static void
HASHclear(Hash *h)
{
BUN i, j, nil = (BUN) HASHnil(h);
for (i = 0, j = h->mask; i <= j; i++)
(void) HASHput(h,i,nil);
}
/* collect HASH statistics for analysis */
static void HASHcollisions(BAT *b, Hash *h)
{
lng cnt, entries=0, max =0;
double total=0;
BUN p, i, j, nil = HASHnil(h);
if ( b == 0 || h == 0 )
return;
for (i = 0, j = h->mask; i <= j; i++)
if ( (p = HASHget(h,i)) != nil){
entries++;
cnt = 0;
for ( ; p != nil; p = HASHgetlink(h,p))
cnt++;
if ( cnt > max ) max = cnt;
total += cnt;
}
fprintf(stderr, "#BAThash: statistics (" BUNFMT ", entries " LLFMT", mask " BUNFMT", max " LLFMT ", avg %2.6f);\n", BATcount(b), entries, h->mask, max, total/entries);
}
/*
* The prime routine for the BAT layer is to create a new hash index.
* Its argument is the element type and the maximum number of BUNs be
* stored under the hash function.
*/
BAT *
BAThash(BAT *b, BUN masksize)
{
BAT *o = NULL;
lng t0,t1;
(void) t0;
(void) t1;
if (VIEWhparent(b)) {
bat p = VIEWhparent(b);
o = b;
b = BATdescriptor(p);
if (!ALIGNsynced(o, b) || BUNfirst(o) != BUNfirst(b)) {
BBPunfix(b->batCacheid);
b = o;
o = NULL;
}
}
MT_lock_set(&GDKhashLock(ABS(b->batCacheid)), "BAThash");
if (b->H->hash == NULL) {
unsigned int tpe = ATOMstorage(b->htype);
BUN cnt = BATcount(b);
BUN mask;
BUN p = BUNfirst(b), q = BUNlast(b), r;
Hash *h = NULL;
Heap *hp = NULL;
str nme = BBP_physical(b->batCacheid);
BATiter bi = bat_iterator(b);
ALGODEBUG fprintf(stderr, "#BAThash: create hash(" BUNFMT ");\n", BATcount(b));
/* cnt = 0, hopefully there is a proper capacity from
* which we can derive enough information */
if (!cnt)
cnt = BATcapacity(b);
if (b->htype == TYPE_void) {
if (b->hseqbase == oid_nil) {
MT_lock_unset(&GDKhashLock(ABS(b->batCacheid)), "BAThash");
ALGODEBUG fprintf(stderr, "#BAThash: cannot create hash-table on void-NIL column.\n");
return NULL;
}
ALGODEBUG fprintf(stderr, "#BAThash: creating hash-table on void column..\n");
tpe = TYPE_void;
}
/* determine hash mask size p = first; then no dynamic
* scheme */
if (masksize > 0) {
mask = HASHmask(masksize);
} else if (ATOMsize(ATOMstorage(tpe)) == 1) {
mask = (1 << 8);
} else if (ATOMsize(ATOMstorage(tpe)) == 2) {
mask = (1 << 12);
} else if (b->hkey) {
mask = HASHmask(cnt);
} else {
/* dynamic hash: we start with
* HASHmask(cnt/64); if there are too many
* collisions we try HASHmask(cnt/16), then
* HASHmask(cnt/4), and finally
* HASHmask(cnt). */
mask = HASHmask(cnt >> 6);
p += (cnt >> 2); /* try out on first 25% of b */
if (p > q)
p = q;
}
if (mask < 1024)
mask = 1024;
t0 = GDKusec();
do {
BUN nslots = mask >> 3; /* 1/8 full is too full */
r = BUNfirst(b);
if (hp) {
HEAPfree(hp);
GDKfree(hp);
}
if (h) {
ALGODEBUG fprintf(stderr, "#BAThash: retry hash construction\n");
GDKfree(h);
}
/* create the hash structures */
hp = (Heap *) GDKzalloc(sizeof(Heap));
if (hp &&
(hp->filename = GDKmalloc(strlen(nme) + 12)) != NULL)
sprintf(hp->filename, "%s.%chash", nme, b->batCacheid > 0 ? 'h' : 't');
if (hp == NULL ||
hp->filename == NULL ||
(h = HASHnew(hp, ATOMtype(b->htype), BATcapacity(b), mask)) == NULL) {
