[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 */
};

#define HV_AUX_SIZE STRUCT_OFFSET(struct xpvhv_aux, xhv_array)

/* 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 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
/* 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.  */

/* 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
b79f7545	42	#define HV_AUX_SIZE STRUCT_OFFSET(struct xpvhv_aux, xhv_array)
b79f7545	43
5cbe4eec	44	/* hash structure: */
6ee623d5	45	/* This structure must match the beginning of struct xpvmg in sv.h. */
79072805	46	struct xpvhv {
311a25d9	47	NV xnv_nv; /* numeric value, if any */
463ee0b2	48	STRLEN xhv_fill; /* how full xhv_array currently is */
463ee0b2	49	STRLEN xhv_max; /* subscript of last element of xhv_array */
e4305a63	50	union {
311a25d9	51	IV xivu_iv; /* integer value or pv offset */
	52	UV xivu_uv;
	53	void * xivu_p1;
	54	} xiv_u;
79072805	55	MAGIC* xmg_magic; /* magic for scalar array */
79072805	56	HV* xmg_stash; /* class package */
79072805	57	};
79072805	58
311a25d9	59	#define xhv_keys xiv_u.xivu_iv
e4305a63	60
c5f87f51	61	#if 0
59813432	62	typedef struct xpvhv xpvhv_allocated;
9f1501b2	63	#else
	64	typedef struct {
	65	STRLEN xhv_fill; /* how full xhv_array currently is */
	66	STRLEN xhv_max; /* subscript of last element of xhv_array */
	67	union {
311a25d9	68	IV xivu_iv; /* integer value or pv offset */
	69	UV xivu_uv;
	70	void * xivu_p1;
	71	} xiv_u;
9f1501b2	72	MAGIC* xmg_magic; /* magic for scalar array */
	73	HV* xmg_stash; /* class package */
	74	} xpvhv_allocated;
	75	#endif
e4305a63	76
5cbe4eec	77	/* hash a key */
5afd6d42	78	/* FYI: This is the "One-at-a-Time" algorithm by Bob Jenkins
	79	* from requirements by Colin Plumb.
	80	* (http://burtleburtle.net/bob/hash/doobs.html) */
	81	/* The use of a temporary pointer and the casting games
	82	* is needed to serve the dual purposes of
	83	* (a) the hashed data being interpreted as "unsigned char" (new since 5.8,
	84	* a "char" can be either signed or signed, depending on the compiler)
	85	* (b) catering for old code that uses a "char"
830b38bd	86	*
504f80c1	87	* The "hash seed" feature was added in Perl 5.8.1 to perturb the results
504f80c1	88	* to avoid "algorithmic complexity attacks".
830b38bd	89	*
	90	* If USE_HASH_SEED is defined, hash randomisation is done by default
	91	* If USE_HASH_SEED_EXPLICIT is defined, hash randomisation is done
	92	* only if the environment variable PERL_HASH_SEED is set.
	93	* For maximal control, one can define PERL_HASH_SEED.
90ce55a1	94	* (see also perl.c:perl_parse()).
5afd6d42	95	*/
830b38bd	96	#ifndef PERL_HASH_SEED
	97	# if defined(USE_HASH_SEED) \|\| defined(USE_HASH_SEED_EXPLICIT)
	98	# define PERL_HASH_SEED PL_hash_seed
	99	# else
	100	# define PERL_HASH_SEED 0
	101	# endif
504f80c1	102	#endif
bf6bd887	103	#define PERL_HASH(hash,str,len) \
bf6bd887	104	STMT_START { \
5afd6d42	105	register const char *s_PeRlHaSh_tmp = str; \
5afd6d42	106	register const unsigned char s_PeRlHaSh = (const unsigned char )s_PeRlHaSh_tmp; \
bf6bd887	107	register I32 i_PeRlHaSh = len; \
504f80c1	108	register U32 hash_PeRlHaSh = PERL_HASH_SEED; \
a6fe520e	109	while (i_PeRlHaSh--) { \
	110	hash_PeRlHaSh += *s_PeRlHaSh++; \
	111	hash_PeRlHaSh += (hash_PeRlHaSh << 10); \
	112	hash_PeRlHaSh ^= (hash_PeRlHaSh >> 6); \
	113	} \
