[perl5.git] / hv.h

/*    hv.h
 *
 *    Copyright (C) 1991, 1992, 1993, 1996, 1997, 1998, 1999,
 *    2000, 2001, 2002, 2005, by Larry Wall and others
 *
 *    You may distribute under the terms of either the GNU General Public
 *    License or the Artistic License, as specified in the README file.
 *
 */

/* entry in hash value chain */
struct he {
    /* Keep hent_next first in this structure, because sv_free_arenas take
       advantage of this to share code between the he arenas and the SV
       body arenas  */
    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 */
    /* the hash-key is \0-terminated */
    /* after the \0 there is a byte for flags, such as whether the key
       is UTF-8 */
};

struct shared_he {
    struct he shared_he_he;
    struct hek shared_he_hek;
};

/* Subject to change.
   Don't access this directly.
*/
struct xpvhv_aux {
    HEK		*xhv_name;	/* name, if a symbol table */
    AV		*xhv_backreferences; /* back references for weak references */
    HE		*xhv_eiter;	/* current entry of iterator */
    I32		xhv_riter;	/* current root of iterator */
};

/* hash structure: */
/* This structure must match the beginning of struct xpvmg in sv.h. */
struct xpvhv {
    NV		xnv_nv;		/* numeric value, if any */
    STRLEN	xhv_fill;	/* how full xhv_array currently is */
    STRLEN	xhv_max;	/* subscript of last element of xhv_array */
    union {
	IV	xivu_iv;	/* integer value or pv offset */
	UV	xivu_uv;
	void *	xivu_p1;
    }		xiv_u;
    MAGIC*	xmg_magic;	/* magic for scalar array */
    HV*		xmg_stash;	/* class package */
};

#define xhv_keys xiv_u.xivu_iv

#if 0
typedef struct xpvhv xpvhv_allocated;
#else
typedef struct {
    STRLEN	xhv_fill;	/* how full xhv_array currently is */
    STRLEN	xhv_max;	/* subscript of last element of xhv_array */
    union {
	IV	xivu_iv;	/* integer value or pv offset */
	UV	xivu_uv;
	void *	xivu_p1;
    }		xiv_u;
    MAGIC*	xmg_magic;	/* magic for scalar array */
    HV*		xmg_stash;	/* class package */
} xpvhv_allocated;
#endif

/* 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) */
/* The use of a temporary pointer and the casting games
 * is needed to serve the dual purposes of
 * (a) the hashed data being interpreted as "unsigned char" (new since 5.8,
 *     a "char" can be either signed or unsigned, depending on the compiler)
 * (b) catering for old code that uses a "char"
 *
 * The "hash seed" feature was added in Perl 5.8.1 to perturb the results
 * to avoid "algorithmic complexity attacks".
 *
 * If USE_HASH_SEED is defined, hash randomisation is done by default
 * If USE_HASH_SEED_EXPLICIT is defined, hash randomisation is done
 * only if the environment variable PERL_HASH_SEED is set.
 * For maximal control, one can define PERL_HASH_SEED.
 * (see also perl.c:perl_parse()).
 */
#ifndef PERL_HASH_SEED
#   if defined(USE_HASH_SEED) || defined(USE_HASH_SEED_EXPLICIT)
#       define PERL_HASH_SEED	PL_hash_seed
#   else
#       define PERL_HASH_SEED	0
#   endif
#endif
#define PERL_HASH(hash,str,len) \
     STMT_START	{ \
	register const char * const s_PeRlHaSh_tmp = str; \
	register const unsigned char *s_PeRlHaSh = (const unsigned char *)s_PeRlHaSh_tmp; \
	register I32 i_PeRlHaSh = len; \
	register U32 hash_PeRlHaSh = PERL_HASH_SEED; \
	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

/* Only hv.c and mod_perl should be doing this.  */
#ifdef PERL_HASH_INTERNAL_ACCESS
#define PERL_HASH_INTERNAL(hash,str,len) \
     STMT_START	{ \
	register const char * const s_PeRlHaSh_tmp = str; \
	register const unsigned char *s_PeRlHaSh = (const unsigned char *)s_PeRlHaSh_tmp; \
	register I32 i_PeRlHaSh = len; \
	register U32 hash_PeRlHaSh = PL_rehash_seed; \
	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
#endif

