diff --git a/mysql_client.lua b/mysql_client.lua
index 652e379..19e540a 100644
--- a/mysql_client.lua
+++ b/mysql_client.lua
@@ -3,7 +3,7 @@
 -- Written by Yichun Zhang (agentzh). BSD license.
 
 local tcp = require'sock'.tcp
-local sha1 = require'sha1'
+local sha1 = require'sha1'.sha1
 local bit = require'bit'
 
 local sub = string.sub
@@ -165,7 +165,7 @@ end
 
 
 local function _from_cstring(data, i)
-    local last = strfind(data, "\0", i, true)
+    local last = strfind(data, '\0', i, true)
     if not last then
         return nil, nil
     end
@@ -175,7 +175,7 @@ end
 
 
 local function _to_cstring(data)
-    return data .. "\0"
+    return data .. '\0'
 end
 
 
@@ -188,9 +188,9 @@ local function _dump(data)
     local len = #data
     local bytes = new_tab(len, 0)
     for i = 1, len do
-        bytes[i] = format("%x", strbyte(data, i))
+        bytes[i] = format('%x', strbyte(data, i))
     end
-    return concat(bytes, " ")
+    return concat(bytes, ' ')
 end
 
 
@@ -200,13 +200,13 @@ local function _dumphex(data)
     for i = 1, len do
         bytes[i] = tohex(strbyte(data, i), 2)
     end
-    return concat(bytes, " ")
+    return concat(bytes, ' ')
 end
 
 
 local function _compute_token(password, scramble)
-    if password == "" then
-        return ""
+    if password == '' then
+        return ''
     end
 
     local stage1 = sha1(password)
@@ -227,68 +227,101 @@ local function _send_packet(self, req, size)
 
     self.packet_no = self.packet_no + 1
 
-    -- print("packet no: ", self.packet_no)
+    -- print('packet no: ', self.packet_no)
 
     local packet = _set_byte3(size) .. strchar(band(self.packet_no, 255)) .. req
 
-    -- print("sending packet: ", _dump(packet))
+    -- print('sending packet: ', _dump(packet))
 
-    -- print("sending packet... of size " .. #packet)
+    -- print('sending packet... of size ' .. #packet)
 
     return sock:send(packet)
 end
 
+--static, auto-growing buffer allocation pattern (ctype must be vla).
+local function grow_buffer(ctype)
+	local vla = ffi.typeof(ctype)
+	local buf, len = nil, -1
+	return function(minlen)
+		if minlen == false then
+			buf, len = nil, -1
+		elseif minlen > len then
+			len = glue.nextpow2(minlen)
+			buf = vla(len)
+		end
+		return buf, len
+	end
+end
+
+local function _recv(self, sz)
+    local buf = self.buf
+    if not buf then
+        buf = grow_buffer'char[?]'
+        self.buf = buf
+    end
+    local buf = buf(sz)
+    local sock = self.sock
+    local offset = 0
+    while sz > 0 do
+        local n, err = sock:recv(buf + offset, sz)
+        if not n then return nil, err end
+        sz = sz - n
+        offset = offset + n
+    end
+    return ffi.string(buf, offset)
+end
+
 
 local function _recv_packet(self)
     local sock = self.sock
 
-    local data, err = sock:receive(4) -- packet header
+    local data, err = _recv(self, 4) -- packet header
     if not data then
-        return nil, nil, "failed to receive packet header: " .. err
+        return nil, nil, 'failed to receive packet header: ' .. err
     end
 
-    --print("packet header: ", _dump(data))
+    --print('packet header: ', _dump(data))
 
     local len, pos = _get_byte3(data, 1)
 
-    --print("packet length: ", len)
+    --print('packet length: ', len)
 
     if len == 0 then
-        return nil, nil, "empty packet"
+        return nil, nil, 'empty packet'
     end
 
     if len > self._max_packet_size then
-        return nil, nil, "packet size too big: " .. len
+        return nil, nil, 'packet size too big: ' .. len
     end
 
     local num = strbyte(data, pos)
 
