The CacheState data structure is actually an enumerated list of constants. Aways use the constant names because values are subject to implementation change.
typedef enum { CACHE_EXISTS_NOT = 0, /* Internal flag -- do not use! */ CACHE_EXISTS, /* Internal flag -- do not use! */ CACHE_NO, /* No caching: don’t read, don’t write cache */ CACHE_CREATE, /* Create cache; don’t read */ CACHE_REFRESH, /* Refresh cache; read if not modified */ CACHE_RETURN_FROM_CACHE, /* Return directly, no check */ CACHE_RETURN_ERROR /* With connect-mode=never when not in cache */ } CacheState;