Merge pull request #3 from abeldekat/add_caching

Add caching for completion items. Enabled by default
Reuse completion_item.documentation if it was already generated

README.md

@@ -86,6 +86,22 @@ return {
 
 </details>
 
+## Options
+
+The default options can be modified in the `sources` field of the `nvim-cmp` spec.
+
+```lua
+sources = cmp.config.sources({
+  {
+    name = "mini_snippets",
+    option = {
+      -- completion items are cached using default mini.snippets context:
+      use_items_cache = false -- default: true
+    }
+  }
+}),
+```
+
 ## LazyVim and mini.snippets
 
 See this [LazyVim] PR for a mini.snippets "extra"...

lua/cmp_mini_snippets/init.lua

@@ -1,90 +1,141 @@
 -- :h cmp-develop
 
+---@class cmp_mini_snippets.Options
+--- @field use_items_cache? boolean completion items are cached using default mini.snippets context
+
+---@type cmp_mini_snippets.Options
+local defaults = {
+  use_items_cache = true, -- allow the user to disable caching completion items
+}
+
 local cmp = require("cmp")
 local util = require("vim.lsp.util")
 
 local source = {}
 
--- Creates a markdown representation of the snippet
--- A fenced code block after convert_input_to_markdown_lines is probably ok.
----@return string
-local function get_documentation(snippet)
-  local header = (snippet.prefix or "") .. " _ `[" .. vim.bo.filetype .. "]`\n"
-  local docstring = { "", "```" .. vim.bo.filetype, snippet.body, "```" }
-  local documentation = { header .. "---", (snippet.desc or ""), docstring }
-  documentation = util.convert_input_to_markdown_lines(documentation)
-
-  return table.concat(documentation, "\n")
+source.new = function()
+  local self = setmetatable({}, { __index = source })
+  self.items_cache = {}
+  return self
 end
 
--- Remove the word inserted by nvim-cmp and insert snippet
--- It's safe to assume that mode is insert during completion
-local function insert_snippet(snippet, word)
-  local cursor = vim.api.nvim_win_get_cursor(0)
-  cursor[1] = cursor[1] - 1 -- nvim_buf_set_text: line is zero based
-  local start_col = cursor[2] - #word
-  vim.api.nvim_buf_set_text(0, cursor[1], start_col, cursor[1], cursor[2], {})
-
-  local insert = MiniSnippets.config.expand.insert or MiniSnippets.default_insert
-  insert({ body = snippet.body }) -- insert at cursor
+---@return cmp_mini_snippets.Options
+local function get_valid_options(params)
+  local opts = vim.tbl_deep_extend("keep", params.option, defaults)
+  vim.validate({
+    use_items_cache = { opts.use_items_cache, "boolean" },
+  })
+  return opts
 end
 
-source.new = function() return setmetatable({}, { __index = source }) end
-
 ---Return the keyword pattern for triggering completion (optional).
 ---If this is omitted, nvim-cmp will use a default keyword pattern. See |cmp-config.completion.keyword_pattern|.
+---Using the same keyword pattern as cmp-luasnip
 ---@return string
-source.get_keyword_pattern = function() -- same as cmp-luasnip!
-  return "\\%([^[:alnum:][:blank:]]\\|\\w\\+\\)"
-end
-
--- Copied from :h nvim-cmp as a reminder...
----Return trigger characters for triggering completion (optional).
--- function source:get_trigger_characters() return { "." } end
+source.get_keyword_pattern = function() return "\\%([^[:alnum:][:blank:]]\\|\\w\\+\\)" end
 
 ---Return whether this source is available in the current context or not (optional).
 ---@return boolean
 function source:is_available()
+  ---@diagnostic disable-next-line: undefined-field
   return _G.MiniSnippets ~= nil -- ensure that user has explicitly setup mini.snippets
 end
 
----Invoke completion (required).
--- -@param params cmp.SourceCompletionApiParams
----@param callback fun(response: lsp.CompletionResponse|nil)
-function source:complete(_, callback)
-  local items = {}
-  local snippets = MiniSnippets.expand({ match = false, insert = false })
-  if not snippets then return items end
+local function to_completion_items(snippets)
+  local result = {}
 
