[p5sagit/p5-mst-13.2.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.
 *
 */

/* 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 */
    /* the hash-key is \0-terminated */
    /* after the \0 there is a byte for flags, such as whether the key
       is UTF-8 */
};


/* Subject to change.
   Don't access this directly.
*/
struct xpvhv_aux {
    char	*xhv_name;	/* name, if a symbol table */
    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 {
    STRLEN	xhv_fill;	/* how full xhv_array currently is */
    STRLEN	xhv_max;	/* subscript of last element of xhv_array */
    IV		for_rent;
    union {
	NV	xnvu_nv;	/* numeric value, if any */
	struct {
	    void *xnv_p1;
	    union {
		void *xnv_p2;
		IV xnv_i2;	/* how many elements in the array */
	    }	xnv_u2;
	}	xnv_s;
    }		xnv_u;
    MAGIC*	xmg_magic;	/* magic for scalar array */
    HV*		xmg_stash;	/* class package */
    /* list of pm's for this package is now stored in symtab magic.  */
};

#define xhv_aux xnv_u.xnv_s.xnv_p1
#define xhv_keys xnv_u.xnv_s.xnv_u2.xnv_i2


/* 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 signed, 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 *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 *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.  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***)&((hv)->sv_u.sv_array))
#define HvFILL(hv)	((XPVHV*)  SvANY(hv))->xhv_fill
#define HvMAX(hv)	((XPVHV*)  SvANY(hv))->xhv_max
#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)	(((XPVHV *)SvANY(hv))->xhv_aux ? \
			 ((struct xpvhv_aux*)((XPVHV *)SvANY(hv))->xhv_aux)->xhv_riter : -1)
#define HvEITER_get(hv)	(((XPVHV *)SvANY(hv))->xhv_aux ? \
			 ((struct xpvhv_aux *)((XPVHV *)SvANY(hv))->xhv_aux)->xhv_eiter : 0)
#define HvNAME(hv)	(*Perl_hv_name_p(aTHX_ (HV*)hv))
/* FIXME - all of these should use a UTF8 aware API, which should also involve
   getting the length. */
#define HvNAME_get(hv)	(((XPVHV *)SvANY(hv))->xhv_aux ? \
			 ((struct xpvhv_aux *)((XPVHV *)SvANY(hv))->xhv_aux)->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.  */

/* 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)

/*
 * 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	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	9	*/
79072805	10
5cbe4eec	11	/* typedefs to eliminate some typing */
79072805	12	typedef struct he HE;
ff68c719	13	typedef struct hek HEK;
79072805	14
5cbe4eec	15	/* entry in hash value chain */
79072805	16	struct he {
5cbe4eec	17	HE hent_next; / next entry in chain */
	18	HEK hent_hek; / hash key */
	19	SV hent_val; / scalar value that was hashed */
bbce6d69	20	};
bbce6d69	21
5cbe4eec	22	/* hash key -- defined separately for use as shared pointer */
ff68c719	23	struct hek {
5cbe4eec	24	U32 hek_hash; /* hash of key */
	25	I32 hek_len; /* length of hash key */
	26	char hek_key[1]; /* variable-length hash key */
e05949c7	27	/* the hash-key is \0-terminated */
1e54db1a	28	/* after the \0 there is a byte for flags, such as whether the key
1e54db1a	29	is UTF-8 */
79072805	30	};
79072805	31
bfcb3514	32
	33	/* Subject to change.
