[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.
 *
 */

/* entry in hash value chain */
struct he {
    /* Keep hent_next first in this structure, because sv_free_arenas take
       advantage of this to share code between the he arenas and the SV
       body arenas  */
    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 */
};

struct shared_he {
    struct he shared_he_he;
    struct hek shared_he_hek;
};

/* 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 */
};

#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 unsigned, 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, or NULL if C<stash> isn't 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)	((hv)->sv_u.svu_hash)
#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)

#define share_hek_hek(hek)						\
    (++(((struct shared_he *)(((char *)hek)				\
			      - STRUCT_OFFSET(struct shared_he,		\
					      shared_he_hek)))		\
	->shared_he_he.hent_val),					\
     hek)

/*
 * 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	/* entry in hash value chain */
79072805	12	struct he {
6f51351d	13	/* Keep hent_next first in this structure, because sv_free_arenas take
	14	advantage of this to share code between the he arenas and the SV
	15	body arenas */
5cbe4eec	16	HE hent_next; / next entry in chain */
	17	HEK hent_hek; / hash key */
	18	SV hent_val; / scalar value that was hashed */
bbce6d69	19	};
bbce6d69	20
5cbe4eec	21	/* hash key -- defined separately for use as shared pointer */
ff68c719	22	struct hek {
5cbe4eec	23	U32 hek_hash; /* hash of key */
	24	I32 hek_len; /* length of hash key */
	25	char hek_key[1]; /* variable-length hash key */
e05949c7	26	/* the hash-key is \0-terminated */
1e54db1a	27	/* after the \0 there is a byte for flags, such as whether the key
1e54db1a	28	is UTF-8 */
79072805	29	};
79072805	30
cbae3960	31	struct shared_he {
	32	struct he shared_he_he;
	33	struct hek shared_he_hek;
	34	};
bfcb3514	35
	36	/* Subject to change.
	37	Don't access this directly.
	38	*/
	39	struct xpvhv_aux {
7423f6db	40	HEK xhv_name; / name, if a symbol table */
bfcb3514	41	HE xhv_eiter; / current entry of iterator */
	42	I32 xhv_riter; /* current root of iterator */
	43	};
	44
5cbe4eec	45	/* hash structure: */
6ee623d5	46	/* This structure must match the beginning of struct xpvmg in sv.h. */
79072805	47	struct xpvhv {
311a25d9	48	NV xnv_nv; /* numeric value, if any */
463ee0b2	49	STRLEN xhv_fill; /* how full xhv_array currently is */
463ee0b2	50	STRLEN xhv_max; /* subscript of last element of xhv_array */
e4305a63	51	union {
311a25d9	52	IV xivu_iv; /* integer value or pv offset */
	53	UV xivu_uv;
	54	void * xivu_p1;
	55	} xiv_u;
79072805	56	MAGIC* xmg_magic; /* magic for scalar array */
79072805	57	HV* xmg_stash; /* class package */
79072805	58	};
79072805	59
311a25d9	60	#define xhv_keys xiv_u.xivu_iv
e4305a63	61
c5f87f51	62	#if 0
59813432	63	typedef struct xpvhv xpvhv_allocated;
9f1501b2	64	#else
	65	typedef struct {
	66	STRLEN xhv_fill; /* how full xhv_array currently is */
	67	STRLEN xhv_max; /* subscript of last element of xhv_array */
	68	union {
311a25d9	69	IV xivu_iv; /* integer value or pv offset */
	70	UV xivu_uv;
	71	void * xivu_p1;
	72	} xiv_u;
9f1501b2	73	MAGIC* xmg_magic; /* magic for scalar array */
	74	HV* xmg_stash; /* class package */
	75	} xpvhv_allocated;
	76	#endif
e4305a63	77
5cbe4eec	78	/* hash a key */
5afd6d42	79	/* FYI: This is the "One-at-a-Time" algorithm by Bob Jenkins
	80	* from requirements by Colin Plumb.
