Message enum and string pair

msg_tips.c

#define MSG_CODEC(ACTION)                                \
    ACTION( UNKNOWN,            ""/* unknown */        ) \
    ACTION( REQ_GET,            "get  "                ) \
    ACTION( REQ_GETS,           "gets "                ) \
    ACTION( REQ_DELETE,         "delete "              ) \
    ACTION( REQ_CAS,            "cas "                 ) \
    ACTION( REQ_SET,            "set "                 ) \
    ACTION( REQ_ADD,            "add "                 ) \
    ACTION( REQ_REPLACE,        "replace "             ) \
    ACTION( REQ_APPEND,         "append  "             ) \
    ACTION( REQ_PREPEND,        "prepend "             ) \
    ACTION( REQ_INCR,           "incr "                ) \
    ACTION( REQ_DECR,           "decr "                ) \
    ACTION( REQ_VERSION,        "version "             ) \
    ACTION( REQ_QUIT,           "quit "                ) \
    ACTION( RSP_NUM,            "" /* na */            ) \
    ACTION( RSP_VALUE,          "VALUE "               ) \
    ACTION( RSP_END,            "END\r\n"              ) \
    ACTION( RSP_STORED,         "STORED\r\n"           ) \
    ACTION( RSP_NOT_STORED,     "NOT_STORED\r\n"       ) \
    ACTION( RSP_EXISTS,         "EXISTS\r\n"           ) \
    ACTION( RSP_NOT_FOUND,      "NOT_FOUND\r\n"        ) \
    ACTION( RSP_DELETED,        "DELETED\r\n"          ) \
    ACTION( RSP_CLIENT_ERROR,   "CLIENT_ERROR "        ) \
    ACTION( RSP_SERVER_ERROR,   "SERVER_ERROR "        ) \
    ACTION( RSP_VERSION,        "VERSION fatcache\r\n" ) \
    ACTION( CRLF,               "\r\n" /* empty */     ) \
    ACTION( EMPTY,              "" /* empty */         ) \

#define DEFINE_ACTION(_hash, _name) MSG_##_hash,
typedef enum msg_type {
    MSG_CODEC( DEFINE_ACTION )
    MSG_SENTINEL
} msg_type_t;
#undef DEFINE_ACTION

#define DEFINE_ACTION(_hash, _name) (_name),
struct char *msg_strings[] = {
    MSG_CODEC( DEFINE_ACTION )
    null_string
};
#undef DEFINE_ACTION