linked_file_bag.c

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/******************************************************************************/
/******************************************************************************/

#include "linked_file_bag.h"

#if !defined(ION_NULL)
#define ION_NULL ((void *) 0)
#endif

ion_err_t
lfb_put(
    ion_lfb_t           *bag,
    ion_byte_t          *to_write,
    unsigned int        num_bytes,
    ion_file_offset_t   next,
    ion_file_offset_t   *wrote_at
) {
    ion_file_offset_t   next_empty;
    ion_err_t           error;

    next_empty = ION_LFB_NULL;

    if (ION_LFB_NULL != bag->next_empty) {
        error = ion_fread_at(bag->file_handle, bag->next_empty, sizeof(ion_file_offset_t), (ion_byte_t *) &next_empty);

        if (err_ok != error) {
            return error;
        }

        *wrote_at = bag->next_empty;
    }
    else {
        *wrote_at = ion_fend(bag->file_handle);
    }

    error = ion_fwrite_at(bag->file_handle, *wrote_at, sizeof(ion_file_offset_t), (ion_byte_t *) &next);

    if (err_ok != error) {
        return error;
    }

    error = ion_fwrite_at(bag->file_handle, *wrote_at + sizeof(ion_file_offset_t), num_bytes, to_write);

    if (err_ok != error) {
        return error;
    }

    bag->next_empty = next_empty;

    return err_ok;
}

ion_err_t
lfb_get(
    ion_lfb_t           *bag,
    ion_file_offset_t   offset,
    unsigned int        num_bytes,
    ion_byte_t          *write_to,
    ion_file_offset_t   *next
) {
    ion_err_t error;

    error = ion_fread_at(bag->file_handle, offset, sizeof(ion_file_offset_t), (ion_byte_t *) next);

    if (err_ok != error) {
        return error;
    }

    error = ion_fread_at(bag->file_handle, offset + sizeof(ion_file_offset_t), num_bytes, write_to);

    return error;
}

ion_err_t
lfb_update_next(
    ion_lfb_t           *bag,
    ion_file_offset_t   offset,
    ion_file_offset_t   next
) {
    ion_err_t error;

    error = ion_fwrite_at(bag->file_handle, offset, sizeof(ion_file_offset_t), (ion_byte_t *) &(next));

    if (err_ok == error) {
        bag->next_empty = offset;
    }

    return error;
}

ion_err_t
lfb_delete(
    ion_lfb_t           *bag,
    ion_file_offset_t   offset
) {
    return lfb_update_next(bag, offset, bag->next_empty);
}

ion_err_t
lfb_delete_all(
    ion_lfb_t           *bag,
    ion_file_offset_t   offset,
    ion_result_count_t  *count
) {
    ion_err_t           error;
    ion_file_offset_t   next;

    while (ION_LFB_NULL != offset) {
        error = ion_fread_at(bag->file_handle, offset, sizeof(ion_file_offset_t), (ion_byte_t *) &next);

        if (err_ok != error) {
            return error;
        }

        error = lfb_delete(bag, offset);

        if (err_ok != error) {
            return error;
        }

        if (NULL != count) {
            (*count)++;
        }

        offset = next;
    }

    return err_ok;
}

ion_err_t
lfb_update(
    ion_lfb_t           *bag,
    ion_file_offset_t   offset,
    unsigned int        num_bytes,
    ion_byte_t          *to_write,
    ion_file_offset_t   *next
) {
    ion_err_t error;

    if (NULL != next) {
        error = lfb_update_next(bag, offset, *next);

        if (err_ok != error) {
            return error;
        }
    }

    error = ion_fwrite_at(bag->file_handle, offset + sizeof(ion_file_offset_t), num_bytes, to_write);

    return error;
}

ion_err_t
lfb_update_all(
    ion_lfb_t           *bag,
    ion_file_offset_t   offset,
    unsigned int        num_bytes,
    ion_byte_t          *to_write,
    ion_result_count_t  *count
) {
    ion_err_t           error;
    ion_file_offset_t   next;

    while (ION_LFB_NULL != offset) {
        error = ion_fread_at(bag->file_handle, offset, sizeof(ion_file_offset_t), (ion_byte_t *) &next);

        if (err_ok != error) {
            return error;
        }

        error = lfb_update(bag, offset, num_bytes, to_write, NULL);

        if (err_ok != error) {
            return error;
        }

        if (NULL != count) {
            (*count)++;
        }

        offset = next;
    }

    return err_ok;
}