[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 {
    HEK		*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 {
	struct {
	    void *xnv_p1;
	    union {
		void *xnv_p2;
		IV xnv_i2;	/* how many elements in the array */
	    }	xnv_u2;
	}	xnv_s;
	NV	xnvu_nv;	/* numeric value, if any */
    }		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

#if !defined(PERL_EXPERIMENTAL_LAYOUT)
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 {
	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 */
} 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 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.svu_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)	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) (((XPVHV *)SvANY(hv))->xhv_aux && (((struct xpvhv_aux *)((XPVHV *)SvANY(hv))->xhv_aux)->xhv_name) ? ((struct xpvhv_aux *)((XPVHV *)SvANY(hv))->xhv_aux)->xhv_name: 0)
#define HvNAME_get(hv)	(((XPVHV *)SvANY(hv))->xhv_aux ? \
			 (((struct xpvhv_aux *)((XPVHV *)SvANY(hv))->xhv_aux)->xhv_name) ? HEK_KEY(((struct xpvhv_aux *)((XPVHV *)SvANY(hv))->xhv_aux)->xhv_name) : 0 : 0)
#define HvNAMELEN_get(hv)	(((XPVHV *)SvANY(hv))->xhv_aux ? \
			 (((struct xpvhv_aux *)((XPVHV *)SvANY(hv))->xhv_aux)->xhv_name) ? HEK_LEN(((struct xpvhv_aux *)((XPVHV *)SvANY(hv))->xhv_aux)->xhv_name) : 0 : 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 {
7423f6db	37	HEK xhv_name; / name, if a symbol table */
bfcb3514	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 {
e4305a63	49	struct {
	50	void *xnv_p1;
	51	union {
	52	void *xnv_p2;
	53	IV xnv_i2; /* how many elements in the array */
	54	} xnv_u2;
	55	} xnv_s;
199f3245	56	NV xnvu_nv; /* numeric value, if any */
e4305a63	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
209b62a3	66	#if !defined(PERL_EXPERIMENTAL_LAYOUT)
59813432	67	typedef struct xpvhv xpvhv_allocated;
9f1501b2	68	#else
	69	typedef struct {
	70	STRLEN xhv_fill; /* how full xhv_array currently is */
	71	STRLEN xhv_max; /* subscript of last element of xhv_array */
	72	union {
	73	NV xnvu_nv; /* numeric value, if any */
	74	struct {
	75	void *xnv_p1;
	76	union {
	77	void *xnv_p2;
	78	IV xnv_i2; /* how many elements in the array */
	79	} xnv_u2;
	80	} xnv_s;
	81	} xnv_u;
	82	MAGIC* xmg_magic; /* magic for scalar array */
	83	HV* xmg_stash; /* class package */
	84	} xpvhv_allocated;
	85	#endif
e4305a63	86
5cbe4eec	87	/* hash a key */
5afd6d42	88	/* FYI: This is the "One-at-a-Time" algorithm by Bob Jenkins
	89	* from requirements by Colin Plumb.
	90	* (http://burtleburtle.net/bob/hash/doobs.html) */
	91	/* The use of a temporary pointer and the casting games
	92	* is needed to serve the dual purposes of
	93	* (a) the hashed data being interpreted as "unsigned char" (new since 5.8,
	94	* a "char" can be either signed or signed, depending on the compiler)
	95	* (b) catering for old code that uses a "char"
830b38bd	96	*
504f80c1	97	* The "hash seed" feature was added in Perl 5.8.1 to perturb the results
504f80c1	98	* to avoid "algorithmic complexity attacks".
830b38bd	99	*
	100	* If USE_HASH_SEED is defined, hash randomisation is done by default
	101	* If USE_HASH_SEED_EXPLICIT is defined, hash randomisation is done
	102	* only if the environment variable PERL_HASH_SEED is set.
	103	* For maximal control, one can define PERL_HASH_SEED.
90ce55a1	104	* (see also perl.c:perl_parse()).