/*
=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, or NULL if C<stash> isn't 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)	((hv)->sv_u.svu_hash)
#define HvFILL(hv)	((XPVHV*)  SvANY(hv))->xhv_fill
#define HvMAX(hv)	((XPVHV*)  SvANY(hv))->xhv_max
/* This quite intentionally does no flag checking first. That's your
   responsibility.  */
#define HvAUX(hv)	((struct xpvhv_aux*)&(HvARRAY(hv)[HvMAX(hv)+1]))
#define HvRITER(hv)	(*Perl_hv_riter_p(aTHX_ (HV*)(hv)))
#define HvEITER(hv)	(*Perl_hv_eiter_p(aTHX_ (HV*)(hv)))
#define HvRITER_set(hv,r)	Perl_hv_riter_set(aTHX_ (HV*)(hv), r)
#define HvEITER_set(hv,e)	Perl_hv_eiter_set(aTHX_ (HV*)(hv), e)
#define HvRITER_get(hv)	(SvOOK(hv) ? HvAUX(hv)->xhv_riter : -1)
#define HvEITER_get(hv)	(SvOOK(hv) ? HvAUX(hv)->xhv_eiter : 0)
#define HvNAME(hv)	HvNAME_get(hv)
/* FIXME - all of these should use a UTF8 aware API, which should also involve
   getting the length. */
/* This macro may go away without notice.  */
#define HvNAME_HEK(hv) (SvOOK(hv) ? HvAUX(hv)->xhv_name : 0)
#define HvNAME_get(hv)	((SvOOK(hv) && (HvAUX(hv)->xhv_name)) \
			 ? HEK_KEY(HvAUX(hv)->xhv_name) : 0)
#define HvNAMELEN_get(hv)	((SvOOK(hv) && (HvAUX(hv)->xhv_name)) \
				 ? HEK_LEN(HvAUX(hv)->xhv_name) : 0)

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

/*
 * 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)		HvUSEDKEYS(hv)
#define HvUSEDKEYS(hv)		(HvTOTALKEYS(hv) - HvPLACEHOLDERS_get(hv))
#define HvTOTALKEYS(hv)		XHvTOTALKEYS((XPVHV*)  SvANY(hv))
#define HvPLACEHOLDERS(hv)	(*Perl_hv_placeholders_p(aTHX_ (HV*)hv))
#define HvPLACEHOLDERS_get(hv)	(SvMAGIC(hv) ? Perl_hv_placeholders_get(aTHX_ (HV*)hv) : 0)
#define HvPLACEHOLDERS_set(hv,p)	Perl_hv_placeholders_set(aTHX_ (HV*)hv, p)

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

/* This is an optimisation flag. It won't be set if all hash keys have a 0
 * flag. Currently the only flags relate to utf8.
 * Hence it won't be set if all keys are 8 bit only. It will be set if any key
 * is utf8 (including 8 bit keys that were entered as utf8, and need upgrading
 * when retrieved during iteration. It may still be set when there are no longer
 * any utf8 keys.
 * See HVhek_ENABLEHVKFLAGS for the trigger.
 */
#define HvHASKFLAGS(hv)		(SvFLAGS(hv) & SVphv_HASKFLAGS)
#define HvHASKFLAGS_on(hv)	(SvFLAGS(hv) |= SVphv_HASKFLAGS)
#define HvHASKFLAGS_off(hv)	(SvFLAGS(hv) &= ~SVphv_HASKFLAGS)

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

#define HvREHASH(hv)		(SvFLAGS(hv) & SVphv_REHASH)
#define HvREHASH_on(hv)		(SvFLAGS(hv) |= SVphv_REHASH)
#define HvREHASH_off(hv)	(SvFLAGS(hv) &= ~SVphv_REHASH)

/* 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 HeKWASUTF8(he)  HEK_WASUTF8(HeKEY_hek(he))
#define HeKREHASH(he)  HEK_REHASH(HeKEY_hek(he))
#define HeKLEN_UTF8(he)  (HeKUTF8(he) ? -HeKLEN(he) : HeKLEN(he))
#define HeKFLAGS(he)  HEK_FLAGS(HeKEY_hek(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_FLAGS(hek)	(*((unsigned char *)(HEK_KEY(hek))+HEK_LEN(hek)+1))

#define HVhek_UTF8	0x01 /* Key is utf8 encoded. */
#define HVhek_WASUTF8	0x02 /* Key is bytes here, but was supplied as utf8. */
#define HVhek_REHASH	0x04 /* This key is in an hv using a custom HASH . */
#define HVhek_FREEKEY	0x100 /* Internal flag to say key is malloc()ed.  */
#define HVhek_PLACEHOLD	0x200 /* Internal flag to create placeholder.
                               * (may change, but Storable is a core module) */
#define HVhek_MASK	0xFF

