buffer: don't use ringbuffer in chunk

We can't use a ringbuffer on the chunk because it implies the
consumer would write to it to update the read position, which we
can't do because the chunk is read-only and might even be shared.
Go back to offset/size pairs, which can sortof do the same thing
if we want later when we keep a non-shared read pointer in the
consumer.
Keep alsa timestamp around and filled state for future.
mmap the input port meta/data/chunk as read-only.
Only do clock update requests when asked.

src/examples/export-source.c

@@ -364,8 +364,8 @@ static int impl_node_process_output(struct spa_node *node)
 	int16_t *dst;
         struct spa_port_io *io = d->io;
 	uint32_t maxsize, index = 0;
-	struct spa_ringbuffer *rb;
 	uint32_t filled, offset;
+	struct spa_data *od;
 
 	if (io->buffer_id < d->n_buffers) {
 		reuse_buffer(d, io->buffer_id);
@@ -378,10 +378,12 @@ static int impl_node_process_output(struct spa_node *node)
         b = spa_list_first(&d->empty, struct buffer, link);
         spa_list_remove(&b->link);
 
-	maxsize = b->buffer->datas[0].maxsize;
-	rb = &b->buffer->datas[0].chunk->area;
+	od = b->buffer->datas;
 
-	filled = spa_ringbuffer_get_write_index(rb, &index);
+	maxsize = od[0].maxsize;
+
+	filled = 0;
+	index = 0;
 	avail = maxsize - filled;
 	offset = index % maxsize;
 
@@ -404,7 +406,9 @@ static int impl_node_process_output(struct spa_node *node)
                         *dst++ = val;
         }
 
-	spa_ringbuffer_write_update(rb, index + avail);
+	od[0].chunk->offset = 0;
+	od[0].chunk->size = avail;
+	od[0].chunk->stride = 0;
 
 	io->buffer_id = b->buffer->id;
 	io->status = SPA_STATUS_HAVE_BUFFER;

src/gst/gstpipewiresink.c

@@ -526,8 +526,8 @@ do_send_buffer (GstPipeWireSink *pwsink)
   for (i = 0; i < data->buf->n_datas; i++) {
     struct spa_data *d = &data->buf->datas[i];
     GstMemory *mem = gst_buffer_peek_memory (buffer, i);
-    d->chunk->area.readindex = mem->offset - data->offset;
-    d->chunk->area.writeindex = d->chunk->area.readindex + mem->size;
+    d->chunk->offset = mem->offset - data->offset;
+    d->chunk->size = mem->size;
   }
 
   if (!(res = pw_stream_send_buffer (pwsink->stream, data->id))) {

src/gst/gstpipewiresrc.c

@@ -464,11 +464,9 @@ on_new_buffer (void *_data,
   }
   for (i = 0; i < data->buf->n_datas; i++) {
     struct spa_data *d = &data->buf->datas[i];
-    uint32_t index;
     GstMemory *mem = gst_buffer_peek_memory (buf, i);
-    mem->size = spa_ringbuffer_get_read_index(&d->chunk->area, &index);
-    mem->offset = index % d->maxsize;
-    spa_ringbuffer_set_avail(&d->chunk->area, 0);
+    mem->offset = SPA_MIN(d->chunk->offset, d->maxsize);
+    mem->size = SPA_MIN(d->chunk->size, d->maxsize - mem->offset);
   }
 
   if (pwsrc->always_copy)
@@ -663,7 +661,7 @@ gst_pipewire_src_negotiate (GstBaseSrc * basesrc)
   pw_stream_connect (pwsrc->stream,
                      PW_DIRECTION_INPUT,
                      pwsrc->path,
-                     PW_STREAM_FLAG_AUTOCONNECT,
+                     PW_STREAM_FLAG_AUTOCONNECT | PW_STREAM_FLAG_CLOCK_UPDATE,
                      (const struct spa_pod **)possible->pdata,
                      possible->len);
   g_ptr_array_free (possible, TRUE);

src/modules/module-client-node/transport.c

@@ -21,6 +21,7 @@
 #include <errno.h>
 #include <sys/mman.h>
 
+#include <spa/utils/ringbuffer.h>
 #include <pipewire/log.h>
 #include <extensions/client-node.h>
 

src/modules/module-jack/jack-node.c

@@ -305,7 +305,9 @@ static int driver_process_output(struct spa_node *node)
 		in_io->status = SPA_STATUS_NEED_BUFFER;
 	}
 