5afd6d42	105	*/
830b38bd	106	#ifndef PERL_HASH_SEED
	107	# if defined(USE_HASH_SEED) \|\| defined(USE_HASH_SEED_EXPLICIT)
	108	# define PERL_HASH_SEED PL_hash_seed
	109	# else
	110	# define PERL_HASH_SEED 0
	111	# endif
504f80c1	112	#endif
bf6bd887	113	#define PERL_HASH(hash,str,len) \
bf6bd887	114	STMT_START { \
5afd6d42	115	register const char *s_PeRlHaSh_tmp = str; \
5afd6d42	116	register const unsigned char s_PeRlHaSh = (const unsigned char )s_PeRlHaSh_tmp; \
bf6bd887	117	register I32 i_PeRlHaSh = len; \
504f80c1	118	register U32 hash_PeRlHaSh = PERL_HASH_SEED; \
a6fe520e	119	while (i_PeRlHaSh--) { \
	120	hash_PeRlHaSh += *s_PeRlHaSh++; \
	121	hash_PeRlHaSh += (hash_PeRlHaSh << 10); \
	122	hash_PeRlHaSh ^= (hash_PeRlHaSh >> 6); \
	123	} \
	124	hash_PeRlHaSh += (hash_PeRlHaSh << 3); \
	125	hash_PeRlHaSh ^= (hash_PeRlHaSh >> 11); \
4fee5c71	126	(hash) = (hash_PeRlHaSh + (hash_PeRlHaSh << 15)); \
bf6bd887	127	} STMT_END
bf6bd887	128
3d78eb94	129	/* Only hv.c and mod_perl should be doing this. */
3d78eb94	130	#ifdef PERL_HASH_INTERNAL_ACCESS
4b5190b5	131	#define PERL_HASH_INTERNAL(hash,str,len) \
	132	STMT_START { \
	133	register const char *s_PeRlHaSh_tmp = str; \
	134	register const unsigned char s_PeRlHaSh = (const unsigned char )s_PeRlHaSh_tmp; \
	135	register I32 i_PeRlHaSh = len; \
008fb0c0	136	register U32 hash_PeRlHaSh = PL_rehash_seed; \
4b5190b5	137	while (i_PeRlHaSh--) { \
	138	hash_PeRlHaSh += *s_PeRlHaSh++; \
	139	hash_PeRlHaSh += (hash_PeRlHaSh << 10); \
	140	hash_PeRlHaSh ^= (hash_PeRlHaSh >> 6); \
	141	} \
	142	hash_PeRlHaSh += (hash_PeRlHaSh << 3); \
	143	hash_PeRlHaSh ^= (hash_PeRlHaSh >> 11); \
	144	(hash) = (hash_PeRlHaSh + (hash_PeRlHaSh << 15)); \
	145	} STMT_END
	146	#endif
	147
954c1994	148	/*
ccfc67b7	149	=head1 Hash Manipulation Functions
ccfc67b7	150
954c1994	151	=for apidoc AmU\|\|HEf_SVKEY
954c1994	152	This flag, used in the length slot of hash entries and magic structures,
d1be9408	153	specifies the structure contains an C<SV> pointer where a C<char> pointer
954c1994	154	is to be expected. (For information only--not to be used).
954c1994	155
ccfc67b7	156	=head1 Handy Values
ccfc67b7	157
954c1994	158	=for apidoc AmU\|\|Nullhv
	159	Null HV pointer.
	160
ccfc67b7	161	=head1 Hash Manipulation Functions
ccfc67b7	162
954c1994	163	=for apidoc Am\|char\|HvNAME\|HV stash
	164	Returns the package name of a stash. See C<SvSTASH>, C<CvSTASH>.
	165
	166	=for apidoc Am\|void\|HeKEY\|HE he
	167	Returns the actual pointer stored in the key slot of the hash entry. The
	168	pointer may be either C<char> or C<SV>, depending on the value of
	169	C<HeKLEN()>. Can be assigned to. The C<HePV()> or C<HeSVKEY()> macros are
	170	usually preferable for finding the value of a key.
