2 This file is part of GNUnet.
3 (C) 2009 Christian Grothoff (and other contributing authors)
5 GNUnet is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 2, or (at your
8 option) any later version.
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
22 * @file util/server_tc.c
23 * @brief convenience functions for transmission of
24 * complex responses as a server
25 * @author Christian Grothoff
29 #include "gnunet_common.h"
30 #include "gnunet_connection_lib.h"
31 #include "gnunet_scheduler_lib.h"
32 #include "gnunet_server_lib.h"
33 #include "gnunet_time_lib.h"
38 * How much buffer space do we want to have at least
39 * before transmitting another increment?
41 #define MIN_BLOCK_SIZE 128
45 struct GNUNET_SERVER_TransmitContext
48 * Which client are we transmitting to?
50 struct GNUNET_SERVER_Client *client;
53 * Transmission buffer. (current offset for writing).
58 * Number of bytes in buf.
63 * Offset for writing in buf.
68 * Timeout for this request.
70 struct GNUNET_TIME_Absolute timeout;
75 * Helper function for incremental transmission of the response.
78 transmit_response (void *cls, size_t size, void *buf)
80 struct GNUNET_SERVER_TransmitContext *tc = cls;
85 GNUNET_SERVER_transmit_context_destroy (tc, GNUNET_SYSERR);
88 if (tc->total - tc->off > size)
91 msize = tc->total - tc->off;
92 memcpy (buf, &tc->buf[tc->off], msize);
94 if (tc->total == tc->off)
97 GNUNET_SERVER_receive_done (tc->client, GNUNET_OK);
98 GNUNET_SERVER_client_drop (tc->client);
99 GNUNET_free_non_null (tc->buf);
105 GNUNET_SERVER_notify_transmit_ready (tc->client,
106 GNUNET_MIN (MIN_BLOCK_SIZE,
107 tc->total - tc->off),
108 GNUNET_TIME_absolute_get_remaining
109 (tc->timeout), &transmit_response,
113 GNUNET_SERVER_transmit_context_destroy (tc, GNUNET_SYSERR);
121 * Create a new transmission context for the
124 * @param client client to create the context for.
125 * @return NULL on error
127 struct GNUNET_SERVER_TransmitContext *
128 GNUNET_SERVER_transmit_context_create (struct GNUNET_SERVER_Client *client)
130 struct GNUNET_SERVER_TransmitContext *tc;
132 GNUNET_assert (client != NULL);
133 tc = GNUNET_malloc (sizeof (struct GNUNET_SERVER_TransmitContext));
134 GNUNET_SERVER_client_keep (client);
141 * Append a message to the transmission context.
142 * All messages in the context will be sent by
143 * the transmit_context_run method.
145 * @param tc context to use
146 * @param data what to append to the result message
147 * @param length length of data
148 * @param type type of the message
151 GNUNET_SERVER_transmit_context_append_data (struct GNUNET_SERVER_TransmitContext
152 *tc, const void *data,
153 size_t length, uint16_t type)
155 struct GNUNET_MessageHeader *msg;
158 GNUNET_assert (length < GNUNET_SERVER_MAX_MESSAGE_SIZE);
159 size = length + sizeof (struct GNUNET_MessageHeader);
160 GNUNET_assert (size > length);
161 tc->buf = GNUNET_realloc (tc->buf, tc->total + size);
162 msg = (struct GNUNET_MessageHeader *) &tc->buf[tc->total];
164 msg->size = htons (size);
165 msg->type = htons (type);
166 memcpy (&msg[1], data, length);
171 * Append a message to the transmission context.
172 * All messages in the context will be sent by
173 * the transmit_context_run method.
175 * @param tc context to use
176 * @param msg message to append
179 GNUNET_SERVER_transmit_context_append_message (struct
180 GNUNET_SERVER_TransmitContext
182 const struct GNUNET_MessageHeader
185 struct GNUNET_MessageHeader *m;
188 size = ntohs (msg->size);
189 tc->buf = GNUNET_realloc (tc->buf, tc->total + size);
190 m = (struct GNUNET_MessageHeader *) &tc->buf[tc->total];
192 memcpy (m, msg, size);
197 * Execute a transmission context. If there is
198 * an error in the transmission, the receive_done
199 * method will be called with an error code (GNUNET_SYSERR),
200 * otherwise with GNUNET_OK.
202 * @param tc transmission context to use
203 * @param timeout when to time out and abort the transmission
206 GNUNET_SERVER_transmit_context_run (struct GNUNET_SERVER_TransmitContext *tc,
207 struct GNUNET_TIME_Relative timeout)
209 tc->timeout = GNUNET_TIME_relative_to_absolute (timeout);
211 GNUNET_SERVER_notify_transmit_ready (tc->client,
212 GNUNET_MIN (MIN_BLOCK_SIZE,
214 &transmit_response, tc))
217 GNUNET_SERVER_transmit_context_destroy (tc, GNUNET_SYSERR);
223 * Destroy a transmission context. This function must not be called
224 * after 'GNUNET_SERVER_transmit_context_run'.
226 * @param tc transmission context to destroy
227 * @param success code to give to 'GNUNET_SERVER_receive_done' for
228 * the client: GNUNET_OK to keep the connection open and
229 * continue to receive
230 * GNUNET_NO to close the connection (normal behavior)
231 * GNUNET_SYSERR to close the connection (signal
235 GNUNET_SERVER_transmit_context_destroy (struct GNUNET_SERVER_TransmitContext
239 GNUNET_SERVER_receive_done (tc->client, success);
240 GNUNET_SERVER_client_drop (tc->client);
241 GNUNET_free_non_null (tc->buf);
246 /* end of server_tc.c */