	81	* (http://burtleburtle.net/bob/hash/doobs.html) */
	82	/* The use of a temporary pointer and the casting games
	83	* is needed to serve the dual purposes of
	84	* (a) the hashed data being interpreted as "unsigned char" (new since 5.8,
df805c3e	85	* a "char" can be either signed or unsigned, depending on the compiler)
5afd6d42	86	* (b) catering for old code that uses a "char"
830b38bd	87	*
504f80c1	88	* The "hash seed" feature was added in Perl 5.8.1 to perturb the results
504f80c1	89	* to avoid "algorithmic complexity attacks".
830b38bd	90	*
	91	* If USE_HASH_SEED is defined, hash randomisation is done by default
	92	* If USE_HASH_SEED_EXPLICIT is defined, hash randomisation is done
	93	* only if the environment variable PERL_HASH_SEED is set.
	94	* For maximal control, one can define PERL_HASH_SEED.
90ce55a1	95	* (see also perl.c:perl_parse()).
5afd6d42	96	*/
830b38bd	97	#ifndef PERL_HASH_SEED
	98	# if defined(USE_HASH_SEED) \|\| defined(USE_HASH_SEED_EXPLICIT)
	99	# define PERL_HASH_SEED PL_hash_seed
	100	# else
	101	# define PERL_HASH_SEED 0
	102	# endif
504f80c1	103	#endif
bf6bd887	104	#define PERL_HASH(hash,str,len) \
bf6bd887	105	STMT_START { \
5afd6d42	106	register const char *s_PeRlHaSh_tmp = str; \
5afd6d42	107	register const unsigned char s_PeRlHaSh = (const unsigned char )s_PeRlHaSh_tmp; \
bf6bd887	108	register I32 i_PeRlHaSh = len; \
504f80c1	109	register U32 hash_PeRlHaSh = PERL_HASH_SEED; \
a6fe520e	110	while (i_PeRlHaSh--) { \
	111	hash_PeRlHaSh += *s_PeRlHaSh++; \
	112	hash_PeRlHaSh += (hash_PeRlHaSh << 10); \
	113	hash_PeRlHaSh ^= (hash_PeRlHaSh >> 6); \
	114	} \
	115	hash_PeRlHaSh += (hash_PeRlHaSh << 3); \
	116	hash_PeRlHaSh ^= (hash_PeRlHaSh >> 11); \
4fee5c71	117	(hash) = (hash_PeRlHaSh + (hash_PeRlHaSh << 15)); \
bf6bd887	118	} STMT_END
bf6bd887	119
3d78eb94	120	/* Only hv.c and mod_perl should be doing this. */
3d78eb94	121	#ifdef PERL_HASH_INTERNAL_ACCESS
4b5190b5	122	#define PERL_HASH_INTERNAL(hash,str,len) \
	123	STMT_START { \
	124	register const char *s_PeRlHaSh_tmp = str; \
	125	register const unsigned char s_PeRlHaSh = (const unsigned char )s_PeRlHaSh_tmp; \
	126	register I32 i_PeRlHaSh = len; \
008fb0c0	127	register U32 hash_PeRlHaSh = PL_rehash_seed; \
4b5190b5	128	while (i_PeRlHaSh--) { \
	129	hash_PeRlHaSh += *s_PeRlHaSh++; \
	130	hash_PeRlHaSh += (hash_PeRlHaSh << 10); \
	131	hash_PeRlHaSh ^= (hash_PeRlHaSh >> 6); \
	132	} \
	133	hash_PeRlHaSh += (hash_PeRlHaSh << 3); \
	134	hash_PeRlHaSh ^= (hash_PeRlHaSh >> 11); \
	135	(hash) = (hash_PeRlHaSh + (hash_PeRlHaSh << 15)); \
	136	} STMT_END
	137	#endif
	138
954c1994	139	/*
ccfc67b7	140	=head1 Hash Manipulation Functions
ccfc67b7	141
954c1994	142	=for apidoc AmU\|\|HEf_SVKEY
954c1994	143	This flag, used in the length slot of hash entries and magic structures,
d1be9408	144	specifies the structure contains an C<SV> pointer where a C<char> pointer
954c1994	145	is to be expected. (For information only--not to be used).
