Make buffer data point to memory blocks

Make buffer data point to a registered memory block by its mem_id.
Add some more helpers to allocate memfd backed memory.
Allocate buffers in memfd so that we easily share them between client
and server.
Update pts and seq in v4l2 now that this change will actually be visible
at the client.

spa/plugins/remote/proxy.c

@@ -17,8 +17,6 @@
  * Boston, MA 02110-1301, USA.
  */
 
-#define _GNU_SOURCE
-
 #include <string.h>
 #include <stddef.h>
 #include <stdio.h>
@@ -31,6 +29,7 @@
 
 
 #include <spa/node.h>
+#include <spa/memory.h>
 #include <spa/control.h>
 
 #define MAX_INPUTS       64
@@ -548,25 +547,6 @@ spa_proxy_node_port_get_status (SpaNode              *node,
   return SPA_RESULT_OK;
 }
 
-static int
-tmpfile_create (void *data, size_t size)
-{
-  char filename[] = "/dev/shm/tmpfilepay.XXXXXX";
-  int fd;
-
-  fd = mkostemp (filename, O_CLOEXEC);
-  if (fd == -1) {
-    fprintf (stderr, "Failed to create temporary file: %s\n", strerror (errno));
-    return -1;
-  }
-  unlink (filename);
-
-  if (write (fd, data, size) != (ssize_t) size)
-    fprintf (stderr, "Failed to write data: %s\n", strerror (errno));
-
-  return fd;
-}
-
 static SpaResult
 add_buffer (SpaProxy *this, uint32_t port_id, SpaBuffer *buffer)
 {
@@ -574,53 +554,57 @@ add_buffer (SpaProxy *this, uint32_t port_id, SpaBuffer *buffer)
   SpaControlBuilder builder;
   uint8_t buf[1024];
   int fds[16];
+  SpaControlCmdAddMem am;
   SpaControlCmdAddBuffer ab;
-  int fd, i;
+  int i;
   SpaResult res;
   SpaBuffer *b;
+  SpaMemory *bmem;
 
   spa_control_builder_init_into (&builder, buf, sizeof (buf), fds, sizeof (fds));
 
-  fd = tmpfile_create (buffer, buffer->size);
+  if (buffer->mem_id == SPA_ID_INVALID) {
+    fprintf (stderr, "proxy %p: alloc buffer space\n", this);
+    bmem = spa_memory_alloc_with_fd (0, buffer, buffer->size);
+    b = spa_memory_ensure_ptr (bmem);
+    b->mem_id = bmem->id;
+    b->offset = 0;
+  } else {
+    bmem = spa_memory_find (0, buffer->mem_id);
+    b = buffer;
+  }
+
+  am.port_id = port_id;
+  am.mem_id = bmem->id;
+  am.mem_type = 0;
+  am.fd_index = spa_control_builder_add_fd (&builder, bmem->fd, false);
+  am.flags = bmem->flags;
+  am.size = bmem->size;
+  spa_control_builder_add_cmd (&builder, SPA_CONTROL_CMD_ADD_MEM, &am);
 
-  b = mmap (NULL, buffer->size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
   for (i = 0; i < b->n_datas; i++) {
     SpaData *d = &SPA_BUFFER_DATAS (b)[i];
-    int fd;
-    SpaControlCmdAddMem am;
-    bool tmpfile;
+    SpaMemory *mem;
 
-    if (d->type == SPA_DATA_TYPE_FD) {
-      fd = SPA_PTR_TO_INT (d->ptr);
-      tmpfile = false;
-    } else if (d->type == SPA_DATA_TYPE_MEMPTR) {
-      fd = tmpfile_create (d->ptr, d->size + d->offset);
-      tmpfile = true;
-    } else {
-      fprintf (stderr, "proxy %p: invalid mem type received %d\n", this, d->type);
+    if (!(mem = spa_memory_find (0, d->mem_id))) {
+      fprintf (stderr, "proxy %p: error invalid memory\n", this);
       continue;
     }
 
