Description:
------------
Socket streams do not implement the PHP_STREAM_OPTION_WRITE_BUFFER call, and the stream chunk size is always fixed at 8192 bytes.

This is not a problem with SOCK_STREAM type sockets, but with SOCK_DGRAM is breaks the datagrams if they are more than 8192 bytes (which is IMHO a bug).

Here is a patch against 5.3.1 to add support for stream_set_write_buffer() with socket streams:

--- main/streams/xp_socket.c.orig       2010-01-17 19:56:39.000000000 +0100
+++ main/streams/xp_socket.c    2010-01-17 19:59:34.000000000 +0100
@@ -266,6 +266,7 @@
        int oldmode, flags;
        php_netstream_data_t *sock = (php_netstream_data_t*)stream->abstract;
        php_stream_xport_param *xparam;
+       size_t size;

        switch(option) {
                case PHP_STREAM_OPTION_CHECK_LIVENESS:
@@ -400,6 +401,14 @@
                                        return PHP_STREAM_OPTION_RETURN_NOTIMPL;
                        }

+               case PHP_STREAM_OPTION_WRITE_BUFFER:
+                       if (ptrparam)
+                               size = *(size_t *)ptrparam;
+                       else
+                               size = PHP_SOCK_CHUNK_SIZE;
+                       php_stream_set_chunk_size(stream, size);
+                       return PHP_STREAM_OPTION_RETURN_OK;
+
                default:
                        return PHP_STREAM_OPTION_RETURN_NOTIMPL;
        }