[perl5.git] / hv.h

/*    hv.h
 *
 *    Copyright (c) 1991-2001, 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.
 *
 */

/* typedefs to eliminate some typing */
typedef struct he HE;
typedef struct hek HEK;

/* entry in hash value chain */
struct he {
    HE		*hent_next;	/* next entry in chain */
    HEK		*hent_hek;	/* hash key */
    SV		*hent_val;	/* scalar value that was hashed */
};

/* hash key -- defined separately for use as shared pointer */
struct hek {
    U32		hek_hash;	/* hash of key */
    I32		hek_len;	/* length of hash key */
    char	hek_key[1];	/* variable-length hash key */
};

/* hash structure: */
/* This structure must match the beginning of struct xpvmg in sv.h. */
struct xpvhv {
    char *	xhv_array;	/* pointer to malloced string */
    STRLEN	xhv_fill;	/* how full xhv_array currently is */
    STRLEN	xhv_max;	/* subscript of last element of xhv_array */
    IV		xhv_keys;	/* how many elements in the array */
    NV		xnv_nv;		/* numeric value, if any */
#define xhv_placeholders xnv_nv
    MAGIC*	xmg_magic;	/* magic for scalar array */
    HV*		xmg_stash;	/* class package */

    I32		xhv_riter;	/* current root of iterator */
    HE		*xhv_eiter;	/* current entry of iterator */
    PMOP	*xhv_pmroot;	/* list of pm's for this package */
    char	*xhv_name;	/* name, if a symbol table */
};

/* hash a key */
/* FYI: This is the "One-at-a-Time" algorithm by Bob Jenkins */
/* from requirements by Colin Plumb. */
/* (http://burtleburtle.net/bob/hash/doobs.html) */
#define PERL_HASH(hash,str,len) \
     STMT_START	{ \
	register const char *s_PeRlHaSh = str; \
	register I32 i_PeRlHaSh = len; \
	register U32 hash_PeRlHaSh = 0; \
	while (i_PeRlHaSh--) { \
	    hash_PeRlHaSh += *s_PeRlHaSh++; \
	    hash_PeRlHaSh += (hash_PeRlHaSh << 10); \
	    hash_PeRlHaSh ^= (hash_PeRlHaSh >> 6); \
	} \
	hash_PeRlHaSh += (hash_PeRlHaSh << 3); \
	hash_PeRlHaSh ^= (hash_PeRlHaSh >> 11); \
	(hash) = (hash_PeRlHaSh + (hash_PeRlHaSh << 15)); \
    } STMT_END

/*
=head1 Hash Manipulation Functions

=for apidoc AmU||HEf_SVKEY
This flag, used in the length slot of hash entries and magic structures,
specifies the structure contains an C<SV*> pointer where a C<char*> pointer
is to be expected. (For information only--not to be used).

=head1 Handy Values

=for apidoc AmU||Nullhv
Null HV pointer.

=head1 Hash Manipulation Functions

=for apidoc Am|char*|HvNAME|HV* stash
Returns the package name of a stash.  See C<SvSTASH>, C<CvSTASH>.

=for apidoc Am|void*|HeKEY|HE* he
Returns the actual pointer stored in the key slot of the hash entry. The
pointer may be either C<char*> or C<SV*>, depending on the value of
C<HeKLEN()>.  Can be assigned to.  The C<HePV()> or C<HeSVKEY()> macros are
usually preferable for finding the value of a key.

=for apidoc Am|STRLEN|HeKLEN|HE* he
If this is negative, and amounts to C<HEf_SVKEY>, it indicates the entry
holds an C<SV*> key.  Otherwise, holds the actual length of the key.  Can
be assigned to. The C<HePV()> macro is usually preferable for finding key
lengths.

=for apidoc Am|SV*|HeVAL|HE* he
Returns the value slot (type C<SV*>) stored in the hash entry.

=for apidoc Am|U32|HeHASH|HE* he
Returns the computed hash stored in the hash entry.

=for apidoc Am|char*|HePV|HE* he|STRLEN len
Returns the key slot of the hash entry as a C<char*> value, doing any
necessary dereferencing of possibly C<SV*> keys.  The length of the string
is placed in C<len> (this is a macro, so do I<not> use C<&len>).  If you do
not care about what the length of the key is, you may use the global
variable C<PL_na>, though this is rather less efficient than using a local
variable.  Remember though, that hash keys in perl are free to contain
embedded nulls, so using C<strlen()> or similar is not a good way to find
the length of hash keys. This is very similar to the C<SvPV()> macro
described elsewhere in this document.