954c1994	146
ccfc67b7	147	=head1 Handy Values
ccfc67b7	148
954c1994	149	=for apidoc AmU\|\|Nullhv
	150	Null HV pointer.
	151
ccfc67b7	152	=head1 Hash Manipulation Functions
ccfc67b7	153
954c1994	154	=for apidoc Am\|char\|HvNAME\|HV stash
9282b5fd	155	Returns the package name of a stash, or NULL if C<stash> isn't a stash.
9282b5fd	156	See C<SvSTASH>, C<CvSTASH>.
954c1994	157
	158	=for apidoc Am\|void\|HeKEY\|HE he
	159	Returns the actual pointer stored in the key slot of the hash entry. The
	160	pointer may be either C<char> or C<SV>, depending on the value of
	161	C<HeKLEN()>. Can be assigned to. The C<HePV()> or C<HeSVKEY()> macros are
	162	usually preferable for finding the value of a key.
	163
	164	=for apidoc Am\|STRLEN\|HeKLEN\|HE* he
	165	If this is negative, and amounts to C<HEf_SVKEY>, it indicates the entry
	166	holds an C<SV*> key. Otherwise, holds the actual length of the key. Can
	167	be assigned to. The C<HePV()> macro is usually preferable for finding key
	168	lengths.
	169
	170	=for apidoc Am\|SV\|HeVAL\|HE he
	171	Returns the value slot (type C<SV*>) stored in the hash entry.
	172
	173	=for apidoc Am\|U32\|HeHASH\|HE* he
	174	Returns the computed hash stored in the hash entry.
	175
	176	=for apidoc Am\|char\|HePV\|HE he\|STRLEN len
	177	Returns the key slot of the hash entry as a C<char*> value, doing any
	178	necessary dereferencing of possibly C<SV*> keys. The length of the string
	179	is placed in C<len> (this is a macro, so do I<not> use C<&len>). If you do
	180	not care about what the length of the key is, you may use the global
	181	variable C<PL_na>, though this is rather less efficient than using a local
	182	variable. Remember though, that hash keys in perl are free to contain
	183	embedded nulls, so using C<strlen()> or similar is not a good way to find
	184	the length of hash keys. This is very similar to the C<SvPV()> macro
	185	described elsewhere in this document.
	186
	187	=for apidoc Am\|SV\|HeSVKEY\|HE he
	188	Returns the key as an C<SV*>, or C<Nullsv> if the hash entry does not
	189	contain an C<SV*> key.
