diff options
Diffstat (limited to 'src/util/server_tc.c')
-rw-r--r-- | src/util/server_tc.c | 247 |
1 files changed, 247 insertions, 0 deletions
diff --git a/src/util/server_tc.c b/src/util/server_tc.c new file mode 100644 index 0000000..ce40db1 --- /dev/null +++ b/src/util/server_tc.c @@ -0,0 +1,247 @@ +/* + This file is part of GNUnet. + (C) 2009 Christian Grothoff (and other contributing authors) + + GNUnet is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published + by the Free Software Foundation; either version 2, or (at your + option) any later version. + + GNUnet is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + General Public License for more details. + + You should have received a copy of the GNU General Public License + along with GNUnet; see the file COPYING. If not, write to the + Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. +*/ + +/** + * @file util/server_tc.c + * @brief convenience functions for transmission of + * complex responses as a server + * @author Christian Grothoff + */ + +#include "platform.h" +#include "gnunet_common.h" +#include "gnunet_connection_lib.h" +#include "gnunet_scheduler_lib.h" +#include "gnunet_server_lib.h" +#include "gnunet_time_lib.h" + + +#define LOG(kind,...) GNUNET_log_from (kind, "util", __VA_ARGS__) + + +/** + * How much buffer space do we want to have at least + * before transmitting another increment? + */ +#define MIN_BLOCK_SIZE 128 + + + +struct GNUNET_SERVER_TransmitContext +{ + /** + * Which client are we transmitting to? + */ + struct GNUNET_SERVER_Client *client; + + /** + * Transmission buffer. (current offset for writing). + */ + char *buf; + + /** + * Number of bytes in buf. + */ + size_t total; + + /** + * Offset for writing in buf. + */ + size_t off; + + /** + * Timeout for this request. + */ + struct GNUNET_TIME_Absolute timeout; +}; + + +/** + * Helper function for incremental transmission of the response. + */ +static size_t +transmit_response (void *cls, size_t size, void *buf) +{ + struct GNUNET_SERVER_TransmitContext *tc = cls; + size_t msize; + + if (buf == NULL) + { + GNUNET_SERVER_transmit_context_destroy (tc, GNUNET_SYSERR); + return 0; + } + if (tc->total - tc->off > size) + msize = size; + else + msize = tc->total - tc->off; + memcpy (buf, &tc->buf[tc->off], msize); + tc->off += msize; + if (tc->total == tc->off) + { + + GNUNET_SERVER_receive_done (tc->client, GNUNET_OK); + GNUNET_SERVER_client_drop (tc->client); + GNUNET_free_non_null (tc->buf); + GNUNET_free (tc); + } + else + { + if (NULL == + GNUNET_SERVER_notify_transmit_ready (tc->client, + GNUNET_MIN (MIN_BLOCK_SIZE, + tc->total - tc->off), + GNUNET_TIME_absolute_get_remaining + (tc->timeout), &transmit_response, + tc)) + { + GNUNET_break (0); + GNUNET_SERVER_transmit_context_destroy (tc, GNUNET_SYSERR); + } + } + return msize; +} + + +/** + * Create a new transmission context for the + * given client. + * + * @param client client to create the context for. + * @return NULL on error + */ +struct GNUNET_SERVER_TransmitContext * +GNUNET_SERVER_transmit_context_create (struct GNUNET_SERVER_Client *client) +{ + struct GNUNET_SERVER_TransmitContext *tc; + + GNUNET_assert (client != NULL); + tc = GNUNET_malloc (sizeof (struct GNUNET_SERVER_TransmitContext)); + GNUNET_SERVER_client_keep (client); + tc->client = client; + return tc; +} + + +/** + * Append a message to the transmission context. + * All messages in the context will be sent by + * the transmit_context_run method. + * + * @param tc context to use + * @param data what to append to the result message + * @param length length of data + * @param type type of the message + */ +void +GNUNET_SERVER_transmit_context_append_data (struct GNUNET_SERVER_TransmitContext + *tc, const void *data, + size_t length, uint16_t type) +{ + struct GNUNET_MessageHeader *msg; + size_t size; + + GNUNET_assert (length < GNUNET_SERVER_MAX_MESSAGE_SIZE); + size = length + sizeof (struct GNUNET_MessageHeader); + GNUNET_assert (size > length); + tc->buf = GNUNET_realloc (tc->buf, tc->total + size); + msg = (struct GNUNET_MessageHeader *) &tc->buf[tc->total]; + tc->total += size; + msg->size = htons (size); + msg->type = htons (type); + memcpy (&msg[1], data, length); +} + + +/** + * Append a message to the transmission context. + * All messages in the context will be sent by + * the transmit_context_run method. + * + * @param tc context to use + * @param msg message to append + */ +void +GNUNET_SERVER_transmit_context_append_message (struct + GNUNET_SERVER_TransmitContext + *tc, + const struct GNUNET_MessageHeader + *msg) +{ + struct GNUNET_MessageHeader *m; + uint16_t size; + + size = ntohs (msg->size); + tc->buf = GNUNET_realloc (tc->buf, tc->total + size); + m = (struct GNUNET_MessageHeader *) &tc->buf[tc->total]; + tc->total += size; + memcpy (m, msg, size); +} + + +/** + * Execute a transmission context. If there is + * an error in the transmission, the receive_done + * method will be called with an error code (GNUNET_SYSERR), + * otherwise with GNUNET_OK. + * + * @param tc transmission context to use + * @param timeout when to time out and abort the transmission + */ +void +GNUNET_SERVER_transmit_context_run (struct GNUNET_SERVER_TransmitContext *tc, + struct GNUNET_TIME_Relative timeout) +{ + tc->timeout = GNUNET_TIME_relative_to_absolute (timeout); + if (NULL == + GNUNET_SERVER_notify_transmit_ready (tc->client, + GNUNET_MIN (MIN_BLOCK_SIZE, + tc->total), timeout, + &transmit_response, tc)) + { + GNUNET_break (0); + GNUNET_SERVER_transmit_context_destroy (tc, GNUNET_SYSERR); + } +} + + +/** + * Destroy a transmission context. This function must not be called + * after 'GNUNET_SERVER_transmit_context_run'. + * + * @param tc transmission context to destroy + * @param success code to give to 'GNUNET_SERVER_receive_done' for + * the client: GNUNET_OK to keep the connection open and + * continue to receive + * GNUNET_NO to close the connection (normal behavior) + * GNUNET_SYSERR to close the connection (signal + * serious error) + */ +void +GNUNET_SERVER_transmit_context_destroy (struct GNUNET_SERVER_TransmitContext + *tc, int success) +{ + GNUNET_SERVER_receive_done (tc->client, success); + GNUNET_SERVER_client_drop (tc->client); + GNUNET_free_non_null (tc->buf); + GNUNET_free (tc); +} + + +/* end of server_tc.c */ |