[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 {
    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 */
    struct xpvhv_aux *xhv_aux;
};

#define xhv_keys xiv_u.xivu_iv

#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 {
	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 */
    struct xpvhv_aux *xhv_aux;
} 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 {
311a25d9	45	NV xnv_nv; /* numeric value, if any */
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 {
311a25d9	49	IV xivu_iv; /* integer value or pv offset */
	50	UV xivu_uv;
	51	void * xivu_p1;
	52	} xiv_u;
79072805	53	MAGIC* xmg_magic; /* magic for scalar array */
79072805	54	HV* xmg_stash; /* class package */
311a25d9	55	struct xpvhv_aux *xhv_aux;
79072805	56	};
79072805	57
311a25d9	58	#define xhv_keys xiv_u.xivu_iv
e4305a63	59
209b62a3	60	#if !defined(PERL_EXPERIMENTAL_LAYOUT)
59813432	61	typedef struct xpvhv xpvhv_allocated;
9f1501b2	62	#else
	63	typedef struct {
	64	STRLEN xhv_fill; /* how full xhv_array currently is */
	65	STRLEN xhv_max; /* subscript of last element of xhv_array */
	66	union {
311a25d9	67	IV xivu_iv; /* integer value or pv offset */
	68	UV xivu_uv;
	69	void * xivu_p1;
	70	} xiv_u;
9f1501b2	71	MAGIC* xmg_magic; /* magic for scalar array */
9f1501b2	72	HV* xmg_stash; /* class package */
311a25d9	73	struct xpvhv_aux *xhv_aux;
9f1501b2	74	} xpvhv_allocated;
9f1501b2	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
bfcb3514	209	#define HvRITER(hv) (Perl_hv_riter_p(aTHX_ (HV)(hv)))
	210	#define HvEITER(hv) (Perl_hv_eiter_p(aTHX_ (HV)(hv)))
	211	#define HvRITER_set(hv,r) Perl_hv_riter_set(aTHX_ (HV*)(hv), r)
	212	#define HvEITER_set(hv,e) Perl_hv_eiter_set(aTHX_ (HV*)(hv), e)
	213	#define HvRITER_get(hv) (((XPVHV *)SvANY(hv))->xhv_aux ? \
	214	((struct xpvhv_aux)((XPVHV )SvANY(hv))->xhv_aux)->xhv_riter : -1)
	215	#define HvEITER_get(hv) (((XPVHV *)SvANY(hv))->xhv_aux ? \
	216	((struct xpvhv_aux )((XPVHV )SvANY(hv))->xhv_aux)->xhv_eiter : 0)
7423f6db	217	#define HvNAME(hv) HvNAME_get(hv)
bfcb3514	218	/* FIXME - all of these should use a UTF8 aware API, which should also involve
bfcb3514	219	getting the length. */
9b9d0b15	220	/* This macro may go away without notice. */
9b9d0b15	221	#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	222	#define HvNAME_get(hv) (((XPVHV *)SvANY(hv))->xhv_aux ? \
7423f6db	223	(((struct xpvhv_aux )((XPVHV )SvANY(hv))->xhv_aux)->xhv_name) ? HEK_KEY(((struct xpvhv_aux )((XPVHV )SvANY(hv))->xhv_aux)->xhv_name) : 0 : 0)
	224	#define HvNAMELEN_get(hv) (((XPVHV *)SvANY(hv))->xhv_aux ? \
	225	(((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	226
8aacddc1	227	/* the number of keys (including any placeholers) */
	228	#define XHvTOTALKEYS(xhv) ((xhv)->xhv_keys)
	229
8aacddc1	230	/*
	231	* HvKEYS gets the number of keys that actually exist(), and is provided
	232	* for backwards compatibility with old XS code. The core uses HvUSEDKEYS
	233	* (keys, excluding placeholdes) and HvTOTALKEYS (including placeholders)
	234	*/
ca732855	235	#define HvKEYS(hv) HvUSEDKEYS(hv)
ca732855	236	#define HvUSEDKEYS(hv) (HvTOTALKEYS(hv) - HvPLACEHOLDERS_get(hv))
8aacddc1	237	#define HvTOTALKEYS(hv) XHvTOTALKEYS((XPVHV*) SvANY(hv))
ca732855	238	#define HvPLACEHOLDERS(hv) (Perl_hv_placeholders_p(aTHX_ (HV)hv))
	239	#define HvPLACEHOLDERS_get(hv) (SvMAGIC(hv) ? Perl_hv_placeholders_get(aTHX_ (HV*)hv) : 0)
	240	#define HvPLACEHOLDERS_set(hv,p) Perl_hv_placeholders_set(aTHX_ (HV*)hv, p)
8aacddc1	241
bf6bd887	242	#define HvSHAREKEYS(hv) (SvFLAGS(hv) & SVphv_SHAREKEYS)
	243	#define HvSHAREKEYS_on(hv) (SvFLAGS(hv) \|= SVphv_SHAREKEYS)
	244	#define HvSHAREKEYS_off(hv) (SvFLAGS(hv) &= ~SVphv_SHAREKEYS)
	245
19692e8d	246	/* This is an optimisation flag. It won't be set if all hash keys have a 0
	247	* flag. Currently the only flags relate to utf8.
