cam: main: Cache lookup of role property

The code handling the stream role option retrieves the role property and
converts it to a string in every branch. Cache it and use the cached
value.

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

1 files changed, 8 insertions, 6 deletions

diff --git a/src/cam/main.cpp b/src/cam/main.cpp
index 2a0a830f..7cdd215b 100644
--- a/src/cam/main.cpp
+++ b/src/cam/main.cpp
@@ -209,17 +209,19 @@ int CamApp::prepareConfig()
 		for (auto const &value : streamOptions) {
 			KeyValueParser::Options opt = value.toKeyValues();
 
-			if (!opt.isSet("role")) {
-				roles.push_back(StreamRole::VideoRecording);
-			} else if (opt["role"].toString() == "viewfinder") {
+			std::string role = opt.isSet("role")
+					 ? opt["role"].toString()
+					 : "viewfinder";
+
+			if (role == "viewfinder") {
 				roles.push_back(StreamRole::Viewfinder);
-			} else if (opt["role"].toString() == "video") {
+			} else if (role == "video") {
 				roles.push_back(StreamRole::VideoRecording);
-			} else if (opt["role"].toString() == "still") {
+			} else if (role == "still") {
 				roles.push_back(StreamRole::StillCapture);
 			} else {
 				std::cerr << "Unknown stream role "
-					  << opt["role"].toString() << std::endl;
+					  << role << std::endl;
 				return -EINVAL;
 			}
 		}