/* hv.c
*
- * Copyright (c) 1991-1999, Larry Wall
+ * Copyright (c) 1991-2000, Larry Wall
*
* You may distribute under the terms of either the GNU General Public
* License or the Artistic License, as specified in the README file.
/* (klen == HEf_SVKEY) is special for MAGICAL hv entries, meaning key slot
* contains an SV* */
+/*
+=for apidoc hv_fetch
+
+Returns the SV which corresponds to the specified key in the hash. The
+C<klen> is the length of the key. If C<lval> is set then the fetch will be
+part of a store. Check that the return value is non-null before
+dereferencing it to a C<SV*>.
+
+See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
+information on how to use this function on tied hashes.
+
+=cut
+*/
+
SV**
Perl_hv_fetch(pTHX_ HV *hv, const char *key, U32 klen, I32 lval)
{
/* returns a HE * structure with the all fields set */
/* note that hent_val will be a mortal sv for MAGICAL hashes */
+/*
+=for apidoc hv_fetch_ent
+
+Returns the hash entry which corresponds to the specified key in the hash.
+C<hash> must be a valid precomputed hash number for the given C<key>, or 0
+if you want the function to compute it. IF C<lval> is set then the fetch
+will be part of a store. Make sure the return value is non-null before
+accessing it. The return value when C<tb> is a tied hash is a pointer to a
+static location, so be sure to make a copy of the structure if you need to
+store it somewhere.
+
+See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
+information on how to use this function on tied hashes.
+
+=cut
+*/
+
HE *
Perl_hv_fetch_ent(pTHX_ HV *hv, SV *keysv, I32 lval, register U32 hash)
{
}
}
+/*
+=for apidoc hv_store
+
+Stores an SV in a hash. The hash key is specified as C<key> and C<klen> is
+the length of the key. The C<hash> parameter is the precomputed hash
+value; if it is zero then Perl will compute it. The return value will be
+NULL if the operation failed or if the value did not need to be actually
+stored within the hash (as in the case of tied hashes). Otherwise it can
+be dereferenced to get the original C<SV*>. Note that the caller is
+responsible for suitably incrementing the reference count of C<val> before
+the call, and decrementing it if the function returned NULL.
+
+See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
+information on how to use this function on tied hashes.
+
+=cut
+*/
+
SV**
Perl_hv_store(pTHX_ HV *hv, const char *key, U32 klen, SV *val, register U32 hash)
{
return &HeVAL(entry);
}
+/*
+=for apidoc hv_store_ent
+
+Stores C<val> in a hash. The hash key is specified as C<key>. The C<hash>
+parameter is the precomputed hash value; if it is zero then Perl will
+compute it. The return value is the new hash entry so created. It will be
+NULL if the operation failed or if the value did not need to be actually
+stored within the hash (as in the case of tied hashes). Otherwise the
+contents of the return value can be accessed using the C<He???> macros
+described here. Note that the caller is responsible for suitably
+incrementing the reference count of C<val> before the call, and
+decrementing it if the function returned NULL.
+
+See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
+information on how to use this function on tied hashes.
+
+=cut
+*/
+
HE *
Perl_hv_store_ent(pTHX_ HV *hv, SV *keysv, SV *val, register U32 hash)
{
return entry;
}
+/*
+=for apidoc hv_delete
+
+Deletes a key/value pair in the hash. The value SV is removed from the
+hash and returned to the caller. The C<klen> is the length of the key.
+The C<flags> value will normally be zero; if set to G_DISCARD then NULL
+will be returned.
+
+=cut
+*/
+
SV *
Perl_hv_delete(pTHX_ HV *hv, const char *key, U32 klen, I32 flags)
{
xhv->xhv_fill--;
if (flags & G_DISCARD)
sv = Nullsv;
- else
- sv = sv_mortalcopy(HeVAL(entry));
+ else {
+ sv = sv_2mortal(HeVAL(entry));
+ HeVAL(entry) = &PL_sv_undef;
+ }
if (entry == xhv->xhv_eiter)
HvLAZYDEL_on(hv);
else
return Nullsv;
}
+/*
+=for apidoc hv_delete_ent
+
+Deletes a key/value pair in the hash. The value SV is removed from the
+hash and returned to the caller. The C<flags> value will normally be zero;
+if set to G_DISCARD then NULL will be returned. C<hash> can be a valid
+precomputed hash value, or 0 to ask for it to be computed.