	190
	191	=for apidoc Am\|SV\|HeSVKEY_force\|HE he
	192	Returns the key as an C<SV*>. Will create and return a temporary mortal
	193	C<SV> if the hash entry contains only a C<char> key.
	194
	195	=for apidoc Am\|SV\|HeSVKEY_set\|HE he\|SV* sv
	196	Sets the key to a given C<SV*>, taking care to set the appropriate flags to
	197	indicate the presence of an C<SV*> key, and returns the same
	198	C<SV*>.
	199
	200	=cut
	201	*/
bf6bd887	202
bf5b86ae	203	/* these hash entry flags ride on hent_klen (for use only in magic/tied HVs) */
d1be9408	204	#define HEf_SVKEY -2 /* hent_key is an SV* */
bf6bd887	205
bf6bd887	206
79072805	207	#define Nullhv Null(HV*)
43e6e717	208	#define HvARRAY(hv) ((hv)->sv_u.svu_hash)
79072805	209	#define HvFILL(hv) ((XPVHV*) SvANY(hv))->xhv_fill
463ee0b2	210	#define HvMAX(hv) ((XPVHV*) SvANY(hv))->xhv_max
b79f7545	211	/* This quite intentionally does no flag checking first. That's your
	212	responsibility. */
	213	#define HvAUX(hv) ((struct xpvhv_aux*)&(HvARRAY(hv)[HvMAX(hv)+1]))
bfcb3514	214	#define HvRITER(hv) (Perl_hv_riter_p(aTHX_ (HV)(hv)))
	215	#define HvEITER(hv) (Perl_hv_eiter_p(aTHX_ (HV)(hv)))
	216	#define HvRITER_set(hv,r) Perl_hv_riter_set(aTHX_ (HV*)(hv), r)
	217	#define HvEITER_set(hv,e) Perl_hv_eiter_set(aTHX_ (HV*)(hv), e)
b79f7545	218	#define HvRITER_get(hv) (SvOOK(hv) ? HvAUX(hv)->xhv_riter : -1)
b79f7545	219	#define HvEITER_get(hv) (SvOOK(hv) ? HvAUX(hv)->xhv_eiter : 0)
7423f6db	220	#define HvNAME(hv) HvNAME_get(hv)
bfcb3514	221	/* FIXME - all of these should use a UTF8 aware API, which should also involve
bfcb3514	222	getting the length. */
9b9d0b15	223	/* This macro may go away without notice. */
b79f7545	224	#define HvNAME_HEK(hv) (SvOOK(hv) ? HvAUX(hv)->xhv_name : 0)
	225	#define HvNAME_get(hv) ((SvOOK(hv) && (HvAUX(hv)->xhv_name)) \
	226	? HEK_KEY(HvAUX(hv)->xhv_name) : 0)
	227	#define HvNAMELEN_get(hv) ((SvOOK(hv) && (HvAUX(hv)->xhv_name)) \
	228	? HEK_LEN(HvAUX(hv)->xhv_name) : 0)
a0d0e21e	229
8aacddc1	230	/* the number of keys (including any placeholers) */
	231	#define XHvTOTALKEYS(xhv) ((xhv)->xhv_keys)
	232
8aacddc1	233	/*
	234	* HvKEYS gets the number of keys that actually exist(), and is provided
	235	* for backwards compatibility with old XS code. The core uses HvUSEDKEYS
	236	* (keys, excluding placeholdes) and HvTOTALKEYS (including placeholders)
	237	*/
ca732855	238	#define HvKEYS(hv) HvUSEDKEYS(hv)
ca732855	239	#define HvUSEDKEYS(hv) (HvTOTALKEYS(hv) - HvPLACEHOLDERS_get(hv))
8aacddc1	240	#define HvTOTALKEYS(hv) XHvTOTALKEYS((XPVHV*) SvANY(hv))
ca732855	241	#define HvPLACEHOLDERS(hv) (Perl_hv_placeholders_p(aTHX_ (HV)hv))
	242	#define HvPLACEHOLDERS_get(hv) (SvMAGIC(hv) ? Perl_hv_placeholders_get(aTHX_ (HV*)hv) : 0)
	243	#define HvPLACEHOLDERS_set(hv,p) Perl_hv_placeholders_set(aTHX_ (HV*)hv, p)
8aacddc1	244
bf6bd887	245	#define HvSHAREKEYS(hv) (SvFLAGS(hv) & SVphv_SHAREKEYS)
	246	#define HvSHAREKEYS_on(hv) (SvFLAGS(hv) \|= SVphv_SHAREKEYS)
	247	#define HvSHAREKEYS_off(hv) (SvFLAGS(hv) &= ~SVphv_SHAREKEYS)
	248
19692e8d	249	/* This is an optimisation flag. It won't be set if all hash keys have a 0
	250	* flag. Currently the only flags relate to utf8.
	251	* Hence it won't be set if all keys are 8 bit only. It will be set if any key
	252	* is utf8 (including 8 bit keys that were entered as utf8, and need upgrading
	253	* when retrieved during iteration. It may still be set when there are no longer
	254	* any utf8 keys.
fdcd69b6	255	* See HVhek_ENABLEHVKFLAGS for the trigger.
