/* Key-spec flags *
 * -------------- */
/* The following refer what the command actually does with the value or metadata
 * of the key, and not necessarily the user data or how it affects it.
 * Each key-spec may must have exaclty one of these. Any operation that's not
 * distinctly deletion, overwrite or read-only would be marked as RW. */
#define CMD_KEY_RO (1ULL<<0)     /* Read-Only - Reads the value of the key, but
                                  * doesn't necessarily returns it. */
#define CMD_KEY_RW (1ULL<<1)     /* Read-Write - Modifies the data stored in the
                                  * value of the key or its metadata. */
#define CMD_KEY_OW (1ULL<<2)     /* Overwrite - Overwrites the data stored in
                                  * the value of the key. */
#define CMD_KEY_RM (1ULL<<3)     /* Deletes the key. */
/* The follwing refer to user data inside the value of the key, not the metadata
 * like LRU, type, cardinality. It refers to the logical operation on the user's
 * data (actual input strings / TTL), being used / returned / copied / changed,
 * It doesn't refer to modification or returning of metadata (like type, count,
 * presence of data). Any write that's not INSERT or DELETE, would be an UPADTE.
 * Each key-spec may have one of the writes with or without access, or none: */
#define CMD_KEY_ACCESS (1ULL<<4) /* Returns, copies or uses the user data from
                                  * the value of the key. */
#define CMD_KEY_UPDATE (1ULL<<5) /* Updates data to the value, new value may
                                  * depend on the old value. */
#define CMD_KEY_INSERT (1ULL<<6) /* Adds data to the value with no chance of,
                                  * modification or deletion of existing data. */
#define CMD_KEY_DELETE (1ULL<<7) /* Explicitly deletes some content
                                  * from the value of the key. */