[p5sagit/p5-mst-13.2.git] / hv.h

/*    hv.h
 *
 *    Copyright (C) 1991, 1992, 1993, 1996, 1997, 1998, 1999,
 *    2000, 2001, 2002, 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 */
};

/* hash structure: */
/* This structure must match the beginning of struct xpvmg in sv.h. */
struct xpvhv {
    char *	xhv_array;	/* pointer to malloced string */
    STRLEN	xhv_fill;	/* how full xhv_array currently is */
    STRLEN	xhv_max;	/* subscript of last element of xhv_array */
    IV		xhv_keys;	/* how many elements in the array */
    NV		xnv_nv;		/* numeric value, if any */
#define xhv_placeholders xnv_nv
    MAGIC*	xmg_magic;	/* magic for scalar array */
    HV*		xmg_stash;	/* class package */

    I32		xhv_riter;	/* current root of iterator */
    HE		*xhv_eiter;	/* current entry of iterator */
    PMOP	*xhv_pmroot;	/* list of pm's for this package */
    char	*xhv_name;	/* name, if a symbol table */
};

/* 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 erl.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

#ifdef PERL_IN_HV_C
#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_new_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
#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***)&((XPVHV*)  SvANY(hv))->xhv_array)
#define HvFILL(hv)	((XPVHV*)  SvANY(hv))->xhv_fill
#define HvMAX(hv)	((XPVHV*)  SvANY(hv))->xhv_max
#define HvRITER(hv)	((XPVHV*)  SvANY(hv))->xhv_riter
#define HvEITER(hv)	((XPVHV*)  SvANY(hv))->xhv_eiter
#define HvPMROOT(hv)	((XPVHV*)  SvANY(hv))->xhv_pmroot
#define HvNAME(hv)	((XPVHV*)  SvANY(hv))->xhv_name

/* the number of keys (including any placeholers) */
#define XHvTOTALKEYS(xhv)	((xhv)->xhv_keys)

/* The number of placeholders in the enumerated-keys hash */
#define XHvPLACEHOLDERS(xhv)	((xhv)->xhv_placeholders)

/* the number of keys that exist() (i.e. excluding placeholders) */
#define XHvUSEDKEYS(xhv)      (XHvTOTALKEYS(xhv) - (IV)XHvPLACEHOLDERS(xhv))

/*
 * 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)		XHvUSEDKEYS((XPVHV*)  SvANY(hv))
#define HvUSEDKEYS(hv)		XHvUSEDKEYS((XPVHV*)  SvANY(hv))
#define HvTOTALKEYS(hv)		XHvTOTALKEYS((XPVHV*)  SvANY(hv))
#define HvPLACEHOLDERS(hv)	XHvPLACEHOLDERS((XPVHV*)  SvANY(hv))

#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.
 */
#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