/* Which flags enable HvHASKFLAGS? Somewhat a hack on a hack, as
   HVhek_REHASH is only needed because the rehash flag has to be duplicated
   into all keys as hv_iternext has no access to the hash flags. At this
   point Storable's tests get upset, because sometimes hashes are "keyed"
   and sometimes not, depending on the order of data insertion, and whether
   it triggered rehashing. So currently HVhek_REHAS is exempt.
*/
   
#define HVhek_ENABLEHVKFLAGS	(HVhek_MASK - HVhek_REHASH)

#define HEK_UTF8(hek)		(HEK_FLAGS(hek) & HVhek_UTF8)
#define HEK_UTF8_on(hek)	(HEK_FLAGS(hek) |= HVhek_UTF8)
#define HEK_UTF8_off(hek)	(HEK_FLAGS(hek) &= ~HVhek_UTF8)
#define HEK_WASUTF8(hek)	(HEK_FLAGS(hek) & HVhek_WASUTF8)
#define HEK_WASUTF8_on(hek)	(HEK_FLAGS(hek) |= HVhek_WASUTF8)
#define HEK_WASUTF8_off(hek)	(HEK_FLAGS(hek) &= ~HVhek_WASUTF8)
#define HEK_REHASH(hek)		(HEK_FLAGS(hek) & HVhek_REHASH)
#define HEK_REHASH_on(hek)	(HEK_FLAGS(hek) |= HVhek_REHASH)

/* calculate HV array allocation */
#ifndef PERL_USE_LARGE_HV_ALLOC
/* Default to allocating the correct size - default to assuming that malloc()
   is not broken and is efficient at allocating blocks sized at powers-of-two.
*/   
#  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

/* Flags for hv_iternext_flags.  */
#define HV_ITERNEXT_WANTPLACEHOLDERS	0x01	/* Don't skip placeholders.  */

#define hv_iternext(hv)	hv_iternext_flags(hv, 0)
#define hv_magic(hv, gv, how) sv_magic((SV*)(hv), (SV*)(gv), how, Nullch, 0)

/* 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)

#define share_hek_hek(hek)						\
    (++(((struct shared_he *)(((char *)hek)				\
			      - STRUCT_OFFSET(struct shared_he,		\
					      shared_he_hek)))		\
	->shared_he_he.hent_val),					\
     hek)