	171
	172	=for apidoc Am\|STRLEN\|HeKLEN\|HE* he
	173	If this is negative, and amounts to C<HEf_SVKEY>, it indicates the entry
	174	holds an C<SV*> key. Otherwise, holds the actual length of the key. Can
	175	be assigned to. The C<HePV()> macro is usually preferable for finding key
	176	lengths.
	177
	178	=for apidoc Am\|SV\|HeVAL\|HE he
	179	Returns the value slot (type C<SV*>) stored in the hash entry.
	180
	181	=for apidoc Am\|U32\|HeHASH\|HE* he
	182	Returns the computed hash stored in the hash entry.
	183
	184	=for apidoc Am\|char\|HePV\|HE he\|STRLEN len
	185	Returns the key slot of the hash entry as a C<char*> value, doing any
	186	necessary dereferencing of possibly C<SV*> keys. The length of the string
	187	is placed in C<len> (this is a macro, so do I<not> use C<&len>). If you do
	188	not care about what the length of the key is, you may use the global
	189	variable C<PL_na>, though this is rather less efficient than using a local
	190	variable. Remember though, that hash keys in perl are free to contain
	191	embedded nulls, so using C<strlen()> or similar is not a good way to find
	192	the length of hash keys. This is very similar to the C<SvPV()> macro
	193	described elsewhere in this document.
	194
	195	=for apidoc Am\|SV\|HeSVKEY\|HE he
	196	Returns the key as an C<SV*>, or C<Nullsv> if the hash entry does not
	197	contain an C<SV*> key.
	198
	199	=for apidoc Am\|SV\|HeSVKEY_force\|HE he
	200	Returns the key as an C<SV*>. Will create and return a temporary mortal
	201	C<SV> if the hash entry contains only a C<char> key.
	202
	203	=for apidoc Am\|SV\|HeSVKEY_set\|HE he\|SV* sv
	204	Sets the key to a given C<SV*>, taking care to set the appropriate flags to
	205	indicate the presence of an C<SV*> key, and returns the same
	206	C<SV*>.
	207
	208	=cut
	209	*/
bf6bd887	210
bf5b86ae	211	/* these hash entry flags ride on hent_klen (for use only in magic/tied HVs) */
d1be9408	212	#define HEf_SVKEY -2 /* hent_key is an SV* */
bf6bd887	213
bf6bd887	214
79072805	215	#define Nullhv Null(HV*)
339049b0	216	#define HvARRAY(hv) ((HE**)&((hv)->sv_u.svu_array))
79072805	217	#define HvFILL(hv) ((XPVHV*) SvANY(hv))->xhv_fill
463ee0b2	218	#define HvMAX(hv) ((XPVHV*) SvANY(hv))->xhv_max
bfcb3514	219	#define HvRITER(hv) (Perl_hv_riter_p(aTHX_ (HV)(hv)))
	220	#define HvEITER(hv) (Perl_hv_eiter_p(aTHX_ (HV)(hv)))
	221	#define HvRITER_set(hv,r) Perl_hv_riter_set(aTHX_ (HV*)(hv), r)
	222	#define HvEITER_set(hv,e) Perl_hv_eiter_set(aTHX_ (HV*)(hv), e)
	223	#define HvRITER_get(hv) (((XPVHV *)SvANY(hv))->xhv_aux ? \