	34	Don't access this directly.
	35	*/
	36	struct xpvhv_aux {
	37	char xhv_name; / name, if a symbol table */
	38	HE xhv_eiter; / current entry of iterator */
	39	I32 xhv_riter; /* current root of iterator */
	40	};
	41
5cbe4eec	42	/* hash structure: */
6ee623d5	43	/* This structure must match the beginning of struct xpvmg in sv.h. */
79072805	44	struct xpvhv {
463ee0b2	45	STRLEN xhv_fill; /* how full xhv_array currently is */
463ee0b2	46	STRLEN xhv_max; /* subscript of last element of xhv_array */
e4305a63	47	IV for_rent;
	48	union {
	49	NV xnvu_nv; /* numeric value, if any */
	50	struct {
	51	void *xnv_p1;
	52	union {
	53	void *xnv_p2;
	54	IV xnv_i2; /* how many elements in the array */
	55	} xnv_u2;
	56	} xnv_s;
	57	} xnv_u;
79072805	58	MAGIC* xmg_magic; /* magic for scalar array */
79072805	59	HV* xmg_stash; /* class package */
8d2f4536	60	/* list of pm's for this package is now stored in symtab magic. */
79072805	61	};
79072805	62
e4305a63	63	#define xhv_aux xnv_u.xnv_s.xnv_p1
	64	#define xhv_keys xnv_u.xnv_s.xnv_u2.xnv_i2
	65
	66
5cbe4eec	67	/* hash a key */
5afd6d42	68	/* FYI: This is the "One-at-a-Time" algorithm by Bob Jenkins
	69	* from requirements by Colin Plumb.
	70	* (http://burtleburtle.net/bob/hash/doobs.html) */
	71	/* The use of a temporary pointer and the casting games
	72	* is needed to serve the dual purposes of
	73	* (a) the hashed data being interpreted as "unsigned char" (new since 5.8,
	74	* a "char" can be either signed or signed, depending on the compiler)
	75	* (b) catering for old code that uses a "char"
830b38bd	76	*
504f80c1	77	* The "hash seed" feature was added in Perl 5.8.1 to perturb the results
504f80c1	78	* to avoid "algorithmic complexity attacks".
830b38bd	79	*
	80	* If USE_HASH_SEED is defined, hash randomisation is done by default
	81	* If USE_HASH_SEED_EXPLICIT is defined, hash randomisation is done
	82	* only if the environment variable PERL_HASH_SEED is set.
	83	* For maximal control, one can define PERL_HASH_SEED.
90ce55a1	84	* (see also perl.c:perl_parse()).
5afd6d42	85	*/
830b38bd	86	#ifndef PERL_HASH_SEED
	87	# if defined(USE_HASH_SEED) \|\| defined(USE_HASH_SEED_EXPLICIT)
	88	# define PERL_HASH_SEED PL_hash_seed
	89	# else
	90	# define PERL_HASH_SEED 0
	91	# endif
504f80c1	92	#endif
bf6bd887	93	#define PERL_HASH(hash,str,len) \
bf6bd887	94	STMT_START { \
5afd6d42	95	register const char *s_PeRlHaSh_tmp = str; \
5afd6d42	96	register const unsigned char s_PeRlHaSh = (const unsigned char )s_PeRlHaSh_tmp; \
bf6bd887	97	register I32 i_PeRlHaSh = len; \
504f80c1	98	register U32 hash_PeRlHaSh = PERL_HASH_SEED; \
a6fe520e	99	while (i_PeRlHaSh--) { \
	100	hash_PeRlHaSh += *s_PeRlHaSh++; \
	101	hash_PeRlHaSh += (hash_PeRlHaSh << 10); \
	102	hash_PeRlHaSh ^= (hash_PeRlHaSh >> 6); \
	103	} \
	104	hash_PeRlHaSh += (hash_PeRlHaSh << 3); \
	105	hash_PeRlHaSh ^= (hash_PeRlHaSh >> 11); \
4fee5c71	106	(hash) = (hash_PeRlHaSh + (hash_PeRlHaSh << 15)); \
bf6bd887	107	} STMT_END
bf6bd887	108
3d78eb94	109	/* Only hv.c and mod_perl should be doing this. */
3d78eb94	110	#ifdef PERL_HASH_INTERNAL_ACCESS
4b5190b5	111	#define PERL_HASH_INTERNAL(hash,str,len) \
	112	STMT_START { \
	113	register const char *s_PeRlHaSh_tmp = str; \
	114	register const unsigned char s_PeRlHaSh = (const unsigned char )s_PeRlHaSh_tmp; \
	115	register I32 i_PeRlHaSh = len; \
008fb0c0	116	register U32 hash_PeRlHaSh = PL_rehash_seed; \
4b5190b5	117	while (i_PeRlHaSh--) { \
	118	hash_PeRlHaSh += *s_PeRlHaSh++; \
	119	hash_PeRlHaSh += (hash_PeRlHaSh << 10); \
	120	hash_PeRlHaSh ^= (hash_PeRlHaSh >> 6); \
	121	} \
	122	hash_PeRlHaSh += (hash_PeRlHaSh << 3); \
	123	hash_PeRlHaSh ^= (hash_PeRlHaSh >> 11); \
	124	(hash) = (hash_PeRlHaSh + (hash_PeRlHaSh << 15)); \
	125	} STMT_END
	126	#endif
	127
954c1994	128	/*
ccfc67b7	129	=head1 Hash Manipulation Functions
ccfc67b7	130
954c1994	131	=for apidoc AmU\|\|HEf_SVKEY
954c1994	132	This flag, used in the length slot of hash entries and magic structures,
d1be9408	133	specifies the structure contains an C<SV> pointer where a C<char> pointer
954c1994	134	is to be expected. (For information only--not to be used).