	114	hash_PeRlHaSh += (hash_PeRlHaSh << 3); \
	115	hash_PeRlHaSh ^= (hash_PeRlHaSh >> 11); \
4fee5c71	116	(hash) = (hash_PeRlHaSh + (hash_PeRlHaSh << 15)); \
bf6bd887	117	} STMT_END
bf6bd887	118
3d78eb94	119	/* Only hv.c and mod_perl should be doing this. */
3d78eb94	120	#ifdef PERL_HASH_INTERNAL_ACCESS
4b5190b5	121	#define PERL_HASH_INTERNAL(hash,str,len) \
	122	STMT_START { \
	123	register const char *s_PeRlHaSh_tmp = str; \
	124	register const unsigned char s_PeRlHaSh = (const unsigned char )s_PeRlHaSh_tmp; \
	125	register I32 i_PeRlHaSh = len; \
008fb0c0	126	register U32 hash_PeRlHaSh = PL_rehash_seed; \
4b5190b5	127	while (i_PeRlHaSh--) { \
	128	hash_PeRlHaSh += *s_PeRlHaSh++; \
	129	hash_PeRlHaSh += (hash_PeRlHaSh << 10); \
	130	hash_PeRlHaSh ^= (hash_PeRlHaSh >> 6); \
	131	} \
	132	hash_PeRlHaSh += (hash_PeRlHaSh << 3); \
	133	hash_PeRlHaSh ^= (hash_PeRlHaSh >> 11); \
	134	(hash) = (hash_PeRlHaSh + (hash_PeRlHaSh << 15)); \
	135	} STMT_END
	136	#endif
	137
954c1994	138	/*
ccfc67b7	139	=head1 Hash Manipulation Functions
ccfc67b7	140
954c1994	141	=for apidoc AmU\|\|HEf_SVKEY
954c1994	142	This flag, used in the length slot of hash entries and magic structures,
d1be9408	143	specifies the structure contains an C<SV> pointer where a C<char> pointer
954c1994	144	is to be expected. (For information only--not to be used).
954c1994	145
ccfc67b7	146	=head1 Handy Values
ccfc67b7	147
954c1994	148	=for apidoc AmU\|\|Nullhv
	149	Null HV pointer.
	150
ccfc67b7	151	=head1 Hash Manipulation Functions
ccfc67b7	152
954c1994	153	=for apidoc Am\|char\|HvNAME\|HV stash
	154	Returns the package name of a stash. See C<SvSTASH>, C<CvSTASH>.
	155
	156	=for apidoc Am\|void\|HeKEY\|HE he
	157	Returns the actual pointer stored in the key slot of the hash entry. The
	158	pointer may be either C<char> or C<SV>, depending on the value of
	159	C<HeKLEN()>. Can be assigned to. The C<HePV()> or C<HeSVKEY()> macros are
	160	usually preferable for finding the value of a key.
	161
	162	=for apidoc Am\|STRLEN\|HeKLEN\|HE* he
	163	If this is negative, and amounts to C<HEf_SVKEY>, it indicates the entry
	164	holds an C<SV*> key. Otherwise, holds the actual length of the key. Can
	165	be assigned to. The C<HePV()> macro is usually preferable for finding key
	166	lengths.
	167
	168	=for apidoc Am\|SV\|HeVAL\|HE he
	169	Returns the value slot (type C<SV*>) stored in the hash entry.
	170
	171	=for apidoc Am\|U32\|HeHASH\|HE* he
	172	Returns the computed hash stored in the hash entry.
	173
	174	=for apidoc Am\|char\|HePV\|HE he\|STRLEN len
	175	Returns the key slot of the hash entry as a C<char*> value, doing any
	176	necessary dereferencing of possibly C<SV*> keys. The length of the string
	177	is placed in C<len> (this is a macro, so do I<not> use C<&len>). If you do
	178	not care about what the length of the key is, you may use the global
	179	variable C<PL_na>, though this is rather less efficient than using a local
	180	variable. Remember though, that hash keys in perl are free to contain
	181	embedded nulls, so using C<strlen()> or similar is not a good way to find
	182	the length of hash keys. This is very similar to the C<SvPV()> macro
	183	described elsewhere in this document.
	184
	185	=for apidoc Am\|SV\|HeSVKEY\|HE he
	186	Returns the key as an C<SV*>, or C<Nullsv> if the hash entry does not
	187	contain an C<SV*> key.