-	spa_ringbuffer_set_avail(&out->outbuf->datas[0].chunk->area, ctrl->buffer_size * sizeof(int16_t) * 2);
+	out->outbuf->datas[0].chunk->offset = 0;
+	out->outbuf->datas[0].chunk->size = ctrl->buffer_size * sizeof(int16_t) * 2;
+	out->outbuf->datas[0].chunk->stride = 0;
 
 	spa_hook_list_call(&nd->listener_list, struct pw_jack_node_events, push);
 	gn->ready[SPA_DIRECTION_INPUT] = gn->required[SPA_DIRECTION_OUTPUT] = 0;

src/pipewire/link.c

@@ -305,7 +305,8 @@ static struct spa_pod *find_param(struct spa_pod **params, int n_params, uint32_
  *   || | ... <n_metas>                |
  *   || +------------------------------+
  *   +->| struct spa_chunk             | memory for n_datas chunks
- *    | |   struct spa_ringbuffer area |
+ *    | |   uint32_t offset            |
+ *    | |   uint32_t size              |
  *    | |   int32_t stride             |
  *    | | ... <n_datas> chunks         |
  *    | +------------------------------+
@@ -438,7 +439,8 @@ static struct spa_buffer **alloc_buffers(struct pw_link *this,
 				d->mapoffset = SPA_PTRDIFF(ddp, mem->ptr);
 				d->maxsize = data_sizes[j];
 				d->data = SPA_MEMBER(mem->ptr, d->mapoffset, void);
-				spa_ringbuffer_set_avail(&d->chunk->area, 0);
+				d->chunk->offset = 0;
+				d->chunk->size = 0;
 				d->chunk->stride = data_strides[j];
 				ddp += data_sizes[j];
 			} else {

src/pipewire/remote.c

@@ -955,8 +955,7 @@ client_node_port_use_buffers(void *object,
 
 		if (mid->ptr == NULL) {
 			mid->ptr =
-			    mmap(NULL, mid->size + mid->offset, prot, MAP_SHARED,
-				 mid->fd, 0);
+			    mmap(NULL, mid->size + mid->offset, prot, MAP_SHARED, mid->fd, 0);
 			if (mid->ptr == MAP_FAILED) {
 				mid->ptr = NULL;
 				pw_log_warn("Failed to mmap memory %d %p: %s", mid->size, mid,

src/pipewire/stream.c

@@ -661,10 +661,12 @@ static void handle_socket(struct pw_stream *stream, int rtreadfd, int rtwritefd)
 					       SPA_IO_ERR | SPA_IO_HUP,
 					       true, on_rtsocket_condition, stream);
 
-	impl->timeout_source = pw_loop_add_timer(stream->remote->core->main_loop, on_timeout, stream);
-	interval.tv_sec = 0;
-	interval.tv_nsec = 100000000;
-	pw_loop_update_timer(stream->remote->core->main_loop, impl->timeout_source, NULL, &interval, false);
+	if (impl->flags & PW_STREAM_FLAG_CLOCK_UPDATE) {
+		impl->timeout_source = pw_loop_add_timer(stream->remote->core->main_loop, on_timeout, stream);
+		interval.tv_sec = 0;
+		interval.tv_nsec = 100000000;
+		pw_loop_update_timer(stream->remote->core->main_loop, impl->timeout_source, NULL, &interval, false);
+	}
 	return;
 }
 
@@ -830,6 +832,9 @@ client_node_port_use_buffers(void *data,
 	struct buffer_id *bid;
 	uint32_t i, j, len;
 	struct spa_buffer *b;
+	int prot;
+
+	prot = PROT_READ | (direction == SPA_DIRECTION_OUTPUT ? PROT_WRITE : 0);
 
 	/* clear previous buffers */
 	clear_buffers(stream);
@@ -845,8 +850,7 @@ client_node_port_use_buffers(void *data,
 
 		if (mid->ptr == NULL) {
 			mid->ptr =
-			    mmap(NULL, mid->size + mid->offset, PROT_READ | PROT_WRITE, MAP_SHARED,
-				 mid->fd, 0);
+			    mmap(NULL, mid->size + mid->offset, prot, MAP_SHARED, mid->fd, 0);
 			if (mid->ptr == MAP_FAILED) {
 				mid->ptr = NULL;
 				pw_log_warn("Failed to mmap memory %d %p: %s", mid->size, mid,