954c1994	135
ccfc67b7	136	=head1 Handy Values
ccfc67b7	137
954c1994	138	=for apidoc AmU\|\|Nullhv
	139	Null HV pointer.
	140
ccfc67b7	141	=head1 Hash Manipulation Functions
ccfc67b7	142
954c1994	143	=for apidoc Am\|char\|HvNAME\|HV stash
	144	Returns the package name of a stash. See C<SvSTASH>, C<CvSTASH>.
	145
	146	=for apidoc Am\|void\|HeKEY\|HE he
	147	Returns the actual pointer stored in the key slot of the hash entry. The
	148	pointer may be either C<char> or C<SV>, depending on the value of
	149	C<HeKLEN()>. Can be assigned to. The C<HePV()> or C<HeSVKEY()> macros are
	150	usually preferable for finding the value of a key.
	151
	152	=for apidoc Am\|STRLEN\|HeKLEN\|HE* he
	153	If this is negative, and amounts to C<HEf_SVKEY>, it indicates the entry
	154	holds an C<SV*> key. Otherwise, holds the actual length of the key. Can
	155	be assigned to. The C<HePV()> macro is usually preferable for finding key
	156	lengths.
	157
	158	=for apidoc Am\|SV\|HeVAL\|HE he
	159	Returns the value slot (type C<SV*>) stored in the hash entry.
	160
	161	=for apidoc Am\|U32\|HeHASH\|HE* he
	162	Returns the computed hash stored in the hash entry.
	163
	164	=for apidoc Am\|char\|HePV\|HE he\|STRLEN len
	165	Returns the key slot of the hash entry as a C<char*> value, doing any
	166	necessary dereferencing of possibly C<SV*> keys. The length of the string
	167	is placed in C<len> (this is a macro, so do I<not> use C<&len>). If you do
	168	not care about what the length of the key is, you may use the global
	169	variable C<PL_na>, though this is rather less efficient than using a local
	170	variable. Remember though, that hash keys in perl are free to contain
	171	embedded nulls, so using C<strlen()> or similar is not a good way to find
	172	the length of hash keys. This is very similar to the C<SvPV()> macro
	173	described elsewhere in this document.
	174
	175	=for apidoc Am\|SV\|HeSVKEY\|HE he
	176	Returns the key as an C<SV*>, or C<Nullsv> if the hash entry does not
	177	contain an C<SV*> key.