-  for _, snippet in ipairs(snippets) do
-    items[#items + 1] = {
-      word = snippet.prefix,
-      label = snippet.prefix,
+  for _, snip in ipairs(snippets) do
+    local item = {
+      word = snip.prefix,
+      label = snip.prefix,
       kind = cmp.lsp.CompletionItemKind.Snippet,
-      data = { snippet = snippet }, -- cmp-luasnip only stores the snippet-id...
+      data = { snip = snip },
     }
+    table.insert(result, item)
   end
+  return result
+end
+
+-- NOTE: Completion items are cached by default using the default 'mini.snippets' context
+--
+-- vim.b.minisnippets_config can contain buffer-local snippets.
+-- a buffer can contain code in multiple languages
+--
+-- See :h MiniSnippets.default_prepare
+--
+-- Return completion items produced from snippets either directly or from cache
+local function get_completion_items(cache)
+  if not cache then return to_completion_items(MiniSnippets.expand({ match = false, insert = false })) end
+
+  -- Compute cache id
+  local _, context = MiniSnippets.default_prepare({})
+  local id = "buf=" .. context.buf_id .. ",lang=" .. context.lang
+
+  -- Return the completion items for this context from cache
+  if cache[id] then return cache[id] end
+
+  -- Retrieve all raw snippets in context and transform into completion items
+  local snippets = MiniSnippets.expand({ match = false, insert = false })
+  local items = to_completion_items(vim.deepcopy(snippets))
+  cache[id] = items
+
+  return items
+end
+
+---Invoke completion (required).
+-- @param params cmp.SourceCompletionApiParams
+---@param callback fun(response: lsp.CompletionResponse|nil)
+function source:complete(params, callback)
+  local opts = get_valid_options(params)
+  local cache = opts.use_items_cache and self.items_cache or nil
+  local items = get_completion_items(cache)
   callback(items)
 end
 
+-- Creates a markdown representation of the snippet
+-- A fenced code block after convert_input_to_markdown_lines is probably ok.
+---@return string
+local function get_documentation(snip)
+  local header = (snip.prefix or "") .. " _ `[" .. vim.bo.filetype .. "]`\n"
+  local docstring = { "", "```" .. vim.bo.filetype, snip.body, "```" }
+  local documentation = { header .. "---", (snip.desc or ""), docstring }
+  documentation = util.convert_input_to_markdown_lines(documentation)
+
+  return table.concat(documentation, "\n")
+end
+
 ---Resolve completion item (optional). This is called right before the completion is about to be displayed.
 ---Useful for setting the text shown in the documentation window (`completion_item.documentation`).
 ---@param completion_item lsp.CompletionItem
 ---@param callback fun(completion_item: lsp.CompletionItem|nil)
 function source:resolve(completion_item, callback) -- modified from cmp-luasnip:
-  local snippet = completion_item.data.snippet
-  completion_item.documentation = {
-    kind = cmp.lsp.MarkupKind.Markdown,
-    value = get_documentation(snippet),
-  }
+  if not completion_item.documentation then
+    completion_item.documentation = {
+      kind = cmp.lsp.MarkupKind.Markdown,
+      value = get_documentation(completion_item.data.snip),
+    }
+  end
+
   callback(completion_item)
 end
 
+-- Remove the word inserted by nvim-cmp and insert snippet
+-- It's safe to assume that mode is insert during completion
+local function insert_snippet(snip, word)
+  local cursor = vim.api.nvim_win_get_cursor(0)
+  cursor[1] = cursor[1] - 1 -- nvim_buf_set_text: line is zero based
+  local start_col = cursor[2] - #word
+  vim.api.nvim_buf_set_text(0, cursor[1], start_col, cursor[1], cursor[2], {})
+
+  local insert = MiniSnippets.config.expand.insert or MiniSnippets.default_insert
+  insert({ body = snip.body }) -- insert at cursor
+end
+
 ---Executed after the item was selected.
 ---@param completion_item lsp.CompletionItem
 ---@param callback fun(completion_item: lsp.CompletionItem|nil)
 function source:execute(completion_item, callback)
-  insert_snippet(completion_item.data.snippet, completion_item.word)
+  insert_snippet(completion_item.data.snip, completion_item.word)
   callback(completion_item)
 end