urisourcebin: add 'download-dir' property

The directory were buffers are downloaded was not documented and not
configurable. Users may want to ensure buffers are saved to a specific
partition for example.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/5227>

subprojects/gst-plugins-base/docs/plugins/gst_plugins_cache.json

@@ -12257,6 +12257,18 @@
                         "type": "gboolean",
                         "writable": true
                     },
+                    "download-dir": {
+                        "blurb": "The directory where buffers are downloaded to, if 'download' is enabled. If not set (default), the XDG cache directory is used.",
+                        "conditionally-available": false,
+                        "construct": false,
+                        "construct-only": false,
+                        "controllable": false,
+                        "default": "NULL",
+                        "mutable": "null",
+                        "readable": true,
+                        "type": "gchararray",
+                        "writable": true
+                    },
                     "high-watermark": {
                         "blurb": "High threshold for buffering to finish. Only used if use-buffering is True",
                         "conditionally-available": false,

subprojects/gst-plugins-base/gst/playback/gsturisourcebin.c

@@ -168,6 +168,7 @@ struct _GstURISourceBin
   guint64 buffer_duration;      /* When buffering, buffer duration (ns) */
   guint buffer_size;            /* When buffering, buffer size (bytes) */
   gboolean download;
+  gchar *download_dir;
   gboolean use_buffering;
   gdouble low_watermark;
   gdouble high_watermark;
@@ -250,6 +251,7 @@ enum
   PROP_BUFFER_SIZE,
   PROP_BUFFER_DURATION,
   PROP_DOWNLOAD,
+  PROP_DOWNLOAD_DIR,
   PROP_USE_BUFFERING,
   PROP_RING_BUFFER_MAX_SIZE,
   PROP_LOW_WATERMARK,
@@ -366,6 +368,20 @@ gst_uri_source_bin_class_init (GstURISourceBinClass * klass)
           "Attempt download buffering when buffering network streams",
           DEFAULT_DOWNLOAD, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
 
+ /**
+   * GstURISourceBin:download-dir:
+   *
+   * The directory where buffers are downloaded to, if 'download' is enabled.
+   * If not set (default), the XDG cache directory is used.
+   *
+   * Since: 1.24
+   */
+  g_object_class_install_property (gobject_class, PROP_DOWNLOAD_DIR,
+      g_param_spec_string ("download-dir", "Download Directory",
+          "The directory where buffers are downloaded to, if 'download' is enabled. "
+          "If not set (default), the XDG cache directory is used.",
+          NULL, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+
   /**
    * GstURISourceBin::use-buffering:
    *
@@ -543,6 +559,7 @@ gst_uri_source_bin_finalize (GObject * obj)
   g_mutex_clear (&urisrc->buffering_lock);
   g_mutex_clear (&urisrc->buffering_post_lock);
   g_free (urisrc->uri);
+  g_free (urisrc->download_dir);
 
   G_OBJECT_CLASS (parent_class)->finalize (obj);
 }
@@ -576,6 +593,10 @@ gst_uri_source_bin_set_property (GObject * object, guint prop_id,
     case PROP_DOWNLOAD:
       urisrc->download = g_value_get_boolean (value);
       break;
+    case PROP_DOWNLOAD_DIR:
+      g_free (urisrc->download_dir);
+      urisrc->download_dir = g_value_dup_string (value);
+      break;
     case PROP_USE_BUFFERING:
       urisrc->use_buffering = g_value_get_boolean (value);
       break;
@@ -634,6 +655,9 @@ gst_uri_source_bin_get_property (GObject * object, guint prop_id,
     case PROP_DOWNLOAD:
       g_value_set_boolean (value, urisrc->download);
       break;
+    case PROP_DOWNLOAD_DIR:
+      g_value_set_string (value, urisrc->download_dir);
+      break;
     case PROP_USE_BUFFERING:
       g_value_set_boolean (value, urisrc->use_buffering);
       break;
@@ -1042,7 +1066,18 @@ setup_downloadbuffer (GstURISourceBin * urisrc, GstElement * downloadbuffer)
   gchar *temp_template, *filename;
   const gchar *tmp_dir, *prgname;
 
-  tmp_dir = g_get_user_cache_dir ();
+  if (urisrc->download_dir) {
+    tmp_dir = urisrc->download_dir;
+
+    if (g_mkdir_with_parents (tmp_dir, 0700) != 0) {
+      GST_ELEMENT_ERROR (urisrc, RESOURCE, SETTINGS,
+          (_("Failed to create download directory '%s'."), tmp_dir), ("%s",
+              g_strerror (errno)));
+    }
+  } else {
+    tmp_dir = g_get_user_cache_dir ();
+  }
+
   prgname = g_get_prgname ();
   if (prgname == NULL)
     prgname = "GStreamer";