/*
 * Local variables:
 * c-indentation-style: bsd
 * c-basic-offset: 4
 * indent-tabs-mode: t
 * End:
 *
 * ex: set ts=8 sts=4 sw=4 noet:
 */
Commit	Line	Data
a0d0e21e	1	/* hv.h
79072805	2	*
4bb101f2	3	* Copyright (C) 1991, 1992, 1993, 1996, 1997, 1998, 1999,
1d325971	4	* 2000, 2001, 2002, 2005, by Larry Wall and others
79072805 LW	5	*
	6	* You may distribute under the terms of either the GNU General Public
	7	* License or the Artistic License, as specified in the README file.
	8	*
79072805 LW	9	*/
79072805 LW	10
5cbe4eec	11	/* entry in hash value chain */
79072805	12	struct he {
6f51351d NC	13	/* Keep hent_next first in this structure, because sv_free_arenas take
	14	advantage of this to share code between the he arenas and the SV
	15	body arenas */
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 */
e05949c7	26	/* the hash-key is \0-terminated */
1e54db1a JH	27	/* after the \0 there is a byte for flags, such as whether the key
1e54db1a JH	28	is UTF-8 */
79072805 LW	29	};
79072805 LW	30
cbae3960 NC	31	struct shared_he {
	32	struct he shared_he_he;
	33	struct hek shared_he_hek;
	34	};
bfcb3514 NC	35
	36	/* Subject to change.
	37	Don't access this directly.
	38	*/
	39	struct xpvhv_aux {
7423f6db	40	HEK xhv_name; / name, if a symbol table */
86f55936	41	AV xhv_backreferences; / back references for weak references */
bfcb3514 NC	42	HE xhv_eiter; / current entry of iterator */
	43	I32 xhv_riter; /* current root of iterator */
	44	};
	45
5cbe4eec	46	/* hash structure: */
6ee623d5	47	/* This structure must match the beginning of struct xpvmg in sv.h. */
79072805	48	struct xpvhv {
311a25d9	49	NV xnv_nv; /* numeric value, if any */
463ee0b2 LW	50	STRLEN xhv_fill; /* how full xhv_array currently is */
463ee0b2 LW	51	STRLEN xhv_max; /* subscript of last element of xhv_array */
e4305a63	52	union {
311a25d9 NC	53	IV xivu_iv; /* integer value or pv offset */
	54	UV xivu_uv;
	55	void * xivu_p1;
	56	} xiv_u;
79072805 LW	57	MAGIC* xmg_magic; /* magic for scalar array */
79072805 LW	58	HV* xmg_stash; /* class package */
79072805 LW	59	};
79072805 LW	60
311a25d9	61	#define xhv_keys xiv_u.xivu_iv
e4305a63	62
c5f87f51	63	#if 0
59813432	64	typedef struct xpvhv xpvhv_allocated;
9f1501b2 NC	65	#else
	66	typedef struct {
	67	STRLEN xhv_fill; /* how full xhv_array currently is */
	68	STRLEN xhv_max; /* subscript of last element of xhv_array */
	69	union {
311a25d9 NC	70	IV xivu_iv; /* integer value or pv offset */
	71	UV xivu_uv;
	72	void * xivu_p1;
	73	} xiv_u;
9f1501b2 NC	74	MAGIC* xmg_magic; /* magic for scalar array */
	75	HV* xmg_stash; /* class package */
	76	} xpvhv_allocated;
	77	#endif
e4305a63	78
5cbe4eec	79	/* hash a key */
5afd6d42 JH	80	/* FYI: This is the "One-at-a-Time" algorithm by Bob Jenkins
	81	* from requirements by Colin Plumb.
	82	* (http://burtleburtle.net/bob/hash/doobs.html) */
	83	/* The use of a temporary pointer and the casting games
	84	* is needed to serve the dual purposes of
	85	* (a) the hashed data being interpreted as "unsigned char" (new since 5.8,
df805c3e	86	* a "char" can be either signed or unsigned, depending on the compiler)
5afd6d42	87	* (b) catering for old code that uses a "char"
830b38bd	88	*
504f80c1 JH	89	* The "hash seed" feature was added in Perl 5.8.1 to perturb the results
504f80c1 JH	90	* to avoid "algorithmic complexity attacks".
830b38bd JH	91	*
	92	* If USE_HASH_SEED is defined, hash randomisation is done by default
	93	* If USE_HASH_SEED_EXPLICIT is defined, hash randomisation is done
