X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=vss.c;h=481c0b68e19fb342489736c3f2c36d6e92eb9b1c;hp=1bd74de69f6d83f0f4e2ef2b28fe3c657d107f17;hb=ac153fd54a0f093581ee863984070a325d5343b8;hpb=e59019f183e080486fda280868cf4669955148c2

diff --git a/vss.c b/vss.c
index 1bd74de6..481c0b68 100644
--- a/vss.c
+++ b/vss.c
@@ -15,14 +15,16 @@
 
 #include "para.h"
 #include "error.h"
+#include "portable_io.h"
+#include "fec.h"
 #include "string.h"
 #include "afh.h"
 #include "afs.h"
 #include "server.h"
 #include "net.h"
 #include "server.cmdline.h"
-#include "vss.h"
 #include "list.h"
+#include "vss.h"
 #include "send.h"
 #include "ipc.h"
 #include "fd.h"
@@ -65,18 +67,335 @@ enum afs_socket_status {
 
 /** The task structure for the virtual streaming system. */
 struct vss_task {
+	/** Copied from the -announce_time command line option. */
 	struct timeval announce_tv;
+	/** End of the announcing interval. */
 	struct timeval data_send_barrier;
+	/** End of the EOF interval. */
 	struct timeval eof_barrier;
+	/** Only used if --autoplay_delay was given. */
 	struct timeval autoplay_barrier;
+	/** Used for afs-server communication. */
 	int afs_socket;
+	/** The current state of \a afs_socket. */
 	enum afs_socket_status afsss;
+	/** The memory mapped audio file. */
 	char *map;
+	/** Used by the scheduler. */
 	struct task task;
+	/** Pointer to the header of the mapped audio file. */
 	const char *header_buf;
+	/** Length of the audio file header. */
 	size_t header_len;
 };
 