19692e8d	256	*/
	257	#define HvHASKFLAGS(hv) (SvFLAGS(hv) & SVphv_HASKFLAGS)
	258	#define HvHASKFLAGS_on(hv) (SvFLAGS(hv) \|= SVphv_HASKFLAGS)
	259	#define HvHASKFLAGS_off(hv) (SvFLAGS(hv) &= ~SVphv_HASKFLAGS)
574c8022	260
bf5b86ae	261	#define HvLAZYDEL(hv) (SvFLAGS(hv) & SVphv_LAZYDEL)
	262	#define HvLAZYDEL_on(hv) (SvFLAGS(hv) \|= SVphv_LAZYDEL)
	263	#define HvLAZYDEL_off(hv) (SvFLAGS(hv) &= ~SVphv_LAZYDEL)
	264
4b5190b5	265	#define HvREHASH(hv) (SvFLAGS(hv) & SVphv_REHASH)
	266	#define HvREHASH_on(hv) (SvFLAGS(hv) \|= SVphv_REHASH)
	267	#define HvREHASH_off(hv) (SvFLAGS(hv) &= ~SVphv_REHASH)
	268
a0d0e21e	269	/* Maybe amagical: */
	270	/* #define HV_AMAGICmb(hv) (SvFLAGS(hv) & (SVpgv_badAM \| SVpgv_AM)) */
	271
	272	#define HV_AMAGIC(hv) (SvFLAGS(hv) & SVpgv_AM)
	273	#define HV_AMAGIC_on(hv) (SvFLAGS(hv) \|= SVpgv_AM)
	274	#define HV_AMAGIC_off(hv) (SvFLAGS(hv) &= ~SVpgv_AM)
	275
	276	/*
	277	#define HV_AMAGICbad(hv) (SvFLAGS(hv) & SVpgv_badAM)
	278	#define HV_badAMAGIC_on(hv) (SvFLAGS(hv) \|= SVpgv_badAM)
	279	#define HV_badAMAGIC_off(hv) (SvFLAGS(hv) &= ~SVpgv_badAM)
	280	*/
bf6bd887	281
	282	#define Nullhe Null(HE*)
	283	#define HeNEXT(he) (he)->hent_next
ff68c719	284	#define HeKEY_hek(he) (he)->hent_hek
ff68c719	285	#define HeKEY(he) HEK_KEY(HeKEY_hek(he))
bbce6d69	286	#define HeKEY_sv(he) ((SV*)HeKEY(he))
ff68c719	287	#define HeKLEN(he) HEK_LEN(HeKEY_hek(he))
da58a35d	288	#define HeKUTF8(he) HEK_UTF8(HeKEY_hek(he))
19692e8d	289	#define HeKWASUTF8(he) HEK_WASUTF8(HeKEY_hek(he))
4b5190b5	290	#define HeKREHASH(he) HEK_REHASH(HeKEY_hek(he))
da58a35d	291	#define HeKLEN_UTF8(he) (HeKUTF8(he) ? -HeKLEN(he) : HeKLEN(he))
19692e8d	292	#define HeKFLAGS(he) HEK_FLAGS(HeKEY_hek(he))
bf6bd887	293	#define HeVAL(he) (he)->hent_val
ff68c719	294	#define HeHASH(he) HEK_HASH(HeKEY_hek(he))
1e422769	295	#define HePV(he,lp) ((HeKLEN(he) == HEf_SVKEY) ? \
	296	SvPV(HeKEY_sv(he),lp) : \
	297	(((lp = HeKLEN(he)) >= 0) ? \
	298	HeKEY(he) : Nullch))
	299
bbce6d69	300	#define HeSVKEY(he) ((HeKEY(he) && \
	301	HeKLEN(he) == HEf_SVKEY) ? \
	302	HeKEY_sv(he) : Nullsv)
	303
	304	#define HeSVKEY_force(he) (HeKEY(he) ? \
	305	((HeKLEN(he) == HEf_SVKEY) ? \
	306	HeKEY_sv(he) : \
79cb57f6	307	sv_2mortal(newSVpvn(HeKEY(he), \
bbce6d69	308	HeKLEN(he)))) : \
3280af22	309	&PL_sv_undef)
1e422769	310	#define HeSVKEY_set(he,sv) ((HeKLEN(he) = HEf_SVKEY), (HeKEY_sv(he) = sv))
bbce6d69	311
ff68c719	312	#define Nullhek Null(HEK*)
71be2cbc	313	#define HEK_BASESIZE STRUCT_OFFSET(HEK, hek_key[0])
ff68c719	314	#define HEK_HASH(hek) (hek)->hek_hash
	315	#define HEK_LEN(hek) (hek)->hek_len
	316	#define HEK_KEY(hek) (hek)->hek_key
19692e8d	317	#define HEK_FLAGS(hek) (((unsigned char )(HEK_KEY(hek))+HEK_LEN(hek)+1))
	318
	319	#define HVhek_UTF8 0x01 /* Key is utf8 encoded. */
	320	#define HVhek_WASUTF8 0x02 /* Key is bytes here, but was supplied as utf8. */
4b5190b5	321	#define HVhek_REHASH 0x04 /* This key is in an hv using a custom HASH . */
19692e8d	322	#define HVhek_FREEKEY 0x100 /* Internal flag to say key is malloc()ed. */
e16e2ff8	323	#define HVhek_PLACEHOLD 0x200 /* Internal flag to create placeholder.