	248	* Hence it won't be set if all keys are 8 bit only. It will be set if any key
	249	* is utf8 (including 8 bit keys that were entered as utf8, and need upgrading
	250	* when retrieved during iteration. It may still be set when there are no longer
	251	* any utf8 keys.
fdcd69b6	252	* See HVhek_ENABLEHVKFLAGS for the trigger.
19692e8d	253	*/
	254	#define HvHASKFLAGS(hv) (SvFLAGS(hv) & SVphv_HASKFLAGS)
	255	#define HvHASKFLAGS_on(hv) (SvFLAGS(hv) \|= SVphv_HASKFLAGS)
	256	#define HvHASKFLAGS_off(hv) (SvFLAGS(hv) &= ~SVphv_HASKFLAGS)
574c8022	257
bf5b86ae	258	#define HvLAZYDEL(hv) (SvFLAGS(hv) & SVphv_LAZYDEL)
	259	#define HvLAZYDEL_on(hv) (SvFLAGS(hv) \|= SVphv_LAZYDEL)
	260	#define HvLAZYDEL_off(hv) (SvFLAGS(hv) &= ~SVphv_LAZYDEL)
	261
4b5190b5	262	#define HvREHASH(hv) (SvFLAGS(hv) & SVphv_REHASH)
	263	#define HvREHASH_on(hv) (SvFLAGS(hv) \|= SVphv_REHASH)
	264	#define HvREHASH_off(hv) (SvFLAGS(hv) &= ~SVphv_REHASH)
	265
a0d0e21e	266	/* Maybe amagical: */
	267	/* #define HV_AMAGICmb(hv) (SvFLAGS(hv) & (SVpgv_badAM \| SVpgv_AM)) */
	268
	269	#define HV_AMAGIC(hv) (SvFLAGS(hv) & SVpgv_AM)
	270	#define HV_AMAGIC_on(hv) (SvFLAGS(hv) \|= SVpgv_AM)
	271	#define HV_AMAGIC_off(hv) (SvFLAGS(hv) &= ~SVpgv_AM)
	272
	273	/*
	274	#define HV_AMAGICbad(hv) (SvFLAGS(hv) & SVpgv_badAM)
	275	#define HV_badAMAGIC_on(hv) (SvFLAGS(hv) \|= SVpgv_badAM)
	276	#define HV_badAMAGIC_off(hv) (SvFLAGS(hv) &= ~SVpgv_badAM)
	277	*/
bf6bd887	278
	279	#define Nullhe Null(HE*)
	280	#define HeNEXT(he) (he)->hent_next
ff68c719	281	#define HeKEY_hek(he) (he)->hent_hek
ff68c719	282	#define HeKEY(he) HEK_KEY(HeKEY_hek(he))
bbce6d69	283	#define HeKEY_sv(he) ((SV*)HeKEY(he))
ff68c719	284	#define HeKLEN(he) HEK_LEN(HeKEY_hek(he))
da58a35d	285	#define HeKUTF8(he) HEK_UTF8(HeKEY_hek(he))
19692e8d	286	#define HeKWASUTF8(he) HEK_WASUTF8(HeKEY_hek(he))
4b5190b5	287	#define HeKREHASH(he) HEK_REHASH(HeKEY_hek(he))
da58a35d	288	#define HeKLEN_UTF8(he) (HeKUTF8(he) ? -HeKLEN(he) : HeKLEN(he))
19692e8d	289	#define HeKFLAGS(he) HEK_FLAGS(HeKEY_hek(he))
bf6bd887	290	#define HeVAL(he) (he)->hent_val
ff68c719	291	#define HeHASH(he) HEK_HASH(HeKEY_hek(he))
1e422769	292	#define HePV(he,lp) ((HeKLEN(he) == HEf_SVKEY) ? \
	293	SvPV(HeKEY_sv(he),lp) : \
	294	(((lp = HeKLEN(he)) >= 0) ? \
	295	HeKEY(he) : Nullch))
	296
bbce6d69	297	#define HeSVKEY(he) ((HeKEY(he) && \
	298	HeKLEN(he) == HEf_SVKEY) ? \
	299	HeKEY_sv(he) : Nullsv)
	300
	301	#define HeSVKEY_force(he) (HeKEY(he) ? \
	302	((HeKLEN(he) == HEf_SVKEY) ? \
	303	HeKEY_sv(he) : \
79cb57f6	304	sv_2mortal(newSVpvn(HeKEY(he), \
bbce6d69	305	HeKLEN(he)))) : \
3280af22	306	&PL_sv_undef)
1e422769	307	#define HeSVKEY_set(he,sv) ((HeKLEN(he) = HEf_SVKEY), (HeKEY_sv(he) = sv))
bbce6d69	308
ff68c719	309	#define Nullhek Null(HEK*)
71be2cbc	310	#define HEK_BASESIZE STRUCT_OFFSET(HEK, hek_key[0])
ff68c719	311	#define HEK_HASH(hek) (hek)->hek_hash