+
+=cut
+*/
+
SV *
Perl_hv_delete_ent(pTHX_ HV *hv, SV *keysv, I32 flags, U32 hash)
{
xhv->xhv_fill--;
if (flags & G_DISCARD)
sv = Nullsv;
- else
- sv = sv_mortalcopy(HeVAL(entry));
+ else {
+ sv = sv_2mortal(HeVAL(entry));
+ HeVAL(entry) = &PL_sv_undef;
+ }
if (entry == xhv->xhv_eiter)
HvLAZYDEL_on(hv);
else
return Nullsv;
}
+/*
+=for apidoc hv_exists
+
+Returns a boolean indicating whether the specified hash key exists. The
+C<klen> is the length of the key.
+
+=cut
+*/
+
bool
Perl_hv_exists(pTHX_ HV *hv, const char *key, U32 klen)
{
}
+/*
+=for apidoc hv_exists_ent
+
+Returns a boolean indicating whether the specified hash key exists. C<hash>
+can be a valid precomputed hash value, or 0 to ask for it to be
+computed.
+
+=cut
+*/
+
bool
Perl_hv_exists_ent(pTHX_ HV *hv, SV *keysv, U32 hash)
{
}
}
+/*
+=for apidoc newHV
+
+Creates a new HV. The reference count is set to 1.
+
+=cut
+*/
+
HV *
Perl_newHV(pTHX)
{
del_he(entry);
}
+/*
+=for apidoc hv_clear
+
+Clears a hash, making it empty.
+
+=cut
+*/
+
void
Perl_hv_clear(pTHX_ HV *hv)
{
(void)hv_iterinit(hv);
}
+/*
+=for apidoc hv_undef
+
+Undefines the hash.
+
+=cut
+*/
+
void
Perl_hv_undef(pTHX_ HV *hv)
{
mg_clear((SV*)hv);
}
+/*
+=for apidoc hv_iterinit
+
+Prepares a starting point to traverse a hash table. Returns the number of
+keys in the hash (i.e. the same as C<HvKEYS(tb)>). The return value is
+currently only meaningful for hashes without tie magic.
+
+NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
+hash buckets that happen to be in use. If you still need that esoteric
+value, you can get it through the macro C<HvFILL(tb)>.
+
+=cut
+*/
+
I32
Perl_hv_iterinit(pTHX_ HV *hv)
{
return xhv->xhv_keys; /* used to be xhv->xhv_fill before 5.004_65 */
}
+/*
+=for apidoc hv_iternext
+
+Returns entries from a hash iterator. See C<hv_iterinit>.
+
+=cut
+*/
+
HE *
Perl_hv_iternext(pTHX_ HV *hv)
{
return entry;
}
+/*
+=for apidoc hv_iterkey
+
+Returns the key from the current position of the hash iterator. See
+C<hv_iterinit>.
+
+=cut
+*/
+
char *
Perl_hv_iterkey(pTHX_ register HE *entry, I32 *retlen)
{
}
/* unlike hv_iterval(), this always returns a mortal copy of the key */
+/*
+=for apidoc hv_iterkeysv
+
+Returns the key as an C<SV*> from the current position of the hash
+iterator. The return value will always be a mortal copy of the key. Also
+see C<hv_iterinit>.
+
+=cut
+*/
+
SV *
Perl_hv_iterkeysv(pTHX_ register HE *entry)
{
HeKLEN(entry)));
}
+/*
+=for apidoc hv_iterval
+
+Returns the value from the current position of the hash iterator. See
+C<hv_iterkey>.
+
+=cut
+*/
+
SV *
Perl_hv_iterval(pTHX_ HV *hv, register HE *entry)
{
return HeVAL(entry);
}
+/*
+=for apidoc hv_iternextsv
+
+Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
+operation.
+
+=cut
+*/
+
SV *
Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
{
return hv_iterval(hv, he);
}
+/*
+=for apidoc hv_magic
+
+Adds magic to a hash. See C<sv_magic>.
+
+=cut
+*/
+
void
Perl_hv_magic(pTHX_ HV *hv, GV *gv, int how)
{
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