Here’s my lighttpd (or lighty) configuration for W3 Total Cache

Update: I split the lua code into 2 and also edit lighttpd.conf. It should be more efficient now.

lighttpd.conf

$HTTP["url"] =~ "\.(css|js)$" {
    expire.url = ( "" => "modification plus 24 hours" )
}

$HTTP["url"] =~ "\.(html|htm|stm)$" {
    expire.url = ( "" => "modification plus 60 minutes" )
}

$HTTP["host"] =~ "^(www.yourdomain.com|yourdomain.com)" {

	$HTTP["url"] =~ "/wp\-content/w3tc/min/" {
		magnet.attract-physical-path-to = ( "/etc/lighttpd/w3tmin.lua" )
	}
	$HTTP["url"] !~ "/(wp\-content|wp\-admin)/" {
		magnet.attract-physical-path-to = ( "/etc/lighttpd/w3tcache.lua" )
	}

}

w3tmin.lua

function explode(d,p)
	local t, ll
	t={}
	ll=0
	if(#p == 1) then return p end
		while true do
			l=string.find(p,d,ll+1,true)
			if l~=nil then
				table.insert(t, string.sub(p,ll,l-1))
				ll=l+1
			else
				table.insert(t, string.sub(p,ll))
				break
			end
		end
	return t
end

function serve_headers()
	lighty.header["X-Powered-By"] = "W3 Total Cache/0.8.5.2"
	lighty.header["Pragma"] = "public"
	lighty.header["Vary"] = "Accept-Encoding"
	cachecontrol = lighty.header["Cache-Control"] or ""
	if(cachecontrol == "") then
		lighty.header["Cache-Control"] = "public, must-revalidate, proxy-revalidate"
	else
		lighty.header["Cache-Control"] = cachecontrol .. ", public, must-revalidate, proxy-revalidate"
	end
end

function serve_html(cached_page)
	if (lighty.stat(cached_page)) then
		serve_headers()
		lighty.env["physical.path"] = cached_page
		return true
	else
		return false
	end
end

function serve_gzip(cached_page)
	if (lighty.stat(cached_page .. ".gzip")) then
		lighty.header["Content-Encoding"] = "gzip"
		if(string.match(lighty.env["physical.rel-path"], "%.js$")) then
			lighty.header["Content-Type"] = "application/x-javascript"
		else
			lighty.header["Content-Type"] = "text/css"
		end
		serve_headers()
		lighty.env["physical.path"] = cached_page .. ".gzip"
		return true
	else
		return false
	end
end

attr = lighty.stat(lighty.env["physical.path"] .. ".gzip")
if (not attr) then
	attr = lighty.stat(lighty.env["physical.path"])
	if (not attr) then
		minfile =  string.gsub(lighty.env["uri.path"], "/wp%-content/w3tc/min/","")
		gggt = explode(".",minfile)

		lighty.env["uri.path"] = "/wp-content/w3tc/min/index.php"
		lighty.env["uri.query"] = "gg=" .. gggt[1] .."&g=" .. gggt[2] .."&t=" .. gggt[3]
		lighty.env["physical.rel-path"] = lighty.env["uri.path"]
		lighty.env["physical.path"] = lighty.env["physical.doc-root"] .. lighty.env["physical.rel-path"]
	else
		cached_page = lighty.env["physical.path"]
		serve_html(cached_page)
	end
else
	accept_encoding = lighty.request["Accept-Encoding"] or "no_acceptance"

	cached_page = lighty.env["physical.path"]

	if (string.find(accept_encoding, "gzip")) then
		if not serve_gzip(cached_page) then serve_html(cached_page) end
	else
		serve_html(cached_page)
	end
end

w3tcache.lua

function serve_headers()
	lighty.header["X-Powered-By"] = "W3 Total Cache/0.8.5.2"
	lighty.header["Pragma"] = "public"
	lighty.header["Vary"] = "Accept-Encoding, Cookie"
	lighty.header["X-Pingback"] = lighty.env["uri.scheme"] .. "://" .. lighty.env["uri.authority"] .. "/xmlrpc.php"
	cachecontrol = lighty.header["Cache-Control"] or ""
	if(cachecontrol == "") then
		lighty.header["Cache-Control"] = "public, must-revalidate, proxy-revalidate"
	else
		lighty.header["Cache-Control"] = cachecontrol .. ", public, must-revalidate, proxy-revalidate"
	end
end

function serve_html(cached_page)
	if (lighty.stat(cached_page)) then
		serve_headers()
		lighty.env["physical.path"] = cached_page
		return true
	else
		return false
	end
end

function serve_gzip(cached_page)
	if (lighty.stat(cached_page .. ".gzip")) then
		lighty.header["Content-Encoding"] = "gzip"
		lighty.header["Content-Type"] = "text/html"
		serve_headers()
		lighty.env["physical.path"] = cached_page .. ".gzip"
		return true
	else
		return false
	end
end

attr = lighty.stat(lighty.env["physical.path"])
if (not attr) then
	lighty.env["uri.path"] = "/index.php"
	lighty.env["physical.rel-path"] = lighty.env["uri.path"]
	lighty.env["physical.path"] = lighty.env["physical.doc-root"] .. lighty.env["physical.rel-path"]

	user_query = lighty.env["uri.query"] or ""
	query_condition = (user_query == "")
	user_cookie = lighty.request["Cookie"] or ""
	cookie_condition = not (string.find(user_cookie, ".*comment_author.*") or string.find(user_cookie, ".*wordpress.*") or string.find(user_cookie, ".*wp-postpass_.*"))
	user_method = lighty.env["request.method"] or ""
	method_condition = (user_method ~= "POST")

	local userAgentsNoCaching = { "bot", "ia_archive", "slurp", "crawl", "spider", "iphone", "ipod", "android", "cupcake", "webos", "incognito", "webmate", "opera mini", "blackberry", "symbian", "series60", "nokia", "samsung" }
	userAgent = lighty.request["User-Agent"]
	if (nil == userAgent) then
		sendCachedFile = true
	else
		userAgent = string.lower(userAgent)
		for i, v in ipairs(userAgentsNoCaching) do
			if string.find(v, userAgent) then
				sendCachedFile = false
				break
			end
		end
	end

	if (query_condition and cookie_condition and method_condition and sendCachedFile) then
		accept_encoding = lighty.request["Accept-Encoding"] or "no_acceptance"
		cached_page = lighty.env["physical.doc-root"] .. "/wp-content/w3tc/pgcache/" .. lighty.env["request.uri"] .. "/_default_.html"
		cached_page = string.gsub(cached_page, "//", "/")

		if (string.find(accept_encoding, "gzip")) then
			if not serve_gzip(cached_page) then serve_html(cached_page) end
		else
			serve_html(cached_page)
		end
	end
end