MT_lock_unset(&GDKhashLock(ABS(b->batCacheid)), "BAThash");
if (hp != NULL) {
GDKfree(hp->filename);
GDKfree(hp);
}
return NULL;
}
switch (tpe) {
case TYPE_bte:
starthash(bte);
break;
case TYPE_sht:
starthash(sht);
break;
case TYPE_int:
case TYPE_flt:
starthash(int);
break;
case TYPE_dbl:
case TYPE_lng:
starthash(lng);
break;
default:
for (; r < p; r++) {
ptr v = BUNhead(bi, r);
BUN c = (BUN) heap_hash_any(b->H->vheap, h, v);
if ( HASHget(h,c) == HASHnil(h) &&
nslots-- == 0)
break; /* mask too full */
HASHputlink(h,r, HASHget(h,c));
HASHput(h,c, r);
}
break;
}
} while (r < p && mask < cnt && (mask <<= 2));
/* finish the hashtable with the current mask */
p = r;
switch (tpe) {
case TYPE_bte:
finishhash(bte);
break;
case TYPE_sht:
finishhash(sht);
break;
case TYPE_int:
case TYPE_flt:
finishhash(int);
break;
case TYPE_dbl:
case TYPE_lng:
finishhash(lng);
break;
default:
for (; p < q; p++) {
ptr v = BUNhead(bi, p);
BUN c = (BUN) heap_hash_any(b->H->vheap, h, v);
HASHputlink(h,p, HASHget(h,c));
HASHput(h,c,p);
}
break;
}
b->H->hash = h;
t1 = GDKusec();
ALGODEBUG
fprintf(stderr, "#BAThash: hash construction "LLFMT" usec\n", t1-t0);
ALGODEBUG HASHcollisions(b,b->H->hash);
}
/*
* The prime routine for the BAT layer is to create a new hash index.
* Its argument is the element type and the maximum number of BUNs be
* stored under the hash function.
*/
gdk_return
BAThash(BAT *b, BUN masksize)
{
BAT *o = NULL;
lng t0 = 0, t1 = 0;
if (BATcheckhash(b)) {
if (o != NULL) {
o->T->hash = b->T->hash;
BBPunfix(b->batCacheid);
}
return GDK_SUCCEED;
}
MT_lock_set(&GDKhashLock(abs(b->batCacheid)), "BAThash");
if (b->T->hash == NULL) {
unsigned int tpe = ATOMbasetype(b->ttype);
BUN cnt = BATcount(b);
BUN mask, maxmask = 0;
BUN p = BUNfirst(b), q = BUNlast(b), r;
Hash *h = NULL;
Heap *hp;
const char *nme = BBP_physical(b->batCacheid);
const char *ext = b->batCacheid > 0 ? "thash" : "hhash";
BATiter bi = bat_iterator(b);
#ifdef PERSISTENTHASH
int fd;
#endif
ALGODEBUG fprintf(stderr, "#BAThash: create hash(" BUNFMT ");\n", BATcount(b));
if ((hp = GDKzalloc(sizeof(*hp))) == NULL ||
(hp->farmid = BBPselectfarm(b->batRole, b->ttype, hashheap)) < 0 ||
(hp->filename = GDKmalloc(strlen(nme) + 12)) == NULL) {
MT_lock_unset(&GDKhashLock(abs(b->batCacheid)), "BAThash");
GDKfree(hp);
return GDK_FAIL;
}
sprintf(hp->filename, "%s.%s", nme, ext);
/* cnt = 0, hopefully there is a proper capacity from
* which we can derive enough information */
if (!cnt)
cnt = BATcapacity(b);
if (b->ttype == TYPE_void) {
if (b->tseqbase == oid_nil) {
MT_lock_unset(&GDKhashLock(abs(b->batCacheid)), "BAThash");
ALGODEBUG fprintf(stderr, "#BAThash: cannot create hash-table on void-NIL column.\n");
GDKfree(hp->filename);
GDKfree(hp);
return GDK_FAIL;
}
ALGODEBUG fprintf(stderr, "#BAThash: creating hash-table on void column..\n");
tpe = TYPE_void;
}
/* determine hash mask size p = first; then no dynamic
* scheme */
if (masksize > 0) {
mask = HASHmask(masksize);
} else if (ATOMsize(tpe) == 1) {
mask = (1 << 8);
} else if (ATOMsize(tpe) == 2) {
mask = (1 << 16);
} else if (b->tkey) {
mask = HASHmask(cnt);
} else {
/* dynamic hash: we start with