	188
	189	=for apidoc Am\|SV\|HeSVKEY_force\|HE he
	190	Returns the key as an C<SV*>. Will create and return a temporary mortal
	191	C<SV> if the hash entry contains only a C<char> key.
	192
	193	=for apidoc Am\|SV\|HeSVKEY_set\|HE he\|SV* sv
	194	Sets the key to a given C<SV*>, taking care to set the appropriate flags to
	195	indicate the presence of an C<SV*> key, and returns the same
	196	C<SV*>.
	197
	198	=cut
	199	*/
bf6bd887	200
bf5b86ae	201	/* these hash entry flags ride on hent_klen (for use only in magic/tied HVs) */
d1be9408	202	#define HEf_SVKEY -2 /* hent_key is an SV* */
bf6bd887	203
bf6bd887	204
79072805	205	#define Nullhv Null(HV*)
339049b0	206	#define HvARRAY(hv) ((HE**)&((hv)->sv_u.svu_array))
79072805	207	#define HvFILL(hv) ((XPVHV*) SvANY(hv))->xhv_fill
463ee0b2	208	#define HvMAX(hv) ((XPVHV*) SvANY(hv))->xhv_max
b79f7545	209	/* This quite intentionally does no flag checking first. That's your
	210	responsibility. */
	211	#define HvAUX(hv) ((struct xpvhv_aux*)&(HvARRAY(hv)[HvMAX(hv)+1]))
bfcb3514	212	#define HvRITER(hv) (Perl_hv_riter_p(aTHX_ (HV)(hv)))
	213	#define HvEITER(hv) (Perl_hv_eiter_p(aTHX_ (HV)(hv)))
	214	#define HvRITER_set(hv,r) Perl_hv_riter_set(aTHX_ (HV*)(hv), r)
	215	#define HvEITER_set(hv,e) Perl_hv_eiter_set(aTHX_ (HV*)(hv), e)
b79f7545	216	#define HvRITER_get(hv) (SvOOK(hv) ? HvAUX(hv)->xhv_riter : -1)
b79f7545	217	#define HvEITER_get(hv) (SvOOK(hv) ? HvAUX(hv)->xhv_eiter : 0)
7423f6db	218	#define HvNAME(hv) HvNAME_get(hv)
bfcb3514	219	/* FIXME - all of these should use a UTF8 aware API, which should also involve
bfcb3514	220	getting the length. */
9b9d0b15	221	/* This macro may go away without notice. */
b79f7545	222	#define HvNAME_HEK(hv) (SvOOK(hv) ? HvAUX(hv)->xhv_name : 0)
	223	#define HvNAME_get(hv) ((SvOOK(hv) && (HvAUX(hv)->xhv_name)) \
	224	? HEK_KEY(HvAUX(hv)->xhv_name) : 0)
	225	#define HvNAMELEN_get(hv) ((SvOOK(hv) && (HvAUX(hv)->xhv_name)) \
	226	? HEK_LEN(HvAUX(hv)->xhv_name) : 0)
a0d0e21e	227
8aacddc1	228	/* the number of keys (including any placeholers) */
	229	#define XHvTOTALKEYS(xhv) ((xhv)->xhv_keys)
	230
8aacddc1	231	/*
	232	* HvKEYS gets the number of keys that actually exist(), and is provided
	233	* for backwards compatibility with old XS code. The core uses HvUSEDKEYS
	234	* (keys, excluding placeholdes) and HvTOTALKEYS (including placeholders)
	235	*/
ca732855	236	#define HvKEYS(hv) HvUSEDKEYS(hv)
ca732855	237	#define HvUSEDKEYS(hv) (HvTOTALKEYS(hv) - HvPLACEHOLDERS_get(hv))
8aacddc1	238	#define HvTOTALKEYS(hv) XHvTOTALKEYS((XPVHV*) SvANY(hv))
ca732855	239	#define HvPLACEHOLDERS(hv) (Perl_hv_placeholders_p(aTHX_ (HV)hv))
	240	#define HvPLACEHOLDERS_get(hv) (SvMAGIC(hv) ? Perl_hv_placeholders_get(aTHX_ (HV*)hv) : 0)
	241	#define HvPLACEHOLDERS_set(hv,p) Perl_hv_placeholders_set(aTHX_ (HV*)hv, p)
8aacddc1	242
bf6bd887	243	#define HvSHAREKEYS(hv) (SvFLAGS(hv) & SVphv_SHAREKEYS)
	244	#define HvSHAREKEYS_on(hv) (SvFLAGS(hv) \|= SVphv_SHAREKEYS)
	245	#define HvSHAREKEYS_off(hv) (SvFLAGS(hv) &= ~SVphv_SHAREKEYS)
	246
19692e8d	247	/* This is an optimisation flag. It won't be set if all hash keys have a 0
	248	* flag. Currently the only flags relate to utf8.
