[core] OnlineFileSource - rate limit

1 files changed, 40 insertions, 0 deletions

diff --git a/src/mbgl/util/http_timeout.cpp b/src/mbgl/util/http_timeout.cpp
new file mode 100644
index 0000000000..ded0128ac9
--- /dev/null
+++ b/src/mbgl/util/http_timeout.cpp
@@ -0,0 +1,40 @@
+#include <mbgl/util/http_timeout.hpp>
+#include <mbgl/util/constants.hpp>
+
+namespace mbgl {
+namespace http {
+
+Duration errorRetryTimeout(Response::Error::Reason failedRequestReason, uint32_t failedRequests, optional<Timestamp> retryAfter) {
+
+    if (failedRequestReason == Response::Error::Reason::Server) {
+        // Retry after one second three times, then start exponential backoff.
+        return Seconds(failedRequests <= 3 ? 1 : 1u << std::min(failedRequests - 3, 31u));
+    } else if (failedRequestReason == Response::Error::Reason::Connection) {
+        // Immediate exponential backoff.
+        assert(failedRequests > 0);
+        return Seconds(1u << std::min(failedRequests - 1, 31u));
+    } else if (failedRequestReason == Response::Error::Reason::RateLimit) {
+        if (retryAfter) {
+            return *retryAfter - util::now();
+        } else {
+            //Default
+            return Seconds(util::DEFAULT_RATE_LIMIT_TIMEOUT);
+        }
+    } else {
+        // No error, or not an error that triggers retries.
+        return Duration::max();
+    }
+}
+
+Duration expirationTimeout(optional<Timestamp> expires, uint32_t expiredRequests) {
+    if (expiredRequests) {
+        return Seconds(1u << std::min(expiredRequests - 1, 31u));
+    } else if (expires) {
+        return std::max(Seconds::zero(), *expires - util::now());
+    } else {
+        return Duration::max();
+    }
+} 
+
+} // namespace http
+} // namespace mbgl