+/**
+ * The list of currently connected fec clients.
+ *
+ * Senders may use \ref vss_add_fec_client() to add entries to the list.
+ */
+static struct list_head fec_client_list;
+
+/**
+ * Describes one slice of a FEC group.
+ *
+ * FEC slices directly correspond to the data packages sent by the paraslash
+ * senders that use FEC. Each slice is identified by its group number and its
+ * number within the group. All slices have the same size, but the last slice
+ * of the group may not be filled entirely.
+ */
+struct fec_slice {
+	/** The slice number within the FEC group. */
+	uint8_t num;
+	/** The number of used bytes in this slice. */
+	uint16_t bytes;
+};
+
+/**
+ * Data associated with one FEC group.
+ *
+ * A FEC group consists of a fixed number of slices and this number is given by
+ * the \a slices_per_group parameter of struct \ref fec_client_parms. Each FEC
+ * group contains a number of chunks of the current audio file.
+ */
+struct fec_group {
+	/** The number of the FEC group. */
+	uint32_t num;
+	/** Number of bytes in this group. */
+	uint32_t bytes;
+	/** The first chunk of the current audio file belonging to the group. */
+	uint32_t first_chunk;
+	/** The number of chunks contained in this group. */
+	uint32_t num_chunks;
+	/** The time needed to play all chunks of the group. */
+	struct timeval duration;
+	/** When the first chunk was sent. */
+	struct timeval start;
+	/** \a The group duration divided by \a slices_per_group. */
+	struct timeval slice_duration;
+};
+
+/**
+ * Describes one connected FEC client.
+ */
+struct fec_client {
+	/** Parameters requested by the client. */
+	struct fec_client_parms *fcp;
+	/** Used by the core FEC code. */
+	struct fec_parms *parms;
+	/** The position of this client in the fec client list. */
+	struct list_head node;
+	/** When the first slice for this client was sent. */
+	struct timeval stream_start;
+	/** The first chunk sent to this FEC client. */
+	int first_stream_chunk;
+	/** Describes the current group. */
+	struct fec_group group;
+	/** Describes the current slice. */
+	struct fec_slice slice;
+	/** The data to be FEC-encoded (point to a region within the mapped audio file). */
+	const unsigned char **src_data;
+	/** Used for the last source pointer of the last group. */
+	unsigned char *extra_src_buf;
+	/** The size of the buffer for the extra source pointer. */
+	size_t extra_src_buf_size;
+	/** Contains FEC-encoded data. */
+	unsigned char *enc_buf;
+	/** Size of \a enc_buf. */
+	size_t enc_buf_size;
+};
+
+/**
+ * Get the chunk time of the current audio file.
+ *
+ * \return A pointer to a struct containing the chunk time, or NULL,
+ * if currently no audio file is selected.
+ */
+struct timeval *vss_chunk_time(void)
+{
+	if (mmd->afd.afhi.chunk_tv.tv_sec == 0 &&
+			mmd->afd.afhi.chunk_tv.tv_usec == 0)
+		return NULL;
+	return &mmd->afd.afhi.chunk_tv;
+}
+
+/**
+ * Write a fec header to a buffer.
+ *
+ * \param buf The buffer to write to.
+ * \param h The fec header to write.
+ */
+static void write_fec_header(struct fec_client *fc)
+{
+	char *buf = (char *)fc->enc_buf;
+
+	write_u32(buf, FEC_MAGIC);
+
+	write_u8(buf + 4, fc->fcp->slices_per_group);
+	write_u8(buf + 5, fc->fcp->data_slices_per_group);
+	write_u32(buf + 6, (uint32_t)0); /* audio header len */
+
+	write_u32(buf + 10, fc->group.num);
+	write_u32(buf + 14, fc->group.bytes);
+
+	write_u8(buf + 18, fc->slice.num);
+	write_u16(buf + 20, fc->slice.bytes);
+	memset(buf + 22, 0, 11);
+}
+
+static int setup_next_fec_group(struct fec_client *fc, struct vss_task *vsst)
+{
+	uint32_t max_group_size, last_payload_size;
+	int i, k = fc->fcp->data_slices_per_group;
+	size_t len;
+	const char *start_buf;
+	struct timeval tmp, *chunk_tv = vss_chunk_time();
+
+	assert(chunk_tv);
+	if (fc->first_stream_chunk < 0) {
+		fc->stream_start = *now;
+		fc->first_stream_chunk = mmd->current_chunk;
+		fc->group.first_chunk = mmd->current_chunk;
+		fc->group.num = 0;
+	} else {
+		fc->group.first_chunk += fc->group.num_chunks;
+		fc->group.num++;
+	}
+	if (fc->group.first_chunk >= mmd->afd.afhi.chunks_total)
+		return 0;
+	max_group_size = (fc->fcp->max_slice_bytes - FEC_HEADER_SIZE) * k;
+	afh_get_chunk(fc->group.first_chunk, &mmd->afd.afhi, vsst->map,
+		&start_buf, &len);
+	for (i = fc->group.first_chunk, fc->group.bytes = 0;
+			i < mmd->afd.afhi.chunks_total; i++) {
+		const char *buf;
+
+		afh_get_chunk(i, &mmd->afd.afhi, vsst->map, &buf, &len);
+		if (fc->group.bytes + len > max_group_size)
+			break;
+		fc->group.bytes += len;
+	}
+	fc->group.num_chunks = i - fc->group.first_chunk;
+	fc->slice.num = 0;
+	fc->slice.bytes = ROUND_UP(fc->group.bytes, k) / k;
+
+	/* The last slice will not be fully used */
+	last_payload_size = fc->group.bytes % fc->slice.bytes;
+	if (!last_payload_size)
+		last_payload_size = fc->slice.bytes;
+
+	tv_scale(fc->group.first_chunk - fc->first_stream_chunk, chunk_tv,
+		&tmp);
+	tv_add(&fc->stream_start, &tmp, &fc->group.start);
+	if (fc->group.num) /* quick hack to avoid buffer underruns */
