Changed send function.

FIX

@@ -1,3 +1,7 @@
+UDP has a reasonable maximum datagram size
+receive accepts the prefix optional argument
+send doesn't support multiple arguments anymore
+send allows the selection of the substring to be sent
 fix bug that caused select return tables not to be associative on windows
 compiles with g++
 new sample unix domain support

TODO

@@ -1,4 +1,7 @@
 
+fix manual for send and receive
+add thanks to mike
+
 change sock:send to use indices just like string.sub?
 use mike's "don't set to blocking before closing unless needed" patch?
 take a look at DB's smtp patch

doc/introduction.html

@@ -113,7 +113,7 @@ The core LuaSocket is almost entirely implemented in C. It is
 usually available as a dynamic library which the interpreter can load 
 with the help of a loader module written in Lua. 
 Beginning with version 2.0 and following the Lua 5.0 trend, all LuaSocket
-functionality is defined inside tables (or rather a namespaces). No global
+functionality is defined inside tables (or rather namespaces). No global
 variables are ever created.
 Namespaces are obtained with the <tt>require</tt> Lua function, which loads
 and initializes any required library and returns the namespace. 

doc/tcp.html

@@ -260,7 +260,7 @@ method returns <b><tt>nil</tt></b> followed by an error message.
 <!-- receive ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ -->
 
 <p class=name id=receive>
-client:<b>receive(</b>[pattern]<b>)</b>
+client:<b>receive(</b>[pattern [, prefix]]<b>)</b>
 </p>
 
 <p class=description>
@@ -283,6 +283,11 @@ the returned line. This is the default pattern;
 of bytes from the socket.
 </ul>
 
+<p class=parameters>
+<tt>Prefix</tt> is an optional string to be concatenated to the beginning
+of any received data before return.
+</p>
+
 <p class=return>
 If successful, the method returns the received pattern. In case of error,
 the method returns <tt><b>nil</b></tt> followed by an error message which
@@ -305,18 +310,18 @@ too.
 <!-- send +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ -->
 
 <p class=name id=send>
-client:<b>send(</b>string<sub>1</sub> [,
-string<sub>2</sub>, ... string<sub>N</sub>]<b>)</b>
+client:<b>send(</b>data [, i [, j]]<b>)</b>
 </p>
 
 <p class=description>
-Sends data through client object.
+Sends <tt>data</tt> through client object.
 </p>
 
 <p class=parameters>
-All parameters should be strings. For small strings, it is always better to
-concatenate them in Lua (with the '<tt>..</tt>' operator) and pass the 
-result to LuaSocket instead of passing several independent strings.
+<tt>Data</tt> is the string to be sent. The optional arguments
+<tt>i</tt> and <tt>j</tt> work exactly like the standard
+<tt>string.sub</tt> Lua function to allow the selection of a 
+substring to be sent.
 </p>
 
 <p class=return>
@@ -341,6 +346,22 @@ Alas, it wasn't returning <tt><b>nil</b></tt> in case of
 error. So it was changed again in beta. 
 </p>
 
+<p class=note>
+<b>Also important</b>: 
+In order to better support non-blocking I/O and to discourage
+bad practice, the <tt>send</tt> method now only sends one string
+per call. The other optional arguments allow the user to select 
+a substring to be sent in a much more efficient way than 
+using <tt>string.sub</tt>.
+</p>
+
+<p class=note>
+Note: Output is <em>not</em> buffered. For small strings, 
+it is always better to concatenate them in Lua 
+(with the '<tt>..</tt>' operator) and send the result in one call 
+instead of calling the method several times. 
+</p>
+
 <!-- setoption ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ -->
 
 <p class=name id=setoption>

src/buffer.c

@@ -64,23 +64,24 @@ int buf_meth_getstats(lua_State *L, p_buf buf) {
 \*-------------------------------------------------------------------------*/
 int buf_meth_send(lua_State *L, p_buf buf) {
     int top = lua_gettop(L);
-    size_t total = 0;
-    int arg, err = IO_DONE;
     p_tm tm = tm_markstart(buf->tm);
-    for (arg = 2; arg <= top; arg++) { /* first arg is socket object */
-        size_t sent, count;
-        const char *data = luaL_optlstring(L, arg, NULL, &count);
-        if (!data || err != IO_DONE) break;
-        err = sendraw(buf, data, count, &sent);
-        total += sent;
-    }
+    int err = IO_DONE;
+    size_t size, sent;
+    const char *data = luaL_checklstring(L, 2, &size);
+    ssize_t start = (ssize_t) luaL_optnumber(L, 3, 1);
+    ssize_t end = (ssize_t) luaL_optnumber(L, 4, -1);
+    if (start < 0) start = size+start+1;
+    if (end < 0) end = size+end+1;
+    if (start < 1) start = 1;
+    if (end > size) end = size;
+    if (start <= end) err = sendraw(buf, data+start-1, end-start+1, &sent);
     /* check if there was an error */
     if (err != IO_DONE) {
         lua_pushnil(L);
         lua_pushstring(L, buf->io->error(buf->io->ctx, err)); 
-        lua_pushnumber(L, total);
+        lua_pushnumber(L, sent);
     } else {
-        lua_pushnumber(L, total);
+        lua_pushnumber(L, sent);
         lua_pushnil(L);
         lua_pushnil(L);
     }

src/wsocket.c

@@ -373,12 +373,10 @@ static const char *wstrerror(int err) {
         case WSANOTINITIALISED: 
             return "Successful WSAStartup not yet performed";
         case WSAEDISCON: return "Graceful shutdown in progress";
-        case WSATYPE_NOT_FOUND: return "Class type not found";
         case WSAHOST_NOT_FOUND: return "Host not found";
         case WSATRY_AGAIN: return "Nonauthoritative host not found";
         case WSANO_RECOVERY: return "Nonrecoverable name lookup error"; 
         case WSANO_DATA: return "Valid name, no data record of requested type";
-        case WSASYSCALLFAILURE: return "System call failure";
         default: return "Unknown error";
     }
 }

test/testclnt.lua

@@ -25,7 +25,7 @@ function remote(...)
     s = string.gsub(s, "\n", ";")
     s = string.gsub(s, "%s+", " ")
     s = string.gsub(s, "^%s*", "")
-    control:send(s, "\n")
+    control:send(s .. "\n")
     control:receive()
 end
 