	224	((struct xpvhv_aux)((XPVHV )SvANY(hv))->xhv_aux)->xhv_riter : -1)
	225	#define HvEITER_get(hv) (((XPVHV *)SvANY(hv))->xhv_aux ? \
	226	((struct xpvhv_aux )((XPVHV )SvANY(hv))->xhv_aux)->xhv_eiter : 0)
7423f6db	227	#define HvNAME(hv) HvNAME_get(hv)
bfcb3514	228	/* FIXME - all of these should use a UTF8 aware API, which should also involve
bfcb3514	229	getting the length. */
9b9d0b15	230	/* This macro may go away without notice. */
9b9d0b15	231	#define HvNAME_HEK(hv) (((XPVHV )SvANY(hv))->xhv_aux && (((struct xpvhv_aux )((XPVHV )SvANY(hv))->xhv_aux)->xhv_name) ? ((struct xpvhv_aux )((XPVHV *)SvANY(hv))->xhv_aux)->xhv_name: 0)
bfcb3514	232	#define HvNAME_get(hv) (((XPVHV *)SvANY(hv))->xhv_aux ? \
7423f6db	233	(((struct xpvhv_aux )((XPVHV )SvANY(hv))->xhv_aux)->xhv_name) ? HEK_KEY(((struct xpvhv_aux )((XPVHV )SvANY(hv))->xhv_aux)->xhv_name) : 0 : 0)
	234	#define HvNAMELEN_get(hv) (((XPVHV *)SvANY(hv))->xhv_aux ? \
	235	(((struct xpvhv_aux )((XPVHV )SvANY(hv))->xhv_aux)->xhv_name) ? HEK_LEN(((struct xpvhv_aux )((XPVHV )SvANY(hv))->xhv_aux)->xhv_name) : 0 : 0)
a0d0e21e	236
8aacddc1	237	/* the number of keys (including any placeholers) */
	238	#define XHvTOTALKEYS(xhv) ((xhv)->xhv_keys)
	239
8aacddc1	240	/*
	241	* HvKEYS gets the number of keys that actually exist(), and is provided
	242	* for backwards compatibility with old XS code. The core uses HvUSEDKEYS
	243	* (keys, excluding placeholdes) and HvTOTALKEYS (including placeholders)
	244	*/
ca732855	245	#define HvKEYS(hv) HvUSEDKEYS(hv)
ca732855	246	#define HvUSEDKEYS(hv) (HvTOTALKEYS(hv) - HvPLACEHOLDERS_get(hv))
8aacddc1	247	#define HvTOTALKEYS(hv) XHvTOTALKEYS((XPVHV*) SvANY(hv))
ca732855	248	#define HvPLACEHOLDERS(hv) (Perl_hv_placeholders_p(aTHX_ (HV)hv))
	249	#define HvPLACEHOLDERS_get(hv) (SvMAGIC(hv) ? Perl_hv_placeholders_get(aTHX_ (HV*)hv) : 0)
	250	#define HvPLACEHOLDERS_set(hv,p) Perl_hv_placeholders_set(aTHX_ (HV*)hv, p)
8aacddc1	251
bf6bd887	252	#define HvSHAREKEYS(hv) (SvFLAGS(hv) & SVphv_SHAREKEYS)
	253	#define HvSHAREKEYS_on(hv) (SvFLAGS(hv) \|= SVphv_SHAREKEYS)
	254	#define HvSHAREKEYS_off(hv) (SvFLAGS(hv) &= ~SVphv_SHAREKEYS)
	255
19692e8d	256	/* This is an optimisation flag. It won't be set if all hash keys have a 0
	257	* flag. Currently the only flags relate to utf8.
	258	* Hence it won't be set if all keys are 8 bit only. It will be set if any key
	259	* is utf8 (including 8 bit keys that were entered as utf8, and need upgrading
	260	* when retrieved during iteration. It may still be set when there are no longer
	261	* any utf8 keys.
fdcd69b6	262	* See HVhek_ENABLEHVKFLAGS for the trigger.