+		fc->group.start.tv_sec--;
+	tv_scale(fc->group.num_chunks, chunk_tv, &fc->group.duration);
+	tv_divide(fc->fcp->slices_per_group, &fc->group.duration,
+		&fc->group.slice_duration);
+
+	for (i = 0; i < k; i++)
+		fc->src_data[i] = (const unsigned char *)start_buf
+			+ i * fc->slice.bytes;
+
+	if (start_buf + k * fc->slice.bytes > vsst->map + mmd->size) {
+		/* can not use last slice as it goes beyond the map */
+		if (fc->extra_src_buf_size < fc->slice.bytes) {
+			fc->extra_src_buf = para_realloc(fc->extra_src_buf, fc->slice.bytes);
+			fc->extra_src_buf_size = fc->slice.bytes;
+		}
+		memcpy(fc->extra_src_buf, start_buf + (k - 1) * fc->slice.bytes,
+			last_payload_size);
+		memset(fc->extra_src_buf + last_payload_size, 0,
+			fc->slice.bytes - last_payload_size);
+		fc->src_data[k - 1] = fc->extra_src_buf;
+	}
+	if (fc->enc_buf_size < fc->slice.bytes + FEC_HEADER_SIZE) {
+		fc->enc_buf_size = fc->slice.bytes + FEC_HEADER_SIZE;
+		fc->enc_buf = para_realloc(fc->enc_buf, fc->enc_buf_size);
+	}
+	PARA_INFO_LOG("FEC group %d: %d chunks (%d - %d), duration: %lums\n",
+		fc->group.num, fc->group.num_chunks, fc->group.first_chunk,
+		fc->group.first_chunk + fc->group.num_chunks - 1,
+		tv2ms(&fc->group.duration));
+	return 1;
+}
+
+static int compute_next_fec_slice(struct fec_client *fc, struct vss_task *vsst)
+{
+	if (fc->first_stream_chunk < 0 || fc->slice.num
+			== fc->fcp->slices_per_group) {
+		if (!setup_next_fec_group(fc, vsst))
+			return 0;
+	}
+	write_fec_header(fc);
+	fec_encode(fc->parms, fc->src_data, fc->enc_buf + FEC_HEADER_SIZE,
+		fc->slice.num, fc->slice.bytes);
+	return 1;
+}
+
+/**
+ * Return a buffer that marks the end of the stream.
+ *
+ * \param buf Result pointer.
+ * \return The length of the eof buffer.
+ *
+ * This is used for (multicast) udp streaming where closing the socket on the
+ * sender might not give rise to an eof condition at the peer.
+ */
+size_t vss_get_fec_eof_packet(const char **buf)
+{
+	static const char fec_eof_packet[FEC_HEADER_SIZE] = FEC_EOF_PACKET;
+	*buf = fec_eof_packet;
+	return FEC_HEADER_SIZE;
+}
+
+/**
+ * Add one entry to the list of active fec clients.
+ *
+ * \param fcp Describes the fec parameters to be used for this client.
+ * \param result An opaque pointer that must be used by remove the client later.
+ *
+ * \return Standard.
+ */
+int vss_add_fec_client(struct fec_client_parms *fcp, struct fec_client **result)
+{
+	int ret;
+	struct fec_client *fc;
+
+	if (fcp->max_slice_bytes < FEC_HEADER_SIZE + fcp->data_slices_per_group)
+		return -ERRNO_TO_PARA_ERROR(EINVAL);
+	fc = para_calloc(sizeof(*fc));
+	fc->fcp = fcp;
+	ret = fec_new(fcp->data_slices_per_group, fcp->slices_per_group,
+		&fc->parms);
+	if (ret < 0)
+		goto err;
+	fc->first_stream_chunk = -1; /* stream not yet started */
+	fc->src_data = para_malloc(fc->fcp->slices_per_group * sizeof(char *));
+	para_list_add(&fc->node, &fec_client_list);
+	*result = fc;
+	return 1;
+err:
+	fec_free(fc->parms);
+	free(fc);
+	*result = NULL;
+	return ret;
+}
+
+/**
+ * Remove one entry from the list of active fec clients.
+ *
+ * \param fc The client to be removed.
+ */
+void vss_del_fec_client(struct fec_client *fc)
+{
+	list_del(&fc->node);
+	free(fc->src_data);
+	free(fc->enc_buf);
+	free(fc->extra_src_buf);
+	fec_free(fc->parms);
+	free(fc);
+}
+
+/*
+ * Compute if/when next slice is due. If it isn't due yet and \a diff is
+ * not \p Null, compute the time difference next - now, where
+ *
+ *	next = stream_start + (first_group_chunk - first_stream_chunk)
+ *		* chunk_time + slice_num * slice_time
+ */
+static int next_slice_is_due(struct fec_client *fc, struct timeval *diff)
+{
+	struct timeval tmp, next;
+	int ret;
+
+	if (fc->first_stream_chunk < 0)
+		return 1;
+	tv_scale(fc->slice.num, &fc->group.slice_duration, &tmp);
+	tv_add(&tmp, &fc->group.start, &next);
+	ret = tv_diff(&next, now, diff);
+	return ret < 0? 1 : 0;
+}
+
+static void compute_slice_timeout(struct timeval *timeout)
+{
+	struct fec_client *fc;
+
+	assert(vss_playing());
+	list_for_each_entry(fc, &fec_client_list, node) {
+		struct timeval diff;
+
+		if (next_slice_is_due(fc, &diff)) {
+			timeout->tv_sec = 0;
+			timeout->tv_usec = 0;
+			return;
+		}
+		/* timeout = min(timeout, diff) */
+		if (tv_diff(&diff, timeout, NULL) < 0)
+			*timeout = diff;
+	}
+}
+
 /**
  * Check if vss status flag \a P (playing) is set.
  *
@@ -174,16 +493,20 @@ static struct timeval *vss_compute_timeout(struct vss_task *vsst)
 		return NULL;
 	compute_chunk_time(mmd->chunks_sent, &mmd->afd.afhi.chunk_tv,
 		&mmd->stream_start, &next_chunk);
-	if (chk_barrier("chunk", &next_chunk, &the_timeout, 0) < 0)
+	if (chk_barrier("chunk", &next_chunk, &the_timeout, 0) >= 0) {
+		/* chunk is due or bof */
+		the_timeout.tv_sec = 0;
+		the_timeout.tv_usec = 0;
 		return &the_timeout;
-	/* chunk is due or bof */
-	the_timeout.tv_sec = 0;
-	the_timeout.tv_usec = 0;
+	}
+	/* compute min of current timeout and next slice time */
+	compute_slice_timeout(&the_timeout);
 	return &the_timeout;
 }
 
