add http.lua

a small http client

http.lua

@@ -0,0 +1,262 @@
+module(..., package.seeall)
+
+-- connection timeout in micro seconds
+TIMEOUT = 30000
+-- default port for document retrieval
+PORT = 80
+-- user agent
+USERAGENT = "myhttp 0.1"
+
+function escape(s)
+	return string.gsub(s, "([^A-Za-z0-9_])", function(c) return string.format("%%%02x", string.byte(c)) end)
+end
+
+function unescape(s)
+	return string.gsub(s, "%%(%x%x)", function(hex) return string.char(tonumber(hex, 16)) end)
+end
+
+-----------------------------------------------------------------------------
+-- <url> ::= <scheme>://<authority>/<path>;<params>?<query>#<fragment>
+-- <authority> ::= <userinfo>@<host>:<port>
+-- <userinfo> ::= <user>[:<password>]
+-- <path> :: = {<segment>/}<segment>
+-----------------------------------------------------------------------------
+
+function parse_url(req)
+
+	if not req.url or req.url == "" then return nil end
+
+	local url = req.url
+	-- get fragment
+	url = string.gsub(url, "#(.*)$", function(f) req.fragment = f return "" end)
+	-- get scheme
+	url = string.gsub(url, "^([%w][%w%+%-%.]*)%:", function(s) req.scheme = s; return "" end)
+	-- get authority
+	url = string.gsub(url, "^//([^/]*)", function(n) req.authority = n return "" end)
+	-- get query stringing
+	url = string.gsub(url, "%?(.*)", function(q) req.query = q return "" end)
+	-- get params
+	url = string.gsub(url, "%;(.*)", function(p) req.params = p return "" end)
+	-- path is whatever was left
+	if url ~= "" then req.path = url end
+
+	local authority = req.authority
+	if not authority then return req end
+
+	-- get userinfo
+	authority = string.gsub(authority,"^([^@]*)@", function(u) req.userinfo = u; return "" end)
+	-- get port
+	authority = string.gsub(authority, ":([^:]*)$", function(p) req.port = p; return "" end)
+	-- host is whatever was left
+	if authority ~= "" then req.host = authority end
+
+	local userinfo = req.userinfo
+	if not userinfo then return req end
+
+	userinfo = string.gsub(userinfo, ":([^:]*)$", function(p) req.password = p; return "" end)
+	req.user = userinfo
+
+	return req
+end
+
+local function adjusturi(req)
+	local uri = req.path 
+	if req.params then uri = uri .. ";" .. req.params end
+	if req.query then uri = uri .. "?" .. req.query end
+
+	local authority = req.authority
+	if req.host then
+		authority = req.host
+		if req.port then authority = authority .. ":" .. req.port end
+		local userinfo = req.userinfo
+		if req.user then
+			userinfo = req.user
+			if req.password then
+				userinfo = userinfo .. ":" .. req.password
+			end
+		end
+		if userinfo then authority = userinfo .. "@" .. authority end
+	end	
+
+	if authority then uri = "//" .. authority .. uri end
+	if req.scheme then uri = req.scheme .. ":" .. uri end
+	if req.fragment then uri = uri .. "#" .. req.fragment end
+
+	return uri
+end
+
+local function adjustheaders(req)
+	-- default headers
+	local lower = {
+		["user-agent"] = USERAGENT,
+		["host"] = req.host,
+		["connection"] = "close, TE",
+		["te"] = "trailers"
+	}
+
+	-- override with user headers
+	for k, v in pairs(req.headers or {}) do
+		lower[string.lower(k)] = v
+	end
+
+	return lower
+end
+
+local function adjustrequest(req)
+	-- compute uri if user hasn't overriden
+	req.uri = req.uri or adjusturi(req)
+	-- adjust headers in request
+	req.headers = adjustheaders(req)
+end
+
+local function init_req(req)
+	req.port = req.port or PORT
+	req.headers = req.headers or {}
+	req.method = req.method or "GET"
+
+	if req.body then
+		req.headers["content-length"] = string.len(req.body)
+		req.headers["content-type"] = "application/x-www-form-urlencoded"
+		req.method = "POST"	
+	end
+end
+
+local function sendrequestline(sock, method, uri)
+	local reqline = string.format("%s %s HTTP/1.1\r\n", method or "GET", uri)
+	sock:send(reqline)
+end
+
+local function sendheaders(sock, headers)
+	local h = "\r\n"
+	for k, v in pairs(headers) do
+		h = k .. ": " .. v .. "\r\n" .. h
+	end
+	sock:send(h)
+end
+
+local function sendbody(sock, body)
+	if body then sock:send(body) end
+end
+
+local function receivestatusline(sock)
+
+	local status = sock:receive(5)
+
+	if status ~= "HTTP/" then return nil, status end
+
+	status = status .. sock:receive("*l")
+
+	local _, _, code = string.find(status, "HTTP/%d*%.%d* (%d%d%d)")
+
+	return tonumber(code), status
+end
+
+local function receiveheaders(sock)
+
+	local line, name, value, err
+
+	local headers = headers or {}
+
+	line, err = sock:receive()
+	if err then return nil, err end
+
+	while line ~= "" do
+		-- get field-name and value
+		_, _, name, value = string.find(line, "^(.-):%s*(.*)")
+		if not (name and value) then return nil, "malformed reponse headers" end
+		name = string.lower(name)
+
+		line, err  = sock:receive()
+		if err then return nil, err end
+		while string.find(line, "^%s") do
+			value = value .. line
+			line = sock:receive()
+			if err then return nil, err end
+		end
+
+		-- save pair in table
+		if headers[name] then headers[name] = headers[name] .. ", " .. value
+		else headers[name] = value end
+	end
+	return headers
+end
+
+local function receivebody(sock, headers)
+	local n, err
+	local body = ""
+
+	if headers["transfer-encoding"] == "chunked" then
+
+		while true do
+			n, err = sock:receive("*l")
+
+			if tonumber(n) == 0 then
+				break;
+			end
+
+			if not n then return nil, err end
+
+			local b
+			b, err = sock:receive(tonumber(n, 16))
+
+			if not b then return nil, err end
+
+			body = body..b
+			n, err = sock:receive()
+		end
+	else
+		body = sock:receive("*a")
+	end
+
+	return body
+end
+
+function request(req)
+	if type(req) ~= "table" then
+		return nil, "req must be a table"
+	end
+
+	init_req(req)
+
+	if not parse_url(req) then
+		return nil, "parse url error : " .. tostring(url)
+	end
+
+	adjustrequest(req)
+
+	local sock = ngx.socket.tcp()
+	sock:settimeout(TIMEOUT)
+	local ok, err = sock:connect(req.host, req.port)
+
+	if not ok then
+		sock:close()
+		return nil, "failed to connect :" .. tostring(host) .. ":" .. tostring(port)
+	end
+
+	sendrequestline(sock, req.method, req.uri)
+	sendheaders(sock, req.headers)
+	sendbody(sock, req.body)
+
+	local code, status = receivestatusline(sock)
+
+	if not code then
+		sock:close()
+		return nil, "no code return"
+	end	
+
+	local headers, err = receiveheaders(sock)	
+
+	if not headers then 
+		sock:close()
+		return nil, err
+	end
+
+	local body, err = receivebody(sock, headers)
+
+	if not body then
+		sock:close()
+		body = ""
+	end	
+
+	return { body = body, headers = headers, code = code, status = status } 
+end