[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 {
    IV		for_rent;
    STRLEN	xhv_fill;	/* how full xhv_array currently is */
    STRLEN	xhv_max;	/* subscript of last element of xhv_array */
    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

typedef struct xpvhv xpvhv_allocated;

/* 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 {
102d3b8a	45	IV for_rent;
463ee0b2	46	STRLEN xhv_fill; /* how full xhv_array currently is */
463ee0b2	47	STRLEN xhv_max; /* subscript of last element of xhv_array */
e4305a63	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
59813432	66	typedef struct xpvhv xpvhv_allocated;
e4305a63	67
5cbe4eec	68	/* hash a key */
5afd6d42	69	/* FYI: This is the "One-at-a-Time" algorithm by Bob Jenkins
	70	* from requirements by Colin Plumb.
	71	* (http://burtleburtle.net/bob/hash/doobs.html) */
	72	/* The use of a temporary pointer and the casting games
	73	* is needed to serve the dual purposes of
	74	* (a) the hashed data being interpreted as "unsigned char" (new since 5.8,
	75	* a "char" can be either signed or signed, depending on the compiler)
	76	* (b) catering for old code that uses a "char"
830b38bd	77	*
504f80c1	78	* The "hash seed" feature was added in Perl 5.8.1 to perturb the results
504f80c1	79	* to avoid "algorithmic complexity attacks".
830b38bd	80	*
	81	* If USE_HASH_SEED is defined, hash randomisation is done by default
	82	* If USE_HASH_SEED_EXPLICIT is defined, hash randomisation is done
	83	* only if the environment variable PERL_HASH_SEED is set.
	84	* For maximal control, one can define PERL_HASH_SEED.
90ce55a1	85	* (see also perl.c:perl_parse()).
5afd6d42	86	*/
830b38bd	87	#ifndef PERL_HASH_SEED
	88	# if defined(USE_HASH_SEED) \|\| defined(USE_HASH_SEED_EXPLICIT)
	89	# define PERL_HASH_SEED PL_hash_seed
	90	# else
	91	# define PERL_HASH_SEED 0
	92	# endif
504f80c1	93	#endif
bf6bd887	94	#define PERL_HASH(hash,str,len) \
bf6bd887	95	STMT_START { \
5afd6d42	96	register const char *s_PeRlHaSh_tmp = str; \
5afd6d42	97	register const unsigned char s_PeRlHaSh = (const unsigned char )s_PeRlHaSh_tmp; \
bf6bd887	98	register I32 i_PeRlHaSh = len; \
504f80c1	99	register U32 hash_PeRlHaSh = PERL_HASH_SEED; \
a6fe520e	100	while (i_PeRlHaSh--) { \
	101	hash_PeRlHaSh += *s_PeRlHaSh++; \
	102	hash_PeRlHaSh += (hash_PeRlHaSh << 10); \
	103	hash_PeRlHaSh ^= (hash_PeRlHaSh >> 6); \
	104	} \
	105	hash_PeRlHaSh += (hash_PeRlHaSh << 3); \
	106	hash_PeRlHaSh ^= (hash_PeRlHaSh >> 11); \
4fee5c71	107	(hash) = (hash_PeRlHaSh + (hash_PeRlHaSh << 15)); \
bf6bd887	108	} STMT_END
bf6bd887	109
3d78eb94	110	/* Only hv.c and mod_perl should be doing this. */
3d78eb94	111	#ifdef PERL_HASH_INTERNAL_ACCESS
4b5190b5	112	#define PERL_HASH_INTERNAL(hash,str,len) \
	113	STMT_START { \
	114	register const char *s_PeRlHaSh_tmp = str; \
	115	register const unsigned char s_PeRlHaSh = (const unsigned char )s_PeRlHaSh_tmp; \
	116	register I32 i_PeRlHaSh = len; \
008fb0c0	117	register U32 hash_PeRlHaSh = PL_rehash_seed; \
4b5190b5	118	while (i_PeRlHaSh--) { \
	119	hash_PeRlHaSh += *s_PeRlHaSh++; \
	120	hash_PeRlHaSh += (hash_PeRlHaSh << 10); \
	121	hash_PeRlHaSh ^= (hash_PeRlHaSh >> 6); \
	122	} \
	123	hash_PeRlHaSh += (hash_PeRlHaSh << 3); \
	124	hash_PeRlHaSh ^= (hash_PeRlHaSh >> 11); \
	125	(hash) = (hash_PeRlHaSh + (hash_PeRlHaSh << 15)); \
	126	} STMT_END
	127	#endif
	128
954c1994	129	/*
ccfc67b7	130	=head1 Hash Manipulation Functions
ccfc67b7	131
954c1994	132	=for apidoc AmU\|\|HEf_SVKEY
954c1994	133	This flag, used in the length slot of hash entries and magic structures,
d1be9408	134	specifies the structure contains an C<SV> pointer where a C<char> pointer
954c1994	135	is to be expected. (For information only--not to be used).
