X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=modules%2Faccess_output%2Fudp.c;h=dae64f1e477c6adf1f2a42e85680276a67252dc7;hb=73b7ed7fa3276a07d9312f833508bb5965afe12d;hp=a624016c23f7fdc33b355e4951824d9e2561305d;hpb=0a23f93ced9b31a297fe1e73c0e3dad84cce2fef;p=vlc diff --git a/modules/access_output/udp.c b/modules/access_output/udp.c index a624016c23..dae64f1e47 100644 --- a/modules/access_output/udp.c +++ b/modules/access_output/udp.c @@ -1,8 +1,8 @@ /***************************************************************************** * udp.c ***************************************************************************** - * Copyright (C) 2001, 2002 VideoLAN - * $Id: udp.c,v 1.9 2003/06/19 18:22:05 gbazin Exp $ + * Copyright (C) 2001-2007 the VideoLAN team + * $Id$ * * Authors: Laurent Aimar * Eric Petit @@ -19,22 +19,27 @@ * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA. + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA. *****************************************************************************/ /***************************************************************************** * Preamble *****************************************************************************/ -#include +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif + +#include +#include + #include #include -#include #include #include +#include -#include -#include -#include +#include +#include #ifdef HAVE_UNISTD_H # include @@ -43,75 +48,92 @@ #ifdef WIN32 # include # include -# ifndef IN_MULTICAST -# define IN_MULTICAST(a) IN_CLASSD(a) -# endif #else # include #endif -#include "network.h" +#include + +#define MAX_EMPTY_BLOCKS 200 -#define DEFAULT_PORT 1234 -#define LATENCY 100000 -#define MAX_ERROR 500000 /***************************************************************************** - * Exported prototypes + * Module descriptor *****************************************************************************/ -static int Open ( vlc_object_t * ); -static void Close ( vlc_object_t * ); - -static int Write( sout_access_out_t *, sout_buffer_t * ); -static int Seek ( sout_access_out_t *, off_t ); +static int Open ( vlc_object_t * ); +static void Close( vlc_object_t * ); -static void ThreadWrite( vlc_object_t * ); +#define SOUT_CFG_PREFIX "sout-udp-" -static sout_buffer_t *NewUDPPacket( sout_access_out_t *, mtime_t ); +#define CACHING_TEXT N_("Caching value (ms)") +#define CACHING_LONGTEXT N_( \ + "Default caching value for outbound UDP streams. This " \ + "value should be set in milliseconds." ) + +#define GROUP_TEXT N_("Group packets") +#define GROUP_LONGTEXT N_("Packets can be sent one by one at the right time " \ + "or by groups. You can choose the number " \ + "of packets that will be sent at a time. It " \ + "helps reducing the scheduling load on " \ + "heavily-loaded systems." ) + +vlc_module_begin () + set_description( N_("UDP stream output") ) + set_shortname( "UDP" ) + set_category( CAT_SOUT ) + set_subcategory( SUBCAT_SOUT_ACO ) + add_integer( SOUT_CFG_PREFIX "caching", DEFAULT_PTS_DELAY / 1000, NULL, CACHING_TEXT, CACHING_LONGTEXT, true ) + add_integer( SOUT_CFG_PREFIX "group", 1, NULL, GROUP_TEXT, GROUP_LONGTEXT, + true ) + add_obsolete_integer( SOUT_CFG_PREFIX "late" ) + add_obsolete_bool( SOUT_CFG_PREFIX "raw" ) + + set_capability( "sout access", 0 ) + add_shortcut( "udp" ) + set_callbacks( Open, Close ) +vlc_module_end () /***************************************************************************** - * Module descriptor + * Exported prototypes *****************************************************************************/ -#define CACHING_TEXT N_("caching value in ms") -#define CACHING_LONGTEXT N_( \ - "Allows you to modify the default caching value for udp streams. This " \ - "value should be set in miliseconds units." ) - -vlc_module_begin(); - set_description( _("UDP stream ouput") ); - add_category_hint( N_("udp stream output"), NULL , VLC_TRUE ); - add_integer( "udp-sout-caching", DEFAULT_PTS_DELAY / 1000, NULL, CACHING_TEXT, CACHING_LONGTEXT, VLC_TRUE ); - set_capability( "sout access", 100 ); - add_shortcut( "udp" ); - add_shortcut( "rtp" ); // Will work only with ts muxer - set_callbacks( Open, Close ); -vlc_module_end(); - -typedef struct sout_access_thread_s -{ - VLC_COMMON_MEMBERS - sout_instance_t *p_sout; +static const char *const ppsz_sout_options[] = { + "caching", + "group", + NULL +}; - sout_fifo_t *p_fifo; +/* Options handled by the libvlc network core */ +static const char *const ppsz_core_options[] = { + "dscp", + "ttl", + "miface", + "miface-addr", + NULL +}; - int i_handle; +static ssize_t Write ( sout_access_out_t *, block_t * ); +static int Seek ( sout_access_out_t *, off_t ); +static int Control( sout_access_out_t *, int, va_list ); -} sout_access_thread_t; +static void* ThreadWrite( void * ); +static block_t *NewUDPPacket( sout_access_out_t *, mtime_t ); struct sout_access_out_sys_t { - int b_rtpts; // 1 if add rtp/ts header - uint16_t i_sequence_number; - uint32_t i_ssrc; + mtime_t i_caching; + int i_handle; + bool b_mtu_warning; + size_t i_mtu; - unsigned int i_mtu; - - sout_buffer_t *p_buffer; - - sout_access_thread_t *p_thread; + block_fifo_t *p_fifo; + block_fifo_t *p_empty_blocks; + block_t *p_buffer; + vlc_thread_t thread; }; +#define DEFAULT_PORT 1234 + /***************************************************************************** * Open: open the file *****************************************************************************/ @@ -120,110 +142,101 @@ static int Open( vlc_object_t *p_this ) sout_access_out_t *p_access = (sout_access_out_t*)p_this; sout_access_out_sys_t *p_sys; - char *psz_parser; - char *psz_dst_addr; + char *psz_dst_addr = NULL; int i_dst_port; - module_t *p_network; - network_socket_t socket_desc; + int i_handle; + + config_ChainParse( p_access, SOUT_CFG_PREFIX, + ppsz_sout_options, p_access->p_cfg ); + config_ChainParse( p_access, "", + ppsz_core_options, p_access->p_cfg ); - if( !( p_sys = p_access->p_sys = - malloc( sizeof( sout_access_out_sys_t ) ) ) ) + if (var_Create (p_access, "dst-port", VLC_VAR_INTEGER) + || var_Create (p_access, "src-port", VLC_VAR_INTEGER) + || var_Create (p_access, "dst-addr", VLC_VAR_STRING) + || var_Create (p_access, "src-addr", VLC_VAR_STRING)) { - msg_Err( p_access, "Not enough memory" ); - return( VLC_EGENERIC ); + return VLC_ENOMEM; } + if( !