-    --print("recv packet: packet no: ", num)
+    --print('recv packet: packet no: ', num)
 
     self.packet_no = num
 
-    data, err = sock:receive(len)
+    data, err = _recv(self, len)
 
-    --print("receive returned")
+    --print('receive returned')
 
     if not data then
-        return nil, nil, "failed to read packet content: " .. err
+        return nil, nil, 'failed to read packet content: ' .. err
     end
 
-    --print("packet content: ", _dump(data))
-    --print("packet content (ascii): ", data)
+    --print('packet content: ', _dump(data))
+    --print('packet content (ascii): ', data)
 
     local field_count = strbyte(data, 1)
 
     local typ
     if field_count == 0x00 then
-        typ = "OK"
+        typ = 'OK'
     elseif field_count == 0xff then
-        typ = "ERR"
+        typ = 'ERR'
     elseif field_count == 0xfe then
-        typ = "EOF"
+        typ = 'EOF'
     else
-        typ = "DATA"
+        typ = 'DATA'
     end
 
     return data, typ
@@ -298,7 +331,7 @@ end
 local function _from_length_coded_bin(data, pos)
     local first = strbyte(data, pos)
 
-    --print("LCB: first: ", first)
+    --print('LCB: first: ', first)
 
     if not first then
         return nil, pos
@@ -348,26 +381,26 @@ local function _parse_ok_packet(packet)
 
     res.affected_rows, pos = _from_length_coded_bin(packet, 2)
 
-    --print("affected rows: ", res.affected_rows, ", pos:", pos)
+    --print('affected rows: ', res.affected_rows, ', pos:', pos)
 
     res.insert_id, pos = _from_length_coded_bin(packet, pos)
 
-    --print("insert id: ", res.insert_id, ", pos:", pos)
+    --print('insert id: ', res.insert_id, ', pos:', pos)
 
     res.server_status, pos = _get_byte2(packet, pos)
 
-    --print("server status: ", res.server_status, ", pos:", pos)
+    --print('server status: ', res.server_status, ', pos:', pos)
 
     res.warning_count, pos = _get_byte2(packet, pos)
 
-    --print("warning count: ", res.warning_count, ", pos: ", pos)
+    --print('warning count: ', res.warning_count, ', pos: ', pos)
 
     local message = _from_length_coded_str(packet, pos)
     if message and message ~= null then
         res.message = message
     end
 
-    --print("message: ", res.message, ", pos:", pos)
+    --print('message: ', res.message, ', pos:', pos)
 
     return res
 end
@@ -437,7 +470,7 @@ local function _parse_field_packet(data)
     col.decimals = strbyte(data, pos)
     pos = pos + 1
     local default = sub(data, pos + 2)
-    if default and default ~= "" then
+    if default and default ~= '' then
         col.default = default
     end
     return col
@@ -460,7 +493,7 @@ local function _parse_row_data_packet(data, cols, compact)
         local typ = col.type
         local name = col.name
 
-        --print("row field value: ", value, ", type: ", typ)
+        --print('row field value: ', value, ', type: ', typ)
 
         if value ~= null then
             local conv = converters[typ]
@@ -486,13 +519,13 @@ local function _recv_field_packet(self)
         return nil, err
     end
 
-    if typ == "ERR" then
+    if typ == 'ERR' then
         local errno, msg, sqlstate = _parse_err_packet(packet)
         return nil, msg, errno, sqlstate
     end
 
     if typ ~= 'DATA' then
-        return nil, "bad field packet type: " .. typ
+        return nil, 'bad field packet type: ' .. typ
     end
 
     -- typ == 'DATA'
@@ -513,7 +546,7 @@ end
 function _M.connect(self, opts)
     local sock = self.sock
     if not sock then
-        return nil, "not initialized"
+        return nil, 'not initialized'
     end
 
     local max_packet_size = opts.max_packet_size
@@ -526,79 +559,52 @@ function _M.connect(self, opts)
 
     self.compact = opts.compact_arrays
 
-    local database = opts.database or ""
-    local user = opts.user or ""
+    local database = opts.database or ''
+    local user = opts.user or ''
 
