+
+#define MAX_REQUEST_SIZE 16384 /* 16 kB. */
+
+RequestParseStatus wait_for_double_newline(string *existing_data, const char *new_data, size_t new_data_size)
+{
+ // Guard against overlong requests gobbling up all of our space.
+ if (existing_data->size() + new_data_size > MAX_REQUEST_SIZE) {
+ return RP_OUT_OF_SPACE;
+ }
+
+ // See if we have \r\n\r\n anywhere in the request. We start three bytes
+ // before what we just appended, in case we just got the final character.
+ size_t existing_data_bytes = existing_data->size();
+ existing_data->append(string(new_data, new_data + new_data_size));
+
+ const size_t start_at = (existing_data_bytes >= 3 ? existing_data_bytes - 3 : 0);
+ const char *ptr = reinterpret_cast<char *>(
+ memmem(existing_data->data() + start_at, existing_data->size() - start_at,
+ "\r\n\r\n", 4));
+ if (ptr == NULL) {
+ return RP_NOT_FINISHED_YET;
+ }
+ if (ptr != existing_data->data() + existing_data->size() - 4) {
+ return RP_EXTRA_DATA;
+ }
+ return RP_FINISHED;
+}