feat: initial commit

lua/lazy/cache.lua

@@ -0,0 +1,87 @@
+local cache_file = vim.fn.stdpath("cache") .. "/lazy/cache.mpack"
+vim.fn.mkdir(vim.fn.fnamemodify(cache_file, ":p:h"), "p")
+
+local M = {}
+---@alias CacheEntry {hash:string, chunk:string, used:boolean}
+
+---@type table<string, CacheEntry>
+M.cache = {}
+M.dirty = false
+M.did_setup = false
+
+function M.hash(modpath)
+	local stat = vim.loop.fs_stat(modpath)
+	if stat then
+		return stat.mtime.sec .. stat.mtime.nsec .. stat.size
+	end
+	error("Could not hash " .. modpath)
+end
+
+function M.load_cache()
+	local f = io.open(cache_file, "rb")
+	if f then
+		M.cache = vim.mpack.decode(f:read("*a")) or {}
+		f:close()
+	end
+end
+
+function M.save_cache()
+	if M.dirty then
+		for key, entry in pairs(M.cache) do
+			if not entry.used then
+				M.cache[key] = nil
+			end
+			entry.used = nil
+		end
+		local f = assert(io.open(cache_file, "wb"))
+		f:write(vim.mpack.encode(M.cache))
+		f:close()
+	end
+end
+
+function M.setup()
+	M.load_cache()
+	vim.api.nvim_create_autocmd("VimLeave", {
+		callback = function()
+			M.save_cache()
+		end,
+	})
+end
+
+function M.load(modpath, modname)
+	if not M.did_setup then
+		M.setup()
+		M.did_setup = true
+	end
+	if type(package.loaded[modname]) ~= "table" then
+		---@type fun()?, string?
+		local chunk, err
+		local entry = M.cache[modname]
+
+		if entry and M.hash(modpath) == entry.hash then
+			entry.used = true
+			chunk, err = loadstring(entry.chunk, "@" .. modpath)
+		end
+
+		-- not cached, or failed to load chunk
+		if not chunk then
+			vim.schedule(function()
+				vim.notify("not cached")
+			end)
+			chunk, err = loadfile(modpath)
+			if chunk then
+				M.cache[modname] = { hash = M.hash(modpath), chunk = string.dump(chunk, true), used = true }
+				M.dirty = true
+			end
+		end
+
+		if not chunk then
+			error(err)
+		end
+		---@diagnostic disable-next-line: no-unknown
+		package.loaded[modname] = chunk()
+	end
+	return package.loaded[modname]
+end
+
+return M