=for apidoc Am|SV*|HeSVKEY|HE* he
Returns the key as an C<SV*>, or C<Nullsv> if the hash entry does not
contain an C<SV*> key.

=for apidoc Am|SV*|HeSVKEY_force|HE* he
Returns the key as an C<SV*>.  Will create and return a temporary mortal
C<SV*> if the hash entry contains only a C<char*> key.

=for apidoc Am|SV*|HeSVKEY_set|HE* he|SV* sv
Sets the key to a given C<SV*>, taking care to set the appropriate flags to
indicate the presence of an C<SV*> key, and returns the same
C<SV*>.

=cut
*/

/* these hash entry flags ride on hent_klen (for use only in magic/tied HVs) */
#define HEf_SVKEY	-2	/* hent_key is an SV* */


#define Nullhv Null(HV*)
#define HvARRAY(hv)	(*(HE***)&((XPVHV*)  SvANY(hv))->xhv_array)
#define HvFILL(hv)	((XPVHV*)  SvANY(hv))->xhv_fill
#define HvMAX(hv)	((XPVHV*)  SvANY(hv))->xhv_max
#define HvRITER(hv)	((XPVHV*)  SvANY(hv))->xhv_riter
#define HvEITER(hv)	((XPVHV*)  SvANY(hv))->xhv_eiter
#define HvPMROOT(hv)	((XPVHV*)  SvANY(hv))->xhv_pmroot
#define HvNAME(hv)	((XPVHV*)  SvANY(hv))->xhv_name

/* the number of keys (including any placeholers) */
#define XHvTOTALKEYS(xhv)	((xhv)->xhv_keys)

/* The number of placeholders in the enumerated-keys hash */
#define XHvPLACEHOLDERS(xhv)	((xhv)->xhv_placeholders)

/* the number of keys that exist() (i.e. excluding placeholers) */
#define XHvUSEDKEYS(xhv)      (XHvTOTALKEYS(xhv) - XHvPLACEHOLDERS(xhv))

/*
 * HvKEYS gets the number of keys that actually exist(), and is provided
 * for backwards compatibility with old XS code. The core uses HvUSEDKEYS
 * (keys, excluding placeholdes) and HvTOTALKEYS (including placeholders)
 */
#define HvKEYS(hv)		XHvUSEDKEYS((XPVHV*)  SvANY(hv))
#define HvUSEDKEYS(hv)		XHvUSEDKEYS((XPVHV*)  SvANY(hv))
#define HvTOTALKEYS(hv)		XHvTOTALKEYS((XPVHV*)  SvANY(hv))
#define HvPLACEHOLDERS(hv)	XHvPLACEHOLDERS((XPVHV*)  SvANY(hv))


#define HvSHAREKEYS(hv)		(SvFLAGS(hv) & SVphv_SHAREKEYS)
#define HvSHAREKEYS_on(hv)	(SvFLAGS(hv) |= SVphv_SHAREKEYS)
#define HvSHAREKEYS_off(hv)	(SvFLAGS(hv) &= ~SVphv_SHAREKEYS)

#define HvLAZYDEL(hv)		(SvFLAGS(hv) & SVphv_LAZYDEL)
#define HvLAZYDEL_on(hv)	(SvFLAGS(hv) |= SVphv_LAZYDEL)
#define HvLAZYDEL_off(hv)	(SvFLAGS(hv) &= ~SVphv_LAZYDEL)

/* Maybe amagical: */
/* #define HV_AMAGICmb(hv)      (SvFLAGS(hv) & (SVpgv_badAM | SVpgv_AM)) */

#define HV_AMAGIC(hv)        (SvFLAGS(hv) &   SVpgv_AM)
#define HV_AMAGIC_on(hv)     (SvFLAGS(hv) |=  SVpgv_AM)
#define HV_AMAGIC_off(hv)    (SvFLAGS(hv) &= ~SVpgv_AM)

/*
#define HV_AMAGICbad(hv)     (SvFLAGS(hv) & SVpgv_badAM)
#define HV_badAMAGIC_on(hv)  (SvFLAGS(hv) |= SVpgv_badAM)
#define HV_badAMAGIC_off(hv) (SvFLAGS(hv) &= ~SVpgv_badAM)
*/

