libcamera: request: Add cookie to make request tracking easier

Applications often have to map requests queued to a camera to external
resources. To make this easy, add a 64-bit integer cookie to the Request
class that is set when the request is created and can be retrieved at
any time, especially in the request completion handler. The cookie is
completely transparent for libcamera and is never modified.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>

1 files changed, 2 insertions, 1 deletions

diff --git a/include/libcamera/camera.h b/include/libcamera/camera.h
index 6d693d9a..21fac550 100644
--- a/include/libcamera/camera.h
+++ b/include/libcamera/camera.h
@@ -10,6 +10,7 @@
 #include <map>
 #include <memory>
 #include <set>
+#include <stdint.h>
 #include <string>
 
 #include <libcamera/controls.h>
@@ -93,7 +94,7 @@ public:
 	int allocateBuffers();
 	int freeBuffers();
 
-	Request *createRequest();
+	Request *createRequest(uint64_t cookie = 0);
 	int queueRequest(Request *request);
 
 	int start();