vss: unify calls to the FEC layer

[paraslash.git] / send.h

diff --git a/send.h b/send.h
index d3be46f07ac756ed270f4908ad3ecf0007025c4f..f831cbc4839b1eb304a8869e234923f375716e88 100644 (file)
--- a/send.h
+++ b/send.h
@@ -1,5 +1,5 @@
 /*
 /*

- * Copyright (C) 2005-2009 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2005-2010 Andre Noll <maan@systemlinux.org>

  *
  * Licensed under the GPL v2. For licencing details see COPYING.
  */
  *
  * Licensed under the GPL v2. For licencing details see COPYING.
  */


@@ -9,6 +9,43 @@
 /** The sender subcommands. */
 enum {SENDER_ADD, SENDER_DELETE, SENDER_ALLOW, SENDER_DENY, SENDER_ON, SENDER_OFF, NUM_SENDER_CMDS};
 
 /** The sender subcommands. */
 enum {SENDER_ADD, SENDER_DELETE, SENDER_ALLOW, SENDER_DENY, SENDER_ON, SENDER_OFF, NUM_SENDER_CMDS};
 

+/**
+ * Each paraslash sender may register arbitrary many clients to the virtual
+ * streaming system, possibly with varying fec parameters. In order to do so,
+ * it must allocate a \a fec_client_parms structure and pass it to \ref
+ * add_fec_client.
+ *
+ * Clients are automatically removed from that list by the vss if an error
+ * occurs, or if the sender requests deletion of a client by calling \ref
+ * vss_del_fec_client().
+ */
+struct fec_client;
+struct sender_client;
+
+/** FEC parameters requested by FEC clients. */
+struct fec_client_parms {
+       /** Number of data slices plus redundant slices. */
+       uint8_t slices_per_group;
+       /** Number of slices minus number of redundant slices. */
+       uint8_t data_slices_per_group;
+       /** Maximal number of bytes per slice, initially zero. */
+       uint16_t max_slice_bytes;
+       /**
+        * Transport-layer initialisation for FEC support.
+        *
+        * This optional function serves (a) to make the transport layer
+        * ready to send FEC slices and (b) to determine the Maximum
+        * Packet Size (MPS) supported by the connection. The MPS value
+        * determines the largest payload size. This value is used to
+        * send FEC slices that are not larger than the path MTU, to avoid
+        * fragmentation and to maximize packet utilization. The user can
+        * alternatively specify a slice size of up to this value.
+        */
+       int (*init_fec)(struct sender_client *sc);
+       /** Push out FEC-encoded packets */
+       int (*send_fec)(struct sender_client *sc, char *buf, size_t len);
+};
+

 /**
  * Describes one supported sender of para_server.
  *
 /**
  * Describes one supported sender of para_server.
  *


@@ -47,10 +84,27 @@ struct sender {
         * only differ if the stream was repositioned by the \a ff or \a jmp
         * command. Of course, \a buf is a pointer to the chunk of data which
         * should be sent, and \a len is the length of this buffer.
         * only differ if the stream was repositioned by the \a ff or \a jmp
         * command. Of course, \a buf is a pointer to the chunk of data which
         * should be sent, and \a len is the length of this buffer.

-       */
+        */

        void (*send)(long unsigned current_chunk, long unsigned chunks_sent,
                const char *buf, size_t len, const char *header_buf,
                size_t header_len);
        void (*send)(long unsigned current_chunk, long unsigned chunks_sent,
                const char *buf, size_t len, const char *header_buf,
                size_t header_len);

+
+       /**
+        * Obtain the FEC parameters of a FEC client.
+        *
+        * This is called once by vss.c at the beginning of a stream. Senders
+        * are supposed to set \a fcp to a struct which is suitable for the FEC
+        * client identified by \a private_data.
+        */
+       int (*open)(void *client, struct fec_client_parms **fcp);
+       /**
+        * Send the next slice to a FEC client.
+        *
+        * Called by vss.c when the next slice should be sent to the FEC client
+        * identified by \a private_data, the pointer which was previously
+        * passed to vss_add_fec_target().
+        */
+       int (*send_fec)(char *buf, size_t num_bytes, void *private_data);

        /**
         * Add file descriptors to fd_sets.
         *
        /**
         * Add file descriptors to fd_sets.
         *


@@ -140,7 +194,7 @@ void generic_com_deny(struct sender_command_data *scd,
 int generic_com_on(struct sender_status *ss, unsigned protocol);
 void generic_com_off(struct sender_status *ss);
 char *generic_sender_help(void);
 int generic_com_on(struct sender_status *ss, unsigned protocol);
 void generic_com_off(struct sender_status *ss);
 char *generic_sender_help(void);

-struct sender_client *accept_sender_client(struct sender_status *ss);
+struct sender_client *accept_sender_client(struct sender_status *ss, fd_set *rfds);

 int send_queued_chunks(int fd, struct chunk_queue *cq,
                size_t max_bytes_per_write);
 int parse_fec_url(const char *arg, struct sender_command_data *scd);
 int send_queued_chunks(int fd, struct chunk_queue *cq,
                size_t max_bytes_per_write);
 int parse_fec_url(const char *arg, struct sender_command_data *scd);