/*
This file is part of GNUnet
- (C) 2009 Christian Grothoff (and other contributing authors)
+ (C) 2009, 2011 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
+ by the Free Software Foundation; either version 3, or (at your
option) any later version.
GNUnet is distributed in the hope that it will be useful, but
* @file include/gnunet_fragmentation_lib.h
* @brief library to help fragment messages
* @author Christian Grothoff
+ *
+ * TODO: consider additional flow-control for sending from
+ * fragmentation based on continuations.
*/
#ifndef GNUNET_FRAGMENTATION_LIB_H
#define GNUNET_FRAGMENTATION_LIB_H
-#include "gnunet_common.h"
+#include "gnunet_util_lib.h"
+#include "gnunet_bandwidth_lib.h"
#include "gnunet_statistics_service.h"
#ifdef __cplusplus
#endif
#endif
+
/**
- * Function that is called with messages
- * created by the fragmentation module.
+ * Fragmentation context.
+ */
+struct GNUNET_FRAGMENT_Context;
+
+
+/**
+ * Function that is called with messages created by the fragmentation
+ * module. In the case of the 'proc' callback of the
+ * GNUNET_FRAGMENT_context_create function, this function must
+ * eventually call 'GNUNET_FRAGMENT_context_transmission_done'.
*
* @param cls closure
* @param msg the message that was created
/**
- * Fragment an over-sized message.
+ * Create a fragmentation context for the given message.
+ * Fragments the message into fragments of size "mtu" or
+ * less. Calls 'proc' on each un-acknowledged fragment,
+ * using both the expected 'delay' between messages and
+ * acknowledgements and the given 'tracker' to guide the
+ * frequency of calls to 'proc'.
*
+ * @param stats statistics context
+ * @param mtu the maximum message size for each fragment
+ * @param tracker bandwidth tracker to use for flow control (can be NULL)
+ * @param delay expected delay between fragment transmission
+ * and ACK based on previous messages
* @param msg the message to fragment
- * @param mtu the maximum message size
- * @param proc function to call for each fragment
+ * @param proc function to call for each fragment to transmit
* @param proc_cls closure for proc
+ * @return the fragmentation context
+ */
+struct GNUNET_FRAGMENT_Context *
+GNUNET_FRAGMENT_context_create (struct GNUNET_STATISTICS_Handle *stats,
+ uint16_t mtu,
+ struct GNUNET_BANDWIDTH_Tracker *tracker,
+ struct GNUNET_TIME_Relative delay,
+ const struct GNUNET_MessageHeader *msg,
+ GNUNET_FRAGMENT_MessageProcessor proc,
+ void *proc_cls);
+
+
+/**
+ * Continuation to call from the 'proc' function after the fragment
+ * has been transmitted (and hence the next fragment can now be
+ * given to proc).
+ *
+ * @param fc fragmentation context
*/
-void GNUNET_FRAGMENT_fragment (const struct GNUNET_MessageHeader *msg,
- uint16_t mtu,
- GNUNET_FRAGMENT_MessageProcessor proc,
- void *proc_cls);
+void
+GNUNET_FRAGMENT_context_transmission_done (struct GNUNET_FRAGMENT_Context *fc);
+
/**
- * Defragmentation context.
+ * Process an acknowledgement message we got from the other
+ * side (to control re-transmits).
+ *
+ * @param fc fragmentation context
+ * @param msg acknowledgement message we received
+ * @return GNUNET_OK if this ack completes the work of the 'fc'
+ * (all fragments have been received);
+ * GNUNET_NO if more messages are pending
+ * GNUNET_SYSERR if this ack is not valid for this fc
*/
-struct GNUNET_FRAGMENT_Context;
+int
+GNUNET_FRAGMENT_process_ack (struct GNUNET_FRAGMENT_Context *fc,
+ const struct GNUNET_MessageHeader *msg);
+
+
+/**
+ * Destroy the given fragmentation context (stop calling 'proc', free
+ * resources).
+ *
+ * @param fc fragmentation context
+ * @return average delay between transmission and ACK for the
+ * last message, FOREVER if the message was not fully transmitted
+ */
+struct GNUNET_TIME_Relative
+GNUNET_FRAGMENT_context_destroy (struct GNUNET_FRAGMENT_Context *fc);
+
+
+/**
+ * Defragmentation context (one per connection).
+ */
+struct GNUNET_DEFRAGMENT_Context;
+
+
+/**
+ * Function that is called with acknowledgement messages created by
+ * the fragmentation module. Acknowledgements are cummulative,
+ * so it is OK to only transmit the 'latest' ack message for the same
+ * message ID.
+ *
+ * @param cls closure
+ * @param id unique message ID (modulo collisions)
+ * @param msg the message that was created
+ */
+typedef void (*GNUNET_DEFRAGMENT_AckProcessor) (void *cls, uint32_t id,
+ const struct
+ GNUNET_MessageHeader * msg);
+
/**
* Create a defragmentation context.
*
* @param stats statistics context
+ * @param mtu the maximum message size for each fragment
+ * @param num_msgs how many fragmented messages
+ * to we defragment at most at the same time?
+ * @param cls closure for proc and ackp
* @param proc function to call with defragmented messages
- * @param proc_cls closure for proc
+ * @param ackp function to call with acknowledgements (to send
+ * back to the other side)
* @return the defragmentation context
*/
-struct GNUNET_FRAGMENT_Context *GNUNET_FRAGMENT_context_create (struct
- GNUNET_STATISTICS_Handle
- *stats,
- GNUNET_FRAGMENT_MessageProcessor
- proc,
- void
- *proc_cls);
+struct GNUNET_DEFRAGMENT_Context *
+GNUNET_DEFRAGMENT_context_create (struct GNUNET_STATISTICS_Handle *stats,
+ uint16_t mtu, unsigned int num_msgs,
+ void *cls,
+ GNUNET_FRAGMENT_MessageProcessor proc,
+ GNUNET_DEFRAGMENT_AckProcessor ackp);
/**
* Destroy the given defragmentation context.
+ *
+ * @param dc defragmentation context
*/
-void GNUNET_FRAGMENT_context_destroy (struct GNUNET_FRAGMENT_Context *ctx);
+void
+GNUNET_DEFRAGMENT_context_destroy (struct GNUNET_DEFRAGMENT_Context *dc);
/**
* We have received a fragment. Process it.
*
- * @param ctx the context
- * @param sender who transmitted the fragment
+ * @param dc the context
* @param msg the message that was received
+ * @return GNUNET_OK on success, GNUNET_NO if this was a duplicate, GNUNET_SYSERR on error
*/
-void GNUNET_FRAGMENT_process (struct GNUNET_FRAGMENT_Context *ctx,
- const struct GNUNET_PeerIdentity *sender,
- const struct GNUNET_MessageHeader *msg);
+int
+GNUNET_DEFRAGMENT_process_fragment (struct GNUNET_DEFRAGMENT_Context *dc,
+ const struct GNUNET_MessageHeader *msg);
#if 0 /* keep Emacsens' auto-indent happy */
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