19692e8d	263	*/
	264	#define HvHASKFLAGS(hv) (SvFLAGS(hv) & SVphv_HASKFLAGS)
	265	#define HvHASKFLAGS_on(hv) (SvFLAGS(hv) \|= SVphv_HASKFLAGS)
	266	#define HvHASKFLAGS_off(hv) (SvFLAGS(hv) &= ~SVphv_HASKFLAGS)
574c8022	267
bf5b86ae	268	#define HvLAZYDEL(hv) (SvFLAGS(hv) & SVphv_LAZYDEL)
	269	#define HvLAZYDEL_on(hv) (SvFLAGS(hv) \|= SVphv_LAZYDEL)
	270	#define HvLAZYDEL_off(hv) (SvFLAGS(hv) &= ~SVphv_LAZYDEL)
	271
4b5190b5	272	#define HvREHASH(hv) (SvFLAGS(hv) & SVphv_REHASH)
	273	#define HvREHASH_on(hv) (SvFLAGS(hv) \|= SVphv_REHASH)
	274	#define HvREHASH_off(hv) (SvFLAGS(hv) &= ~SVphv_REHASH)
	275
a0d0e21e	276	/* Maybe amagical: */
	277	/* #define HV_AMAGICmb(hv) (SvFLAGS(hv) & (SVpgv_badAM \| SVpgv_AM)) */
	278
	279	#define HV_AMAGIC(hv) (SvFLAGS(hv) & SVpgv_AM)
	280	#define HV_AMAGIC_on(hv) (SvFLAGS(hv) \|= SVpgv_AM)
	281	#define HV_AMAGIC_off(hv) (SvFLAGS(hv) &= ~SVpgv_AM)
	282
	283	/*
	284	#define HV_AMAGICbad(hv) (SvFLAGS(hv) & SVpgv_badAM)
	285	#define HV_badAMAGIC_on(hv) (SvFLAGS(hv) \|= SVpgv_badAM)
	286	#define HV_badAMAGIC_off(hv) (SvFLAGS(hv) &= ~SVpgv_badAM)
	287	*/
bf6bd887	288
	289	#define Nullhe Null(HE*)
	290	#define HeNEXT(he) (he)->hent_next
ff68c719	291	#define HeKEY_hek(he) (he)->hent_hek
ff68c719	292	#define HeKEY(he) HEK_KEY(HeKEY_hek(he))
bbce6d69	293	#define HeKEY_sv(he) ((SV*)HeKEY(he))
ff68c719	294	#define HeKLEN(he) HEK_LEN(HeKEY_hek(he))
da58a35d	295	#define HeKUTF8(he) HEK_UTF8(HeKEY_hek(he))
19692e8d	296	#define HeKWASUTF8(he) HEK_WASUTF8(HeKEY_hek(he))
4b5190b5	297	#define HeKREHASH(he) HEK_REHASH(HeKEY_hek(he))
da58a35d	298	#define HeKLEN_UTF8(he) (HeKUTF8(he) ? -HeKLEN(he) : HeKLEN(he))
19692e8d	299	#define HeKFLAGS(he) HEK_FLAGS(HeKEY_hek(he))
bf6bd887	300	#define HeVAL(he) (he)->hent_val
ff68c719	301	#define HeHASH(he) HEK_HASH(HeKEY_hek(he))
1e422769	302	#define HePV(he,lp) ((HeKLEN(he) == HEf_SVKEY) ? \
	303	SvPV(HeKEY_sv(he),lp) : \
	304	(((lp = HeKLEN(he)) >= 0) ? \
	305	HeKEY(he) : Nullch))
	306
bbce6d69	307	#define HeSVKEY(he) ((HeKEY(he) && \
	308	HeKLEN(he) == HEf_SVKEY) ? \
	309	HeKEY_sv(he) : Nullsv)
	310
	311	#define HeSVKEY_force(he) (HeKEY(he) ? \
	312	((HeKLEN(he) == HEf_SVKEY) ? \
	313	HeKEY_sv(he) : \
79cb57f6	314	sv_2mortal(newSVpvn(HeKEY(he), \
bbce6d69	315	HeKLEN(he)))) : \
3280af22	316	&PL_sv_undef)
1e422769	317	#define HeSVKEY_set(he,sv) ((HeKLEN(he) = HEf_SVKEY), (HeKEY_sv(he) = sv))
bbce6d69	318
ff68c719	319	#define Nullhek Null(HEK*)
71be2cbc	320	#define HEK_BASESIZE STRUCT_OFFSET(HEK, hek_key[0])
ff68c719	321	#define HEK_HASH(hek) (hek)->hek_hash
	322	#define HEK_LEN(hek) (hek)->hek_len
	323	#define HEK_KEY(hek) (hek)->hek_key
19692e8d	324	#define HEK_FLAGS(hek) (((unsigned char )(HEK_KEY(hek))+HEK_LEN(hek)+1))
	325
	326	#define HVhek_UTF8 0x01 /* Key is utf8 encoded. */
	327	#define HVhek_WASUTF8 0x02 /* Key is bytes here, but was supplied as utf8. */
4b5190b5	328	#define HVhek_REHASH 0x04 /* This key is in an hv using a custom HASH . */
19692e8d	329	#define HVhek_FREEKEY 0x100 /* Internal flag to say key is malloc()ed. */
e16e2ff8	330	#define HVhek_PLACEHOLD 0x200 /* Internal flag to create placeholder.
