16

    17

    /*

    18

     * Return some information about the available data.

    19

     */

    20

    int (*fn_op_available) (struct cache_op *op, size_t *size, size_t *offset);

    28

    29

    /*

    30

     * Read some data from the given fd into this cache entry. Size may contain a non-zero value to hint at how many

    31

     * bytes should be read, or zero to just read a suitable amount. Should be updated to how many bytes were actually

    32

     * written (may be zero if writes are currently paused).

    33

     */

    34

    int (*fn_op_push) (struct cache_op *op, int fd, size_t *size);

    36

    /*

    37

     * No more calls to fn_op_push will take place. The cache entry now contains the complete data.

    38

     */

    39

    int (*fn_op_done) (struct cache_op *op);

    40

    41

    /*

    42

     * The op is not needed for any operations anymore. Free any resources and memory associated with this op,

    43

     * including the op itself.

    44

     */

    45

    int (*fn_op_close) (struct cache_op *op);