 static void vss_eof(struct vss_task *vsst)
 {
+
 	mmd->stream_start = *now;
 	if (!vsst->map)
 		return;
@@ -220,20 +543,6 @@ const char *supported_audio_formats(void)
 	return SUPPORTED_AUDIO_FORMATS;
 }
 
-/**
- * Get the chunk time of the current audio file.
- *
- * \return A pointer to a struct containing the chunk time, or NULL,
- * if currently no audio file is selected.
- */
-struct timeval *vss_chunk_time(void)
-{
-	if (mmd->afd.afhi.chunk_tv.tv_sec == 0 &&
-			mmd->afd.afhi.chunk_tv.tv_usec == 0)
-		return NULL;
-	return &mmd->afd.afhi.chunk_tv;
-}
-
 static int need_to_request_new_audio_file(struct vss_task *vsst)
 {
 	struct timeval diff;
@@ -252,6 +561,8 @@ static int need_to_request_new_audio_file(struct vss_task *vsst)
 	return 1;
 }
 
+
+
 /**
  * Compute the timeout for para_server's main select-loop.
  *
@@ -275,9 +586,14 @@ static void vss_pre_select(struct sched *s, struct task *t)
 	struct timeval *tv, diff;
 	struct vss_task *vsst = container_of(t, struct vss_task, task);
 
-	if (!vsst->map || vss_next() || vss_paused() || vss_repos())
+	if (!vsst->map || vss_next() || vss_paused() || vss_repos()) {
+		struct fec_client *fc, *tmp;
 		for (i = 0; senders[i].name; i++)
-			senders[i].shutdown_clients();
+			if (senders[i].shutdown_clients)
+				senders[i].shutdown_clients();
+		list_for_each_entry_safe(fc, tmp, &fec_client_list, node)
+			fc->first_stream_chunk = -1;
+	}
 	if (vss_next())
 		vss_eof(vsst);
 	else if (vss_paused()) {
@@ -372,8 +688,10 @@ static void recv_afs_result(struct vss_task *vsst)
 	}
 	mmd->size = statbuf.st_size;
 	mmd->mtime = statbuf.st_mtime;
-	vsst->map = para_mmap(mmd->size, PROT_READ, MAP_PRIVATE,
-		passed_fd, 0);
+	ret = para_mmap(mmd->size, PROT_READ, MAP_PRIVATE, passed_fd,
+		0, &vsst->map);
+	if (ret < 0)
+		goto err;
 	close(passed_fd);
 	mmd->chunks_sent = 0;
 	mmd->current_chunk = 0;
@@ -395,25 +713,20 @@ err:
 /**
  * Main sending function.
  *
- * This function gets called from para_server as soon as the next chunk of data
- * should be pushed out. It obtains a pointer to the data to be sent out as
- * well as its length from mmd->afd.afhi. This information is then passed to
- * each supported sender's send() function which is supposed to send out the data
- * to all connected clients.
+ * This function gets called from vss_post_select(). It checks whether the next
+ * chunk of data should be pushed out. It obtains a pointer to the data to be
+ * sent out as well as its length from mmd->afd.afhi. This information is then
+ * passed to each supported sender's send() function as well as to the send()
+ * functions of each registered fec client.
  */
-static void vss_send_chunk(struct vss_task *vsst)
+static void vss_send(struct vss_task *vsst)
 {
 	int i;
 	struct timeval due;
-	const char *buf;
-	size_t len;
+	struct fec_client *fc, *tmp_fc;
 