	249	* Hence it won't be set if all keys are 8 bit only. It will be set if any key
	250	* is utf8 (including 8 bit keys that were entered as utf8, and need upgrading
	251	* when retrieved during iteration. It may still be set when there are no longer
	252	* any utf8 keys.
fdcd69b6	253	* See HVhek_ENABLEHVKFLAGS for the trigger.
19692e8d	254	*/
	255	#define HvHASKFLAGS(hv) (SvFLAGS(hv) & SVphv_HASKFLAGS)
	256	#define HvHASKFLAGS_on(hv) (SvFLAGS(hv) \|= SVphv_HASKFLAGS)
	257	#define HvHASKFLAGS_off(hv) (SvFLAGS(hv) &= ~SVphv_HASKFLAGS)
574c8022	258
bf5b86ae	259	#define HvLAZYDEL(hv) (SvFLAGS(hv) & SVphv_LAZYDEL)
	260	#define HvLAZYDEL_on(hv) (SvFLAGS(hv) \|= SVphv_LAZYDEL)
	261	#define HvLAZYDEL_off(hv) (SvFLAGS(hv) &= ~SVphv_LAZYDEL)
	262
4b5190b5	263	#define HvREHASH(hv) (SvFLAGS(hv) & SVphv_REHASH)
	264	#define HvREHASH_on(hv) (SvFLAGS(hv) \|= SVphv_REHASH)
	265	#define HvREHASH_off(hv) (SvFLAGS(hv) &= ~SVphv_REHASH)
	266
a0d0e21e	267	/* Maybe amagical: */
	268	/* #define HV_AMAGICmb(hv) (SvFLAGS(hv) & (SVpgv_badAM \| SVpgv_AM)) */
	269
	270	#define HV_AMAGIC(hv) (SvFLAGS(hv) & SVpgv_AM)
	271	#define HV_AMAGIC_on(hv) (SvFLAGS(hv) \|= SVpgv_AM)
	272	#define HV_AMAGIC_off(hv) (SvFLAGS(hv) &= ~SVpgv_AM)
	273
	274	/*
	275	#define HV_AMAGICbad(hv) (SvFLAGS(hv) & SVpgv_badAM)
	276	#define HV_badAMAGIC_on(hv) (SvFLAGS(hv) \|= SVpgv_badAM)
	277	#define HV_badAMAGIC_off(hv) (SvFLAGS(hv) &= ~SVpgv_badAM)
	278	*/
bf6bd887	279
	280	#define Nullhe Null(HE*)
	281	#define HeNEXT(he) (he)->hent_next
ff68c719	282	#define HeKEY_hek(he) (he)->hent_hek
ff68c719	283	#define HeKEY(he) HEK_KEY(HeKEY_hek(he))
bbce6d69	284	#define HeKEY_sv(he) ((SV*)HeKEY(he))
ff68c719	285	#define HeKLEN(he) HEK_LEN(HeKEY_hek(he))
da58a35d	286	#define HeKUTF8(he) HEK_UTF8(HeKEY_hek(he))
19692e8d	287	#define HeKWASUTF8(he) HEK_WASUTF8(HeKEY_hek(he))
4b5190b5	288	#define HeKREHASH(he) HEK_REHASH(HeKEY_hek(he))
da58a35d	289	#define HeKLEN_UTF8(he) (HeKUTF8(he) ? -HeKLEN(he) : HeKLEN(he))
19692e8d	290	#define HeKFLAGS(he) HEK_FLAGS(HeKEY_hek(he))
bf6bd887	291	#define HeVAL(he) (he)->hent_val
ff68c719	292	#define HeHASH(he) HEK_HASH(HeKEY_hek(he))
1e422769	293	#define HePV(he,lp) ((HeKLEN(he) == HEf_SVKEY) ? \
	294	SvPV(HeKEY_sv(he),lp) : \
	295	(((lp = HeKLEN(he)) >= 0) ? \
	296	HeKEY(he) : Nullch))
	297
bbce6d69	298	#define HeSVKEY(he) ((HeKEY(he) && \
	299	HeKLEN(he) == HEf_SVKEY) ? \
	300	HeKEY_sv(he) : Nullsv)
	301
	302	#define HeSVKEY_force(he) (HeKEY(he) ? \
	303	((HeKLEN(he) == HEf_SVKEY) ? \
	304	HeKEY_sv(he) : \
79cb57f6	305	sv_2mortal(newSVpvn(HeKEY(he), \
bbce6d69	306	HeKLEN(he)))) : \
3280af22	307	&PL_sv_undef)
1e422769	308	#define HeSVKEY_set(he,sv) ((HeKLEN(he) = HEf_SVKEY), (HeKEY_sv(he) = sv))
bbce6d69	309
ff68c719	310	#define Nullhek Null(HEK*)
71be2cbc	311	#define HEK_BASESIZE STRUCT_OFFSET(HEK, hek_key[0])
ff68c719	312	#define HEK_HASH(hek) (hek)->hek_hash
	313	#define HEK_LEN(hek) (hek)->hek_len
	314	#define HEK_KEY(hek) (hek)->hek_key
19692e8d	315	#define HEK_FLAGS(hek) (((unsigned char )(HEK_KEY(hek))+HEK_LEN(hek)+1))
	316
	317	#define HVhek_UTF8 0x01 /* Key is utf8 encoded. */
	318	#define HVhek_WASUTF8 0x02 /* Key is bytes here, but was supplied as utf8. */
4b5190b5	319	#define HVhek_REHASH 0x04 /* This key is in an hv using a custom HASH . */
19692e8d	320	#define HVhek_FREEKEY 0x100 /* Internal flag to say key is malloc()ed. */
e16e2ff8	321	#define HVhek_PLACEHOLD 0x200 /* Internal flag to create placeholder.