954c1994	136
ccfc67b7	137	=head1 Handy Values
ccfc67b7	138
954c1994	139	=for apidoc AmU\|\|Nullhv
	140	Null HV pointer.
	141
ccfc67b7	142	=head1 Hash Manipulation Functions
ccfc67b7	143
954c1994	144	=for apidoc Am\|char\|HvNAME\|HV stash
	145	Returns the package name of a stash. See C<SvSTASH>, C<CvSTASH>.
	146
	147	=for apidoc Am\|void\|HeKEY\|HE he
	148	Returns the actual pointer stored in the key slot of the hash entry. The
	149	pointer may be either C<char> or C<SV>, depending on the value of
	150	C<HeKLEN()>. Can be assigned to. The C<HePV()> or C<HeSVKEY()> macros are
	151	usually preferable for finding the value of a key.
	152
	153	=for apidoc Am\|STRLEN\|HeKLEN\|HE* he
	154	If this is negative, and amounts to C<HEf_SVKEY>, it indicates the entry
	155	holds an C<SV*> key. Otherwise, holds the actual length of the key. Can
	156	be assigned to. The C<HePV()> macro is usually preferable for finding key
	157	lengths.
	158
	159	=for apidoc Am\|SV\|HeVAL\|HE he
	160	Returns the value slot (type C<SV*>) stored in the hash entry.
	161
	162	=for apidoc Am\|U32\|HeHASH\|HE* he
	163	Returns the computed hash stored in the hash entry.
	164
	165	=for apidoc Am\|char\|HePV\|HE he\|STRLEN len
	166	Returns the key slot of the hash entry as a C<char*> value, doing any
	167	necessary dereferencing of possibly C<SV*> keys. The length of the string
	168	is placed in C<len> (this is a macro, so do I<not> use C<&len>). If you do
	169	not care about what the length of the key is, you may use the global
	170	variable C<PL_na>, though this is rather less efficient than using a local
	171	variable. Remember though, that hash keys in perl are free to contain
	172	embedded nulls, so using C<strlen()> or similar is not a good way to find
	173	the length of hash keys. This is very similar to the C<SvPV()> macro
	174	described elsewhere in this document.
	175
	176	=for apidoc Am\|SV\|HeSVKEY\|HE he
	177	Returns the key as an C<SV*>, or C<Nullsv> if the hash entry does not
	178	contain an C<SV*> key.
