optimize: corrected the initial table size of req socket objects.

The req socket uses two slots in array and three slots in hash at most.

At first it uses one array slot and one hash slot:
array part: upstream udata
hash part: __index

After calling settimeouts, it uses two array slots and three hash slots:

array part:
    [1] upstream udata
    [2] connect timeout
hash part:
    __index
    [4] send timeout
    [5] read timeout

Signed-off-by: Yichun Zhang (agentzh) <agentzh@gmail.com>

Author: spacewander

src/ngx_http_lua_socket_tcp.c

@@ -4390,7 +4390,7 @@ ngx_http_lua_req_socket(lua_State *L)
         r->request_body = rb;
     }
 
-    lua_createtable(L, 3 /* narr */, 1 /* nrec */); /* the object */
+    lua_createtable(L, 2 /* narr */, 3 /* nrec */); /* the object */
 
     if (raw) {
         lua_pushlightuserdata(L, &ngx_http_lua_raw_req_socket_metatable_key);

t/062-count.t

@@ -494,3 +494,77 @@ GET /test
 n = 6
 --- no_error_log
 [error]
+
+
+
+=== TEST 22: entries under the req raw sockets
+--- config
+        location = /test {
+            content_by_lua_block {
+                local narr = 0
+                local nrec = 0
+                ngx.req.read_body()
+                local sock, err = ngx.req.socket(true)
+                if not sock then
+                    ngx.log(ngx.ERR, "server: failed to get raw req socket: ", err)
+                    return
+                end
+                sock:settimeouts(1, 2, 3)
+                for k, v in ipairs(sock) do
+                    narr = narr + 1
+                end
+                for k, v in pairs(sock) do
+                    nrec = nrec + 1
+                end
+                -- include '__index'
+                nrec = nrec - narr + 1
+
+                local ok, err = sock:send("HTTP/1.1 200 OK\r\n\r\nnarr = "..narr.."\nnrec = "..nrec.."\n")
+                if not ok then
+                    ngx.log(ngx.ERR, "failed to send: ", err)
+                    return
+                end
+            }
+        }
+--- request
+GET /test
+--- response_body
+narr = 2
+nrec = 3
+--- no_error_log
+[error]
+
+
+
+=== TEST 23: entries under the req sockets
+--- config
+        location = /test {
+            content_by_lua_block {
+                local narr = 0
+                local nrec = 0
+                local sock, err = ngx.req.socket()
+                if not sock then
+                    ngx.log(ngx.ERR, "server: failed to get req socket: ", err)
+                    return
+                end
+                sock:settimeouts(1, 2, 3)
+                for k, v in ipairs(sock) do
+                    narr = narr + 1
+                end
+                for k, v in pairs(sock) do
+                    nrec = nrec + 1
+                end
+                -- include '__index'
+                nrec = nrec - narr + 1
+
+                ngx.say("narr = "..narr.."\nnrec = "..nrec)
+            }
+        }
+--- request
+POST /test
+hello world
+--- response_body
+narr = 2
+nrec = 3
+--- no_error_log
+[error]