[core] more robust max-age parsing

3 files changed, 56 insertions, 5 deletions

diff --git a/src/mbgl/storage/http_request_base.cpp b/src/mbgl/storage/http_request_base.cpp
index 2da453ead8..f9e40c4f2b 100644
--- a/src/mbgl/storage/http_request_base.cpp
+++ b/src/mbgl/storage/http_request_base.cpp
@@ -1,18 +1,18 @@
 #include <mbgl/storage/http_request_base.hpp>
 
+#include <mbgl/util/http_header.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) {
+        const auto cacheControl = http::CacheControl::parse(value);
+
+        if (cacheControl.maxAge) {
             return std::chrono::duration_cast<std::chrono::seconds>(
                        std::chrono::system_clock::now().time_since_epoch()).count() +
-                   seconds;
+                   *cacheControl.maxAge;
         }
     }
 
diff --git a/src/mbgl/util/http_header.cpp b/src/mbgl/util/http_header.cpp
new file mode 100644
index 0000000000..00aee151c8
--- /dev/null
+++ b/src/mbgl/util/http_header.cpp
@@ -0,0 +1,29 @@
+#include <mbgl/util/http_header.hpp>
+
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wunknown-pragmas"
+#pragma GCC diagnostic ignored "-Wunused-parameter"
+#pragma GCC diagnostic ignored "-Wshadow"
+#include <boost/spirit/include/qi.hpp>
+#include <boost/spirit/include/phoenix_core.hpp>
+#include <boost/spirit/include/phoenix_operator.hpp>
+#pragma GCC diagnostic pop
+
+namespace mbgl {
+namespace http {
+
+CacheControl CacheControl::parse(const std::string& value) {
+    namespace qi = boost::spirit::qi;
+    namespace phoenix = boost::phoenix;
+
+    CacheControl result;
+    qi::phrase_parse(value.begin(), value.end(), (
+        (qi::lit("must-revalidate") [ phoenix::ref(result.mustRevalidate) = true ]) |
+        (qi::lit("max-age") >> '=' >> qi::ulong_long [ phoenix::ref(result.maxAge) = qi::_1 ]) |
+        (*(('"' >> *(('\\' >> qi::char_) | (qi::char_ - '"')) >> '"') | (qi::char_ - '"' - ',')))
+    ) % ',', qi::ascii::space);
+    return result;
+}
+
+} // namespace http
+} // namespace mbgl
diff --git a/src/mbgl/util/http_header.hpp b/src/mbgl/util/http_header.hpp
new file mode 100644
index 0000000000..bd1f809cee
--- /dev/null
+++ b/src/mbgl/util/http_header.hpp
@@ -0,0 +1,22 @@
+#ifndef MBGL_UTIL_HTTP_HEADER
+#define MBGL_UTIL_HTTP_HEADER
+
+#include <mapbox/optional.hpp>
+
+#include <string>
+
+namespace mbgl {
+namespace http {
+
+class CacheControl {
+public:
+    static CacheControl parse(const std::string&);
+
+    mapbox::util::optional<uint64_t> maxAge;
+    bool mustRevalidate = false;
+};
+
+} // namespace http
+} // namespace mbgl
+
+#endif