	94	* only if the environment variable PERL_HASH_SEED is set.
	95	* For maximal control, one can define PERL_HASH_SEED.
90ce55a1	96	* (see also perl.c:perl_parse()).
5afd6d42	97	*/
830b38bd JH	98	#ifndef PERL_HASH_SEED
	99	# if defined(USE_HASH_SEED) \|\| defined(USE_HASH_SEED_EXPLICIT)
	100	# define PERL_HASH_SEED PL_hash_seed
	101	# else
	102	# define PERL_HASH_SEED 0
	103	# endif
504f80c1	104	#endif
bf6bd887	105	#define PERL_HASH(hash,str,len) \
bf6bd887	106	STMT_START { \
0bd48802	107	register const char * const s_PeRlHaSh_tmp = str; \
5afd6d42	108	register const unsigned char s_PeRlHaSh = (const unsigned char )s_PeRlHaSh_tmp; \
bf6bd887	109	register I32 i_PeRlHaSh = len; \
504f80c1	110	register U32 hash_PeRlHaSh = PERL_HASH_SEED; \
a6fe520e MLF	111	while (i_PeRlHaSh--) { \
	112	hash_PeRlHaSh += *s_PeRlHaSh++; \
	113	hash_PeRlHaSh += (hash_PeRlHaSh << 10); \
	114	hash_PeRlHaSh ^= (hash_PeRlHaSh >> 6); \
	115	} \
	116	hash_PeRlHaSh += (hash_PeRlHaSh << 3); \
	117	hash_PeRlHaSh ^= (hash_PeRlHaSh >> 11); \
4fee5c71	118	(hash) = (hash_PeRlHaSh + (hash_PeRlHaSh << 15)); \
bf6bd887	119	} STMT_END
bf6bd887	120
3d78eb94 NC	121	/* Only hv.c and mod_perl should be doing this. */
3d78eb94 NC	122	#ifdef PERL_HASH_INTERNAL_ACCESS
4b5190b5 NC	123	#define PERL_HASH_INTERNAL(hash,str,len) \
4b5190b5 NC	124	STMT_START { \
0bd48802	125	register const char * const s_PeRlHaSh_tmp = str; \
4b5190b5 NC	126	register const unsigned char s_PeRlHaSh = (const unsigned char )s_PeRlHaSh_tmp; \
4b5190b5 NC	127	register I32 i_PeRlHaSh = len; \
008fb0c0	128	register U32 hash_PeRlHaSh = PL_rehash_seed; \
4b5190b5 NC	129	while (i_PeRlHaSh--) { \
	130	hash_PeRlHaSh += *s_PeRlHaSh++; \
	131	hash_PeRlHaSh += (hash_PeRlHaSh << 10); \
	132	hash_PeRlHaSh ^= (hash_PeRlHaSh >> 6); \
	133	} \
	134	hash_PeRlHaSh += (hash_PeRlHaSh << 3); \
	135	hash_PeRlHaSh ^= (hash_PeRlHaSh >> 11); \
	136	(hash) = (hash_PeRlHaSh + (hash_PeRlHaSh << 15)); \
	137	} STMT_END
	138	#endif
	139
954c1994	140	/*
ccfc67b7 JH	141	=head1 Hash Manipulation Functions
ccfc67b7 JH	142
954c1994 GS	143	=for apidoc AmU\|\|HEf_SVKEY
954c1994 GS	144	This flag, used in the length slot of hash entries and magic structures,
d1be9408	145	specifies the structure contains an C<SV> pointer where a C<char> pointer
954c1994 GS	146	is to be expected. (For information only--not to be used).
954c1994 GS	147
ccfc67b7 JH	148	=head1 Handy Values
ccfc67b7 JH	149
954c1994 GS	150	=for apidoc AmU\|\|Nullhv
	151	Null HV pointer.
	152
ccfc67b7 JH	153	=head1 Hash Manipulation Functions
ccfc67b7 JH	154
954c1994	155	=for apidoc Am\|char\|HvNAME\|HV stash
9282b5fd SH	156	Returns the package name of a stash, or NULL if C<stash> isn't a stash.
9282b5fd SH	157	See C<SvSTASH>, C<CvSTASH>.
954c1994 GS	158
	159	=for apidoc Am\|void\|HeKEY\|HE he
	160	Returns the actual pointer stored in the key slot of the hash entry. The
	161	pointer may be either C<char> or C<SV>, depending on the value of
	162	C<HeKLEN()>. Can be assigned to. The C<HePV()> or C<HeSVKEY()> macros are
	163	usually preferable for finding the value of a key.
	164
	165	=for apidoc Am\|STRLEN\|HeKLEN\|HE* he
	166	If this is negative, and amounts to C<HEf_SVKEY>, it indicates the entry
	167	holds an C<SV*> key. Otherwise, holds the actual length of the key. Can
	168	be assigned to. The C<HePV()> macro is usually preferable for finding key
	169	lengths.
	170
	171	=for apidoc Am\|SV\|HeVAL\|HE he
