1 files changed, 198 insertions, 0 deletions

diff --git a/src/util/server_tc.c b/src/util/server_tc.c
new file mode 100644
index 000000000..dc51e1433
--- /dev/null
+++ b/src/util/server_tc.c
@@ -0,0 +1,198 @@
+/*
+     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_network_lib.h"
+#include "gnunet_scheduler_lib.h"
+#include "gnunet_server_lib.h"
+#include "gnunet_time_lib.h"
+
+
+
+/**
+ * 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_receive_done (tc->client, GNUNET_SYSERR);
+      GNUNET_free_non_null (tc->buf);
+      GNUNET_free (tc);
+      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_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_receive_done (tc->client, GNUNET_SYSERR);
+          GNUNET_free_non_null (tc->buf);
+          GNUNET_free (tc);
+        }
+    }
+  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));
+  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 (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);
+}
+
+
+/**
+ * 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_receive_done (tc->client, GNUNET_SYSERR);
+      GNUNET_free_non_null (tc->buf);
+      GNUNET_free (tc);
+    }
+}
+
+/* end of server_tc.c */