e16e2ff8	322	* (may change, but Storable is a core module) */
19692e8d	323	#define HVhek_MASK 0xFF
19692e8d	324
fdcd69b6	325	/* Which flags enable HvHASKFLAGS? Somewhat a hack on a hack, as
	326	HVhek_REHASH is only needed because the rehash flag has to be duplicated
	327	into all keys as hv_iternext has no access to the hash flags. At this
	328	point Storable's tests get upset, because sometimes hashes are "keyed"
	329	and sometimes not, depending on the order of data insertion, and whether
	330	it triggered rehashing. So currently HVhek_REHAS is exempt.
	331	*/
	332
	333	#define HVhek_ENABLEHVKFLAGS (HVhek_MASK - HVhek_REHASH)
	334
19692e8d	335	#define HEK_UTF8(hek) (HEK_FLAGS(hek) & HVhek_UTF8)
	336	#define HEK_UTF8_on(hek) (HEK_FLAGS(hek) \|= HVhek_UTF8)
	337	#define HEK_UTF8_off(hek) (HEK_FLAGS(hek) &= ~HVhek_UTF8)
	338	#define HEK_WASUTF8(hek) (HEK_FLAGS(hek) & HVhek_WASUTF8)
	339	#define HEK_WASUTF8_on(hek) (HEK_FLAGS(hek) \|= HVhek_WASUTF8)
	340	#define HEK_WASUTF8_off(hek) (HEK_FLAGS(hek) &= ~HVhek_WASUTF8)
4b5190b5	341	#define HEK_REHASH(hek) (HEK_FLAGS(hek) & HVhek_REHASH)
4b5190b5	342	#define HEK_REHASH_on(hek) (HEK_FLAGS(hek) \|= HVhek_REHASH)
d18c6117	343
5cbe4eec	344	/* calculate HV array allocation */
36768cf4	345	#ifndef PERL_USE_LARGE_HV_ALLOC
	346	/* Default to allocating the correct size - default to assuming that malloc()
	347	is not broken and is efficient at allocating blocks sized at powers-of-two.
	348	*/
d18c6117	349	# define PERL_HV_ARRAY_ALLOC_BYTES(size) ((size) * sizeof(HE*))
	350	#else
	351	# define MALLOC_OVERHEAD 16
	352	# define PERL_HV_ARRAY_ALLOC_BYTES(size) \
	353	(((size) < 64) \
	354	? (size) * sizeof(HE*) \
	355	: (size) * sizeof(HE) 2 - MALLOC_OVERHEAD)
	356	#endif
37d85e3a	357
e16e2ff8	358	/* Flags for hv_iternext_flags. */
	359	#define HV_ITERNEXT_WANTPLACEHOLDERS 0x01 /* Don't skip placeholders. */
	360
37d85e3a	361	/* available as a function in hv.c */
	362	#define Perl_sharepvn(sv, len, hash) HEK_KEY(share_hek(sv, len, hash))
	363	#define sharepvn(sv, len, hash) Perl_sharepvn(sv, len, hash)
bfcb3514	364
	365	/*
	366	* Local variables:
	367	* c-indentation-style: bsd
	368	* c-basic-offset: 4
	369	* indent-tabs-mode: t
	370	* End:
	371	*
	372	* ex: set ts=8 sts=4 sw=4 noet:
	373	*/