 	if (!vsst->map || !vss_playing())
 		return;
-	compute_chunk_time(mmd->chunks_sent, &mmd->afd.afhi.chunk_tv,
-		&mmd->stream_start, &due);
-	if (tv_diff(&due, now, NULL) > 0)
-		return;
 	if (chk_barrier("eof", &vsst->eof_barrier, &due, 1) < 0)
 		return;
 	if (chk_barrier("data send", &vsst->data_send_barrier,
@@ -423,10 +736,6 @@ static void vss_send_chunk(struct vss_task *vsst)
 		mmd->new_vss_status_flags |= VSS_NEXT;
 		return;
 	}
-	/*
-	 * We call the send function also in case of empty chunks as they
-	 * might have still some data queued which can be sent in this case.
-	 */
 	if (!mmd->chunks_sent) {
 		struct timeval tmp;
 		mmd->stream_start = *now;
@@ -434,10 +743,37 @@ static void vss_send_chunk(struct vss_task *vsst)
 		mmd->offset = tv2ms(&tmp);
 		mmd->events++;
 	}
-	afh_get_chunk(mmd->current_chunk, &mmd->afd.afhi, vsst->map, &buf, &len);
-	for (i = 0; senders[i].name; i++)
-		senders[i].send(mmd->current_chunk, mmd->chunks_sent, buf, len,
-			vsst->header_buf, vsst->header_len);
+	compute_chunk_time(mmd->chunks_sent, &mmd->afd.afhi.chunk_tv,
+		&mmd->stream_start, &due);
+	if (tv_diff(&due, now, NULL) <= 0) {
+		const char *buf;
+		size_t len;
+		/*
+		 * We call the send function also in case of empty chunks as
+		 * they might have still some data queued which can be sent in
+		 * this case.
+		 */
+		afh_get_chunk(mmd->current_chunk, &mmd->afd.afhi, vsst->map,
+			&buf, &len);
+		for (i = 0; senders[i].name; i++) {
+			if (!senders[i].send)
+				continue;
+			senders[i].send(mmd->current_chunk, mmd->chunks_sent,
+				buf, len, vsst->header_buf, vsst->header_len);
+		}
+	}
+	list_for_each_entry_safe(fc, tmp_fc, &fec_client_list, node) {
+		if (!next_slice_is_due(fc, NULL))
+			continue;
+		if (!compute_next_fec_slice(fc, vsst))
+			continue;
+		PARA_DEBUG_LOG("sending %d:%d (%u bytes)\n", fc->group.num,
+			fc->slice.num, fc->slice.bytes);
+		fc->fcp->send((char *)fc->enc_buf,
+			fc->slice.bytes + FEC_HEADER_SIZE,
+			fc->fcp->private_data);
+		fc->slice.num++;
+	}
 	mmd->new_vss_status_flags |= VSS_PLAYING;
 	mmd->chunks_sent++;
 	mmd->current_chunk++;
@@ -472,7 +808,7 @@ static void vss_post_select(struct sched *s, struct task *t)
 	if ((vss_playing() && !(mmd->vss_status_flags & VSS_PLAYING)) ||
 			(vss_next() && vss_playing()))
 		tv_add(now, &vsst->announce_tv, &vsst->data_send_barrier);
-	vss_send_chunk(vsst);
+	vss_send(vsst);
 }
 
 /**
@@ -515,5 +851,6 @@ void init_vss_task(int afs_socket)
 		tv_add(&vsst->autoplay_barrier, &vsst->announce_tv,
 			&vsst->data_send_barrier);
 	}
+	INIT_LIST_HEAD(&fec_client_list);
 	register_task(&vsst->task);
 }