	178
	179	=for apidoc Am\|SV\|HeSVKEY_force\|HE he
	180	Returns the key as an C<SV*>. Will create and return a temporary mortal
	181	C<SV> if the hash entry contains only a C<char> key.
	182
	183	=for apidoc Am\|SV\|HeSVKEY_set\|HE he\|SV* sv
	184	Sets the key to a given C<SV*>, taking care to set the appropriate flags to
	185	indicate the presence of an C<SV*> key, and returns the same
	186	C<SV*>.
	187
	188	=cut
	189	*/
bf6bd887	190
bf5b86ae	191	/* these hash entry flags ride on hent_klen (for use only in magic/tied HVs) */
d1be9408	192	#define HEf_SVKEY -2 /* hent_key is an SV* */
bf6bd887	193
bf6bd887	194
79072805	195	#define Nullhv Null(HV*)
7b2c381c	196	#define HvARRAY(hv) ((HE**)&((hv)->sv_u.sv_array))
79072805	197	#define HvFILL(hv) ((XPVHV*) SvANY(hv))->xhv_fill
463ee0b2	198	#define HvMAX(hv) ((XPVHV*) SvANY(hv))->xhv_max
bfcb3514	199	#define HvRITER(hv) (Perl_hv_riter_p(aTHX_ (HV)(hv)))
	200	#define HvEITER(hv) (Perl_hv_eiter_p(aTHX_ (HV)(hv)))
	201	#define HvRITER_set(hv,r) Perl_hv_riter_set(aTHX_ (HV*)(hv), r)
	202	#define HvEITER_set(hv,e) Perl_hv_eiter_set(aTHX_ (HV*)(hv), e)
	203	#define HvRITER_get(hv) (((XPVHV *)SvANY(hv))->xhv_aux ? \
	204	((struct xpvhv_aux)((XPVHV )SvANY(hv))->xhv_aux)->xhv_riter : -1)
	205	#define HvEITER_get(hv) (((XPVHV *)SvANY(hv))->xhv_aux ? \
	206	((struct xpvhv_aux )((XPVHV )SvANY(hv))->xhv_aux)->xhv_eiter : 0)
	207	#define HvNAME(hv) (Perl_hv_name_p(aTHX_ (HV)hv))
	208	/* FIXME - all of these should use a UTF8 aware API, which should also involve
	209	getting the length. */
	210	#define HvNAME_get(hv) (((XPVHV *)SvANY(hv))->xhv_aux ? \
	211	((struct xpvhv_aux )((XPVHV )SvANY(hv))->xhv_aux)->xhv_name : 0)
a0d0e21e	212
8aacddc1	213	/* the number of keys (including any placeholers) */
	214	#define XHvTOTALKEYS(xhv) ((xhv)->xhv_keys)
	215
8aacddc1	216	/*
	217	* HvKEYS gets the number of keys that actually exist(), and is provided
	218	* for backwards compatibility with old XS code. The core uses HvUSEDKEYS
	219	* (keys, excluding placeholdes) and HvTOTALKEYS (including placeholders)
	220	*/
ca732855	221	#define HvKEYS(hv) HvUSEDKEYS(hv)
ca732855	222	#define HvUSEDKEYS(hv) (HvTOTALKEYS(hv) - HvPLACEHOLDERS_get(hv))
8aacddc1	223	#define HvTOTALKEYS(hv) XHvTOTALKEYS((XPVHV*) SvANY(hv))
ca732855	224	#define HvPLACEHOLDERS(hv) (Perl_hv_placeholders_p(aTHX_ (HV)hv))
	225	#define HvPLACEHOLDERS_get(hv) (SvMAGIC(hv) ? Perl_hv_placeholders_get(aTHX_ (HV*)hv) : 0)
	226	#define HvPLACEHOLDERS_set(hv,p) Perl_hv_placeholders_set(aTHX_ (HV*)hv, p)
8aacddc1	227
bf6bd887	228	#define HvSHAREKEYS(hv) (SvFLAGS(hv) & SVphv_SHAREKEYS)
	229	#define HvSHAREKEYS_on(hv) (SvFLAGS(hv) \|= SVphv_SHAREKEYS)
	230	#define HvSHAREKEYS_off(hv) (SvFLAGS(hv) &= ~SVphv_SHAREKEYS)
	231
19692e8d	232	/* This is an optimisation flag. It won't be set if all hash keys have a 0
	233	* flag. Currently the only flags relate to utf8.
	234	* Hence it won't be set if all keys are 8 bit only. It will be set if any key
	235	* is utf8 (including 8 bit keys that were entered as utf8, and need upgrading
	236	* when retrieved during iteration. It may still be set when there are no longer
	237	* any utf8 keys.
fdcd69b6	238	* See HVhek_ENABLEHVKFLAGS for the trigger.
