Add monitor interface

Add an interface to monitor devices and helper program
Add v4l2 monitor
Add simple dictionary with key/value pairs

spa/tools/spa-monitor.c

@@ -0,0 +1,229 @@
+/* Pinos
+ * Copyright (C) 2016 Wim Taymans <wim.taymans@gmail.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <dlfcn.h>
+#include <errno.h>
+#include <poll.h>
+
+#include <spa/monitor.h>
+#include <spa/poll.h>
+#include <spa/debug.h>
+
+static void
+inspect_item (SpaMonitorItem *item)
+{
+  fprintf (stderr, "  name:  %s\n", item->name);
+  fprintf (stderr, "  class: %s\n", item->klass);
+  if (item->info)
+    spa_debug_dict (item->info);
+}
+
+typedef struct {
+  unsigned int n_poll;
+  SpaPollItem poll[16];
+
+  bool rebuild_fds;
+  SpaPollFd fds[16];
+  unsigned int n_fds;
+} PollData;
+
+static void
+on_monitor_event  (SpaMonitor      *monitor,
+                   SpaMonitorEvent *event,
+                   void            *user_data)
+{
+  PollData *data = user_data;
+
+  switch (event->type) {
+    case SPA_MONITOR_EVENT_TYPE_ADDED:
+    {
+      SpaMonitorItem *item = event->data;
+      fprintf (stderr, "added:\n");
+      inspect_item (item);
+      break;
+    }
+    case SPA_MONITOR_EVENT_TYPE_REMOVED:
+    {
+      SpaMonitorItem *item = event->data;
+      fprintf (stderr, "removed:\n");
+      inspect_item (item);
+      break;
+    }
+    case SPA_MONITOR_EVENT_TYPE_CHANGED:
+    {
+      SpaMonitorItem *item = event->data;
+      fprintf (stderr, "changed:\n");
+      inspect_item (item);
+      break;
+    }
+    case SPA_MONITOR_EVENT_TYPE_ADD_POLL:
+    {
+      SpaPollItem *item = event->data;
+
+      data->poll[data->n_poll] = *item;
+      data->n_poll++;
+      if (item->n_fds)
+        data->rebuild_fds = true;
+      break;
+    }
+
+    case SPA_MONITOR_EVENT_TYPE_UPDATE_POLL:
+      break;
+    case SPA_MONITOR_EVENT_TYPE_REMOVE_POLL:
+      break;
+    default:
+      break;
+  }
+}
+
+static void
+handle_monitor (SpaMonitor *monitor)
+{
+  SpaResult res;
+  void *state = NULL;
+  PollData data = { 0, };
+
+  if (monitor->info)
+    spa_debug_dict (monitor->info);
+
+  while (true) {
+    SpaMonitorItem *item;
+
+    if ((res = spa_monitor_enum_items (monitor, &item, &state)) < 0) {
+      if (res != SPA_RESULT_ENUM_END)
+        printf ("spa_monitor_enum_items: got error %d\n", res);
+      break;
+    }
+    inspect_item (item);
+  }
+
+  spa_monitor_set_event_callback (monitor, on_monitor_event, &data);
+
+  while (true) {
+    SpaPollNotifyData ndata;
+    int i, j, r;
+
+    /* rebuild */
+    if (data.rebuild_fds) {
+      data.n_fds = 0;
+      for (i = 0; i < data.n_poll; i++) {
+        SpaPollItem *p = &data.poll[i];
+
+        if (!p->enabled)
+          continue;
+
+        for (j = 0; j < p->n_fds; j++)
+          data.fds[data.n_fds + j] = p->fds[j];
+        p->fds = &data.fds[data.n_fds];
+        data.n_fds += p->n_fds;
+      }
+      data.rebuild_fds = false;
+    }
+
+    r = poll ((struct pollfd *) data.fds, data.n_fds, -1);
+    if (r < 0) {
+      if (errno == EINTR)
+        continue;
+      break;
+    }
+    if (r == 0) {
+      fprintf (stderr, "monitor %p: select timeout", monitor);
+      break;
+    }
+
+    /* after */
+    for (i = 0; i < data.n_poll; i++) {
+      SpaPollItem *p = &data.poll[i];
+
+      if (p->enabled && p->after_cb) {
+        ndata.fds = p->fds;
+        ndata.n_fds = p->n_fds;
+        ndata.user_data = p->user_data;
+        p->after_cb (&ndata);
+      }
+    }
+  }
+}
+
+int
+main (int argc, char *argv[])
+{
+  SpaResult res;
+  void *handle;
+  SpaEnumHandleFactoryFunc enum_func;
+  void *fstate = NULL;
+
+  if (argc < 2) {
+    printf ("usage: %s <plugin.so>\n", argv[0]);
+    return -1;
+  }
+
+  if ((handle = dlopen (argv[1], RTLD_NOW)) == NULL) {
+    printf ("can't load %s\n", argv[1]);
+    return -1;
+  }
+  if ((enum_func = dlsym (handle, "spa_enum_handle_factory")) == NULL) {
+    printf ("can't find function\n");
+    return -1;
+  }
+
+  while (true) {
+    const SpaHandleFactory *factory;
+    void *istate = NULL;
+
+    if ((res = enum_func (&factory, &fstate)) < 0) {
+      if (res != SPA_RESULT_ENUM_END)
+        printf ("can't enumerate factories: %d\n", res);
+      break;
+    }
+
+    while (true) {
+      const SpaInterfaceInfo *info;
+
+      if ((res = spa_handle_factory_enum_interface_info (factory, &info, &istate)) < 0) {
+        if (res != SPA_RESULT_ENUM_END)
+          printf ("can't enumerate interfaces: %d\n", res);
+        break;
+      }
+
+      if (info->interface_id == SPA_INTERFACE_ID_MONITOR) {
+        SpaHandle *handle;
+        void *interface;
+
+        handle = calloc (1, factory->size);
+        if ((res = spa_handle_factory_init (factory, handle, NULL)) < 0) {
+          printf ("can't make factory instance: %d\n", res);
+          continue;
+        }
+
+        if ((res = spa_handle_get_interface (handle, info->interface_id, &interface)) < 0) {
+          printf ("can't get interface: %d\n", res);
+          continue;
+        }
+        handle_monitor (interface);
+      }
+    }
+  }
+
+  return 0;
+}