( p_sys = malloc ( sizeof( *p_sys ) ) ) ) + return VLC_ENOMEM; + p_access->p_sys = p_sys; - if( p_access->psz_access != NULL && - !strcmp( p_access->psz_access, "rtp" ) ) - { - msg_Warn( p_access, "becarefull that rtp ouput work only with ts " - "payload(not an error)" ); - p_sys->b_rtpts = 1; - } - else + i_dst_port = DEFAULT_PORT; + char *psz_parser = psz_dst_addr = strdup( p_access->psz_path ); + if( !psz_dst_addr ) { - p_sys->b_rtpts = 0; + free( p_sys ); + return VLC_ENOMEM; } - psz_parser = strdup( p_access->psz_name ); - - psz_dst_addr = psz_parser; - i_dst_port = 0; + if (psz_parser[0] == '[') + psz_parser = strchr (psz_parser, ']'); - if ( *psz_parser == '[' ) + psz_parser = strchr (psz_parser ? psz_parser : psz_dst_addr, ':'); + if (psz_parser != NULL) { - while( *psz_parser && *psz_parser != ']' ) - { - psz_parser++; - } - } - while( *psz_parser && *psz_parser != ':' ) - { - psz_parser++; - } - if( *psz_parser == ':' ) - { - *psz_parser = '\0'; - psz_parser++; - i_dst_port = atoi( psz_parser ); - } - if( i_dst_port <= 0 ) - { - i_dst_port = DEFAULT_PORT; + *psz_parser++ = '\0'; + i_dst_port = atoi (psz_parser); } - p_sys->p_thread = - vlc_object_create( p_access, sizeof( sout_access_thread_t ) ); - if( !p_sys->p_thread ) - { - msg_Err( p_access, "out of memory" ); - return( VLC_EGENERIC ); - } + i_handle = net_ConnectDgram( p_this, psz_dst_addr, i_dst_port, -1, + IPPROTO_UDP ); + free (psz_dst_addr); - p_sys->p_thread->p_sout = p_access->p_sout; - p_sys->p_thread->b_die = 0; - p_sys->p_thread->b_error= 0; - p_sys->p_thread->p_fifo = sout_FifoCreate( p_access->p_sout ); - - socket_desc.i_type = NETWORK_UDP; - socket_desc.psz_server_addr = psz_dst_addr; - socket_desc.i_server_port = i_dst_port; - socket_desc.psz_bind_addr = ""; - socket_desc.i_bind_port = 0; - p_sys->p_thread->p_private = (void*)&socket_desc; - if( !( p_network = module_Need( p_sys->p_thread, - "network", "" ) ) ) + if( i_handle == -1 ) { - msg_Err( p_access, "failed to open a connection (udp)" ); - return( VLC_EGENERIC ); + msg_Err( p_access, "failed to create raw UDP socket" ); + free (p_sys); + return VLC_EGENERIC; } - module_Unneed( p_sys->p_thread, p_network ); + else + { + char addr[NI_MAXNUMERICHOST]; + int port; - p_sys->p_thread->i_handle = socket_desc.i_handle; - p_sys->i_mtu = socket_desc.i_mtu; + if (net_GetSockAddress (i_handle, addr, &port) == 0) + { + msg_Dbg (p_access, "source: %s port %d", addr, port); + var_SetString (p_access, "src-addr", addr); + var_SetInteger (p_access, "src-port", port); + } - if( vlc_thread_create( p_sys->p_thread, "sout write thread", ThreadWrite, - VLC_THREAD_PRIORITY_OUTPUT, VLC_FALSE ) ) + if (net_GetPeerAddress (i_handle, addr, &port) == 0) + { + msg_Dbg (p_access, "destination: %s port %d", addr, port); + var_SetString (p_access, "dst-addr", addr); + var_SetInteger (p_access, "dst-port", port); + } + } + shutdown( i_handle, SHUT_RD ); + + p_sys->i_caching = UINT64_C(1000) + * var_GetInteger( p_access, SOUT_CFG_PREFIX "caching"); + p_sys->i_handle = i_handle; + p_sys->i_mtu = var_CreateGetInteger( p_this, "mtu" ); + p_sys->b_mtu_warning = false; + p_sys->p_fifo = block_FifoNew(); + p_sys->p_empty_blocks = block_FifoNew(); + p_sys->p_buffer = NULL; + + if( vlc_clone( &p_sys->thread, ThreadWrite, p_access, + VLC_THREAD_PRIORITY_HIGHEST ) ) { - msg_Err( p_access->p_sout, "cannot spawn sout access thread" ); - vlc_object_destroy( p_sys->p_thread ); - return( VLC_EGENERIC ); + msg_Err( p_access, "cannot spawn sout access thread" ); + block_FifoRelease( p_sys->p_fifo ); + block_FifoRelease( p_sys->p_empty_blocks ); + net_Close (i_handle); + free (p_sys); + return VLC_EGENERIC; } - srand( (uint32_t)mdate()); - p_sys->p_buffer = NULL; - p_sys->i_sequence_number = rand()&0xffff; - p_sys->i_ssrc = rand()&0xffffffff; - - p_access->pf_write = Write; - p_access->pf_seek = Seek; + p_access->pf_write = Write; + p_access->pf_seek = Seek; + p_access->pf_control = Control; - msg_Info( p_access, "Open: addr:`%s' port:`%d'", - psz_dst_addr, i_dst_port ); - - free( psz_dst_addr ); return VLC_SUCCESS; } @@ -232,88 +245,118 @@ static int Open( vlc_object_t *p_this ) *****************************************************************************/ static void Close( vlc_object_t * p_this ) { - sout_access_out_t *p_access = (sout_access_out_t*)p_this; - sout_access_out_sys_t *p_sys = p_access->p_sys; - int i; + sout_access_out_t *p_access = (sout_access_out_t*)p_this; + sout_access_out_sys_t *p_sys = p_access->p_sys; - p_sys->p_thread->b_die = 1; - for( i = 0; i < 10; i++ ) - { - sout_buffer_t *p_dummy; + vlc_cancel( p_sys->thread ); + vlc_join( p_sys->thread, NULL ); + block_FifoRelease( p_sys->p_fifo ); + block_FifoRelease( p_sys->p_empty_blocks ); - p_dummy = sout_BufferNew( p_access->p_sout, p_sys->i_mtu ); - p_dummy->i_dts = 0; - p_dummy->i_pts = 0; - p_dummy->i_length = 0; - sout_FifoPut( p_sys->p_thread->p_fifo, p_dummy ); - } - vlc_thread_join( p_sys->p_thread ); + if( p_sys->p_buffer ) block_Release( p_sys->p_buffer ); + + net_Close( p_sys->i_handle ); + free( p_sys ); +} - sout_FifoDestroy( p_access->p_sout, p_sys->p_thread->p_fifo ); +static int Control( sout_access_out_t *p_access, int i_query, va_list args ) +{ + (void)p_access; - if( p_sys->p_buffer ) + switch( i_query ) { - sout_BufferDelete( p_access->p_sout, p_sys->p_buffer ); - } - -#if defined( UNDER_CE ) - CloseHandle( (HANDLE)p_sys->p_thread->i_handle ); -#elif defined( WIN32 ) - closesocket( p_sys->p_thread->i_handle ); -#else - close( p_sys->p_thread->i_handle ); -#endif + case ACCESS_OUT_CONTROLS_PACE: + *va_arg( args, bool * ) = false; + break; - free( p_sys ); - msg_Info( p_access, "Close" ); + default: + return VLC_EGENERIC; + } + return VLC_SUCCESS; } /***************************************************************************** - * Read: standard read on a file descriptor. + * Write: standard write on a file descriptor. *****************************************************************************/ -static int Write( sout_access_out_t *p_access, sout_buffer_t *p_buffer ) +static ssize_t Write( sout_access_out_t *p_access, block_t *p_buffer ) { - sout_access_out_sys_t *p_sys = p_access->p_sys; - unsigned int i_write; + sout_access_out_sys_t *p_sys = p_access->p_sys; + int i_len = 0; while( p_buffer ) { - sout_buffer_t *p_next; - if( p_buffer->i_size > p_sys->i_mtu ) - { - msg_Warn( p_access, "arggggggggggggg packet size > mtu" ); - i_write = p_sys->i_mtu; - } - else + block_t *p_next; + int i_packets = 0; + mtime_t now = mdate(); + + if( !p_sys->b_mtu_warning && p_buffer->i_buffer > p_sys->i_mtu ) { - i_write = p_buffer->i_size; + msg_Warn( p_access, "packet size > MTU, you should probably " + "increase the MTU" ); + p_sys->b_mtu_warning = true; } - /* if we have enough data, enque the buffer */ + /* Check if there is enough space in the buffer */ if( p_sys->p_buffer && - p_sys->p_buffer->i_size + i_write > p_sys->i_mtu ) + p_sys->p_buffer->i_buffer + p_buffer->i_buffer > p_sys->i_mtu ) { - sout_FifoPut( p_sys->p_thread->p_fifo, p_sys->p_buffer ); + if( p_sys->p_buffer->i_dts + p_sys->i_caching < now ) + { + msg_Dbg( p_access, "late packet for UDP input (%"PRId64 ")", + now - p_sys->p_buffer->i_dts + - p_sys->i_caching ); + } + block_FifoPut( p_sys->p_fifo, p_sys->p_buffer ); p_sys->p_buffer = NULL; } - if( !p_sys->p_buffer ) + i_len += p_buffer->i_buffer; + while( p_buffer->i_buffer ) { - p_sys->p_buffer = NewUDPPacket( p_access, p_buffer->i_dts ); - } + size_t i_payload_size = p_sys->i_mtu; + size_t i_write = __MIN( p_buffer->i_buffer, i_payload_size ); - if( p_buffer->i_size > 0 ) - { - memcpy( p_sys->p_buffer->p_buffer + p_sys->p_buffer->i_size, + i_packets++; + + if( !p_sys->p_buffer ) + { + p_sys->p_buffer = NewUDPPacket( p_access, p_buffer->i_dts ); + if( !p_sys->p_buffer ) break; + } + + memcpy( p_sys->p_buffer->p_buffer + p_sys->p_buffer->i_buffer, p_buffer->p_buffer, i_write ); - p_sys->p_buffer->i_size += i_write; + + p_sys->p_buffer->i_buffer += i_write; + p_buffer->p_buffer += i_write; + p_buffer->i_buffer -= i_write; + if ( p_buffer->i_flags & BLOCK_FLAG_CLOCK ) + { + if ( p_sys->p_buffer->i_flags & BLOCK_FLAG_CLOCK ) + msg_Warn( p_access, "putting two PCRs at once" ); + p_sys->p_buffer->i_flags |= BLOCK_FLAG_CLOCK; + } + + if( p_sys->p_buffer->i_buffer == p_sys->i_mtu || i_packets > 1 ) + { + /* Flush */ + if( p_sys->p_buffer->i_dts + p_sys->i_caching < now ) + { + msg_Dbg( p_access, "late packet for udp input (%"PRId64 ")", + mdate() - p_sys->p_buffer->i_dts + - p_sys->i_caching ); + } + block_FifoPut( p_sys->p_fifo, p_sys->p_buffer ); + p_sys->p_buffer = NULL; + } } + p_next = p_buffer->p_next; - sout_BufferDelete( p_access->p_sout, p_buffer ); + block_Release( p_buffer ); p_buffer = p_next; } - return( p_sys->p_thread->b_error ? -1 : 0 ); + return i_len; } /***************************************************************************** @@ -321,97 +364,112 @@ static int Write( sout_access_out_t *p_access, sout_buffer_t *p_buffer ) *****************************************************************************/ static int Seek( sout_access_out_t *p_access, off_t i_pos ) { - - msg_Err( p_access, "udp sout access cannot seek" ); - return( -1 ); + (void) i_pos; + msg_Err( p_access, "UDP sout access cannot seek" ); + return -1; } /***************************************************************************** * NewUDPPacket: allocate a new UDP packet of size p_sys->i_mtu *****************************************************************************/ -static sout_buffer_t *NewUDPPacket( sout_access_out_t *p_access, mtime_t i_dts) +static block_t *NewUDPPacket( sout_access_out_t *p_access, mtime_t i_dts) { sout_access_out_sys_t *p_sys = p_access->p_sys; - sout_buffer_t *p_buffer; + block_t *p_buffer; - p_buffer = sout_BufferNew( p_access->p_sout, p_sys->i_mtu ); - p_buffer->i_dts = i_dts; - p_buffer->i_size = 0; - - if( p_sys->b_rtpts ) + while ( block_FifoCount( p_sys->p_empty_blocks ) > MAX_EMPTY_BLOCKS ) { - mtime_t i_timestamp = p_buffer->i_dts * 9 / 100; - - /* add rtp/ts header */ - p_buffer->p_buffer[0] = 0x80; - p_buffer->p_buffer[1] = 0x21; // mpeg2-ts - - p_buffer->p_buffer[2] = ( p_sys->i_sequence_number >> 8 )&0xff; - p_buffer->p_buffer[3] = p_sys->i_sequence_number&0xff; - p_sys->i_sequence_number++; - - p_buffer->p_buffer[4] = ( i_timestamp >> 24 )&0xff; - p_buffer->p_buffer[5] = ( i_timestamp >> 16 )&0xff; - p_buffer->p_buffer[6] = ( i_timestamp >> 8 )&0xff; - p_buffer->p_buffer[7] = i_timestamp&0xff; - - p_buffer->p_buffer[ 8] = ( p_sys->i_ssrc >> 24 )&0xff; - p_buffer->p_buffer[ 