#define Nullhe Null(HE*)
#define HeNEXT(he)		(he)->hent_next
#define HeKEY_hek(he)		(he)->hent_hek
#define HeKEY(he)		HEK_KEY(HeKEY_hek(he))
#define HeKEY_sv(he)		(*(SV**)HeKEY(he))
#define HeKLEN(he)		HEK_LEN(HeKEY_hek(he))
#define HeKUTF8(he)  HEK_UTF8(HeKEY_hek(he))
#define HeKLEN_UTF8(he)  (HeKUTF8(he) ? -HeKLEN(he) : HeKLEN(he))
#define HeVAL(he)		(he)->hent_val
#define HeHASH(he)		HEK_HASH(HeKEY_hek(he))
#define HePV(he,lp)		((HeKLEN(he) == HEf_SVKEY) ?		\
				 SvPV(HeKEY_sv(he),lp) :		\
				 (((lp = HeKLEN(he)) >= 0) ?		\
				  HeKEY(he) : Nullch))

#define HeSVKEY(he)		((HeKEY(he) && 				\
				  HeKLEN(he) == HEf_SVKEY) ?		\
				 HeKEY_sv(he) : Nullsv)

#define HeSVKEY_force(he)	(HeKEY(he) ?				\
				 ((HeKLEN(he) == HEf_SVKEY) ?		\
				  HeKEY_sv(he) :			\
				  sv_2mortal(newSVpvn(HeKEY(he),	\
						     HeKLEN(he)))) :	\
				 &PL_sv_undef)
#define HeSVKEY_set(he,sv)	((HeKLEN(he) = HEf_SVKEY), (HeKEY_sv(he) = sv))

#define Nullhek Null(HEK*)
#define HEK_BASESIZE		STRUCT_OFFSET(HEK, hek_key[0])
#define HEK_HASH(hek)		(hek)->hek_hash
#define HEK_LEN(hek)		(hek)->hek_len
#define HEK_KEY(hek)		(hek)->hek_key
#define HEK_UTF8(hek)  (*(HEK_KEY(hek)+HEK_LEN(hek)))

/* calculate HV array allocation */
#if defined(STRANGE_MALLOC) || defined(MYMALLOC)
#  define PERL_HV_ARRAY_ALLOC_BYTES(size) ((size) * sizeof(HE*))
#else
#  define MALLOC_OVERHEAD 16
#  define PERL_HV_ARRAY_ALLOC_BYTES(size) \
			(((size) < 64)					\
			 ? (size) * sizeof(HE*)				\
			 : (size) * sizeof(HE*) * 2 - MALLOC_OVERHEAD)
#endif

