Revision 8d5da6a0040f0cc55af5fd99588383f5582ff98f authored by Jameson Nash on 03 May 2017, 22:11:39 UTC, committed by Jameson Nash on 03 May 2017, 22:11:39 UTC
unlike codegen, only bitstypes (!isptr) fields are permitted in the union and the offset count starts from 0 instead of 1 but otherwise the tindex counter is compatible
1 parent 5f296f3
table.c
// This file is a part of Julia. License is MIT: https://julialang.org/license
#define hash_size(h) (jl_array_len(h)/2)
// compute empirical max-probe for a given size
#define max_probe(size) ((size)<=1024 ? 16 : (size)>>6)
#define keyhash(k) jl_object_id(k)
#define h2index(hv,sz) (size_t)(((hv) & ((sz)-1))*2)
static void **jl_table_lookup_bp(jl_array_t **pa, void *key);
JL_DLLEXPORT jl_array_t *jl_idtable_rehash(jl_array_t *a, size_t newsz)
{
// Assume *pa don't need a write barrier
// pa doesn't have to be a GC slot but *pa needs to be rooted
size_t sz = jl_array_len(a);
size_t i;
void **ol = (void**)a->data;
jl_array_t *newa = jl_alloc_vec_any(newsz);
// keep the original array in the original slot since we need `ol`
// to be valid in the loop below.
JL_GC_PUSH1(&newa);
for(i=0; i < sz; i+=2) {
if (ol[i+1] != NULL) {
(*jl_table_lookup_bp(&newa, ol[i])) = ol[i+1];
jl_gc_wb(newa, ol[i+1]);
// it is however necessary here because allocation
// can (and will) occur in a recursive call inside table_lookup_bp
}
}
// we do not check the write barrier here
// because pa always points to a C stack location
// (see jl_eqtable_put and jl_finalize_deserializer)
// it should be changed if this assumption no longer holds
JL_GC_POP();
return newa;
}
static void **jl_table_lookup_bp(jl_array_t **pa, void *key)
{
// pa points to a **rooted** gc frame slot
uint_t hv;
jl_array_t *a = *pa;
size_t orig, index, iter;
size_t newsz, sz = hash_size(a);
assert(sz >= 1);
size_t maxprobe = max_probe(sz);
void **tab = (void**)a->data;
hv = keyhash((jl_value_t*)key);
retry_bp:
iter = 0;
index = h2index(hv,sz);
sz *= 2;
orig = index;
do {
if (tab[index+1] == NULL) {
tab[index] = key;
jl_gc_wb(a, key);
return &tab[index+1];
}
if (jl_egal((jl_value_t*)key, (jl_value_t*)tab[index]))
return &tab[index+1];
index = (index+2) & (sz-1);
iter++;
if (iter > maxprobe)
break;
} while (index != orig);
/* table full */
/* quadruple size, rehash, retry the insert */
/* it's important to grow the table really fast; otherwise we waste */
/* lots of time rehashing all the keys over and over. */
sz = jl_array_len(a);
if (sz >= (1<<19) || (sz <= (1<<8)))
newsz = sz<<1;
else if (sz <= HT_N_INLINE)
newsz = HT_N_INLINE;
else
newsz = sz<<2;
*pa = jl_idtable_rehash(*pa, newsz);
a = *pa;
tab = (void**)a->data;
sz = hash_size(a);
maxprobe = max_probe(sz);
goto retry_bp;
return NULL;
}
/* returns bp if key is in hash, otherwise NULL */
/* if return is non-NULL and *bp == NULL then key was deleted */
static void **jl_table_peek_bp(jl_array_t *a, void *key)
{
size_t sz = hash_size(a);
assert(sz >= 1);
size_t maxprobe = max_probe(sz);
void **tab = (void**)a->data;
uint_t hv = keyhash((jl_value_t*)key);
size_t index = h2index(hv, sz);
sz *= 2;
size_t orig = index;
size_t iter = 0;
do {
if (tab[index] == NULL)
return NULL;
if (jl_egal((jl_value_t*)key, (jl_value_t*)tab[index]))
return &tab[index+1];
index = (index+2) & (sz-1);
iter++;
if (iter > maxprobe)
break;
} while (index != orig);
return NULL;
}
JL_DLLEXPORT
jl_array_t *jl_eqtable_put(jl_array_t *h, void *key, void *val)
{
JL_GC_PUSH1(&h);
// &h may be assigned to in jl_idtable_rehash so it need to be rooted
void **bp = jl_table_lookup_bp(&h, key);
*bp = val;
jl_gc_wb(h, val);
JL_GC_POP();
return h;
}
JL_DLLEXPORT
jl_value_t *jl_eqtable_get(jl_array_t *h, void *key, jl_value_t *deflt)
{
void **bp = jl_table_peek_bp(h, key);
if (bp == NULL || *bp == NULL)
return deflt;
return (jl_value_t*)*bp;
}
JL_DLLEXPORT
jl_value_t *jl_eqtable_pop(jl_array_t *h, void *key, jl_value_t *deflt)
{
void **bp = jl_table_peek_bp(h, key);
if (bp == NULL || *bp == NULL)
return deflt;
jl_value_t *val = (jl_value_t*)*bp;
*(bp-1) = jl_nothing; // clear the key
*bp = NULL;
return val;
}
JL_DLLEXPORT
size_t jl_eqtable_nextind(jl_array_t *t, size_t i)
{
if (i&1) i++;
size_t alen = jl_array_dim0(t);
while (i < alen && ((void**)t->data)[i+1] == NULL)
i+=2;
if (i >= alen) return (size_t)-1;
return i;
}
#undef hash_size
#undef max_probe
![swh spinner](/static/img/swh-spinner.gif)
Computing file changes ...