	172	Returns the value slot (type C<SV*>) stored in the hash entry.
	173
	174	=for apidoc Am\|U32\|HeHASH\|HE* he
	175	Returns the computed hash stored in the hash entry.
	176
	177	=for apidoc Am\|char\|HePV\|HE he\|STRLEN len
	178	Returns the key slot of the hash entry as a C<char*> value, doing any
	179	necessary dereferencing of possibly C<SV*> keys. The length of the string
	180	is placed in C<len> (this is a macro, so do I<not> use C<&len>). If you do
	181	not care about what the length of the key is, you may use the global
	182	variable C<PL_na>, though this is rather less efficient than using a local
	183	variable. Remember though, that hash keys in perl are free to contain
	184	embedded nulls, so using C<strlen()> or similar is not a good way to find
	185	the length of hash keys. This is very similar to the C<SvPV()> macro
	186	described elsewhere in this document.
	187
	188	=for apidoc Am\|SV\|HeSVKEY\|HE he
	189	Returns the key as an C<SV*>, or C<Nullsv> if the hash entry does not
	190	contain an C<SV*> key.
	191
	192	=for apidoc Am\|SV\|HeSVKEY_force\|HE he
	193	Returns the key as an C<SV*>. Will create and return a temporary mortal
	194	C<SV> if the hash entry contains only a C<char> key.
	195
	196	=for apidoc Am\|SV\|HeSVKEY_set\|HE he\|SV* sv
	197	Sets the key to a given C<SV*>, taking care to set the appropriate flags to
	198	indicate the presence of an C<SV*> key, and returns the same
	199	C<SV*>.
	200
	201	=cut
	202	*/
bf6bd887	203
bf5b86ae	204	/* these hash entry flags ride on hent_klen (for use only in magic/tied HVs) */
d1be9408	205	#define HEf_SVKEY -2 /* hent_key is an SV* */
bf6bd887	206
bf6bd887	207
79072805	208	#define Nullhv Null(HV*)
43e6e717	209	#define HvARRAY(hv) ((hv)->sv_u.svu_hash)
79072805	210	#define HvFILL(hv) ((XPVHV*) SvANY(hv))->xhv_fill
463ee0b2	211	#define HvMAX(hv) ((XPVHV*) SvANY(hv))->xhv_max
b79f7545 NC	212	/* This quite intentionally does no flag checking first. That's your
	213	responsibility. */
	214	#define HvAUX(hv) ((struct xpvhv_aux*)&(HvARRAY(hv)[HvMAX(hv)+1]))
bfcb3514 NC	215	#define HvRITER(hv) (Perl_hv_riter_p(aTHX_ (HV)(hv)))
	216	#define HvEITER(hv) (Perl_hv_eiter_p(aTHX_ (HV)(hv)))
	217	#define HvRITER_set(hv,r) Perl_hv_riter_set(aTHX_ (HV*)(hv), r)
	218	#define HvEITER_set(hv,e) Perl_hv_eiter_set(aTHX_ (HV*)(hv), e)
b79f7545 NC	219	#define HvRITER_get(hv) (SvOOK(hv) ? HvAUX(hv)->xhv_riter : -1)
b79f7545 NC	220	#define HvEITER_get(hv) (SvOOK(hv) ? HvAUX(hv)->xhv_eiter : 0)
7423f6db	221	#define HvNAME(hv) HvNAME_get(hv)
bfcb3514 NC	222	/* FIXME - all of these should use a UTF8 aware API, which should also involve
bfcb3514 NC	223	getting the length. */
9b9d0b15	224	/* This macro may go away without notice. */
b79f7545 NC	225	#define HvNAME_HEK(hv) (SvOOK(hv) ? HvAUX(hv)->xhv_name : 0)
	226	#define HvNAME_get(hv) ((SvOOK(hv) && (HvAUX(hv)->xhv_name)) \
	227	? HEK_KEY(HvAUX(hv)->xhv_name) : 0)
	228	#define HvNAMELEN_get(hv) ((SvOOK(hv) && (HvAUX(hv)->xhv_name)) \
	229	? HEK_LEN(HvAUX(hv)->xhv_name) : 0)
a0d0e21e	230
8aacddc1 NIS	231	/* the number of keys (including any placeholers) */
	232	#define XHvTOTALKEYS(xhv) ((xhv)->xhv_keys)
	233
8aacddc1 NIS	234	/*
	235	* HvKEYS gets the number of keys that actually exist(), and is provided
	236	* for backwards compatibility with old XS code. The core uses HvUSEDKEYS
	237	* (keys, excluding placeholdes) and HvTOTALKEYS (including placeholders)
	238	*/
ca732855 NC	239	#define HvKEYS(hv) HvUSEDKEYS(hv)