	179
	180	=for apidoc Am\|SV\|HeSVKEY_force\|HE he
	181	Returns the key as an C<SV*>. Will create and return a temporary mortal
	182	C<SV> if the hash entry contains only a C<char> key.
	183
	184	=for apidoc Am\|SV\|HeSVKEY_set\|HE he\|SV* sv
	185	Sets the key to a given C<SV*>, taking care to set the appropriate flags to
	186	indicate the presence of an C<SV*> key, and returns the same
	187	C<SV*>.
	188
	189	=cut
	190	*/
bf6bd887	191
bf5b86ae	192	/* these hash entry flags ride on hent_klen (for use only in magic/tied HVs) */
d1be9408	193	#define HEf_SVKEY -2 /* hent_key is an SV* */
bf6bd887	194
bf6bd887	195
79072805	196	#define Nullhv Null(HV*)
7b2c381c	197	#define HvARRAY(hv) ((HE**)&((hv)->sv_u.sv_array))
79072805	198	#define HvFILL(hv) ((XPVHV*) SvANY(hv))->xhv_fill
463ee0b2	199	#define HvMAX(hv) ((XPVHV*) SvANY(hv))->xhv_max
bfcb3514	200	#define HvRITER(hv) (Perl_hv_riter_p(aTHX_ (HV)(hv)))
	201	#define HvEITER(hv) (Perl_hv_eiter_p(aTHX_ (HV)(hv)))
	202	#define HvRITER_set(hv,r) Perl_hv_riter_set(aTHX_ (HV*)(hv), r)
	203	#define HvEITER_set(hv,e) Perl_hv_eiter_set(aTHX_ (HV*)(hv), e)
	204	#define HvRITER_get(hv) (((XPVHV *)SvANY(hv))->xhv_aux ? \
	205	((struct xpvhv_aux)((XPVHV )SvANY(hv))->xhv_aux)->xhv_riter : -1)
	206	#define HvEITER_get(hv) (((XPVHV *)SvANY(hv))->xhv_aux ? \
	207	((struct xpvhv_aux )((XPVHV )SvANY(hv))->xhv_aux)->xhv_eiter : 0)
	208	#define HvNAME(hv) (Perl_hv_name_p(aTHX_ (HV)hv))
	209	/* FIXME - all of these should use a UTF8 aware API, which should also involve
	210	getting the length. */
	211	#define HvNAME_get(hv) (((XPVHV *)SvANY(hv))->xhv_aux ? \
	212	((struct xpvhv_aux )((XPVHV )SvANY(hv))->xhv_aux)->xhv_name : 0)
a0d0e21e	213
8aacddc1	214	/* the number of keys (including any placeholers) */
	215	#define XHvTOTALKEYS(xhv) ((xhv)->xhv_keys)
	216
8aacddc1	217	/*
	218	* HvKEYS gets the number of keys that actually exist(), and is provided
	219	* for backwards compatibility with old XS code. The core uses HvUSEDKEYS
	220	* (keys, excluding placeholdes) and HvTOTALKEYS (including placeholders)
	221	*/
ca732855	222	#define HvKEYS(hv) HvUSEDKEYS(hv)
ca732855	223	#define HvUSEDKEYS(hv) (HvTOTALKEYS(hv) - HvPLACEHOLDERS_get(hv))
8aacddc1	224	#define HvTOTALKEYS(hv) XHvTOTALKEYS((XPVHV*) SvANY(hv))
ca732855	225	#define HvPLACEHOLDERS(hv) (Perl_hv_placeholders_p(aTHX_ (HV)hv))
	226	#define HvPLACEHOLDERS_get(hv) (SvMAGIC(hv) ? Perl_hv_placeholders_get(aTHX_ (HV*)hv) : 0)
	227	#define HvPLACEHOLDERS_set(hv,p) Perl_hv_placeholders_set(aTHX_ (HV*)hv, p)
8aacddc1	228
bf6bd887	229	#define HvSHAREKEYS(hv) (SvFLAGS(hv) & SVphv_SHAREKEYS)
	230	#define HvSHAREKEYS_on(hv) (SvFLAGS(hv) \|= SVphv_SHAREKEYS)
	231	#define HvSHAREKEYS_off(hv) (SvFLAGS(hv) &= ~SVphv_SHAREKEYS)
	232
19692e8d	233	/* This is an optimisation flag. It won't be set if all hash keys have a 0
	234	* flag. Currently the only flags relate to utf8.
	235	* Hence it won't be set if all keys are 8 bit only. It will be set if any key
	236	* is utf8 (including 8 bit keys that were entered as utf8, and need upgrading
	237	* when retrieved during iteration. It may still be set when there are no longer
	238	* any utf8 keys.
fdcd69b6	239	* See HVhek_ENABLEHVKFLAGS for the trigger.
