Reduce work done by hashing.

Curtail traversal of objects and strings.

* hash.c (struct hash): hash_fun member takes int *
parameter now.
(HASH_STR_LIMIT, HASH_REC_LIMIT): New macros.
(hash_c_str): Hash only HASH_STR_LIMIT characters.
(equal_hash): Becomes extern function. Takes pointer-to-int
count argument, which is decremented. Function stops
recursing and returns zero when this hits zero.
(eql_hash): Also takes int * param, for compatibility
with function pointer in struct hash. This parameter
is not used, though.
(cobj_hash_op): Take pointer-to-count parameter,
but ignore it.
(hash_hash_op): Take pointer-to-count parameter,
decrement and check that it has not hit zero,
pass down to equal hash.
(hash_grow, gethash_c, gethash, gethash_f, gethash_n,
remhash): Initialize a counter to HASH_REC_LIMIT and
pass down to hashing function.
(hash_eql): Pass down a pointer to a dummy counter
to eql_hash.
(hash_equal): Initialize a counter to HASH_REC_LIMIT
and pass down to hash_equal.

* hash.h (equal_hash): Declared.

* lib.h (cobj_ops): hash member takes int * parameter.
(cobj_hash_op): Declaration updated with new param.

* struct.c (struct_inst_hash): Takes new int * parameter
for count. Calls equal_hash instead of hash_equal,
eliminating c_num calls; pointer to count is
passed to equal_hash.

1 files changed, 1 insertions, 0 deletions

diff --git a/hash.h b/hash.h
index a1ec19fc..29ff19d7 100644
--- a/hash.h
+++ b/hash.h
@@ -26,6 +26,7 @@
 
 extern val weak_keys_k, weak_vals_k, equal_based_k;
 
+cnum equal_hash(val obj, int *count);
 val make_hash(val weak_keys, val weak_vals, val equal_based);
 val make_similar_hash(val existing);
 val copy_hash(val existing);