@@ -120,7 +120,7 @@ function test_mixed(len)
     local bp1, bp2, bp3, bp4
 remote (string.format("str = data:receive(%d)", 
             string.len(p1)+string.len(p2)+string.len(p3)+string.len(p4)))
-    sent, err = data:send(p1, p2, p3, p4)
+    sent, err = data:send(p1..p2..p3..p4)
     if err then fail(err) end
 remote "data:send(str); data:close()"
     bp1, err = data:receive()
@@ -144,9 +144,9 @@ function test_asciiline(len)
     str10 = string.rep("aZb.c#dAe?", math.floor(len/10))
     str = str .. str10
 remote "str = data:receive()"
-    sent, err = data:send(str, "\n")
+    sent, err = data:send(str.."\n")
     if err then fail(err) end
-remote "data:send(str, '\\n')"
+remote "data:send(str ..'\\n')"
     back, err = data:receive()
     if err then fail(err) end
     if back == str then pass("lines match")
@@ -162,9 +162,9 @@ function test_rawline(len)
             math.floor(len/10))
     str = str .. str10
 remote "str = data:receive()"
-    sent, err = data:send(str, "\n")
+    sent, err = data:send(str.."\n")
     if err then fail(err) end
-remote "data:send(str, '\\n')"
+remote "data:send(str..'\\n')"
     back, err = data:receive()
     if err then fail(err) end
     if back == str then pass("lines match")
@@ -457,7 +457,62 @@ function getstats_test()
     print("ok")
 end
 
+
 ------------------------------------------------------------------------
+function test_nonblocking(size) 
+    reconnect()
+remote(string.format([[
+    data:send(string.rep("a", %d))
+    socket.sleep(0.5)
+    data:send(string.rep("b", %d))
+]], size, size))
+    local err = "timeout"
+    local part = ""
+    local str
+    data:settimeout(0)
+    while 1 do
+        str, err, part = data:receive(2*size - string.len(part), part)
+        if err ~= "timeout" then break end
+    end
+    assert(str == (string.rep("a", size) .. string.rep("b", size)))
+    reconnect()
+remote(string.format([[
+    str = data:receive(%d)
+    socket.sleep(0.5)
+    str = data:receive(%d, str)
+    str = data:receive("*l", str)
+    data:send(str)
+    data:send("\n")
+]], size, size))
+    data:settimeout(0)
+    local sofar = 1
+    while 1 do
+        _, err, part = data:send(str, sofar)
+        if err ~= "timeout" then break end
+        sofar = sofar + part
+    end
+    data:send("\n")
+    data:settimeout(-1)
+    local back = data:receive()
+    assert(back == str)
+    print("ok")
+end
+
+
+------------------------------------------------------------------------
+test("non-blocking transfer")
+test_nonblocking(1)
+test_nonblocking(17)
+test_nonblocking(200)
+test_nonblocking(4091)
+test_nonblocking(80199)
+test_nonblocking(8000000)
+test_nonblocking(80199)
+test_nonblocking(4091)
+test_nonblocking(200)
+test_nonblocking(17)
+test_nonblocking(1)
+
 test("method registration")
 test_methods(socket.tcp(), {
     "accept",
@@ -548,7 +603,6 @@ test_mixed(1)
 
 
 test("binary line")
-reconnect()
 test_rawline(1)
 test_rawline(17)
 test_rawline(200)
@@ -562,24 +616,6 @@ test_rawline(17)
 test_rawline(1)
 
 test("raw transfer")
-reconnect()
-test_raw(1)
-test_raw(17)
-test_raw(200)
-test_raw(4091)
-test_raw(80199)
-test_raw(8000000)
-test_raw(80199)
-test_raw(4091)
-test_raw(200)
-test_raw(17)
-test_raw(1)
-
-test("non-blocking transfer")
-reconnect()
--- the value is not important, we only want 
--- to test non-blocking I/O anyways
-data:settimeout(200)
 test_raw(1)
 test_raw(17)
 test_raw(200)

test/testsrvr.lua

@@ -1,29 +1,14 @@
-socket = require"socket"
-
-host = host or "localhost"
-port = port or "8080"
-
-server, error = socket.bind(host, port)
-if not server then print("server: " .. tostring(error)) os.exit() end
-ack = "\n"
+socket = require("socket");
+host = host or "localhost";
+port = port or "8080";
+server = assert(socket.bind(host, port));
+ack = "\n";
 while 1 do
     print("server: waiting for client connection...");
-    control, error = server:accept()
-    assert(control, error)
-    -- control:setoption("nodelay", true)
+    control = assert(server:accept());
     while 1 do 
-        command, error = control:receive()
-        if error then
-            control:close()
-            print("server: closing connection...")
-            break
-        end
-        sent, error = control:send(ack)
-        if error then
-            control:close()
-            print("server: closing connection...")
-            break
-        end
-        (loadstring(command))()
+        command = assert(control:receive());
+        assert(control:send(ack));
+        (loadstring(command))();
     end
 end