[core] Move parseCacheControl() up in the class hierarchy

Avoid duplicating it on all the ports.

2 files changed, 24 insertions, 0 deletions

diff --git a/src/mbgl/storage/http_request_base.cpp b/src/mbgl/storage/http_request_base.cpp
new file mode 100644
index 0000000000..2da453ead8
--- /dev/null
+++ b/src/mbgl/storage/http_request_base.cpp
@@ -0,0 +1,22 @@
+#include <mbgl/storage/http_request_base.hpp>
+
+#include <mbgl/util/chrono.hpp>
+
+namespace mbgl {
+
+int64_t HTTPRequestBase::parseCacheControl(const char *value) {
+    if (value) {
+        unsigned long long seconds = 0;
+        // TODO: cache-control may contain other information as well:
+        // http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.9
+        if (std::sscanf(value, "max-age=%llu", &seconds) == 1) {
+            return std::chrono::duration_cast<std::chrono::seconds>(
+                       std::chrono::system_clock::now().time_since_epoch()).count() +
+                   seconds;
+        }
+    }
+
+    return 0;
+}
+
+}
diff --git a/src/mbgl/storage/http_request_base.hpp b/src/mbgl/storage/http_request_base.hpp
index 508095e3c1..b28cb9fcc1 100644
--- a/src/mbgl/storage/http_request_base.hpp
+++ b/src/mbgl/storage/http_request_base.hpp
@@ -46,6 +46,8 @@ public:
     virtual void retry() = 0;
 
 protected:
+    static int64_t parseCacheControl(const char *value);
+
     bool cancelled;
 };