-    local charset = CHARSET_MAP[opts.charset or "_default"]
+    local charset = CHARSET_MAP[opts.charset or '_default']
     if not charset then
-        return nil, "charset '" .. opts.charset .. "' is not supported"
+        return nil, 'charset \'' .. opts.charset .. '\' is not supported'
     end
 
-    local pool = opts.pool
-
     local host = opts.host
-    if host then
-        local port = opts.port or 3306
-        if not pool then
-            pool = user .. ":" .. database .. ":" .. host .. ":" .. port
-        end
-
-        ok, err = sock:connect(host, port, { pool = pool })
-
-    else
-        local path = opts.path
-        if not path then
-            return nil, 'neither "host" nor "path" options are specified'
-        end
-
-        if not pool then
-            pool = user .. ":" .. database .. ":" .. path
-        end
-
-        ok, err = sock:connect("unix:" .. path, { pool = pool })
-    end
+    local port = opts.port or 3306
+    ok, err = sock:connect(host, port)
 
     if not ok then
         return nil, 'failed to connect: ' .. err
     end
 
-    local reused = sock:getreusedtimes()
-
-    if reused and reused > 0 then
-        self.state = STATE_CONNECTED
-        return 1
-    end
-
     local packet, typ, err = _recv_packet(self)
     if not packet then
         return nil, err
     end
 
-    if typ == "ERR" then
+    if typ == 'ERR' then
         local errno, msg, sqlstate = _parse_err_packet(packet)
         return nil, msg, errno, sqlstate
     end
 
     self.protocol_ver = strbyte(packet)
 
-    --print("protocol version: ", self.protocol_ver)
+    --print('protocol version: ', self.protocol_ver)
 
     local server_ver, pos = _from_cstring(packet, 2)
     if not server_ver then
-        return nil, "bad handshake initialization packet: bad server version"
+        return nil, 'bad handshake initialization packet: bad server version'
     end
 
-    --print("server version: ", server_ver)
+    --print('server version: ', server_ver)
 
     self._server_ver = server_ver
 
     local thread_id, pos = _get_byte4(packet, pos)
 
-    --print("thread id: ", thread_id)
+    --print('thread id: ', thread_id)
 
     local scramble = sub(packet, pos, pos + 8 - 1)
     if not scramble then
-        return nil, "1st part of scramble not found"
+        return nil, '1st part of scramble not found'
     end
 
     pos = pos + 9 -- skip filler
@@ -607,38 +613,38 @@ function _M.connect(self, opts)
     local capabilities  -- server capabilities
     capabilities, pos = _get_byte2(packet, pos)
 
-    -- print(format("server capabilities: %#x", capabilities))
+    -- print(format('server capabilities: %#x', capabilities))
 
     self._server_lang = strbyte(packet, pos)
     pos = pos + 1
 
-    --print("server lang: ", self._server_lang)
+    --print('server lang: ', self._server_lang)
 
     self._server_status, pos = _get_byte2(packet, pos)
 
-    --print("server status: ", self._server_status)
+    --print('server status: ', self._server_status)
 
     local more_capabilities
     more_capabilities, pos = _get_byte2(packet, pos)
 
     capabilities = bor(capabilities, lshift(more_capabilities, 16))
 
-    --print("server capabilities: ", capabilities)
+    --print('server capabilities: ', capabilities)
 
     -- local len = strbyte(packet, pos)
     local len = 21 - 8 - 1
 
-    --print("scramble len: ", len)
+    --print('scramble len: ', len)
 
     pos = pos + 1 + 10
 
     local scramble_part2 = sub(packet, pos, pos + len - 1)
     if not scramble_part2 then
-        return nil, "2nd part of scramble not found"
+        return nil, '2nd part of scramble not found'
     end
 
     scramble = scramble .. scramble_part2
-    --print("scramble: ", _dump(scramble))
+    --print('scramble: ', _dump(scramble))
 
     local client_flags = 0x3f7cf;
 