ca732855 NC	240	#define HvUSEDKEYS(hv) (HvTOTALKEYS(hv) - HvPLACEHOLDERS_get(hv))
8aacddc1	241	#define HvTOTALKEYS(hv) XHvTOTALKEYS((XPVHV*) SvANY(hv))
ca732855 NC	242	#define HvPLACEHOLDERS(hv) (Perl_hv_placeholders_p(aTHX_ (HV)hv))
	243	#define HvPLACEHOLDERS_get(hv) (SvMAGIC(hv) ? Perl_hv_placeholders_get(aTHX_ (HV*)hv) : 0)
	244	#define HvPLACEHOLDERS_set(hv,p) Perl_hv_placeholders_set(aTHX_ (HV*)hv, p)
8aacddc1	245
bf6bd887	246	#define HvSHAREKEYS(hv) (SvFLAGS(hv) & SVphv_SHAREKEYS)
	247	#define HvSHAREKEYS_on(hv) (SvFLAGS(hv) \|= SVphv_SHAREKEYS)
	248	#define HvSHAREKEYS_off(hv) (SvFLAGS(hv) &= ~SVphv_SHAREKEYS)
	249
19692e8d NC	250	/* This is an optimisation flag. It won't be set if all hash keys have a 0
	251	* flag. Currently the only flags relate to utf8.
	252	* Hence it won't be set if all keys are 8 bit only. It will be set if any key
	253	* is utf8 (including 8 bit keys that were entered as utf8, and need upgrading
	254	* when retrieved during iteration. It may still be set when there are no longer
	255	* any utf8 keys.
fdcd69b6	256	* See HVhek_ENABLEHVKFLAGS for the trigger.
19692e8d NC	257	*/
	258	#define HvHASKFLAGS(hv) (SvFLAGS(hv) & SVphv_HASKFLAGS)
	259	#define HvHASKFLAGS_on(hv) (SvFLAGS(hv) \|= SVphv_HASKFLAGS)
	260	#define HvHASKFLAGS_off(hv) (SvFLAGS(hv) &= ~SVphv_HASKFLAGS)
574c8022	261
bf5b86ae GS	262	#define HvLAZYDEL(hv) (SvFLAGS(hv) & SVphv_LAZYDEL)
	263	#define HvLAZYDEL_on(hv) (SvFLAGS(hv) \|= SVphv_LAZYDEL)
	264	#define HvLAZYDEL_off(hv) (SvFLAGS(hv) &= ~SVphv_LAZYDEL)
	265
4b5190b5 NC	266	#define HvREHASH(hv) (SvFLAGS(hv) & SVphv_REHASH)
	267	#define HvREHASH_on(hv) (SvFLAGS(hv) \|= SVphv_REHASH)
	268	#define HvREHASH_off(hv) (SvFLAGS(hv) &= ~SVphv_REHASH)
	269
a0d0e21e LW	270	/* Maybe amagical: */
	271	/* #define HV_AMAGICmb(hv) (SvFLAGS(hv) & (SVpgv_badAM \| SVpgv_AM)) */
	272
	273	#define HV_AMAGIC(hv) (SvFLAGS(hv) & SVpgv_AM)
	274	#define HV_AMAGIC_on(hv) (SvFLAGS(hv) \|= SVpgv_AM)
	275	#define HV_AMAGIC_off(hv) (SvFLAGS(hv) &= ~SVpgv_AM)
	276
	277	/*
	278	#define HV_AMAGICbad(hv) (SvFLAGS(hv) & SVpgv_badAM)
	279	#define HV_badAMAGIC_on(hv) (SvFLAGS(hv) \|= SVpgv_badAM)
	280	#define HV_badAMAGIC_off(hv) (SvFLAGS(hv) &= ~SVpgv_badAM)
	281	*/
bf6bd887	282
	283	#define Nullhe Null(HE*)
	284	#define HeNEXT(he) (he)->hent_next
ff68c719	285	#define HeKEY_hek(he) (he)->hent_hek
ff68c719	286	#define HeKEY(he) HEK_KEY(HeKEY_hek(he))
bbce6d69	287	#define HeKEY_sv(he) ((SV*)HeKEY(he))
ff68c719	288	#define HeKLEN(he) HEK_LEN(HeKEY_hek(he))
da58a35d	289	#define HeKUTF8(he) HEK_UTF8(HeKEY_hek(he))
19692e8d	290	#define HeKWASUTF8(he) HEK_WASUTF8(HeKEY_hek(he))
4b5190b5	291	#define HeKREHASH(he) HEK_REHASH(HeKEY_hek(he))
da58a35d	292	#define HeKLEN_UTF8(he) (HeKUTF8(he) ? -HeKLEN(he) : HeKLEN(he))
19692e8d	293	#define HeKFLAGS(he) HEK_FLAGS(HeKEY_hek(he))
bf6bd887	294	#define HeVAL(he) (he)->hent_val
ff68c719	295	#define HeHASH(he) HEK_HASH(HeKEY_hek(he))
1e422769	296	#define HePV(he,lp) ((HeKLEN(he) == HEf_SVKEY) ? \
	297	SvPV(HeKEY_sv(he),lp) : \
	298	(((lp = HeKLEN(he)) >= 0) ? \
	299	HeKEY(he) : Nullch))
	300
bbce6d69	301	#define HeSVKEY(he) ((HeKEY(he) && \
	302	HeKLEN(he) == HEf_SVKEY) ? \
	303	HeKEY_sv(he) : Nullsv)
	304
	305	#define HeSVKEY_force(he) (HeKEY(he) ? \
	306	((HeKLEN(he) == HEf_SVKEY) ? \
	307	HeKEY_sv(he) : \
79cb57f6	308	sv_2mortal(newSVpvn(HeKEY(he), \
bbce6d69	309	HeKLEN(he)))) : \
3280af22	310	&PL_sv_undef)
1e422769	311	#define HeSVKEY_set(he,sv) ((HeKLEN(he) = HEf_SVKEY), (HeKEY_sv(he) = sv))
