结构体dict_field_t

typedef struct dict_field_struct dict_field_t;

typedef struct dict_field_struct    dict_field_t;

/** Data structure for a field in an index */
struct dict_field_struct{
    dict_col_t*    col;        /*!< pointer to the table column */
    const char*    name;        /*!< name of the column */
    unsigned    prefix_len:;    /*!< 0 or the length of the column
                    prefix in bytes in a MySQL index of
                    type, e.g., INDEX (textcol(25));
                    must be smaller than
                    DICT_MAX_FIELD_LEN_BY_FORMAT;
                    NOTE that in the UTF-8 charset, MySQL
                    sets this to (mbmaxlen * the prefix len)
                    in UTF-8 chars */
    unsigned    fixed_len:;    /*!< 0 or the fixed length of the
                    column if smaller than
                    DICT_ANTELOPE_MAX_INDEX_COL_LEN */
};