1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
|
%%%-------------------------------------------------------------------
%%% File : mysql_recv.erl
%%% Author : Fredrik Thulin <ft@it.su.se>
%%% Descrip.: Handles data being received on a MySQL socket. Decodes
%%% per-row framing and sends each row to parent.
%%%
%%% Created : 4 Aug 2005 by Fredrik Thulin <ft@it.su.se>
%%%
%%% Note : All MySQL code was written by Magnus Ahltorp, originally
%%% in the file mysql.erl - I just moved it here.
%%%
%%% Copyright (c) 2001-2004 Kungliga Tekniska Högskolan
%%% See the file COPYING
%%%
%%% Signals this receiver process can send to it's parent
%%% (the parent is a mysql_conn connection handler) :
%%%
%%% {mysql_recv, self(), data, Packet, Num}
%%% {mysql_recv, self(), closed, {error, Reason}}
%%% {mysql_recv, self(), closed, normal}
%%%
%%% Internally (from inside init/4 to start_link/4) the
%%% following signals may be sent to the parent process :
%%%
%%% {mysql_recv, self(), init, {ok, Sock}}
%%% {mysql_recv, self(), init, {error, E}}
%%%
%%%-------------------------------------------------------------------
-module(mysql_recv).
%%--------------------------------------------------------------------
%% External exports (should only be used by the 'mysql_conn' module)
%%--------------------------------------------------------------------
-export([start_link/4
]).
-record(state, {
socket,
parent,
log_fun,
data
}).
-define(SECURE_CONNECTION, 32768).
-define(CONNECT_TIMEOUT, 5000).
%%====================================================================
%% External functions
%%====================================================================
%%--------------------------------------------------------------------
%% Function: start_link(Host, Port, LogFun, Parent)
%% Host = string()
%% Port = integer()
%% LogFun = undefined | function() of arity 3
%% Parent = pid(), process that should get received frames
%% Descrip.: Start a process that connects to Host:Port and waits for
%% data. When it has received a MySQL frame, it sends it to
%% Parent and waits for the next frame.
%% Returns : {ok, RecvPid, Socket} |
%% {error, Reason}
%% RecvPid = pid(), receiver process pid
%% Socket = term(), gen_tcp socket
%% Reason = atom() | string()
%%--------------------------------------------------------------------
start_link(Host, Port, LogFun, Parent) when is_list(Host), is_integer(Port) ->
RecvPid =
spawn_link(fun () ->
init(Host, Port, LogFun, Parent)
end),
%% wait for the socket from the spawned pid
receive
{mysql_recv, RecvPid, init, {error, E}} ->
{error, E};
{mysql_recv, RecvPid, init, {ok, Socket}} ->
{ok, RecvPid, Socket}
after ?CONNECT_TIMEOUT ->
catch exit(RecvPid, kill),
{error, "timeout"}
end.
%%====================================================================
%% Internal functions
%%====================================================================
%%--------------------------------------------------------------------
%% Function: init((Host, Port, LogFun, Parent)
%% Host = string()
%% Port = integer()
%% LogFun = undefined | function() of arity 3
%% Parent = pid(), process that should get received frames
%% Descrip.: Connect to Host:Port and then enter receive-loop.
%% Returns : error | never returns
%%--------------------------------------------------------------------
init(Host, Port, LogFun, Parent) ->
case gen_tcp:connect(Host, Port, [binary, {packet, 0}]) of
{ok, Sock} ->
Parent ! {mysql_recv, self(), init, {ok, Sock}},
State = #state{socket = Sock,
parent = Parent,
log_fun = LogFun,
data = <<>>
},
loop(State);
E ->
mysql:log(LogFun, error,
"mysql_recv: Failed connecting to ~p:~p : ~p",
[Host, Port, E]),
Msg = lists:flatten(io_lib:format("connect failed : ~p", [E])),
Parent ! {mysql_recv, self(), init, {error, Msg}}
end.
%%--------------------------------------------------------------------
%% Function: loop(State)
%% State = state record()
%% Descrip.: The main loop. Wait for data from our TCP socket and act
%% on received data or signals that our socket was closed.
%% Returns : error | never returns
%%--------------------------------------------------------------------
loop(State) ->
Sock = State#state.socket,
receive
{tcp, Sock, InData} ->
NewData = list_to_binary([State#state.data, InData]),
%% send data to parent if we have enough data
Rest = sendpacket(State#state.parent, NewData),
loop(State#state{data = Rest});
{tcp_error, Sock, Reason} ->
mysql:log(State#state.log_fun, error, "mysql_recv: "
"Socket ~p closed : ~p", [Sock, Reason]),
State#state.parent ! {mysql_recv, self(), closed,
{error, Reason}},
error;
{tcp_closed, Sock} ->
mysql:log(State#state.log_fun, debug, "mysql_recv: "
"Socket ~p closed", [Sock]),
State#state.parent ! {mysql_recv, self(), closed, normal},
error
end.
%%--------------------------------------------------------------------
%% Function: sendpacket(Parent, Data)
%% Parent = pid()
%% Data = binary()
%% Descrip.: Check if we have received one or more complete frames by
%% now, and if so - send them to Parent.
%% Returns : Rest = binary()
%%--------------------------------------------------------------------
%% send data to parent if we have enough data
sendpacket(Parent, Data) ->
case Data of
<<Length:24/little, Num:8, D/binary>> ->
if
Length =< size(D) ->
{Packet, Rest} = split_binary(D, Length),
Parent ! {mysql_recv, self(), data, Packet, Num},
sendpacket(Parent, Rest);
true ->
Data
end;
_ ->
Data
end.
|
