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-rw-r--r--erts/emulator/beam/utils.c394
1 files changed, 390 insertions, 4 deletions
diff --git a/erts/emulator/beam/utils.c b/erts/emulator/beam/utils.c
index c8a21adf17..67331a37f6 100644
--- a/erts/emulator/beam/utils.c
+++ b/erts/emulator/beam/utils.c
@@ -1154,6 +1154,11 @@ make_hash2(Eterm term)
#define HCONST_14 0xa708a81eUL
#define HCONST_15 0x454021d7UL
#define HCONST_16 0xe3779b90UL
+#define HCONST_17 0x81af1549UL
+#define HCONST_18 0x1fe68f02UL
+#define HCONST_19 0xbe1e08bbUL
+#define HCONST_20 0x5c558274UL
+#define HCONST_21 0xfa8cfc2dUL
#define HASH_MAP_TAIL (_make_header(1,_TAG_HEADER_REF))
#define HASH_MAP_PAIR (_make_header(2,_TAG_HEADER_REF))
@@ -1180,6 +1185,13 @@ make_hash2(Eterm term)
} while(0)
#define IS_SSMALL28(x) (((Uint) (((x) >> (28-1)) + 1)) < 2)
+
+#ifdef ARCH_64
+# define POINTER_HASH(Ptr, AConst) UINT32_HASH_2((Uint32)(UWord)(Ptr), (((UWord)(Ptr)) >> 32), AConst)
+#else
+# define POINTER_HASH(Ptr, AConst) UINT32_HASH(Ptr, Const)
+#endif
+
/* Optimization. Simple cases before declaration of estack. */
if (primary_tag(term) == TAG_PRIMARY_IMMED1) {
switch (term & _TAG_IMMED1_MASK) {
@@ -1339,7 +1351,6 @@ make_hash2(Eterm term)
case EXPORT_SUBTAG:
{
Export* ep = *((Export **) (export_val(term) + 1));
-
UINT32_HASH_2
(ep->code[2],
atom_tab(atom_val(ep->code[0]))->slot.bucket.hvalue,
@@ -1354,7 +1365,6 @@ make_hash2(Eterm term)
{
ErlFunThing* funp = (ErlFunThing *) fun_val(term);
Uint num_free = funp->num_free;
-
UINT32_HASH_2
(num_free,
atom_tab(atom_val(funp->fe->module))->slot.bucket.hvalue,
@@ -1558,10 +1568,386 @@ make_hash2(Eterm term)
}
}
}
+}
+
+/* Term hash function for internal use.
+ * Is not "portable" in any way betweem different VM instances.
+ *
+ * One IMPORTANT property must hold (for hamt).
+ * EVERY BIT of the term that is significant for equality (see EQ)
+ * must be used as input for the hash. Two different terms must always have a
+ * chance of hashing different when salted: h([Salt|A]) vs h([Salt|B]).
+ *
+ * This is why we can not use cached hash values for atoms for example.
+ */
+
+#define CONST_HASH(AConst) \
+do { /* Lightweight mixing of constant (type info) */ \
+ hash ^= AConst; \
+ hash = (hash << 17) ^ (hash >> (32-17)); \
+} while (0)
+
+Uint32
+make_internal_hash(Eterm term)
+{
+ Uint32 hash;
+ Uint32 hash_xor_pairs;
+
+ ERTS_UNDEF(hash_xor_pairs, 0);
+
+ /* Optimization. Simple cases before declaration of estack. */
+ if (primary_tag(term) == TAG_PRIMARY_IMMED1) {
+ hash = 0;
+ #if ERTS_SIZEOF_ETERM == 8
+ UINT32_HASH_2((Uint32)term, (Uint32)(term >> 32), HCONST);
