int
dict_find(const ref * pdref, const ref * pkey, ref ** ppvalue)
{
dict *pdict = pdref->value.pdict;
int code = real_dict_find(pdref, pkey, ppvalue);
stats_dict.lookups++;
if (r_has_type(pkey, t_name) && dict_is_packed(pdict)) {
uint nidx = name_index(dict_mem(pdict), pkey);
uint hash =
dict_hash_mod(dict_name_index_hash(nidx), npairs(pdict)) + 1;
if (pdict->keys.value.packed[hash] ==
pt_tag(pt_literal_name) + nidx
)
stats_dict.probe1++;
else if (pdict->keys.value.packed[hash - 1] ==
pt_tag(pt_literal_name) + nidx
)
stats_dict.probe2++;
}
/* Do the cheap flag test before the expensive remainder test. */
if (gs_debug_c('d') && !(stats_dict.lookups % 1000))
dlprintf3("[d]lookups=%ld probe1=%ld probe2=%ld\n",
stats_dict.lookups, stats_dict.probe1, stats_dict.probe2);
return code;
}
ref *
dstack_find_name_by_index(dict_stack_t * pds, uint nidx)
{
ref *pvalue = real_dstack_find_name_by_index(pds, nidx);
dict *pdict = pds->stack.p->value.pdict;
INCR(lookups);
if (dict_is_packed(pdict)) {
uint hash =
dict_hash_mod(dict_name_index_hash(nidx), npairs(pdict)) + 1;
if (pdict->keys.value.packed[hash] ==
pt_tag(pt_literal_name) + nidx
)
INCR(probes[0]);
else if (pdict->keys.value.packed[hash - 1] ==
pt_tag(pt_literal_name) + nidx
)
INCR(probes[1]);
}
if (gs_debug_c('d') && !(stats_dstack.lookups % 1000))
dlprintf3("[d]lookups=%ld probe1=%ld probe2=%ld\n",
stats_dstack.lookups, stats_dstack.probes[0],
stats_dstack.probes[1]);
return pvalue;
}
/*
* Look up a key in a dictionary. Store a pointer to the value slot
* where found, or to the (value) slot for inserting.
* See idict.h for the possible return values.
*/
int
dict_find(const ref * pdref, const ref * pkey,
ref ** ppvalue /* result is stored here */ )
{
dict *pdict = pdref->value.pdict;
uint size = npairs(pdict);
register int etype;
uint nidx;
ref_packed kpack;
uint hash;
int ktype;
const gs_memory_t *mem = dict_mem(pdict);
/* Compute hash. The only types we bother with are strings, */
/* names, and (unlikely, but worth checking for) integers. */
switch (r_type(pkey)) {
case t_name:
nidx = name_index(mem, pkey);
nh:
hash = dict_name_index_hash(nidx);
kpack = packed_name_key(nidx);
ktype = t_name;
break;
case t_string: /* convert to a name first */
{
ref nref;
int code;
if (!r_has_attr(pkey, a_read))
return_error(gs_error_invalidaccess);
code = name_ref(mem, pkey->value.bytes, r_size(pkey), &nref, 1);
if (code < 0)
return code;
nidx = name_index(mem, &nref);
}
goto nh;
case t_real:
/*
* Make sure that equal reals and integers hash the same.
*/
{
int expt, i;
double mant = frexp(pkey->value.realval, &expt);
/*
* The value is mant * 2^expt, where 0.5 <= mant < 1,
* or else expt == mant == 0.
*/
if (expt < sizeof(long) * 8 || pkey->value.realval == min_long)
i = (int)pkey->value.realval;
else
i = (int)(mant * min_long); /* MSVC 6.00.8168.0 cannot compile this */
hash = (uint)i * 30503; /* with -O2 as a single expression */
}
goto ih;
case t_integer:
hash = (uint)pkey->value.intval * 30503;
ih:
kpack = packed_key_impossible;
ktype = -1;
nidx = 0; /* only to pacify gcc */
break;
case t_null: /* not allowed as a key */
return_error(gs_error_typecheck);
default:
hash = r_btype(pkey) * 99; /* yech */
kpack = packed_key_impossible;
ktype = -1;
nidx = 0; /* only to pacify gcc */
}
/* Search the dictionary */
if (dict_is_packed(pdict)) {
const ref_packed *pslot = 0;
# define found *ppvalue = packed_search_value_pointer; return 1
# define deleted if (pslot == 0) pslot = kp
# define missing goto miss
# include "idicttpl.h"
# undef missing
# undef deleted
# undef found
/*
* Double wraparound, dict is full.
* Note that even if there was an empty slot (pslot != 0),
* we must return dictfull if length = maxlength.
*/
if (pslot == 0 || d_length(pdict) == d_maxlength(pdict))
return_error(gs_error_dictfull);
*ppvalue = pdict->values.value.refs + (pslot - kbot);
return 0;
miss: /* Key is missing, not double wrap. See above re dictfull. */
if (d_length(pdict) == d_maxlength(pdict))
return_error(gs_error_dictfull);
if (pslot == 0)
pslot = kp;
*ppvalue = pdict->values.value.refs + (pslot - kbot);
return 0;
} else {
ref *kbot = pdict->keys.value.refs;
register ref *kp;
ref *pslot = 0;
int wrap = 0;
for (kp = kbot + dict_hash_mod(hash, size) + 2;;) {
--kp;
if ((etype = r_type(kp)) == ktype) { /* Fast comparison if both keys are names */
if (name_index(mem, kp) == nidx) {
*ppvalue = pdict->values.value.refs + (kp - kbot);
return 1;
}
} else if (etype == t_null) { /* Empty, deleted, or wraparound. */
/* Figure out which. */
if (kp == kbot) { /* wrap */
if (wrap++) { /* wrapped twice */
if (pslot == 0)
return_error(gs_error_dictfull);
break;
}
kp += size + 1;
} else if (r_has_attr(kp, a_executable)) { /* Deleted entry, save the slot. */
if (pslot == 0)
pslot = kp;
} else /* key not found */
break;
} else {
if (obj_eq(mem, kp, pkey)) {
*ppvalue = pdict->values.value.refs + (kp - kbot);
return 1;
}
}
}
if (d_length(pdict) == d_maxlength(pdict))
return_error(gs_error_dictfull);
*ppvalue = pdict->values.value.refs +
((pslot != 0 ? pslot : kp) - kbot);
return 0;
}
}