19692e8d	240	*/
	241	#define HvHASKFLAGS(hv) (SvFLAGS(hv) & SVphv_HASKFLAGS)
	242	#define HvHASKFLAGS_on(hv) (SvFLAGS(hv) \|= SVphv_HASKFLAGS)
	243	#define HvHASKFLAGS_off(hv) (SvFLAGS(hv) &= ~SVphv_HASKFLAGS)
574c8022	244
bf5b86ae	245	#define HvLAZYDEL(hv) (SvFLAGS(hv) & SVphv_LAZYDEL)
	246	#define HvLAZYDEL_on(hv) (SvFLAGS(hv) \|= SVphv_LAZYDEL)
	247	#define HvLAZYDEL_off(hv) (SvFLAGS(hv) &= ~SVphv_LAZYDEL)
	248
4b5190b5	249	#define HvREHASH(hv) (SvFLAGS(hv) & SVphv_REHASH)
	250	#define HvREHASH_on(hv) (SvFLAGS(hv) \|= SVphv_REHASH)
	251	#define HvREHASH_off(hv) (SvFLAGS(hv) &= ~SVphv_REHASH)
	252
a0d0e21e	253	/* Maybe amagical: */
	254	/* #define HV_AMAGICmb(hv) (SvFLAGS(hv) & (SVpgv_badAM \| SVpgv_AM)) */
	255
	256	#define HV_AMAGIC(hv) (SvFLAGS(hv) & SVpgv_AM)
	257	#define HV_AMAGIC_on(hv) (SvFLAGS(hv) \|= SVpgv_AM)
	258	#define HV_AMAGIC_off(hv) (SvFLAGS(hv) &= ~SVpgv_AM)
	259
	260	/*
	261	#define HV_AMAGICbad(hv) (SvFLAGS(hv) & SVpgv_badAM)
	262	#define HV_badAMAGIC_on(hv) (SvFLAGS(hv) \|= SVpgv_badAM)
	263	#define HV_badAMAGIC_off(hv) (SvFLAGS(hv) &= ~SVpgv_badAM)
	264	*/
bf6bd887	265
	266	#define Nullhe Null(HE*)
	267	#define HeNEXT(he) (he)->hent_next
ff68c719	268	#define HeKEY_hek(he) (he)->hent_hek
ff68c719	269	#define HeKEY(he) HEK_KEY(HeKEY_hek(he))
bbce6d69	270	#define HeKEY_sv(he) ((SV*)HeKEY(he))
ff68c719	271	#define HeKLEN(he) HEK_LEN(HeKEY_hek(he))
da58a35d	272	#define HeKUTF8(he) HEK_UTF8(HeKEY_hek(he))
19692e8d	273	#define HeKWASUTF8(he) HEK_WASUTF8(HeKEY_hek(he))
4b5190b5	274	#define HeKREHASH(he) HEK_REHASH(HeKEY_hek(he))
da58a35d	275	#define HeKLEN_UTF8(he) (HeKUTF8(he) ? -HeKLEN(he) : HeKLEN(he))
19692e8d	276	#define HeKFLAGS(he) HEK_FLAGS(HeKEY_hek(he))
bf6bd887	277	#define HeVAL(he) (he)->hent_val
ff68c719	278	#define HeHASH(he) HEK_HASH(HeKEY_hek(he))
1e422769	279	#define HePV(he,lp) ((HeKLEN(he) == HEf_SVKEY) ? \
	280	SvPV(HeKEY_sv(he),lp) : \
	281	(((lp = HeKLEN(he)) >= 0) ? \
	282	HeKEY(he) : Nullch))
	283
bbce6d69	284	#define HeSVKEY(he) ((HeKEY(he) && \
	285	HeKLEN(he) == HEf_SVKEY) ? \
	286	HeKEY_sv(he) : Nullsv)
	287
	288	#define HeSVKEY_force(he) (HeKEY(he) ? \
	289	((HeKLEN(he) == HEf_SVKEY) ? \
	290	HeKEY_sv(he) : \
79cb57f6	291	sv_2mortal(newSVpvn(HeKEY(he), \
bbce6d69	292	HeKLEN(he)))) : \
3280af22	293	&PL_sv_undef)
1e422769	294	#define HeSVKEY_set(he,sv) ((HeKLEN(he) = HEf_SVKEY), (HeKEY_sv(he) = sv))
bbce6d69	295
ff68c719	296	#define Nullhek Null(HEK*)
71be2cbc	297	#define HEK_BASESIZE STRUCT_OFFSET(HEK, hek_key[0])
ff68c719	298	#define HEK_HASH(hek) (hek)->hek_hash
	299	#define HEK_LEN(hek) (hek)->hek_len
	300	#define HEK_KEY(hek) (hek)->hek_key
19692e8d	301	#define HEK_FLAGS(hek) (((unsigned char )(HEK_KEY(hek))+HEK_LEN(hek)+1))
	302
	303	#define HVhek_UTF8 0x01 /* Key is utf8 encoded. */
	304	#define HVhek_WASUTF8 0x02 /* Key is bytes here, but was supplied as utf8. */
4b5190b5	305	#define HVhek_REHASH 0x04 /* This key is in an hv using a custom HASH . */
19692e8d	306	#define HVhek_FREEKEY 0x100 /* Internal flag to say key is malloc()ed. */
e16e2ff8	307	#define HVhek_PLACEHOLD 0x200 /* Internal flag to create placeholder.