+ #elif ERTS_SIZEOF_ETERM == 4
+ UINT32_HASH(term, HCONST);
+ #else
+ # error "No you don't"
+ #endif
+ return hash;
+ }
+ {
+ Eterm tmp;
+ DECLARE_ESTACK(s);
+
+ UseTmpHeapNoproc(2);
+ hash = 0;
+ for (;;) {
+ switch (primary_tag(term)) {
+ case TAG_PRIMARY_LIST:
+ {
+ int c = 0;
+ Uint32 sh = 0;
+ Eterm* ptr = list_val(term);
+ while (is_byte(*ptr)) {
+ /* Optimization for strings. */
+ sh = (sh << 8) + unsigned_val(*ptr);
+ if (c == 3) {
+ UINT32_HASH(sh, HCONST_4);
+ c = sh = 0;
+ } else {
+ c++;
+ }
+ term = CDR(ptr);
+ if (is_not_list(term))
+ break;
+ ptr = list_val(term);
+ }
+ if (c > 0)
+ UINT32_HASH(sh, HCONST_4);
+ if (is_list(term)) {
+ tmp = CDR(ptr);
+ CONST_HASH(HCONST_17); /* Hash CAR in cons cell */
+ ESTACK_PUSH(s, tmp);
+ if (is_not_list(tmp)) {
+ ESTACK_PUSH(s, HASH_CDR);
+ }
+ term = CAR(ptr);
+ }
+ }
+ break;
+ case TAG_PRIMARY_BOXED:
+ {
+ Eterm hdr = *boxed_val(term);
+ ASSERT(is_header(hdr));
+ switch (hdr & _TAG_HEADER_MASK) {
+ case ARITYVAL_SUBTAG:
+ {
+ int i;
+ int arity = header_arity(hdr);
+ Eterm* elem = tuple_val(term);
+ UINT32_HASH(arity, HCONST_9);
+ if (arity == 0) /* Empty tuple */
+ goto pop_next;
+ for (i = arity; ; i--) {
+ term = elem[i];
+ if (i == 1)
+ break;
+ ESTACK_PUSH(s, term);
+ }
+ }
+ break;
+ case MAP_SUBTAG:
+ {
+ map_t *mp = (map_t *)map_val(term);
+ int i;
+ int size = map_get_size(mp);
+ Eterm *ks = map_get_keys(mp);
+ Eterm *vs = map_get_values(mp);
+ UINT32_HASH(size, HCONST_16);
+ if (size == 0) {
+ goto pop_next;
+ }
+ /* We want a hash function that is *independent* of
+ * the order in which keys and values are encountered.
+ * We therefore calculate context independent hashes for all .
+ * key-value pairs and then xor them together.
+ */
+ ESTACK_PUSH(s, hash_xor_pairs);
+ ESTACK_PUSH(s, hash);
+ ESTACK_PUSH(s, HASH_MAP_TAIL);
+ hash = 0;
+ hash_xor_pairs = 0;
+ for (i = size - 1; i >= 0; i--) {
+ ESTACK_PUSH(s, HASH_MAP_PAIR);
+ ESTACK_PUSH(s, vs[i]);
+ ESTACK_PUSH(s, ks[i]);
+ }
+ goto pop_next;
+ }
+ break;
+ case HASHMAP_SUBTAG:
+ {
+ Eterm* ptr = boxed_val(term) + 1;
+ Uint size;
+ int i;
+ switch (hdr & _HEADER_MAP_SUBTAG_MASK) {
+ case HAMT_SUBTAG_HEAD_ARRAY:
+ case HAMT_SUBTAG_HEAD_BITMAP:
+ size = *ptr++;
+ UINT32_HASH(size, HCONST_16);
+ if (size == 0)
+ goto pop_next;
+ ESTACK_PUSH(s, hash_xor_pairs);
+ ESTACK_PUSH(s, hash);
+ ESTACK_PUSH(s, HASH_MAP_TAIL);
+ hash = 0;
+ hash_xor_pairs = 0;
+ }
+ switch (hdr & _HEADER_MAP_SUBTAG_MASK) {
+ case HAMT_SUBTAG_HEAD_ARRAY:
+ case HAMT_SUBTAG_NODE_ARRAY:
+ i = 16;
+ break;
+ case HAMT_SUBTAG_HEAD_BITMAP:
+ case HAMT_SUBTAG_NODE_BITMAP:
+ i = hashmap_bitcount(MAP_HEADER_VAL(hdr));