9] = ( p_sys->i_ssrc >> 16 )&0xff; - p_buffer->p_buffer[10] = ( p_sys->i_ssrc >> 8 )&0xff; - p_buffer->p_buffer[11] = p_sys->i_ssrc&0xff; + p_buffer = block_FifoGet( p_sys->p_empty_blocks ); + block_Release( p_buffer ); + } - p_buffer->i_size = 12; + if( block_FifoCount( p_sys->p_empty_blocks ) == 0 ) + { + p_buffer = block_Alloc( p_sys->i_mtu ); + } + else + { + p_buffer = block_FifoGet(p_sys->p_empty_blocks ); + p_buffer->i_flags = 0; + p_buffer = block_Realloc( p_buffer, 0, p_sys->i_mtu ); } + p_buffer->i_dts = i_dts; + p_buffer->i_buffer = 0; + return p_buffer; } /***************************************************************************** * ThreadWrite: Write a packet on the network at the good time. *****************************************************************************/ -static void ThreadWrite( vlc_object_t *p_this ) +static void* ThreadWrite( void *data ) { - sout_access_thread_t *p_thread = (sout_access_thread_t*)p_this; - sout_instance_t *p_sout = p_thread->p_sout; - sout_buffer_t *p_buffer; - mtime_t i_date, i_pts_delay; - - /* Get the i_pts_delay value */ - i_pts_delay = config_GetInt( p_this, "udp-sout-caching" ) * 1000; - - while( !p_thread->b_die && p_thread->p_fifo->i_depth < 5 ) - { - msleep( 10000 ); - } - if( p_thread->b_die ) - { - return; - } - p_buffer = sout_FifoShow( p_thread->p_fifo ); - i_date = mdate() + i_pts_delay - p_buffer->i_dts; + sout_access_out_t *p_access = data; + sout_access_out_sys_t *p_sys = p_access->p_sys; + mtime_t i_date_last = -1; + const unsigned i_group = var_GetInteger( p_access, + SOUT_CFG_PREFIX "group" ); + mtime_t i_to_send = i_group; + unsigned i_dropped_packets = 0; - while( 1 ) + for (;;) { - mtime_t i_wait; - - p_buffer = sout_FifoGet( p_thread->p_fifo ); + block_t *p_pk = block_FifoGet( p_sys->p_fifo ); + mtime_t i_date, i_sent; - if( p_thread->b_die ) return; + i_date = p_sys->i_caching + p_pk->i_dts; + if( i_date_last > 0 ) + { + if( i_date - i_date_last > 2000000 ) + { + if( !i_dropped_packets ) + msg_Dbg( p_access, "mmh, hole (%"PRId64" > 2s) -> drop", + i_date - i_date_last ); + + block_FifoPut( p_sys->p_empty_blocks, p_pk ); + + i_date_last = i_date; + i_dropped_packets++; + continue; + } + else if( i_date - i_date_last < -1000 ) + { + if( !i_dropped_packets ) + msg_Dbg( p_access, "mmh, packets in the past (%"PRId64")", + i_date_last - i_date ); + } + } - i_wait = i_date + p_buffer->i_dts; + block_cleanup_push( p_pk ); + i_to_send--; + if( !i_to_send || (p_pk->i_flags & BLOCK_FLAG_CLOCK) ) + { + mwait( i_date ); + i_to_send = i_group; + } + if ( send( p_sys->i_handle, p_pk->p_buffer, p_pk->i_buffer, 0 ) == -1 ) + msg_Warn( p_access, "send error: %m" ); + vlc_cleanup_pop(); - if( i_wait - mdate() > MAX_ERROR || i_wait - mdate() < -MAX_ERROR ) + if( i_dropped_packets ) { - msg_Warn( p_sout, "resetting clock" ); - i_date = mdate() + i_pts_delay - p_buffer->i_dts; + msg_Dbg( p_access, "dropped %i packets", i_dropped_packets ); + i_dropped_packets = 0; } - else + +#if 1 + i_sent = mdate(); + if ( i_sent > i_date + 20000 ) { - mwait( i_wait ); + msg_Dbg( p_access, "packet has been sent too late (%"PRId64 ")", + i_sent - i_date ); } +#endif - send( p_thread->i_handle, p_buffer->p_buffer, p_buffer->i_size, 0 ); + block_FifoPut( p_sys->p_empty_blocks, p_pk ); - sout_BufferDelete( p_sout, p_buffer ); + i_date_last = i_date; } + return NULL; }