src/server/ucx/dlist.c

#include "dlist.h"

UcxDlist *ucx_dlist_clone(UcxDlist *l, copy_func fnc, void *data) {
    UcxDlist *ret = NULL;
    while (l != NULL) {
        if (fnc != NULL) {
            ret = ucx_dlist_append(ret, fnc(l->data, data));
        } else {
            ret = ucx_dlist_append(ret, l->data);
        }
        l = l->next;
    }
    return ret;
}

int ucx_dlist_equals(UcxDlist *l1, UcxDlist *l2, cmp_func fnc, void* data) {
    if (l1 == l2) return 1;
    
    while (l1 != NULL && l2 != NULL) {
        if (fnc == NULL) {
            if (l1->data != l2->data) return 0;
        } else {
            if (fnc(l1->data, l2->data, data) != 0) return 0;
        }
        l1 = l1->next;
        l2 = l2->next;
    }
    
    return (l1 == NULL && l2 == NULL);
}

void ucx_dlist_free(UcxDlist *l) {
    UcxDlist *e = l, *f;
    while (e != NULL) {
        f = e;
        e = e->next;
        free(f);
    }
}

UcxDlist *ucx_dlist_append(UcxDlist *l, void *data)  {
    UcxDlist *nl = (UcxDlist*) malloc(sizeof(UcxDlist));
    if (nl == NULL) return NULL;
    
    nl->data = data;
    nl->next = NULL;
    if (l == NULL) {
        nl->prev = NULL;
        return nl;
    } else {
        UcxDlist *t = ucx_dlist_last(l);
        t->next = nl;
        nl->prev = t;
        return l;
    }
}

UcxDlist *ucx_dlist_prepend(UcxDlist *l, void *data) {
    UcxDlist *nl = ucx_dlist_append(NULL, data);
    if (nl == NULL) return NULL;
    
    if (l != NULL) {
        nl->next = l;
        l->prev = nl;
    }
    return nl;
}

UcxDlist *ucx_dlist_concat(UcxDlist *l1, UcxDlist *l2) {
    if (l1 == NULL) {
        return l2;
    } else {
        UcxDlist *last = ucx_dlist_last(l1);
        last->next = l2;
        l2->prev = last;
        return l1;
    }
}

UcxDlist *ucx_dlist_last(UcxDlist *l) {
    if (l == NULL) return NULL;
    
    UcxDlist *e = l;
    while (e->next != NULL) {
        e = e->next;
    }
    return e;
}

UcxDlist *ucx_dlist_get(UcxDlist *l, int index) {
    if (l == NULL) return NULL;

    UcxDlist *e = l;
    while (e->next != NULL && index > 0) {
        e = e->next;
        index--;
    }
    
    return index == 0 ? e : NULL;
}

size_t ucx_dlist_size(UcxDlist *l) {
    if (l == NULL) return 0;
    
    UcxDlist *e = l;
    size_t s = 1;
    while (e->next != NULL) {
        e = e->next;
        s++;
    }

    return s;
}

UcxDlist *ucx_dlist_sort_merge(int length,
        UcxDlist* ls, UcxDlist* rs, UcxDlist* le, UcxDlist* re,
        cmp_func fnc, void* data) {
    UcxDlist *sorted[length];
    UcxDlist *rc, *lc;

    lc = ls; rc = rs;
    int n = 0;
    while (lc != le && rc != re) {
        if (fnc(lc->data, rc->data, data) <= 0) {
            sorted[n] = lc;
            lc = lc->next;
        } else {
            sorted[n] = rc;
            rc = rc->next;
        }
        n++;
    }
    while (lc != le) {
        sorted[n] = lc;
        lc = lc->next;
        n++;
    }
    while (rc != re) {
        sorted[n] = rc;
        rc = rc->next;
        n++;
    }

    // Update pointer
    sorted[0]->prev = NULL;
    for (int i = 0 ; i < length-1 ; i++) {
        sorted[i]->next = sorted[i+1];
        sorted[i+1]->prev = sorted[i];
    }
    sorted[length-1]->next = NULL;

    return sorted[0];
}

UcxDlist *ucx_dlist_sort(UcxDlist *l, cmp_func fnc, void *data) {
    if (l == NULL) {
        return NULL;
    }

    UcxDlist *lc;
    int ln = 1;

    UcxDlist *ls = l, *le;
    lc = ls;
    while (lc->next != NULL && fnc(lc->next->data, lc->data, data) > 0) {
        lc = lc->next;
        ln++;
    }
    le = lc->next;

    UcxDlist *rs = le, *re;
    if (rs == NULL) {
        return l; // this list is already sorted :)
    } else {
        UcxDlist *rc;
        int rn = 1;
        rc = rs;
        while (rc->next != NULL && fnc(rc->next->data, rc->data, data) > 0) {
            rc = rc->next;
            rn++;
        }
        re = rc->next;

        // Something left? Sort it!
        UcxDlist *remainder = re;
        size_t remainder_length = ucx_dlist_size(remainder);
        if (remainder != NULL) {
            remainder = ucx_dlist_sort(remainder, fnc, data);
        }

        // {ls,...,le->prev} and {rs,...,re->prev} are sorted - merge them
        UcxDlist *sorted = ucx_dlist_sort_merge(ln+rn,
                ls, rs, le, re,
                fnc, data);

        // merge sorted list with (also sorted) remainder
        l = ucx_dlist_sort_merge(ln+rn+remainder_length,
                sorted, remainder, NULL, NULL,
                fnc, data);

        return l;
    }
}

/* dlist specific functions */
UcxDlist *ucx_dlist_first(UcxDlist *l) {
    if (l == NULL) return NULL;
    
    UcxDlist *e = l;
    while (e->prev != NULL) {
        e = e->prev;
    }
    return e;
}

UcxDlist *ucx_dlist_remove(UcxDlist *l, UcxDlist *e) {
    if (e->prev == NULL) {
        if(e->next != NULL) {
            e->next->prev = NULL;
            l = e->next;
        } else {
            l = NULL;
        }
        
    } else {
        e->prev->next = e->next;
        e->next->prev = e->prev;
    }
    free(e);
    return l;
}