19692e8d	239	*/
	240	#define HvHASKFLAGS(hv) (SvFLAGS(hv) & SVphv_HASKFLAGS)
	241	#define HvHASKFLAGS_on(hv) (SvFLAGS(hv) \|= SVphv_HASKFLAGS)
	242	#define HvHASKFLAGS_off(hv) (SvFLAGS(hv) &= ~SVphv_HASKFLAGS)
574c8022	243
bf5b86ae	244	#define HvLAZYDEL(hv) (SvFLAGS(hv) & SVphv_LAZYDEL)
	245	#define HvLAZYDEL_on(hv) (SvFLAGS(hv) \|= SVphv_LAZYDEL)
	246	#define HvLAZYDEL_off(hv) (SvFLAGS(hv) &= ~SVphv_LAZYDEL)
	247
4b5190b5	248	#define HvREHASH(hv) (SvFLAGS(hv) & SVphv_REHASH)
	249	#define HvREHASH_on(hv) (SvFLAGS(hv) \|= SVphv_REHASH)
	250	#define HvREHASH_off(hv) (SvFLAGS(hv) &= ~SVphv_REHASH)
	251
a0d0e21e	252	/* Maybe amagical: */
	253	/* #define HV_AMAGICmb(hv) (SvFLAGS(hv) & (SVpgv_badAM \| SVpgv_AM)) */
	254
	255	#define HV_AMAGIC(hv) (SvFLAGS(hv) & SVpgv_AM)
	256	#define HV_AMAGIC_on(hv) (SvFLAGS(hv) \|= SVpgv_AM)
	257	#define HV_AMAGIC_off(hv) (SvFLAGS(hv) &= ~SVpgv_AM)
	258
	259	/*
	260	#define HV_AMAGICbad(hv) (SvFLAGS(hv) & SVpgv_badAM)
	261	#define HV_badAMAGIC_on(hv) (SvFLAGS(hv) \|= SVpgv_badAM)
	262	#define HV_badAMAGIC_off(hv) (SvFLAGS(hv) &= ~SVpgv_badAM)
	263	*/
bf6bd887	264
	265	#define Nullhe Null(HE*)
	266	#define HeNEXT(he) (he)->hent_next
ff68c719	267	#define HeKEY_hek(he) (he)->hent_hek
ff68c719	268	#define HeKEY(he) HEK_KEY(HeKEY_hek(he))
bbce6d69	269	#define HeKEY_sv(he) ((SV*)HeKEY(he))
ff68c719	270	#define HeKLEN(he) HEK_LEN(HeKEY_hek(he))
da58a35d	271	#define HeKUTF8(he) HEK_UTF8(HeKEY_hek(he))
19692e8d	272	#define HeKWASUTF8(he) HEK_WASUTF8(HeKEY_hek(he))
4b5190b5	273	#define HeKREHASH(he) HEK_REHASH(HeKEY_hek(he))
da58a35d	274	#define HeKLEN_UTF8(he) (HeKUTF8(he) ? -HeKLEN(he) : HeKLEN(he))
19692e8d	275	#define HeKFLAGS(he) HEK_FLAGS(HeKEY_hek(he))
bf6bd887	276	#define HeVAL(he) (he)->hent_val
ff68c719	277	#define HeHASH(he) HEK_HASH(HeKEY_hek(he))
1e422769	278	#define HePV(he,lp) ((HeKLEN(he) == HEf_SVKEY) ? \
	279	SvPV(HeKEY_sv(he),lp) : \
	280	(((lp = HeKLEN(he)) >= 0) ? \
	281	HeKEY(he) : Nullch))
	282
bbce6d69	283	#define HeSVKEY(he) ((HeKEY(he) && \
	284	HeKLEN(he) == HEf_SVKEY) ? \
	285	HeKEY_sv(he) : Nullsv)
	286
	287	#define HeSVKEY_force(he) (HeKEY(he) ? \
	288	((HeKLEN(he) == HEf_SVKEY) ? \
	289	HeKEY_sv(he) : \
79cb57f6	290	sv_2mortal(newSVpvn(HeKEY(he), \
bbce6d69	291	HeKLEN(he)))) : \
3280af22	292	&PL_sv_undef)
1e422769	293	#define HeSVKEY_set(he,sv) ((HeKLEN(he) = HEf_SVKEY), (HeKEY_sv(he) = sv))
bbce6d69	294
ff68c719	295	#define Nullhek Null(HEK*)
71be2cbc	296	#define HEK_BASESIZE STRUCT_OFFSET(HEK, hek_key[0])
ff68c719	297	#define HEK_HASH(hek) (hek)->hek_hash
	298	#define HEK_LEN(hek) (hek)->hek_len
	299	#define HEK_KEY(hek) (hek)->hek_key
19692e8d	300	#define HEK_FLAGS(hek) (((unsigned char )(HEK_KEY(hek))+HEK_LEN(hek)+1))
	301
	302	#define HVhek_UTF8 0x01 /* Key is utf8 encoded. */
	303	#define HVhek_WASUTF8 0x02 /* Key is bytes here, but was supplied as utf8. */
4b5190b5	304	#define HVhek_REHASH 0x04 /* This key is in an hv using a custom HASH . */
19692e8d	305	#define HVhek_FREEKEY 0x100 /* Internal flag to say key is malloc()ed. */
e16e2ff8	306	#define HVhek_PLACEHOLD 0x200 /* Internal flag to create placeholder.