/* available as a function in hv.c */
#define Perl_sharepvn(sv, len, hash) HEK_KEY(share_hek(sv, len, hash))
#define sharepvn(sv, len, hash)	     Perl_sharepvn(sv, len, hash)
Commit	Line	Data
a0d0e21e	1	/* hv.h
79072805	2	*
bc89e66f	3	* Copyright (c) 1991-2001, Larry Wall
79072805 LW	4	*
	5	* You may distribute under the terms of either the GNU General Public
	6	* License or the Artistic License, as specified in the README file.
	7	*
79072805 LW	8	*/
79072805 LW	9
5cbe4eec	10	/* typedefs to eliminate some typing */
79072805	11	typedef struct he HE;
ff68c719	12	typedef struct hek HEK;
79072805	13
5cbe4eec	14	/* entry in hash value chain */
79072805	15	struct he {
5cbe4eec MLF	16	HE hent_next; / next entry in chain */
	17	HEK hent_hek; / hash key */
	18	SV hent_val; / scalar value that was hashed */
bbce6d69	19	};
bbce6d69	20
5cbe4eec	21	/* hash key -- defined separately for use as shared pointer */
ff68c719	22	struct hek {
5cbe4eec MLF	23	U32 hek_hash; /* hash of key */
	24	I32 hek_len; /* length of hash key */
	25	char hek_key[1]; /* variable-length hash key */
79072805 LW	26	};
79072805 LW	27
5cbe4eec	28	/* hash structure: */
6ee623d5	29	/* This structure must match the beginning of struct xpvmg in sv.h. */
79072805	30	struct xpvhv {
463ee0b2 LW	31	char * xhv_array; /* pointer to malloced string */
	32	STRLEN xhv_fill; /* how full xhv_array currently is */
	33	STRLEN xhv_max; /* subscript of last element of xhv_array */
6ee623d5	34	IV xhv_keys; /* how many elements in the array */
65202027	35	NV xnv_nv; /* numeric value, if any */
8aacddc1	36	#define xhv_placeholders xnv_nv
79072805 LW	37	MAGIC* xmg_magic; /* magic for scalar array */
	38	HV* xmg_stash; /* class package */
	39
79072805 LW	40	I32 xhv_riter; /* current root of iterator */
	41	HE xhv_eiter; / current entry of iterator */
	42	PMOP xhv_pmroot; / list of pm's for this package */
	43	char xhv_name; / name, if a symbol table */
79072805 LW	44	};
79072805 LW	45
5cbe4eec	46	/* hash a key */
a6fe520e MLF	47	/* FYI: This is the "One-at-a-Time" algorithm by Bob Jenkins */
	48	/* from requirements by Colin Plumb. */
	49	/* (http://burtleburtle.net/bob/hash/doobs.html) */
bf6bd887	50	#define PERL_HASH(hash,str,len) \
bf6bd887	51	STMT_START { \
08105a92	52	register const char *s_PeRlHaSh = str; \
bf6bd887	53	register I32 i_PeRlHaSh = len; \
bf6bd887	54	register U32 hash_PeRlHaSh = 0; \
a6fe520e MLF	55	while (i_PeRlHaSh--) { \
	56	hash_PeRlHaSh += *s_PeRlHaSh++; \
	57	hash_PeRlHaSh += (hash_PeRlHaSh << 10); \
	58	hash_PeRlHaSh ^= (hash_PeRlHaSh >> 6); \
	59	} \
	60	hash_PeRlHaSh += (hash_PeRlHaSh << 3); \
	61	hash_PeRlHaSh ^= (hash_PeRlHaSh >> 11); \
4fee5c71	62	(hash) = (hash_PeRlHaSh + (hash_PeRlHaSh << 15)); \
bf6bd887	63	} STMT_END
bf6bd887	64
954c1994	65	/*
ccfc67b7 JH	66	=head1 Hash Manipulation Functions
ccfc67b7 JH	67
954c1994 GS	68	=for apidoc AmU\|\|HEf_SVKEY
954c1994 GS	69	This flag, used in the length slot of hash entries and magic structures,
d1be9408	70	specifies the structure contains an C<SV> pointer where a C<char> pointer
954c1994 GS	71	is to be expected. (For information only--not to be used).
954c1994 GS	72
ccfc67b7 JH	73	=head1 Handy Values
ccfc67b7 JH	74
954c1994 GS	75	=for apidoc AmU\|\|Nullhv
	76	Null HV pointer.
	77
ccfc67b7 JH	78	=head1 Hash Manipulation Functions
ccfc67b7 JH	79
954c1994 GS	80	=for apidoc Am\|char\|HvNAME\|HV stash
