stream_cb: add cancel_fn callback

This allows stream_cb backends to implement blocking
behavior inside read_fn, and still get notified when the user
wants to cancel and stop playback.

Signed-off-by: Aman Gupta <aman@tmm1.net>

4 files changed, 27 insertions, 1 deletions

diff --git a/DOCS/client-api-changes.rst b/DOCS/client-api-changes.rst
index 81e915d4eb..11c7f2393e 100644
--- a/DOCS/client-api-changes.rst
+++ b/DOCS/client-api-changes.rst
@@ -32,6 +32,7 @@ API changes
 
 ::
  --- mpv 0.30.0 ---
+ 1.106  - Add cancel_fn to mpv_stream_cb_info
  1.105  - Fix deadlock problems with MPV_RENDER_PARAM_ADVANCED_CONTROL and if
           the "vd-lavc-dr" option is enabled (which it is by default).
           There were no actual API changes.
diff --git a/libmpv/client.h b/libmpv/client.h
index 670f45c626..8ee7d87f17 100644
--- a/libmpv/client.h
+++ b/libmpv/client.h
@@ -223,7 +223,7 @@ extern "C" {
  * relational operators (<, >, <=, >=).
  */
 #define MPV_MAKE_VERSION(major, minor) (((major) << 16) | (minor) | 0UL)
-#define MPV_CLIENT_API_VERSION MPV_MAKE_VERSION(1, 105)
+#define MPV_CLIENT_API_VERSION MPV_MAKE_VERSION(1, 106)
 
 /**
  * The API user is allowed to "#define MPV_ENABLE_DEPRECATED 0" before
diff --git a/libmpv/stream_cb.h b/libmpv/stream_cb.h
index 45e81b8e38..63593d7228 100644
--- a/libmpv/stream_cb.h
+++ b/libmpv/stream_cb.h
@@ -148,6 +148,22 @@ typedef int64_t (*mpv_stream_cb_size_fn)(void *cookie);
 typedef void (*mpv_stream_cb_close_fn)(void *cookie);
 
 /**
+ * Cancel callback used to implement a custom stream.
+ *
+ * This callback is used to interrupt any current or future read and seek
+ * operations. It will be called from a separate thread than the demux
+ * thread, and should not block.
+ *
+ * This callback can be NULL.
+ *
+ * Available since API 1.106.
+ *
+ * @param cookie opaque cookie identifying the stream,
+ *               returned from mpv_stream_cb_open_fn
+ */
+typedef void (*mpv_stream_cb_cancel_fn)(void *cookie);
+
+/**
  * See mpv_stream_cb_open_ro_fn callback.
  */
 typedef struct mpv_stream_cb_info {
@@ -170,6 +186,7 @@ typedef struct mpv_stream_cb_info {
     mpv_stream_cb_seek_fn seek_fn;
     mpv_stream_cb_size_fn size_fn;
     mpv_stream_cb_close_fn close_fn;
+    mpv_stream_cb_cancel_fn cancel_fn; /* since API 1.106 */
 } mpv_stream_cb_info;
 
 /**
diff --git a/stream/stream_cb.c b/stream/stream_cb.c
index fa8871ddf6..fa52935a4b 100644
--- a/stream/stream_cb.c
+++ b/stream/stream_cb.c
@@ -17,9 +17,11 @@
 #include "options/path.h"
 #include "player/client.h"
 #include "libmpv/stream_cb.h"
+#include "misc/thread_tools.h"
 
 struct priv {
     mpv_stream_cb_info info;
+    struct mp_cancel *cancel;
 };
 
 static int fill_buffer(stream_t *s, char *buffer, int max_len)
@@ -98,6 +100,12 @@ static int open_cb(stream_t *stream)
     stream->read_chunk = 64 * 1024;
     stream->close = s_close;
 
+    if (p->info.cancel_fn && stream->cancel) {
+        p->cancel = mp_cancel_new(p);
+        mp_cancel_set_parent(p->cancel, stream->cancel);
+        mp_cancel_set_cb(p->cancel, p->info.cancel_fn, p->info.cookie);
+    }
+
     return STREAM_OK;
 }