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-rw-r--r--src/util/server_tc.c247
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diff --git a/src/util/server_tc.c b/src/util/server_tc.c
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+/*
+ 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 */