* HASHmask(cnt)/64; if there are too many
* collisions we try HASHmask(cnt)/16, then
* HASHmask(cnt)/4, and finally
* HASHmask(cnt). */
maxmask = HASHmask(cnt);
mask = maxmask >> 6;
p += (cnt >> 2); /* try out on first 25% of b */
if (p > q)
p = q;
}
t0 = GDKusec();
do {
BUN nslots = mask >> 3; /* 1/8 full is too full */
r = BUNfirst(b);
if (h) {
char *fnme;
bte farmid;
ALGODEBUG fprintf(stderr, "#BAThash: retry hash construction\n");
fnme = GDKstrdup(hp->filename);
farmid = hp->farmid;
HEAPfree(hp, 1);
memset(hp, 0, sizeof(*hp));
hp->filename = fnme;
hp->farmid = farmid;
GDKfree(h);
h = NULL;
}
/* create the hash structures */
if ((h = HASHnew(hp, ATOMtype(b->ttype), BATcapacity(b), mask, BATcount(b))) == NULL) {
MT_lock_unset(&GDKhashLock(abs(b->batCacheid)), "BAThash");
GDKfree(hp->filename);
GDKfree(hp);
return GDK_FAIL;
}
switch (tpe) {
case TYPE_bte:
starthash(bte);
break;
case TYPE_sht:
starthash(sht);
break;
case TYPE_int:
case TYPE_flt:
#if SIZEOF_OID == SIZEOF_INT
case TYPE_oid:
#endif
#if SIZEOF_WRD == SIZEOF_INT
case TYPE_wrd:
#endif
starthash(int);
break;
case TYPE_dbl:
case TYPE_lng:
#if SIZEOF_OID == SIZEOF_LNG
case TYPE_oid:
#endif
#if SIZEOF_WRD == SIZEOF_LNG
case TYPE_wrd:
#endif
starthash(lng);
break;
#ifdef HAVE_HGE
case TYPE_hge:
starthash(hge);
break;
#endif
default:
for (; r < p; r++) {
ptr v = BUNtail(bi, r);
BUN c = (BUN) heap_hash_any(b->T->vheap, h, v);
if (HASHget(h, c) == HASHnil(h) &&
nslots-- == 0)
break; /* mask too full */
HASHputlink(h, r, HASHget(h, c));
HASHput(h, c, r);
}
break;
}
} while (r < p && mask < maxmask && (mask <<= 2));
/* finish the hashtable with the current mask */
p = r;
switch (tpe) {
case TYPE_bte:
finishhash(bte);
break;
case TYPE_sht:
finishhash(sht);
break;
case TYPE_int:
case TYPE_flt:
#if SIZEOF_OID == SIZEOF_INT
case TYPE_oid:
#endif
#if SIZEOF_WRD == SIZEOF_INT
case TYPE_wrd:
#endif
finishhash(int);
break;
case TYPE_dbl:
case TYPE_lng:
#if SIZEOF_OID == SIZEOF_LNG
case TYPE_oid:
#endif
#if SIZEOF_WRD == SIZEOF_LNG
case TYPE_wrd:
#endif
finishhash(lng);
break;
#ifdef HAVE_HGE
case TYPE_hge:
finishhash(hge);
break;
#endif
default:
for (; p < q; p++) {
ptr v = BUNtail(bi, p);
BUN c = (BUN) heap_hash_any(b->T->vheap, h, v);
HASHputlink(h, p, HASHget(h, c));
HASHput(h, c, p);
}
break;
}
#ifdef PERSISTENTHASH
if ((BBP_status(b->batCacheid) & BBPEXISTING) &&
b->batInserted == b->batCount &&
HEAPsave(hp, nme, ext) == GDK_SUCCEED &&
(fd = GDKfdlocate(hp->farmid, nme, "rb+", ext)) >= 0) {
ALGODEBUG fprintf(stderr, "#BAThash: persisting hash %d\n", b->batCacheid);
((size_t *) hp->base)[0] |= 1 << 24;
if (write(fd, hp->base, SIZEOF_SIZE_T) < 0)
perror("write hash");
if (!(GDKdebug & FORCEMITOMASK)) {
#if defined(NATIVE_WIN32)
_commit(fd);
#elif defined(HAVE_FDATASYNC)
fdatasync(fd);
#elif defined(HAVE_FSYNC)
fsync(fd);
#endif
}
close(fd);
} else
ALGODEBUG fprintf(stderr, "#BAThash: NOT persisting hash %d\n", b->batCacheid);
#endif
b->T->hash = h;
t1 = GDKusec();
ALGODEBUG fprintf(stderr, "#BAThash: hash construction " LLFMT " usec\n", t1 - t0);
ALGODEBUG HASHcollisions(b, b->T->hash);
}