@@ -647,37 +653,37 @@ function _M.connect(self, opts)
 
     if use_ssl then
         if band(capabilities, CLIENT_SSL) == 0 then
-            return nil, "ssl disabled on server"
+            return nil, 'ssl disabled on server'
         end
 
         -- send a SSL Request Packet
         local req = _set_byte4(bor(client_flags, CLIENT_SSL))
                     .. _set_byte4(self._max_packet_size)
                     .. strchar(charset)
-                    .. strrep("\0", 23)
+                    .. strrep('\0', 23)
 
         local packet_len = 4 + 4 + 1 + 23
         local bytes, err = _send_packet(self, req, packet_len)
         if not bytes then
-            return nil, "failed to send client authentication packet: " .. err
+            return nil, 'failed to send client authentication packet: ' .. err
         end
 
         local ok, err = sock:sslhandshake(false, nil, ssl_verify)
         if not ok then
-            return nil, "failed to do ssl handshake: " .. (err or "")
+            return nil, 'failed to do ssl handshake: ' .. (err or '')
         end
     end
 
-    local password = opts.password or ""
+    local password = opts.password or ''
 
     local token = _compute_token(password, scramble)
 
-    --print("token: ", _dump(token))
+    --print('token: ', _dump(token))
 
     local req = _set_byte4(client_flags)
                 .. _set_byte4(self._max_packet_size)
                 .. strchar(charset)
-                .. strrep("\0", 23)
+                .. strrep('\0', 23)
                 .. _to_cstring(user)
                 .. _to_binary_coded_string(token)
                 .. _to_cstring(database)
@@ -685,19 +691,19 @@ function _M.connect(self, opts)
     local packet_len = 4 + 4 + 1 + 23 + #user + 1
         + #token + 1 + #database + 1
 
-    -- print("packet content length: ", packet_len)
-    -- print("packet content: ", _dump(concat(req, "")))
+    -- print('packet content length: ', packet_len)
+    -- print('packet content: ', _dump(concat(req, '')))
 
     local bytes, err = _send_packet(self, req, packet_len)
     if not bytes then
-        return nil, "failed to send client authentication packet: " .. err
+        return nil, 'failed to send client authentication packet: ' .. err
     end
 
-    --print("packet sent ", bytes, " bytes")
+    --print('packet sent ', bytes, ' bytes')
 
     local packet, typ, err = _recv_packet(self)
     if not packet then
-        return nil, "failed to receive the result packet: " .. err
+        return nil, 'failed to receive the result packet: ' .. err
     end
 
     if typ == 'ERR' then
@@ -706,11 +712,11 @@ function _M.connect(self, opts)
     end
 
     if typ == 'EOF' then
-        return nil, "old pre-4.1 authentication protocol not supported"
+        return nil, 'old pre-4.1 authentication protocol not supported'
     end
 
     if typ ~= 'OK' then
-        return nil, "bad packet type: " .. typ
+        return nil, 'bad packet type: ' .. typ
     end
 
     self.state = STATE_CONNECTED
@@ -718,37 +724,10 @@ function _M.connect(self, opts)
     return 1
 end
 
-
-function _M.set_keepalive(self, ...)
-    local sock = self.sock
-    if not sock then
-        return nil, "not initialized"
-    end
-
-    if self.state ~= STATE_CONNECTED then
-        return nil, "cannot be reused in the current connection state: "
-                    .. (self.state or "nil")
-    end
-
-    self.state = nil
-    return sock:setkeepalive(...)
-end
-
-
-function _M.get_reused_times(self)
-    local sock = self.sock
-    if not sock then
-        return nil, "not initialized"
-    end
-
-    return sock:getreusedtimes()
-end
-
-
 function _M.close(self)
     local sock = self.sock
     if not sock then
-        return nil, "not initialized"
+        return nil, 'not initialized'
     end
 
     self.state = nil
@@ -761,21 +740,19 @@ function _M.close(self)
     return sock:close()
 end
 