bbce6d69	312
ff68c719	313	#define Nullhek Null(HEK*)
71be2cbc	314	#define HEK_BASESIZE STRUCT_OFFSET(HEK, hek_key[0])
ff68c719	315	#define HEK_HASH(hek) (hek)->hek_hash
	316	#define HEK_LEN(hek) (hek)->hek_len
	317	#define HEK_KEY(hek) (hek)->hek_key
19692e8d NC	318	#define HEK_FLAGS(hek) (((unsigned char )(HEK_KEY(hek))+HEK_LEN(hek)+1))
	319
	320	#define HVhek_UTF8 0x01 /* Key is utf8 encoded. */
	321	#define HVhek_WASUTF8 0x02 /* Key is bytes here, but was supplied as utf8. */
4b5190b5	322	#define HVhek_REHASH 0x04 /* This key is in an hv using a custom HASH . */
19692e8d	323	#define HVhek_FREEKEY 0x100 /* Internal flag to say key is malloc()ed. */
e16e2ff8 NC	324	#define HVhek_PLACEHOLD 0x200 /* Internal flag to create placeholder.
e16e2ff8 NC	325	* (may change, but Storable is a core module) */
19692e8d NC	326	#define HVhek_MASK 0xFF
19692e8d NC	327
fdcd69b6 NC	328	/* Which flags enable HvHASKFLAGS? Somewhat a hack on a hack, as
	329	HVhek_REHASH is only needed because the rehash flag has to be duplicated
	330	into all keys as hv_iternext has no access to the hash flags. At this
	331	point Storable's tests get upset, because sometimes hashes are "keyed"
	332	and sometimes not, depending on the order of data insertion, and whether
	333	it triggered rehashing. So currently HVhek_REHAS is exempt.
	334	*/
	335
	336	#define HVhek_ENABLEHVKFLAGS (HVhek_MASK - HVhek_REHASH)
	337
19692e8d NC	338	#define HEK_UTF8(hek) (HEK_FLAGS(hek) & HVhek_UTF8)
	339	#define HEK_UTF8_on(hek) (HEK_FLAGS(hek) \|= HVhek_UTF8)
	340	#define HEK_UTF8_off(hek) (HEK_FLAGS(hek) &= ~HVhek_UTF8)
	341	#define HEK_WASUTF8(hek) (HEK_FLAGS(hek) & HVhek_WASUTF8)
	342	#define HEK_WASUTF8_on(hek) (HEK_FLAGS(hek) \|= HVhek_WASUTF8)
	343	#define HEK_WASUTF8_off(hek) (HEK_FLAGS(hek) &= ~HVhek_WASUTF8)
4b5190b5 NC	344	#define HEK_REHASH(hek) (HEK_FLAGS(hek) & HVhek_REHASH)
4b5190b5 NC	345	#define HEK_REHASH_on(hek) (HEK_FLAGS(hek) \|= HVhek_REHASH)
d18c6117	346
5cbe4eec	347	/* calculate HV array allocation */
36768cf4 NC	348	#ifndef PERL_USE_LARGE_HV_ALLOC
	349	/* Default to allocating the correct size - default to assuming that malloc()
	350	is not broken and is efficient at allocating blocks sized at powers-of-two.
	351	*/
d18c6117 GS	352	# define PERL_HV_ARRAY_ALLOC_BYTES(size) ((size) * sizeof(HE*))
	353	#else
	354	# define MALLOC_OVERHEAD 16
	355	# define PERL_HV_ARRAY_ALLOC_BYTES(size) \
	356	(((size) < 64) \
	357	? (size) * sizeof(HE*) \
	358	: (size) * sizeof(HE) 2 - MALLOC_OVERHEAD)
	359	#endif
37d85e3a	360
e16e2ff8 NC	361	/* Flags for hv_iternext_flags. */
	362	#define HV_ITERNEXT_WANTPLACEHOLDERS 0x01 /* Don't skip placeholders. */
	363
7a7b9979	364	#define hv_iternext(hv) hv_iternext_flags(hv, 0)
bc5cdc23	365	#define hv_magic(hv, gv, how) sv_magic((SV)(hv), (SV)(gv), how, Nullch, 0)
7a7b9979	366
37d85e3a JH	367	/* available as a function in hv.c */
	368	#define Perl_sharepvn(sv, len, hash) HEK_KEY(share_hek(sv, len, hash))
	369	#define sharepvn(sv, len, hash) Perl_sharepvn(sv, len, hash)
bfcb3514	370
d1db91c6 NC	371	#define share_hek_hek(hek) \
	372	(++(((struct shared_he )(((char )hek) \
	373	- STRUCT_OFFSET(struct shared_he, \
	374	shared_he_hek))) \
	375	->shared_he_he.hent_val), \
	376	hek)
	377
bfcb3514 NC	378	/*
	379	* Local variables:
	380	* c-indentation-style: bsd
	381	* c-basic-offset: 4
	382	* indent-tabs-mode: t
	383	* End:
	384	*
	385	* ex: set ts=8 sts=4 sw=4 noet:
	386	*/