+ break;
+ default:
+ erl_exit(1, "bad header");
+ }
+ while (i) {
+ if (is_list(*ptr)) {
+ Eterm* cons = list_val(*ptr);
+ ESTACK_PUSH(s, HASH_MAP_PAIR);
+ ESTACK_PUSH(s, CDR(cons));
+ ESTACK_PUSH(s, CAR(cons));
+ }
+ else {
+ ASSERT(is_boxed(*ptr));
+ ESTACK_PUSH(s, *ptr);
+ }
+ i--; ptr++;
+ }
+ goto pop_next;
+ }
+ break;
+ case EXPORT_SUBTAG:
+ {
+ Export* ep = *((Export **) (export_val(term) + 1));
+ /* Assumes Export entries never moves */
+ POINTER_HASH(ep, HCONST_14);
+ goto pop_next;
+ }
+
+ case FUN_SUBTAG:
+ {
+ ErlFunThing* funp = (ErlFunThing *) fun_val(term);
+ Uint num_free = funp->num_free;
+ UINT32_HASH_2(num_free, funp->fe->module, HCONST_20);
+ UINT32_HASH_2(funp->fe->old_index, funp->fe->old_uniq, HCONST_21);
+ if (num_free == 0) {
+ goto pop_next;
+ } else {
+ Eterm* bptr = funp->env + num_free - 1;
+ while (num_free-- > 1) {
+ term = *bptr--;
+ ESTACK_PUSH(s, term);
+ }
+ term = *bptr;
+ }
+ }
+ break;
+ case REFC_BINARY_SUBTAG:
+ case HEAP_BINARY_SUBTAG:
+ case SUB_BINARY_SUBTAG:
+ {
+ byte* bptr;
+ unsigned sz = binary_size(term);
+ Uint32 con = HCONST_13 + hash;
+ Uint bitoffs;
+ Uint bitsize;
+
+ ERTS_GET_BINARY_BYTES(term, bptr, bitoffs, bitsize);
+ if (sz == 0 && bitsize == 0) {
+ hash = con;
+ } else {
+ if (bitoffs == 0) {
+ hash = block_hash(bptr, sz, con);
+ if (bitsize > 0) {
+ UINT32_HASH_2(bitsize, (bptr[sz] >> (8 - bitsize)),
+ HCONST_15);
+ }
+ } else {
+ byte* buf = (byte *) erts_alloc(ERTS_ALC_T_TMP,
+ sz + (bitsize != 0));
+ erts_copy_bits(bptr, bitoffs, 1, buf, 0, 1, sz*8+bitsize);
+ hash = block_hash(buf, sz, con);
+ if (bitsize > 0) {
+ UINT32_HASH_2(bitsize, (buf[sz] >> (8 - bitsize)),
+ HCONST_15);
+ }
+ erts_free(ERTS_ALC_T_TMP, (void *) buf);
+ }
+ }
+ goto pop_next;
+ }
+ break;
+ case POS_BIG_SUBTAG:
+ case NEG_BIG_SUBTAG:
+ {
+ Eterm* ptr = big_val(term);
+ Uint i = 0;
+ Uint n = BIG_SIZE(ptr);
+ Uint32 con = BIG_SIGN(ptr) ? HCONST_10 : HCONST_11;
+#if D_EXP == 16
+ do {
+ Uint32 x, y;
+ x = i < n ? BIG_DIGIT(ptr, i++) : 0;
+ x += (Uint32)(i < n ? BIG_DIGIT(ptr, i++) : 0) << 16;
+ y = i < n ? BIG_DIGIT(ptr, i++) : 0;
+ y += (Uint32)(i < n ? BIG_DIGIT(ptr, i++) : 0) << 16;
+ UINT32_HASH_2(x, y, con);
+ } while (i < n);
+#elif D_EXP == 32
+ do {
+ Uint32 x, y;
+ x = i < n ? BIG_DIGIT(ptr, i++) : 0;
+ y = i < n ? BIG_DIGIT(ptr, i++) : 0;
+ UINT32_HASH_2(x, y, con);
+ } while (i < n);
+#elif D_EXP == 64
+ do {
+ Uint t;
+ Uint32 x, y;
+ ASSERT(i < n);
+ t = BIG_DIGIT(ptr, i++);
+ x = t & 0xffffffff;
+ y = t >> 32;
+ UINT32_HASH_2(x, y, con);
+ } while (i < n);
+#else
+#error "unsupported D_EXP size"
+#endif
+ goto pop_next;
+ }
+ break;
+ case REF_SUBTAG:
+ UINT32_HASH(internal_ref_numbers(term)[0], HCONST_7);
+ ASSERT(internal_ref_no_of_numbers(term) == 3);
+ UINT32_HASH_2(internal_ref_numbers(term)[1],
+ internal_ref_numbers(term)[2], HCONST_8);
+ goto pop_next;
+
+ case EXTERNAL_REF_SUBTAG:
+ {
+ ExternalThing* thing = external_thing_ptr(term);
+
+ ASSERT(external_thing_ref_no_of_numbers(thing) == 3);
+ /*SVERK Is it really ok to hash node POINTER? */
+ #ifdef ARCH_64
+ POINTER_HASH(thing->node, HCONST_7);
+ UINT32_HASH(external_thing_ref_numbers(thing)[0], HCONST_7);
+ #else
+ UINT32_HASH_2(thing->node,
+ external_thing_ref_numbers(thing)[0], HCONST_7);
+ #endif
+ UINT32_HASH_2(external_thing_ref_numbers(thing)[1],
+ external_thing_ref_numbers(thing)[2], HCONST_8);
+ goto pop_next;
+ }
+ case EXTERNAL_PID_SUBTAG: {
+ ExternalThing* thing = external_thing_ptr(term);
+ /*SVERK Is it really ok to hash node POINTER? */
+ #ifdef ARCH_64
+ POINTER_HASH(thing->node, HCONST_5);
+ UINT32_HASH(thing->data.ui[0], HCONST_5);
+ #else
+ UINT32_HASH_2(thing->node, thing->data.ui[0], HCONST_5);
+ #endif
+ goto pop_next;
+ }
+ case EXTERNAL_PORT_SUBTAG: {
+ ExternalThing* thing = external_thing_ptr(term);
+ /*SVERK Is it really ok to hash node POINTER? */
+ #ifdef ARCH_64
+ POINTER_HASH(thing->node, HCONST_6);
+ UINT32_HASH(thing->data.ui[0], HCONST_6);
+ #else
+ UINT32_HASH_2(thing->node, thing->data.ui[0], HCONST_6);
+ #endif
+ goto pop_next;
+ }
+ case FLOAT_SUBTAG:
+ {
+ FloatDef ff;
+ GET_DOUBLE(term, ff);
+ UINT32_HASH_2(ff.fw[0], ff.fw[1], HCONST_12);
+ goto pop_next;
+ }
+
+ default:
+ erl_exit(1, "Invalid tag in make_hash2(0x%X)\n", term);
+ }
+ }
+ break;
+ case TAG_PRIMARY_IMMED1:
+ #if ERTS_SIZEOF_ETERM == 8
+ UINT32_HASH_2((Uint32)term, (Uint32)(term >> 32), HCONST);
+ #else
+ UINT32_HASH(term, HCONST);
+ #endif
+ goto pop_next;
+
+ default:
+ erl_exit(1, "Invalid tag in make_hash2(0x%X)\n", term);
+
+ pop_next:
+ if (ESTACK_ISEMPTY(s)) {
+ DESTROY_ESTACK(s);
+ UnUseTmpHeapNoproc(2);
+ return hash;
+ }
+
+ term = ESTACK_POP(s);
+
+ switch (term) {
+ case HASH_MAP_TAIL: {
+ hash = (Uint32) ESTACK_POP(s);
+ UINT32_HASH(hash_xor_pairs, HCONST_19);
+ hash_xor_pairs = (Uint32) ESTACK_POP(s);
+ goto pop_next;
+ }
+ case HASH_MAP_PAIR:
+ hash_xor_pairs ^= hash;
+ hash = 0;
+ goto pop_next;
+
+ case HASH_CDR:
+ CONST_HASH(HCONST_18); /* Hash CDR i cons cell */
+ goto pop_next;
+ default:
+ break;
+ }
+ }
+ }
+ }
+#undef CONST_HASH
#undef HASH_MAP_TAIL
-#undef HASH_MAP_KEY
-#undef HASH_MAP_VAL
+#undef HASH_MAP_PAIR
+#undef HASH_CDR
#undef UINT32_HASH_2
#undef UINT32_HASH
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-23 21:29:31 +0000