-
 function _M.server_ver(self)
     return self._server_ver
 end
 
-
 local function send_query(self, query)
     if self.state ~= STATE_CONNECTED then
-        return nil, "cannot send query in the current context: "
-                    .. (self.state or "nil")
+        return nil, 'cannot send query in the current context: '
+                    .. (self.state or 'nil')
     end
 
     local sock = self.sock
     if not sock then
-        return nil, "not initialized"
+        return nil, 'not initialized'
     end
 
     self.packet_no = -1
@@ -790,22 +767,21 @@ local function send_query(self, query)
 
     self.state = STATE_COMMAND_SENT
 
-    --print("packet sent ", bytes, " bytes")
+    --print('packet sent ', bytes, ' bytes')
 
     return bytes
 end
 _M.send_query = send_query
 
-
 local function read_result(self, est_nrows)
     if self.state ~= STATE_COMMAND_SENT then
-        return nil, "cannot read result in the current context: "
-                    .. (self.state or "nil")
+        return nil, 'cannot read result in the current context: '
+                    .. (self.state or 'nil')
     end
 
     local sock = self.sock
     if not sock then
-        return nil, "not initialized"
+        return nil, 'not initialized'
     end
 
     local packet, typ, err = _recv_packet(self)
@@ -813,7 +789,7 @@ local function read_result(self, est_nrows)
         return nil, err
     end
 
-    if typ == "ERR" then
+    if typ == 'ERR' then
         self.state = STATE_CONNECTED
 
         local errno, msg, sqlstate = _parse_err_packet(packet)
@@ -823,7 +799,7 @@ local function read_result(self, est_nrows)
     if typ == 'OK' then
         local res = _parse_ok_packet(packet)
         if res and band(res.server_status, SERVER_MORE_RESULTS_EXISTS) ~= 0 then
-            return res, "again"
+            return res, 'again'
         end
 
         self.state = STATE_CONNECTED
@@ -833,16 +809,16 @@ local function read_result(self, est_nrows)
     if typ ~= 'DATA' then
         self.state = STATE_CONNECTED
 
-        return nil, "packet type " .. typ .. " not supported"
+        return nil, 'packet type ' .. typ .. ' not supported'
     end
 
     -- typ == 'DATA'
 
-    --print("read the result set header packet")
+    --print('read the result set header packet')
 
     local field_count, extra = _parse_result_set_header_packet(packet)
 
-    --print("field count: ", field_count)
+    --print('field count: ', field_count)
 
     local cols = new_tab(field_count, 0)
     for i = 1, field_count do
@@ -860,8 +836,8 @@ local function read_result(self, est_nrows)
     end
 
     if typ ~= 'EOF' then
-        return nil, "unexpected packet type " .. typ .. " while eof packet is "
-            .. "expected"
+        return nil, 'unexpected packet type ' .. typ .. ' while eof packet is '
+            .. 'expected'
     end
 
     -- typ == 'EOF'
@@ -871,7 +847,7 @@ local function read_result(self, est_nrows)
     local rows = new_tab(est_nrows or 4, 0)
     local i = 0
     while true do
-        --print("reading a row")
+        --print('reading a row')
 
         packet, typ, err = _recv_packet(self)
         if not packet then
@@ -881,10 +857,10 @@ local function read_result(self, est_nrows)
         if typ == 'EOF' then
             local warning_count, status_flags = _parse_eof_packet(packet)
 
-            --print("status flags: ", status_flags)
+            --print('status flags: ', status_flags)
 
             if band(status_flags, SERVER_MORE_RESULTS_EXISTS) ~= 0 then
-                return rows, "again", cols
+                return rows, 'again', cols
             end
 
             break
@@ -907,17 +883,15 @@ local function read_result(self, est_nrows)
 end
 _M.read_result = read_result
 
-
 function _M.query(self, query, est_nrows)
     local bytes, err = send_query(self, query)
     if not bytes then
-        return nil, "failed to send query: " .. err
+        return nil, 'failed to send query: ' .. err
     end
 
     return read_result(self, est_nrows)
 end
 
-
 function _M.set_compact_arrays(self, value)
     self.compact = value
 end