e16e2ff8	324	* (may change, but Storable is a core module) */
19692e8d	325	#define HVhek_MASK 0xFF
19692e8d	326
fdcd69b6	327	/* Which flags enable HvHASKFLAGS? Somewhat a hack on a hack, as
	328	HVhek_REHASH is only needed because the rehash flag has to be duplicated
	329	into all keys as hv_iternext has no access to the hash flags. At this
	330	point Storable's tests get upset, because sometimes hashes are "keyed"
	331	and sometimes not, depending on the order of data insertion, and whether
	332	it triggered rehashing. So currently HVhek_REHAS is exempt.
	333	*/
	334
	335	#define HVhek_ENABLEHVKFLAGS (HVhek_MASK - HVhek_REHASH)
	336
19692e8d	337	#define HEK_UTF8(hek) (HEK_FLAGS(hek) & HVhek_UTF8)
	338	#define HEK_UTF8_on(hek) (HEK_FLAGS(hek) \|= HVhek_UTF8)
	339	#define HEK_UTF8_off(hek) (HEK_FLAGS(hek) &= ~HVhek_UTF8)
	340	#define HEK_WASUTF8(hek) (HEK_FLAGS(hek) & HVhek_WASUTF8)
	341	#define HEK_WASUTF8_on(hek) (HEK_FLAGS(hek) \|= HVhek_WASUTF8)
	342	#define HEK_WASUTF8_off(hek) (HEK_FLAGS(hek) &= ~HVhek_WASUTF8)
4b5190b5	343	#define HEK_REHASH(hek) (HEK_FLAGS(hek) & HVhek_REHASH)
4b5190b5	344	#define HEK_REHASH_on(hek) (HEK_FLAGS(hek) \|= HVhek_REHASH)
d18c6117	345
5cbe4eec	346	/* calculate HV array allocation */
36768cf4	347	#ifndef PERL_USE_LARGE_HV_ALLOC
	348	/* Default to allocating the correct size - default to assuming that malloc()
	349	is not broken and is efficient at allocating blocks sized at powers-of-two.
	350	*/
d18c6117	351	# define PERL_HV_ARRAY_ALLOC_BYTES(size) ((size) * sizeof(HE*))
	352	#else
	353	# define MALLOC_OVERHEAD 16
	354	# define PERL_HV_ARRAY_ALLOC_BYTES(size) \
	355	(((size) < 64) \
	356	? (size) * sizeof(HE*) \
	357	: (size) * sizeof(HE) 2 - MALLOC_OVERHEAD)
	358	#endif
37d85e3a	359
e16e2ff8	360	/* Flags for hv_iternext_flags. */
	361	#define HV_ITERNEXT_WANTPLACEHOLDERS 0x01 /* Don't skip placeholders. */
	362
37d85e3a	363	/* available as a function in hv.c */
	364	#define Perl_sharepvn(sv, len, hash) HEK_KEY(share_hek(sv, len, hash))
	365	#define sharepvn(sv, len, hash) Perl_sharepvn(sv, len, hash)
bfcb3514	366
d1db91c6	367	#define share_hek_hek(hek) \
	368	(++(((struct shared_he )(((char )hek) \
	369	- STRUCT_OFFSET(struct shared_he, \
	370	shared_he_hek))) \
	371	->shared_he_he.hent_val), \
	372	hek)
	373
bfcb3514	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	*/