perf(snippets): fix previous attempt at caching snippet lazy vars

Related to #2024

Author: Saghen

lua/blink/cmp/sources/snippets/default/builtin.lua

@@ -7,17 +7,28 @@ local builtin = {
   lazy = {},
 }
 
-function builtin.lazy.TM_FILENAME() return vim.fn.expand('%:t') end
-
-function builtin.lazy.TM_FILENAME_BASE() return vim.fn.expand('%:t:s?\\.[^\\.]\\+$??') end
-
-function builtin.lazy.TM_DIRECTORY() return vim.fn.expand('%:p:h') end
-
-function builtin.lazy.TM_FILEPATH() return vim.fn.expand('%:p') end
-
-function builtin.lazy.TM_SELECTED_TEXT() return vim.fn.trim(vim.fn.getreg(vim.v.register, true), '\n', 2) end
+--- Higher-order function to add single-value caching
+local function cached(fn)
+  local cache_key = -1
+  local cached_value = nil
+  return function(key, ...)
+    assert(key ~= -1, 'key cannot be -1')
+    if cache_key == key then return cached_value end
+
+    cached_value = fn(...)
+    cache_key = key
+    return cached_value
+  end
+end
 
-function builtin.lazy.CLIPBOARD(opts) return vim.fn.getreg(opts.clipboard_register or vim.v.register, true) end
+builtin.lazy.TM_FILENAME = cached(function() return vim.fn.expand('%:t') end)
+builtin.lazy.TM_FILENAME_BASE = cached(function() return vim.fn.expand('%:t:s?\\.[^\\.]\\+$??') end)
+builtin.lazy.TM_DIRECTORY = cached(function() return vim.fn.expand('%:p:h') end)
+builtin.lazy.TM_FILEPATH = cached(function() return vim.fn.expand('%:p') end)
+builtin.lazy.TM_SELECTED_TEXT = cached(function() return vim.fn.trim(vim.fn.getreg(vim.v.register, true), '\n', 2) end)
+builtin.lazy.CLIPBOARD = cached(
+  function(opts) return vim.fn.getreg(opts.clipboard_register or vim.v.register, true) end
+)
 
 local function buf_to_ws_part()
   local LSP_WORSKPACE_PARTS = 'LSP_WORSKPACE_PARTS'
@@ -38,18 +49,18 @@ local function buf_to_ws_part()
   return ws_parts
 end
 
-function builtin.lazy.RELATIVE_FILEPATH() -- The relative (to the opened workspace or folder) file path of the current document
-  return buf_to_ws_part()[2]
-end
-
-function builtin.lazy.WORKSPACE_FOLDER() -- The path of the opened workspace or folder
+builtin.lazy.RELATIVE_FILEPATH = cached(
+  function() -- The relative (to the opened workspace or folder) file path of the current document
+    return buf_to_ws_part()[2]
+  end
+)
+builtin.lazy.WORKSPACE_FOLDER = cached(function() -- The path of the opened workspace or folder
   return buf_to_ws_part()[1]
-end
-
-function builtin.lazy.WORKSPACE_NAME() -- The name of the opened workspace or folder
+end)
+builtin.lazy.WORKSPACE_NAME = cached(function() -- The name of the opened workspace or folder
   local parts = vim.split(buf_to_ws_part()[1] or '', '[\\/]')
   return parts[#parts]
-end
+end)
 
 function builtin.lazy.CURRENT_YEAR() return os.date('%Y') end
 
@@ -129,11 +140,9 @@ local function buffer_comment_chars()
   return comments
 end
 
-function builtin.lazy.LINE_COMMENT() return buffer_comment_chars()[1] end
-
-function builtin.lazy.BLOCK_COMMENT_START() return buffer_comment_chars()[2] end
-
-function builtin.lazy.BLOCK_COMMENT_END() return buffer_comment_chars()[3] end
+builtin.lazy.LINE_COMMENT = cached(function() return buffer_comment_chars()[1] end)
+builtin.lazy.BLOCK_COMMENT_START = cached(function() return buffer_comment_chars()[2] end)
+builtin.lazy.BLOCK_COMMENT_END = cached(function() return buffer_comment_chars()[3] end)
 
 local function get_cursor()
   local c = vim.api.nvim_win_get_cursor(0)

lua/blink/cmp/sources/snippets/default/init.lua

@@ -35,7 +35,7 @@ function snippets:get_completions(context, callback)
   end
 
   local items = vim.tbl_map(
-    function(item) return self.registry:snippet_to_completion_item(item) end,
+    function(item) return self.registry:snippet_to_completion_item(item, context.id) end,
     self.cache[filetype]
   )
   callback({

lua/blink/cmp/sources/snippets/default/registry.lua

@@ -106,30 +106,24 @@ function registry:get_global_snippets()
 end
 
 --- @param snippet blink.cmp.Snippet
+--- @param cache_key number
 --- @return blink.cmp.CompletionItem
-function registry:snippet_to_completion_item(snippet)
+function registry:snippet_to_completion_item(snippet, cache_key)
   local body = type(snippet.body) == 'string' and snippet.body or table.concat(snippet.body, '\n')
   return {
     kind = require('blink.cmp.types').CompletionItemKind.Snippet,
     label = snippet.prefix,
     insertTextFormat = vim.lsp.protocol.InsertTextFormat.Snippet,
-    insertText = self:expand_vars(body),
+    insertText = self:expand_vars(body, cache_key),
     description = snippet.description,
   }
 end
 
 --- @param snippet string
+--- @param cache_key number
 --- @return string
-function registry:parse_body(snippet)
-  local parse = utils.safe_parse(self:expand_vars(snippet))
-  return parse and tostring(parse) or snippet
-end
-
---- @param snippet string
---- @return string
-function registry:expand_vars(snippet)
+function registry:expand_vars(snippet, cache_key)
   local lazy_vars = self.builtin_vars.lazy
-  local lazy_vars_cache = {}
   local eager_vars = self.builtin_vars.eager or {}
 
   local resolved_snippet = snippet
@@ -151,9 +145,7 @@ function registry:expand_vars(snippet)
       if eager_vars[data.name] then
         resolved_snippet = resolved_snippet:gsub('%$[{]?(' .. data.name .. ')[}]?', eager_vars[data.name])
       elseif lazy_vars[data.name] then
-        local replacement = lazy_vars_cache[data.name]
-          or lazy_vars[data.name]({ clipboard_register = self.config.clipboard_register })
-        lazy_vars_cache[data.name] = replacement
+        local replacement = lazy_vars[data.name](cache_key, { clipboard_register = self.config.clipboard_register })
         -- gsub otherwise fails with strings like `%20` in the replacement string
         local escaped_for_gsub = replacement:gsub('%%', '%%%%')
         resolved_snippet = resolved_snippet:gsub('%$[{]?(' .. data.name .. ')[}]?', escaped_for_gsub)