     am.port_id = port_id;
-    am.mem_id = b->id * 64 + i;
+    am.mem_id = mem->id;
     am.mem_type = 0;
-    am.fd_index = spa_control_builder_add_fd (&builder, fd, tmpfile ? true : false);
-    am.offset = d->offset;
-    am.size = d->size;
+    am.fd_index = spa_control_builder_add_fd (&builder, mem->fd, false);
+    am.flags = mem->flags;
+    am.size = mem->size;
     spa_control_builder_add_cmd (&builder, SPA_CONTROL_CMD_ADD_MEM, &am);
-
-    d->type = SPA_DATA_TYPE_MEMID;
-    d->ptr_type = NULL;
-    d->ptr = SPA_UINT32_TO_PTR (am.mem_id);
-    d->offset = 0;
   }
   ab.port_id = port_id;
   ab.buffer_id = b->id;
-  ab.fd_index = spa_control_builder_add_fd (&builder, fd, true);
-  ab.offset = 0;
+  ab.mem_id = bmem->id;
+  ab.offset = b->offset;
   ab.size = b->size;
   spa_control_builder_add_cmd (&builder, SPA_CONTROL_CMD_ADD_BUFFER, &ab);
-  munmap (b, buffer->size);
 
   spa_control_builder_end (&builder, &control);
 
@@ -632,6 +616,71 @@ add_buffer (SpaProxy *this, uint32_t port_id, SpaBuffer *buffer)
   return SPA_RESULT_OK;
 }
 
+#if 0
+static SpaResult
+add_buffer (SpaProxy *this, uint32_t port_id, SpaBuffer *buffer)
+{
+  SpaControl control;
+  SpaControlBuilder builder;
+  uint8_t buf[1024];
+  int fds[16];
+  SpaControlCmdAddMem am;
+  SpaControlCmdAddBuffer ab;
+  int i;
+  SpaResult res;
+  SpaBuffer *b;
+  SpaMemory *bmem;
+
+  spa_control_builder_init_into (&builder, buf, sizeof (buf), fds, sizeof (fds));
+
+  bmem = spa_memory_alloc_with_fd (0, buffer, buffer->size);
+  b = spa_memory_ensure_ptr (bmem);
+  b->mem_id = bmem->id;
+  b->offset = 0;
+
+  am.port_id = port_id;
+  am.mem_id = bmem->id;
+  am.mem_type = 0;
+  am.fd_index = spa_control_builder_add_fd (&builder, bmem->fd, false);
+  am.offset = 0;
+  am.size = buffer->size;
+  spa_control_builder_add_cmd (&builder, SPA_CONTROL_CMD_ADD_MEM, &am);
+
+  for (i = 0; i < b->n_datas; i++) {
+    SpaData *d = &SPA_BUFFER_DATAS (b)[i];
+    SpaMemory *mem;
+
+    if (!(mem = spa_memory_find (0, d->mem_id))) {
+      fprintf (stderr, "proxy %p: error invalid memory\n", this);
+      continue;
+    }
+
+    am.port_id = port_id;
+    am.mem_id = mem->id;
+    am.mem_type = 0;
+    am.fd_index = spa_control_builder_add_fd (&builder, mem->fd, false);
+    am.offset = d->offset;
+    am.size = d->size;
+    spa_control_builder_add_cmd (&builder, SPA_CONTROL_CMD_ADD_MEM, &am);
+  }
+  ab.port_id = port_id;
+  ab.buffer_id = b->id;
+  ab.mem_id = bmem->id;
+  ab.offset = 0;
+  ab.size = b->size;
+  spa_control_builder_add_cmd (&builder, SPA_CONTROL_CMD_ADD_BUFFER, &ab);
+
+  spa_control_builder_end (&builder, &control);
+
+  if ((res = spa_control_write (&control, this->fds[0].fd)) < 0)
+    fprintf (stderr, "proxy %p: error writing control\n", this);
+
+  spa_control_clear (&control);
+
+  return SPA_RESULT_OK;
+}
+#endif
+
 static SpaResult
 remove_buffer (SpaProxy *this, uint32_t port_id, SpaBuffer *buffer)
 {