	81	Returns the package name of a stash. See C<SvSTASH>, C<CvSTASH>.
	82
	83	=for apidoc Am\|void\|HeKEY\|HE he
	84	Returns the actual pointer stored in the key slot of the hash entry. The
	85	pointer may be either C<char> or C<SV>, depending on the value of
	86	C<HeKLEN()>. Can be assigned to. The C<HePV()> or C<HeSVKEY()> macros are
	87	usually preferable for finding the value of a key.
	88
	89	=for apidoc Am\|STRLEN\|HeKLEN\|HE* he
	90	If this is negative, and amounts to C<HEf_SVKEY>, it indicates the entry
	91	holds an C<SV*> key. Otherwise, holds the actual length of the key. Can
	92	be assigned to. The C<HePV()> macro is usually preferable for finding key
	93	lengths.
	94
	95	=for apidoc Am\|SV\|HeVAL\|HE he
	96	Returns the value slot (type C<SV*>) stored in the hash entry.
	97
	98	=for apidoc Am\|U32\|HeHASH\|HE* he
	99	Returns the computed hash stored in the hash entry.
	100
	101	=for apidoc Am\|char\|HePV\|HE he\|STRLEN len
	102	Returns the key slot of the hash entry as a C<char*> value, doing any
	103	necessary dereferencing of possibly C<SV*> keys. The length of the string
	104	is placed in C<len> (this is a macro, so do I<not> use C<&len>). If you do
	105	not care about what the length of the key is, you may use the global
	106	variable C<PL_na>, though this is rather less efficient than using a local
	107	variable. Remember though, that hash keys in perl are free to contain
	108	embedded nulls, so using C<strlen()> or similar is not a good way to find
	109	the length of hash keys. This is very similar to the C<SvPV()> macro
	110	described elsewhere in this document.
	111
	112	=for apidoc Am\|SV\|HeSVKEY\|HE he
	113	Returns the key as an C<SV*>, or C<Nullsv> if the hash entry does not
	114	contain an C<SV*> key.
	115
	116	=for apidoc Am\|SV\|HeSVKEY_force\|HE he
	117	Returns the key as an C<SV*>. Will create and return a temporary mortal
	118	C<SV> if the hash entry contains only a C<char> key.
	119
	120	=for apidoc Am\|SV\|HeSVKEY_set\|HE he\|SV* sv
	121	Sets the key to a given C<SV*>, taking care to set the appropriate flags to
	122	indicate the presence of an C<SV*> key, and returns the same
	123	C<SV*>.
	124
	125	=cut
	126	*/
bf6bd887	127
bf5b86ae	128	/* these hash entry flags ride on hent_klen (for use only in magic/tied HVs) */
d1be9408	129	#define HEf_SVKEY -2 /* hent_key is an SV* */
bf6bd887	130
bf6bd887	131
79072805	132	#define Nullhv Null(HV*)
4efcf9a2	133	#define HvARRAY(hv) ((HE*)&((XPVHV) SvANY(hv))->xhv_array)
79072805	134	#define HvFILL(hv) ((XPVHV*) SvANY(hv))->xhv_fill
463ee0b2	135	#define HvMAX(hv) ((XPVHV*) SvANY(hv))->xhv_max
79072805 LW	136	#define HvRITER(hv) ((XPVHV*) SvANY(hv))->xhv_riter
	137	#define HvEITER(hv) ((XPVHV*) SvANY(hv))->xhv_eiter
	138	#define HvPMROOT(hv) ((XPVHV*) SvANY(hv))->xhv_pmroot
	139	#define HvNAME(hv) ((XPVHV*) SvANY(hv))->xhv_name
a0d0e21e	140
8aacddc1 NIS	141	/* the number of keys (including any placeholers) */
	142	#define XHvTOTALKEYS(xhv) ((xhv)->xhv_keys)
	143
	144	/* The number of placeholders in the enumerated-keys hash */
205c8ad3	145	#define XHvPLACEHOLDERS(xhv) ((xhv)->xhv_placeholders)
8aacddc1 NIS	146
	147	/* the number of keys that exist() (i.e. excluding placeholers) */
	148	#define XHvUSEDKEYS(xhv) (XHvTOTALKEYS(xhv) - XHvPLACEHOLDERS(xhv))
	149
	150	/*
	151	* HvKEYS gets the number of keys that actually exist(), and is provided