e16e2ff8	331	* (may change, but Storable is a core module) */
19692e8d	332	#define HVhek_MASK 0xFF
19692e8d	333
fdcd69b6	334	/* Which flags enable HvHASKFLAGS? Somewhat a hack on a hack, as
	335	HVhek_REHASH is only needed because the rehash flag has to be duplicated
	336	into all keys as hv_iternext has no access to the hash flags. At this
	337	point Storable's tests get upset, because sometimes hashes are "keyed"
	338	and sometimes not, depending on the order of data insertion, and whether
	339	it triggered rehashing. So currently HVhek_REHAS is exempt.
	340	*/
	341
	342	#define HVhek_ENABLEHVKFLAGS (HVhek_MASK - HVhek_REHASH)
	343
19692e8d	344	#define HEK_UTF8(hek) (HEK_FLAGS(hek) & HVhek_UTF8)
	345	#define HEK_UTF8_on(hek) (HEK_FLAGS(hek) \|= HVhek_UTF8)
	346	#define HEK_UTF8_off(hek) (HEK_FLAGS(hek) &= ~HVhek_UTF8)
	347	#define HEK_WASUTF8(hek) (HEK_FLAGS(hek) & HVhek_WASUTF8)
	348	#define HEK_WASUTF8_on(hek) (HEK_FLAGS(hek) \|= HVhek_WASUTF8)
	349	#define HEK_WASUTF8_off(hek) (HEK_FLAGS(hek) &= ~HVhek_WASUTF8)
4b5190b5	350	#define HEK_REHASH(hek) (HEK_FLAGS(hek) & HVhek_REHASH)
4b5190b5	351	#define HEK_REHASH_on(hek) (HEK_FLAGS(hek) \|= HVhek_REHASH)
d18c6117	352
5cbe4eec	353	/* calculate HV array allocation */
36768cf4	354	#ifndef PERL_USE_LARGE_HV_ALLOC
	355	/* Default to allocating the correct size - default to assuming that malloc()
	356	is not broken and is efficient at allocating blocks sized at powers-of-two.
	357	*/
d18c6117	358	# define PERL_HV_ARRAY_ALLOC_BYTES(size) ((size) * sizeof(HE*))
	359	#else
	360	# define MALLOC_OVERHEAD 16
	361	# define PERL_HV_ARRAY_ALLOC_BYTES(size) \
	362	(((size) < 64) \
	363	? (size) * sizeof(HE*) \
	364	: (size) * sizeof(HE) 2 - MALLOC_OVERHEAD)
	365	#endif
37d85e3a	366
e16e2ff8	367	/* Flags for hv_iternext_flags. */
	368	#define HV_ITERNEXT_WANTPLACEHOLDERS 0x01 /* Don't skip placeholders. */
	369
37d85e3a	370	/* available as a function in hv.c */
	371	#define Perl_sharepvn(sv, len, hash) HEK_KEY(share_hek(sv, len, hash))
	372	#define sharepvn(sv, len, hash) Perl_sharepvn(sv, len, hash)
bfcb3514	373
	374	/*
	375	* Local variables:
	376	* c-indentation-style: bsd
	377	* c-basic-offset: 4
	378	* indent-tabs-mode: t
	379	* End:
	380	*
	381	* ex: set ts=8 sts=4 sw=4 noet:
	382	*/