feat(opt-in): kill previous searches when a new search is started (#100)

Issue
=====

When typing text, if there are no matches for a ripgrep search, each
keypresses starts a new ripgrep search. This can lead to many searches
being active at the same time. This takes up resources and is not useful
(if the word did not match previously, it will never match with a longer
search string).

Solution
========

Stop previously running searches when a new search is started. This is
currently disabled by default (soft launch). To opt in, see the README.

If this works well for some time, it might become the default in the
future.

README.md

@@ -45,7 +45,7 @@ return {
     sources = {
       default = {
         "buffer",
-        "ripgrep",  -- 👈🏻 add "ripgrep" here
+        "ripgrep", -- 👈🏻 add "ripgrep" here
       },
       providers = {
         -- 👇🏻👇🏻 add the ripgrep provider config below
@@ -108,6 +108,14 @@ return {
             -- Show debug information in `:messages` that can help in
             -- diagnosing issues with the plugin.
             debug = false,
+
+            -- Features that are not yet stable and might change in the future.
+            future_features = {
+              -- Kill previous searches when a new search is started. This is
+              -- useful to save resources and might become the default in the
+              -- future.
+              kill_previous_searches = false,
+            },
           },
           -- (optional) customize how the results are displayed. Many options
           -- are available - make sure your lua LSP is set up so you get

integration-tests/cypress/support/tui-sandbox.ts

@@ -127,5 +127,19 @@ declare global {
 
 afterEach(async () => {
   if (!testWindow) return
-  await testWindow.runExCommand({ command: "messages", log: true })
+  const timeout = new Promise<void>((resolve, reject) =>
+    setTimeout(() => {
+      Cypress.log({
+        name: "timeout when waiting for :messages to finish. Neovim might be stuck.",
+      })
+      reject(
+        "timeout when waiting for :messages to finish. Neovim might be stuck.",
+      )
+    }, 5_000),
+  )
+
+  await Promise.race([
+    timeout,
+    testWindow.runExCommand({ command: "messages" }),
+  ])
 })

integration-tests/package.json

@@ -17,7 +17,7 @@
     "zod": "3.24.1"
   },
   "devDependencies": {
-    "@tui-sandbox/library": "7.5.5",
+    "@tui-sandbox/library": "7.5.6",
     "@types/node": "22.10.3",
     "@types/tinycolor2": "1.4.6",
     "@typescript-eslint/eslint-plugin": "8.19.0",

integration-tests/test-environment/.config/nvim/init.lua

@@ -71,6 +71,9 @@ local plugins = {
             ---@type blink-ripgrep.Options
             opts = {
               debug = true,
+              future_features = {
+                kill_previous_searches = true,
+              },
             },
           },
         },

lua/blink-ripgrep/init.lua

@@ -11,6 +11,10 @@
 ---@field fallback_to_regex_highlighting? boolean # (default: true) When a result is found for a file whose filetype does not have a treesitter parser installed, fall back to regex based highlighting that is bundled in Neovim.
 ---@field project_root_marker? unknown # Specifies how to find the root of the project where the ripgrep search will start from. Accepts the same options as the marker given to `:h vim.fs.root()` which offers many possibilities for configuration. Defaults to ".git".
 ---@field debug? boolean # Show debug information in `:messages` that can help in diagnosing issues with the plugin.
+---@field future_features? blink-ripgrep.FutureFeatures # Features that are not yet stable and might change in the future.
+
+---@class blink-ripgrep.FutureFeatures
+---@field kill_previous_searches? boolean # Kill previous searches when a new search is started. This is useful to save resources and might become the default in the future.
 
 ---@class blink-ripgrep.RgSource : blink.cmp.Source
 ---@field get_command fun(context: blink.cmp.Context, prefix: string): string[]
@@ -55,6 +59,9 @@ RgSource.config = {
   search_casing = "--ignore-case",
   fallback_to_regex_highlighting = true,
   project_root_marker = ".git",
+  future_features = {
+    kill_previous_searches = false,
+  },
 }
 
 -- set up default options so that they are used by the next search
@@ -157,6 +164,9 @@ local function render_item_documentation(opts, file, match)
   )
 end
 
+---@type vim.Ringbuf<vim.SystemObj>
+local ripgrep_invocations = vim.ringbuf(3)
+
 function RgSource:get_completions(context, resolve)
   local prefix = self.get_prefix(context)
 
@@ -184,7 +194,24 @@ function RgSource:get_completions(context, resolve)
     end
   end
 
-  vim.system(cmd, nil, function(result)
+  local kill_previous_searches = (
+    RgSource.config.future_features
+    and RgSource.config.future_features.kill_previous_searches
+  ) or false
+
+  if kill_previous_searches then
+    -- drain all previous invocations and kill them to save resources
+    for val in ripgrep_invocations do
+      ---@cast val vim.SystemObj
+      val:kill(9)
+      if RgSource.config.debug then
+        vim.api.nvim_exec2("echomsg 'killed previous invocation'", {})
+      end
+    end
+    assert(#ripgrep_invocations == 0)
+  end
+
+  local rg = vim.system(cmd, nil, function(result)
     vim.schedule(function()
       if result.code ~= 0 then
         resolve()
@@ -244,6 +271,10 @@ function RgSource:get_completions(context, resolve)
       end)
     end)
   end)
+
+  if kill_previous_searches then
+    ripgrep_invocations:push(rg)
+  end
 end
 
 return RgSource

vim.toml

@@ -20,6 +20,9 @@ type = "function"
 [[after_each.args]]
 type = "function"
 
+[assert]
+any = true
+
 [assert.is_not]
 any = true