e16e2ff8	308	* (may change, but Storable is a core module) */
19692e8d	309	#define HVhek_MASK 0xFF
19692e8d	310
fdcd69b6	311	/* Which flags enable HvHASKFLAGS? Somewhat a hack on a hack, as
	312	HVhek_REHASH is only needed because the rehash flag has to be duplicated
	313	into all keys as hv_iternext has no access to the hash flags. At this
	314	point Storable's tests get upset, because sometimes hashes are "keyed"
	315	and sometimes not, depending on the order of data insertion, and whether
	316	it triggered rehashing. So currently HVhek_REHAS is exempt.
	317	*/
	318
	319	#define HVhek_ENABLEHVKFLAGS (HVhek_MASK - HVhek_REHASH)
	320
19692e8d	321	#define HEK_UTF8(hek) (HEK_FLAGS(hek) & HVhek_UTF8)
	322	#define HEK_UTF8_on(hek) (HEK_FLAGS(hek) \|= HVhek_UTF8)
	323	#define HEK_UTF8_off(hek) (HEK_FLAGS(hek) &= ~HVhek_UTF8)
	324	#define HEK_WASUTF8(hek) (HEK_FLAGS(hek) & HVhek_WASUTF8)
	325	#define HEK_WASUTF8_on(hek) (HEK_FLAGS(hek) \|= HVhek_WASUTF8)
	326	#define HEK_WASUTF8_off(hek) (HEK_FLAGS(hek) &= ~HVhek_WASUTF8)
4b5190b5	327	#define HEK_REHASH(hek) (HEK_FLAGS(hek) & HVhek_REHASH)
4b5190b5	328	#define HEK_REHASH_on(hek) (HEK_FLAGS(hek) \|= HVhek_REHASH)
d18c6117	329
5cbe4eec	330	/* calculate HV array allocation */
36768cf4	331	#ifndef PERL_USE_LARGE_HV_ALLOC
	332	/* Default to allocating the correct size - default to assuming that malloc()
	333	is not broken and is efficient at allocating blocks sized at powers-of-two.
	334	*/
d18c6117	335	# define PERL_HV_ARRAY_ALLOC_BYTES(size) ((size) * sizeof(HE*))
	336	#else
	337	# define MALLOC_OVERHEAD 16
	338	# define PERL_HV_ARRAY_ALLOC_BYTES(size) \
	339	(((size) < 64) \
	340	? (size) * sizeof(HE*) \
	341	: (size) * sizeof(HE) 2 - MALLOC_OVERHEAD)
	342	#endif
37d85e3a	343
e16e2ff8	344	/* Flags for hv_iternext_flags. */
	345	#define HV_ITERNEXT_WANTPLACEHOLDERS 0x01 /* Don't skip placeholders. */
	346
37d85e3a	347	/* available as a function in hv.c */
	348	#define Perl_sharepvn(sv, len, hash) HEK_KEY(share_hek(sv, len, hash))
	349	#define sharepvn(sv, len, hash) Perl_sharepvn(sv, len, hash)
bfcb3514	350
	351	/*
	352	* Local variables:
	353	* c-indentation-style: bsd
	354	* c-basic-offset: 4
	355	* indent-tabs-mode: t
	356	* End:
	357	*
	358	* ex: set ts=8 sts=4 sw=4 noet:
	359	*/