	152	* for backwards compatibility with old XS code. The core uses HvUSEDKEYS
	153	* (keys, excluding placeholdes) and HvTOTALKEYS (including placeholders)
	154	*/
	155	#define HvKEYS(hv) XHvUSEDKEYS((XPVHV*) SvANY(hv))
	156	#define HvUSEDKEYS(hv) XHvUSEDKEYS((XPVHV*) SvANY(hv))
	157	#define HvTOTALKEYS(hv) XHvTOTALKEYS((XPVHV*) SvANY(hv))
	158	#define HvPLACEHOLDERS(hv) XHvPLACEHOLDERS((XPVHV*) SvANY(hv))
	159
	160
bf6bd887	161	#define HvSHAREKEYS(hv) (SvFLAGS(hv) & SVphv_SHAREKEYS)
	162	#define HvSHAREKEYS_on(hv) (SvFLAGS(hv) \|= SVphv_SHAREKEYS)
	163	#define HvSHAREKEYS_off(hv) (SvFLAGS(hv) &= ~SVphv_SHAREKEYS)
	164
bf5b86ae GS	165	#define HvLAZYDEL(hv) (SvFLAGS(hv) & SVphv_LAZYDEL)
	166	#define HvLAZYDEL_on(hv) (SvFLAGS(hv) \|= SVphv_LAZYDEL)
	167	#define HvLAZYDEL_off(hv) (SvFLAGS(hv) &= ~SVphv_LAZYDEL)
	168
a0d0e21e LW	169	/* Maybe amagical: */
	170	/* #define HV_AMAGICmb(hv) (SvFLAGS(hv) & (SVpgv_badAM \| SVpgv_AM)) */
	171
	172	#define HV_AMAGIC(hv) (SvFLAGS(hv) & SVpgv_AM)
	173	#define HV_AMAGIC_on(hv) (SvFLAGS(hv) \|= SVpgv_AM)
	174	#define HV_AMAGIC_off(hv) (SvFLAGS(hv) &= ~SVpgv_AM)
	175
	176	/*
	177	#define HV_AMAGICbad(hv) (SvFLAGS(hv) & SVpgv_badAM)
	178	#define HV_badAMAGIC_on(hv) (SvFLAGS(hv) \|= SVpgv_badAM)
	179	#define HV_badAMAGIC_off(hv) (SvFLAGS(hv) &= ~SVpgv_badAM)
	180	*/
bf6bd887	181
	182	#define Nullhe Null(HE*)
	183	#define HeNEXT(he) (he)->hent_next
ff68c719	184	#define HeKEY_hek(he) (he)->hent_hek
ff68c719	185	#define HeKEY(he) HEK_KEY(HeKEY_hek(he))
bbce6d69	186	#define HeKEY_sv(he) ((SV*)HeKEY(he))
ff68c719	187	#define HeKLEN(he) HEK_LEN(HeKEY_hek(he))
da58a35d JH	188	#define HeKUTF8(he) HEK_UTF8(HeKEY_hek(he))
da58a35d JH	189	#define HeKLEN_UTF8(he) (HeKUTF8(he) ? -HeKLEN(he) : HeKLEN(he))
bf6bd887	190	#define HeVAL(he) (he)->hent_val
ff68c719	191	#define HeHASH(he) HEK_HASH(HeKEY_hek(he))
1e422769	192	#define HePV(he,lp) ((HeKLEN(he) == HEf_SVKEY) ? \
	193	SvPV(HeKEY_sv(he),lp) : \
	194	(((lp = HeKLEN(he)) >= 0) ? \
	195	HeKEY(he) : Nullch))
	196
bbce6d69	197	#define HeSVKEY(he) ((HeKEY(he) && \
	198	HeKLEN(he) == HEf_SVKEY) ? \
	199	HeKEY_sv(he) : Nullsv)
	200
	201	#define HeSVKEY_force(he) (HeKEY(he) ? \
	202	((HeKLEN(he) == HEf_SVKEY) ? \
	203	HeKEY_sv(he) : \
79cb57f6	204	sv_2mortal(newSVpvn(HeKEY(he), \
bbce6d69	205	HeKLEN(he)))) : \
3280af22	206	&PL_sv_undef)
1e422769	207	#define HeSVKEY_set(he,sv) ((HeKLEN(he) = HEf_SVKEY), (HeKEY_sv(he) = sv))
bbce6d69	208
ff68c719	209	#define Nullhek Null(HEK*)
71be2cbc	210	#define HEK_BASESIZE STRUCT_OFFSET(HEK, hek_key[0])
ff68c719	211	#define HEK_HASH(hek) (hek)->hek_hash
	212	#define HEK_LEN(hek) (hek)->hek_len
	213	#define HEK_KEY(hek) (hek)->hek_key
da58a35d	214	#define HEK_UTF8(hek) (*(HEK_KEY(hek)+HEK_LEN(hek)))
d18c6117	215
5cbe4eec	216	/* calculate HV array allocation */
d18c6117 GS	217	#if defined(STRANGE_MALLOC) \|\| defined(MYMALLOC)
	218	# define PERL_HV_ARRAY_ALLOC_BYTES(size) ((size) * sizeof(HE*))
	219	#else
	220	# define MALLOC_OVERHEAD 16
	221	# define PERL_HV_ARRAY_ALLOC_BYTES(size) \
	222	(((size) < 64) \
	223	? (size) * sizeof(HE*) \
	224	: (size) * sizeof(HE) 2 - MALLOC_OVERHEAD)
	225	#endif
37d85e3a JH	226
	227	/* available as a function in hv.c */
	228	#define Perl_sharepvn(sv, len, hash) HEK_KEY(share_hek(sv, len, hash))
	229	#define sharepvn(sv, len, hash) Perl_sharepvn(sv, len, hash)