	312	#define HEK_LEN(hek) (hek)->hek_len
	313	#define HEK_KEY(hek) (hek)->hek_key
19692e8d	314	#define HEK_FLAGS(hek) (((unsigned char )(HEK_KEY(hek))+HEK_LEN(hek)+1))
	315
	316	#define HVhek_UTF8 0x01 /* Key is utf8 encoded. */
	317	#define HVhek_WASUTF8 0x02 /* Key is bytes here, but was supplied as utf8. */
4b5190b5	318	#define HVhek_REHASH 0x04 /* This key is in an hv using a custom HASH . */
19692e8d	319	#define HVhek_FREEKEY 0x100 /* Internal flag to say key is malloc()ed. */
e16e2ff8	320	#define HVhek_PLACEHOLD 0x200 /* Internal flag to create placeholder.
e16e2ff8	321	* (may change, but Storable is a core module) */
19692e8d	322	#define HVhek_MASK 0xFF
19692e8d	323
fdcd69b6	324	/* Which flags enable HvHASKFLAGS? Somewhat a hack on a hack, as
	325	HVhek_REHASH is only needed because the rehash flag has to be duplicated
	326	into all keys as hv_iternext has no access to the hash flags. At this
	327	point Storable's tests get upset, because sometimes hashes are "keyed"
	328	and sometimes not, depending on the order of data insertion, and whether
	329	it triggered rehashing. So currently HVhek_REHAS is exempt.
	330	*/
	331
	332	#define HVhek_ENABLEHVKFLAGS (HVhek_MASK - HVhek_REHASH)
	333
19692e8d	334	#define HEK_UTF8(hek) (HEK_FLAGS(hek) & HVhek_UTF8)
	335	#define HEK_UTF8_on(hek) (HEK_FLAGS(hek) \|= HVhek_UTF8)
	336	#define HEK_UTF8_off(hek) (HEK_FLAGS(hek) &= ~HVhek_UTF8)
	337	#define HEK_WASUTF8(hek) (HEK_FLAGS(hek) & HVhek_WASUTF8)
	338	#define HEK_WASUTF8_on(hek) (HEK_FLAGS(hek) \|= HVhek_WASUTF8)
	339	#define HEK_WASUTF8_off(hek) (HEK_FLAGS(hek) &= ~HVhek_WASUTF8)
4b5190b5	340	#define HEK_REHASH(hek) (HEK_FLAGS(hek) & HVhek_REHASH)
4b5190b5	341	#define HEK_REHASH_on(hek) (HEK_FLAGS(hek) \|= HVhek_REHASH)
d18c6117	342
5cbe4eec	343	/* calculate HV array allocation */
36768cf4	344	#ifndef PERL_USE_LARGE_HV_ALLOC
	345	/* Default to allocating the correct size - default to assuming that malloc()
	346	is not broken and is efficient at allocating blocks sized at powers-of-two.
	347	*/
d18c6117	348	# define PERL_HV_ARRAY_ALLOC_BYTES(size) ((size) * sizeof(HE*))
	349	#else
	350	# define MALLOC_OVERHEAD 16
	351	# define PERL_HV_ARRAY_ALLOC_BYTES(size) \
	352	(((size) < 64) \
	353	? (size) * sizeof(HE*) \
	354	: (size) * sizeof(HE) 2 - MALLOC_OVERHEAD)
	355	#endif
37d85e3a	356
e16e2ff8	357	/* Flags for hv_iternext_flags. */
	358	#define HV_ITERNEXT_WANTPLACEHOLDERS 0x01 /* Don't skip placeholders. */
	359
37d85e3a	360	/* available as a function in hv.c */
	361	#define Perl_sharepvn(sv, len, hash) HEK_KEY(share_hek(sv, len, hash))
	362	#define sharepvn(sv, len, hash) Perl_sharepvn(sv, len, hash)
bfcb3514	363
	364	/*
	365	* Local variables:
	366	* c-indentation-style: bsd
	367	* c-basic-offset: 4
	368	* indent-tabs-mode: t
	369	* End:
	370	*
	371	* ex: set ts=8 sts=4 sw=4 noet:
	372	*/