ function IndentMod:createAutocmd()
     })
     api.nvim_create_autocmd({ "TextChanged", "TextChangedI" }, {
         group = self.meta.augroup_name,
-        callback = throttle_render_cb_with_pre_hook,
+        callback = function(e)
+            self.meta.cache = {}
+            throttle_render_cb_with_pre_hook(e)
+        end,
     })
     api.nvim_create_autocmd({ "BufWinEnter" }, {
         group = self.meta.augroup_name,

lua/hlchunk/utils/cFunc.lua

@@ -1,20 +1,25 @@
 local ffi = require("ffi")
 
 ffi.cdef([[
-  typedef struct {} Error;
-  typedef struct file_buffer buf_T;
-  typedef int32_t linenr_T;
-  buf_T *find_buffer_by_handle(int buffer, Error *err);
-  int get_indent_buf(buf_T *buf, linenr_T lnum);
-  int get_sw_value(buf_T *buf);
+    typedef struct {} Error;
+    typedef struct file_buffer buf_T;
+    typedef int32_t linenr_T;
+    buf_T *find_buffer_by_handle(int buffer, Error *err);
+    int get_indent_buf(buf_T *buf, linenr_T lnum);
+    int get_sw_value(buf_T *buf);
 ]])
 local C = ffi.C
 
 local M = {}
 
 ---@param bufnr number
 ---@param row number 0-index
+---@return number
 function M.get_indent(bufnr, row)
+    local line_cnt = vim.api.nvim_buf_line_count(bufnr)
+    if row >= line_cnt then
+        return -1
+    end
     local handler = C.find_buffer_by_handle(bufnr, ffi.new("Error"))
     return C.get_indent_buf(handler, row + 1)
 end

lua/hlchunk/utils/indentHelper.lua

@@ -2,20 +2,13 @@ local fn = vim.fn
 local cFunc = require("hlchunk.utils.cFunc")
 
 -- get the virtual indent of the given line
----@param rows_indent table<number, number>
+---@param bufnr number
 ---@param line number
 ---@return number
-local function get_virt_indent(rows_indent, line)
-    local cur = line + 1
-    while rows_indent[cur] do
-        if rows_indent[cur] == 0 then
-            break
-        elseif rows_indent[cur] > 0 then
-            return rows_indent[cur]
-        end
-        cur = cur + 1
-    end
-    return -1
+local function get_virt_indent(bufnr, line)
+    return vim.api.nvim_buf_call(bufnr, function()
+        return cFunc.get_indent(bufnr, fn.nextnonblank(line + 1) - 1)
+    end)
 end
 
 local indentHelper = {}
@@ -42,39 +35,39 @@ indentHelper.ROWS_INDENT_RETCODE = {
     NO_TS = 1,
 }
 
+---@param range Scope
+---@return ROWS_INDENT_RETCODE
+---@return table<number, number>
 local function get_rows_indent_by_context(range)
-    local begRow = range.start + 1
-    local endRow = range.finish + 1
-
     local rows_indent = {}
 
-    for i = endRow, begRow, -1 do
-        rows_indent[i] = cFunc.get_indent(range.bufnr, i - 1)
-        if rows_indent[i] == 0 and #fn.getline(i) == 0 then
-            rows_indent[i] = get_virt_indent(rows_indent, i) or -1
+    for i = range.finish, range.start, -1 do
+        rows_indent[i] = cFunc.get_indent(range.bufnr, i)
+        if rows_indent[i] == 0 and #fn.getline(i + 1) == 0 then
+            rows_indent[i] = get_virt_indent(range.bufnr, i)
         end
     end
 
     return indentHelper.ROWS_INDENT_RETCODE.OK, rows_indent
 end
 
+---@param range Scope
+---@return ROWS_INDENT_RETCODE
+---@return table<number, number>
 local function get_rows_indent_by_treesitter(range)
-    local begRow = range.start + 1
-    local endRow = range.finish + 1
-
     local rows_indent = {}
     local ts_indent_status, ts_indent = pcall(require, "nvim-treesitter.indent")
     if not ts_indent_status then
         return indentHelper.ROWS_INDENT_RETCODE.NO_TS, {}
     end
 
-    for i = endRow, begRow, -1 do
+    for i = range.start, range.finish, -1 do
         rows_indent[i] = vim.api.nvim_buf_call(range.bufnr, function()
-            local indent = ts_indent.get_indent(i)
+            local indent = ts_indent.get_indent(i + 1)
             if indent == -1 then
-                indent = fn.indent(i)
-                if indent == 0 and #fn.getline(i) == 0 then
-                    indent = get_virt_indent(rows_indent, i) or -1
+                indent = fn.indent(i + 1)
+                if indent == 0 and #fn.getline(i + 1) == 0 then
+                    indent = get_virt_indent(range.bufnr, i)
                 end
             end
             ---@diagnostic disable-next-line: redundant-return-value