diff options
Diffstat (limited to 'hash.c')
| -rw-r--r-- | hash.c | 43 |
1 files changed, 37 insertions, 6 deletions
@@ -34,6 +34,9 @@ #include <signal.h> #include "config.h" #include ALLOCA_H +#if HAVE_UNISTD_H +#include <unistd.h> +#endif #include "lib.h" #include "gc.h" #include "args.h" @@ -44,6 +47,7 @@ #include "eval.h" #include "cadr.h" #include "itypes.h" +#include "arith.h" #include "hash.h" typedef enum hash_flags { @@ -82,10 +86,13 @@ struct hash_iter { val cons; }; +#define hash_seed (deref(lookup_var_l(nil, hash_seed_s))) + static_forward(struct hash_ops hash_eql_ops); static_forward(struct hash_ops hash_equal_ops); val weak_keys_k, weak_vals_k, equal_based_k, eql_based_k, userdata_k; +val hash_seed_s; /* * Dynamic lists built up during gc. @@ -681,7 +688,7 @@ static_def(struct hash_ops hash_equal_ops = hash_ops_init(equal_hash, equal, hash_assoc, hash_acons_new_c)); -val make_hash(val weak_keys, val weak_vals, val equal_based) +val make_seeded_hash(val weak_keys, val weak_vals, val equal_based, val seed) { if (weak_keys && equal_based) { uw_throwf(error_s, @@ -694,7 +701,9 @@ val make_hash(val weak_keys, val weak_vals, val equal_based) val table = vector(mod, nil); val hash = cobj(coerce(mem_t *, h), hash_s, &hash_ops); - h->seed = 0; + h->seed = convert(u32_t, c_unum(default_arg(seed, + if3(hash_seed_s, + hash_seed, zero)))); h->flags = convert(hash_flags_t, flags); h->modulus = c_num(mod); h->count = 0; @@ -708,6 +717,11 @@ val make_hash(val weak_keys, val weak_vals, val equal_based) } } +val make_hash(val weak_keys, val weak_vals, val equal_based) +{ + return make_seeded_hash(weak_keys, weak_vals, equal_based, nil); +} + val make_similar_hash(val existing) { struct hash *ex = coerce(struct hash *, cobj_handle(existing, hash_s)); @@ -965,10 +979,10 @@ val hash_eql(val obj) return num_fast(eql_hash(obj, &lim)); } -val hash_equal(val obj) +val hash_equal(val obj, val seed) { int lim = hash_rec_limit; - return num_fast(equal_hash(obj, &lim, 0)); + return num_fast(equal_hash(obj, &lim, if3(missingp(seed), 0, c_unum(seed)))); } /* @@ -1499,6 +1513,19 @@ static val set_hash_rec_limit(val lim) return old; } +static val gen_hash_seed(void) +{ + val time = time_sec_usec(); + ucnum sec = convert(ucnum, c_num(car(time))); + ucnum usec = convert(ucnum, c_num(cdr(time))); +#if HAVE_UNISTD_H + ucnum pid = convert(ucnum, getpid()); +#else + ucnum pid = 0; +#endif + return unum(sec ^ (usec << 12) ^ pid); +} + void hash_init(void) { weak_keys_k = intern(lit("weak-keys"), keyword_package); @@ -1506,9 +1533,12 @@ void hash_init(void) equal_based_k = intern(lit("equal-based"), keyword_package); eql_based_k = intern(lit("eql-based"), keyword_package); userdata_k = intern(lit("userdata"), keyword_package); + hash_seed_s = intern(lit("*hash-seed*"), user_package); val ghu = func_n1(get_hash_userdata); - reg_fun(intern(lit("make-hash"), user_package), func_n3(make_hash)); + reg_var(hash_seed_s, zero); + + reg_fun(intern(lit("make-hash"), user_package), func_n4o(make_seeded_hash, 3)); reg_fun(intern(lit("make-similar-hash"), user_package), func_n1(make_similar_hash)); reg_fun(intern(lit("copy-hash"), user_package), func_n1(copy_hash)); reg_fun(intern(lit("hash"), user_package), func_n0v(hashv)); @@ -1529,7 +1559,7 @@ void hash_init(void) reg_fun(intern(lit("hashp"), user_package), func_n1(hashp)); reg_fun(intern(lit("maphash"), user_package), func_n2(maphash)); reg_fun(intern(lit("hash-eql"), user_package), func_n1(hash_eql)); - reg_fun(intern(lit("hash-equal"), user_package), func_n1(hash_equal)); + reg_fun(intern(lit("hash-equal"), user_package), func_n2o(hash_equal, 1)); reg_fun(intern(lit("hash-keys"), user_package), func_n1(hash_keys)); reg_fun(intern(lit("hash-values"), user_package), func_n1(hash_values)); reg_fun(intern(lit("hash-pairs"), user_package), func_n1(hash_pairs)); @@ -1552,4 +1582,5 @@ void hash_init(void) func_n1(set_hash_str_limit)); reg_fun(intern(lit("set-hash-rec-limit"), system_package), func_n1(set_hash_rec_limit)); + reg_fun(intern(lit("gen-hash-seed"), user_package), func_n0(gen_hash_seed)); } |