perf(git/repo): cache ref/file lookups, invalidate on status refresh

lua/git/cmd.lua

@@ -317,22 +317,26 @@ end
 ---@param dir string
 ---@return string[]
 local function list_files(r, dir)
+    return r:get_cached("files:" .. dir, function(self)
         local cmd = { "git", "ls-files" }
         if dir ~= "" then
             table.insert(cmd, dir)
         end
-    local out = util.exec(cmd, { cwd = r.worktree, silent = true })
+        local out = util.exec(cmd, { cwd = self.worktree, silent = true })
         return out and util.split_lines(out) or {}
+    end)
 end
 
 ---@param r ow.Git.Repo
 ---@return string[]
 local function list_remotes(r)
+    return r:get_cached("remotes", function(self)
         local out = util.exec(
             { "git", "remote" },
-        { cwd = r.worktree, silent = true }
+            { cwd = self.worktree, silent = true }
         )
         return out and util.split_lines(out) or {}
+    end)
 end
 
 ---@type table<string, string[]>
@@ -469,7 +473,8 @@ function M.complete_rev(arg_lead)
 
     local colon = arg_lead:find(":", 1, true)
     if not colon then
-        local refs = r:list_refs()
+        local refs = {}
+        vim.list_extend(refs, r:list_refs())
         vim.list_extend(refs, r:list_pseudo_refs())
         vim.list_extend(refs, r:list_stash_refs())
         return prefix_filter(refs, arg_lead)

lua/git/repo.lua

@@ -35,6 +35,7 @@ local global = util.Emitter.new()
 ---@field private _watcher? uv.uv_fs_event_t
 ---@field private _schedule_refresh fun(self: ow.Git.Repo)
 ---@field private _refresh_handle ow.Git.Util.DebounceHandle
+---@field private _cache table<string, any>
 local Repo = {}
 Repo.__index = Repo
 
@@ -56,6 +57,7 @@ function Repo:_fetch_status()
         STATUS_CMD,
         { cwd = self.worktree, text = true },
         vim.schedule_wrap(function(obj)
+            self._cache = {}
             if obj.code ~= 0 then
                 util.error("git status failed: %s", vim.trim(obj.stderr or ""))
                 return
@@ -82,6 +84,7 @@ function Repo.new(gitdir, worktree)
         tabs = {},
         status = status.parse(""),
         _events = util.Emitter.new(),
+        _cache = {},
     }, Repo)
     self._schedule_refresh, self._refresh_handle =
         util.debounce(Repo._fetch_status, 50)
@@ -90,6 +93,20 @@ function Repo.new(gitdir, worktree)
     return self
 end
 
+---@generic T
+---@param key string
+---@param compute fun(self: ow.Git.Repo): T
+---@return T
+function Repo:get_cached(key, compute)
+    local hit = self._cache[key]
+    if hit ~= nil then
+        return hit
+    end
+    local value = compute(self)
+    self._cache[key] = value
+    return value
+end
+
 function Repo:start_watcher()
     local watcher, err = vim.uv.new_fs_event()
     if not watcher then
@@ -168,6 +185,7 @@ end
 
 ---@return string[]
 function Repo:list_refs()
+    return self:get_cached("refs", function(self)
         local out = util.exec({
             "git",
             "for-each-ref",
@@ -180,6 +198,7 @@ function Repo:list_refs()
             return {}
         end
         return util.split_lines(out)
+    end)
 end
 
 local PSEUDO_REFS = {
@@ -194,6 +213,7 @@ local PSEUDO_REFS = {
 
 ---@return string[]
 function Repo:list_pseudo_refs()
+    return self:get_cached("pseudo_refs", function(self)
         local refs = {}
         for _, name in ipairs(PSEUDO_REFS) do
             if name == "HEAD" or vim.uv.fs_stat(self.gitdir .. "/" .. name) then
@@ -201,10 +221,12 @@ function Repo:list_pseudo_refs()
             end
         end
         return refs
+    end)
 end
 
 ---@return string[]
 function Repo:list_stash_refs()
+    return self:get_cached("stash_refs", function(self)
         if not vim.uv.fs_stat(self.gitdir .. "/refs/stash") then
             return {}
         end
@@ -219,6 +241,7 @@ function Repo:list_stash_refs()
             end
         end
         return refs
+    end)
 end
 
 ---@param rev string