e16e2ff8	307	* (may change, but Storable is a core module) */
19692e8d	308	#define HVhek_MASK 0xFF
19692e8d	309
fdcd69b6	310	/* Which flags enable HvHASKFLAGS? Somewhat a hack on a hack, as
	311	HVhek_REHASH is only needed because the rehash flag has to be duplicated
	312	into all keys as hv_iternext has no access to the hash flags. At this
	313	point Storable's tests get upset, because sometimes hashes are "keyed"
	314	and sometimes not, depending on the order of data insertion, and whether
	315	it triggered rehashing. So currently HVhek_REHAS is exempt.
	316	*/
	317
	318	#define HVhek_ENABLEHVKFLAGS (HVhek_MASK - HVhek_REHASH)
	319
19692e8d	320	#define HEK_UTF8(hek) (HEK_FLAGS(hek) & HVhek_UTF8)
	321	#define HEK_UTF8_on(hek) (HEK_FLAGS(hek) \|= HVhek_UTF8)
	322	#define HEK_UTF8_off(hek) (HEK_FLAGS(hek) &= ~HVhek_UTF8)
	323	#define HEK_WASUTF8(hek) (HEK_FLAGS(hek) & HVhek_WASUTF8)
	324	#define HEK_WASUTF8_on(hek) (HEK_FLAGS(hek) \|= HVhek_WASUTF8)
	325	#define HEK_WASUTF8_off(hek) (HEK_FLAGS(hek) &= ~HVhek_WASUTF8)
4b5190b5	326	#define HEK_REHASH(hek) (HEK_FLAGS(hek) & HVhek_REHASH)
4b5190b5	327	#define HEK_REHASH_on(hek) (HEK_FLAGS(hek) \|= HVhek_REHASH)
d18c6117	328
5cbe4eec	329	/* calculate HV array allocation */
36768cf4	330	#ifndef PERL_USE_LARGE_HV_ALLOC
	331	/* Default to allocating the correct size - default to assuming that malloc()
	332	is not broken and is efficient at allocating blocks sized at powers-of-two.
	333	*/
d18c6117	334	# define PERL_HV_ARRAY_ALLOC_BYTES(size) ((size) * sizeof(HE*))
	335	#else
	336	# define MALLOC_OVERHEAD 16
	337	# define PERL_HV_ARRAY_ALLOC_BYTES(size) \
	338	(((size) < 64) \
	339	? (size) * sizeof(HE*) \
	340	: (size) * sizeof(HE) 2 - MALLOC_OVERHEAD)
	341	#endif
37d85e3a	342
e16e2ff8	343	/* Flags for hv_iternext_flags. */
	344	#define HV_ITERNEXT_WANTPLACEHOLDERS 0x01 /* Don't skip placeholders. */
	345
37d85e3a	346	/* available as a function in hv.c */
	347	#define Perl_sharepvn(sv, len, hash) HEK_KEY(share_hek(sv, len, hash))
	348	#define sharepvn(sv, len, hash) Perl_sharepvn(sv, len, hash)
bfcb3514	349
	350	/*
	351	* Local variables:
	352	* c-indentation-style: bsd
	353	* c-basic-offset: 4
	354	* indent-tabs-mode: t
	355	* End:
	356	*
	357	* ex: set ts=8 sts=4 sw=4 noet:
	358	*/