/* BLURB gpl

                           Coda File System
                              Release 8

          Copyright (c) 1987-2021 Carnegie Mellon University
                  Additional copyrights listed below

This  code  is  distributed "AS IS" without warranty of any kind under
the terms of the GNU General Public Licence Version 2, as shown in the
file  LICENSE.  The  technical and financial  contributors to Coda are
listed in the file CREDITS.

                        Additional copyrights
                           none currently

#*/

/*
 *
 * rec_dhash.c -- Implementation of rec_dhashtab type.
 *
 */

#ifdef __cplusplus
extern "C" {
#endif

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <setjmp.h>

#ifdef __cplusplus
}
#endif

#include "rec_dhash.h"

/* DEBUGGING! -JJK */
/*
extern FILE *logFile;
extern void Die(char * ...);
*/

void *rec_dhashtab::operator new(size_t size)
{
    rec_dhashtab *r = (rec_dhashtab *)rvmlib_rec_malloc(sizeof(rec_dhashtab));
    CODA_ASSERT(r);
    return (r);
}

void rec_dhashtab::operator delete(void *deadobj)
{
    rvmlib_rec_free(deadobj);
}

rec_dhashtab::rec_dhashtab(int hashtabsize, RHFN hashfn, RCFN CF)
{
    Init(hashtabsize, hashfn, CF);
}

rec_dhashtab::~rec_dhashtab()
{
    DeInit();
}

void rec_dhashtab::Init(int hashtabsize, RHFN hashfn, RCFN CF)
{
    /* Ensure that hashtabsize is a power of 2 so that we can use "AND" for modulus division. */
    if (hashtabsize <= 0)
        abort();
    for (sz = 1; sz < hashtabsize; sz *= 2)
        ;
    if (sz != hashtabsize)
        abort();

    RVMLIB_REC_OBJECT(*this);

    /* Allocate and initialize the array. */
    /* N.B. Normal vector construction won't work because RECOVERABLE vector must be allocated! */
    {
        a = (rec_dlist *)rvmlib_rec_malloc(sz * sizeof(rec_dlist));

        for (int bucket = 0; bucket < sz; bucket++)
            a[bucket].Init(CF);
    }

    /* Store the hash function. */
    hfn = hashfn;

    cnt = 0;
}

rec_dhashtab::rec_dhashtab(rec_dhashtab &ht)
{
    abort();
}

int rec_dhashtab::operator=(rec_dhashtab &ht)
{
    abort();
    return (0); /* keep C++ happy */
}

void rec_dhashtab::DeInit()
{
    RVMLIB_REC_OBJECT(*this);

    /* free up array */
    {
        for (int bucket = 0; bucket < sz; bucket++)
            a[bucket].DeInit();

        rvmlib_rec_free(a);
    }

    a   = NULL;
    sz  = 0;
    hfn = NULL;
    cnt = 0;
}

/* The hash function is not necessarily recoverable, so don't insist on an enclosing transaction! */
void rec_dhashtab::SetHFn(RHFN hashfn) TRANSACTION_OPTIONAL
{
    if (rvmlib_thread_data()->tid != 0)
        RVMLIB_REC_OBJECT(*this);
    hfn = hashfn;
}

/* The compare function is not necessarily recoverable, so don't insist on an enclosing transaction! */
void rec_dhashtab::SetCmpFn(RCFN F)
{
    for (int i = 0; i < sz; i++)
        a[i].SetCmpFn(F);
}

void rec_dhashtab::insert(void *key, rec_dlink *p)
{
    RVMLIB_REC_OBJECT(*this);
    int bucket = hfn(key) & (sz - 1);
    a[bucket].insert(p);
    cnt++;
}

void rec_dhashtab::prepend(void *key, rec_dlink *p)
{
    RVMLIB_REC_OBJECT(*this);
    int bucket = hfn(key) & (sz - 1);
    a[bucket].prepend(p);
    cnt++;
}

void rec_dhashtab::append(void *key, rec_dlink *p)
{
    RVMLIB_REC_OBJECT(*this);
    int bucket = hfn(key) & (sz - 1);
    a[bucket].append(p);
    cnt++;
}

rec_dlink *rec_dhashtab::remove(void *key, rec_dlink *p)
{
    RVMLIB_REC_OBJECT(*this);
    int bucket = hfn(key) & (sz - 1);
    return (cnt--, a[bucket].remove(p));
}

rec_dlink *rec_dhashtab::first()
{
    if (cnt == 0)
        return (0);

    for (int i = 0; i < sz; i++) {
        rec_dlink *p = a[i].first();
        if (p != 0)
            return (p);
    }
    abort();
    return (0); /* keep g++ happy */
}

rec_dlink *rec_dhashtab::last()
{
    if (cnt == 0)
        return (0);

    for (int i = sz - 1; i >= 0; i--) {
        rec_dlink *p = a[i].last();
        if (p != 0)
            return (p);
    }
    abort();
    return (0); /* keep g++ happy */
}

rec_dlink *rec_dhashtab::get(void *key, DlGetType type)
{
    if (cnt == 0)
        return (0);

    RVMLIB_REC_OBJECT(*this);
    int bucket = hfn(key) & (sz - 1);
    return (cnt--, a[bucket].get(type));
}

int rec_dhashtab::count()
{
    return (cnt);
}

int rec_dhashtab::IsMember(void *key, rec_dlink *p)
{
    int bucket = hfn(key) & (sz - 1);
    return (a[bucket].IsMember(p));
}

int rec_dhashtab::bucket(void *key)
{
    return (hfn(key) & (sz - 1));
}

void rec_dhashtab::print()
{
    print(stderr);
}

void rec_dhashtab::print(FILE *fp)
{
    fflush(fp);
    print(fileno(fp));
}

void rec_dhashtab::print(int fd)
{
    /* first print out the rec_dhashtab header */
    char buf[40];
    sprintf(buf, "%p : Default rec_dhashtab\n", this);
    write(fd, buf, strlen(buf));

    /* then print out all of the dlists */
    for (int i = 0; i < sz; i++)
        a[i].print(fd);
}

rec_dhashtab_iterator::rec_dhashtab_iterator(rec_dhashtab &ht,
                                             DhIterOrder Order, void *key)
{
    chashtab   = &ht;
    allbuckets = (key == (void *)-1);
    order      = Order;
    cbucket    = allbuckets ? (order == DhAscending ? 0 : chashtab->sz - 1) :
                           (chashtab->bucket(key));
    nextlink = new rec_dlist_iterator(chashtab->a[cbucket],
                                      order == DhAscending ? DlAscending :
                                                             DlDescending);
}

rec_dhashtab_iterator::~rec_dhashtab_iterator()
{
    delete nextlink;
}

rec_dlink *rec_dhashtab_iterator::operator()()
{
    for (;;) {
        /* Take next entry from the current bucket. */
        rec_dlink *l = (*nextlink)();
        if (l)
            return (l);

        /* Can we continue with the next bucket? */
        if (!allbuckets)
            return (0);

        /* Try the next bucket. */
        if (order == DhAscending) {
            if (++cbucket >= chashtab->sz)
                return (0);
        } else {
            if (--cbucket < 0)
                return (0);
        }
        delete nextlink;
        nextlink = new rec_dlist_iterator(chashtab->a[cbucket],
                                          order == DhAscending ? DlAscending :
                                                                 DlDescending);
    }
}