#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 */
#if defined(STRANGE_MALLOC) || defined(MYMALLOC)
#  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)
Commit	Line	Data
a0d0e21e	1	/* hv.h
79072805	2	*
4bb101f2	3	* Copyright (C) 1991, 1992, 1993, 1996, 1997, 1998, 1999,
4bb101f2	4	* 2000, 2001, 2002, 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
5cbe4eec	32	/* hash structure: */
6ee623d5	33	/* This structure must match the beginning of struct xpvmg in sv.h. */
79072805	34	struct xpvhv {
463ee0b2	35	char * xhv_array; /* pointer to malloced string */
	36	STRLEN xhv_fill; /* how full xhv_array currently is */
	37	STRLEN xhv_max; /* subscript of last element of xhv_array */
6ee623d5	38	IV xhv_keys; /* how many elements in the array */
65202027	39	NV xnv_nv; /* numeric value, if any */
8aacddc1	40	#define xhv_placeholders xnv_nv
79072805	41	MAGIC* xmg_magic; /* magic for scalar array */
	42	HV* xmg_stash; /* class package */
	43
79072805	44	I32 xhv_riter; /* current root of iterator */
	45	HE xhv_eiter; / current entry of iterator */
	46	PMOP xhv_pmroot; / list of pm's for this package */
	47	char xhv_name; / name, if a symbol table */
79072805	48	};
79072805	49
5cbe4eec	50	/* hash a key */
5afd6d42	51	/* FYI: This is the "One-at-a-Time" algorithm by Bob Jenkins
	52	* from requirements by Colin Plumb.
	53	* (http://burtleburtle.net/bob/hash/doobs.html) */
	54	/* The use of a temporary pointer and the casting games
	55	* is needed to serve the dual purposes of
	56	* (a) the hashed data being interpreted as "unsigned char" (new since 5.8,
	57	* a "char" can be either signed or signed, depending on the compiler)
	58	* (b) catering for old code that uses a "char"
830b38bd	59	*
504f80c1	60	* The "hash seed" feature was added in Perl 5.8.1 to perturb the results
504f80c1	61	* to avoid "algorithmic complexity attacks".
830b38bd	62	*
	63	* If USE_HASH_SEED is defined, hash randomisation is done by default
	64	* If USE_HASH_SEED_EXPLICIT is defined, hash randomisation is done
	65	* only if the environment variable PERL_HASH_SEED is set.
	66	* For maximal control, one can define PERL_HASH_SEED.
	67	* (see also erl.c:perl_parse()).
5afd6d42	68	*/
830b38bd	69	#ifndef PERL_HASH_SEED
	70	# if defined(USE_HASH_SEED) \|\| defined(USE_HASH_SEED_EXPLICIT)
	71	# define PERL_HASH_SEED PL_hash_seed
	72	# else
	73	# define PERL_HASH_SEED 0
	74	# endif
504f80c1	75	#endif
bf6bd887	76	#define PERL_HASH(hash,str,len) \
bf6bd887	77	STMT_START { \
5afd6d42	78	register const char *s_PeRlHaSh_tmp = str; \
5afd6d42	79	register const unsigned char s_PeRlHaSh = (const unsigned char )s_PeRlHaSh_tmp; \
bf6bd887	80	register I32 i_PeRlHaSh = len; \
504f80c1	81	register U32 hash_PeRlHaSh = PERL_HASH_SEED; \
a6fe520e	82	while (i_PeRlHaSh--) { \
	83	hash_PeRlHaSh += *s_PeRlHaSh++; \
	84	hash_PeRlHaSh += (hash_PeRlHaSh << 10); \
	85	hash_PeRlHaSh ^= (hash_PeRlHaSh >> 6); \
	86	} \
	87	hash_PeRlHaSh += (hash_PeRlHaSh << 3); \
	88	hash_PeRlHaSh ^= (hash_PeRlHaSh >> 11); \
4fee5c71	89	(hash) = (hash_PeRlHaSh + (hash_PeRlHaSh << 15)); \
bf6bd887	90	} STMT_END
bf6bd887	91
4b5190b5	92	#ifdef PERL_IN_HV_C
	93	#define PERL_HASH_INTERNAL(hash,str,len) \
	94	STMT_START { \
	95	register const char *s_PeRlHaSh_tmp = str; \
	96	register const unsigned char s_PeRlHaSh = (const unsigned char )s_PeRlHaSh_tmp; \
	97	register I32 i_PeRlHaSh = len; \
	98	register U32 hash_PeRlHaSh = PL_new_hash_seed; \
	99	while (i_PeRlHaSh--) { \
	100	hash_PeRlHaSh += *s_PeRlHaSh++; \
	101	hash_PeRlHaSh += (hash_PeRlHaSh << 10); \
	102	hash_PeRlHaSh ^= (hash_PeRlHaSh >> 6); \
	103	} \
	104	hash_PeRlHaSh += (hash_PeRlHaSh << 3); \
	105	hash_PeRlHaSh ^= (hash_PeRlHaSh >> 11); \
	106	(hash) = (hash_PeRlHaSh + (hash_PeRlHaSh << 15)); \
	107	} STMT_END
	108	#endif
	109
954c1994	110	/*
ccfc67b7	111	=head1 Hash Manipulation Functions
ccfc67b7	112
954c1994	113	=for apidoc AmU\|\|HEf_SVKEY
954c1994	114	This flag, used in the length slot of hash entries and magic structures,
d1be9408	115	specifies the structure contains an C<SV> pointer where a C<char> pointer
954c1994	116	is to be expected. (For information only--not to be used).
954c1994	117
ccfc67b7	118	=head1 Handy Values
ccfc67b7	119
954c1994	120	=for apidoc AmU\|\|Nullhv
	121	Null HV pointer.
	122
ccfc67b7	123	=head1 Hash Manipulation Functions
ccfc67b7	124
954c1994	125	=for apidoc Am\|char\|HvNAME\|HV stash
	126	Returns the package name of a stash. See C<SvSTASH>, C<CvSTASH>.
	127
	128	=for apidoc Am\|void\|HeKEY\|HE he
	129	Returns the actual pointer stored in the key slot of the hash entry. The
	130	pointer may be either C<char> or C<SV>, depending on the value of
	131	C<HeKLEN()>. Can be assigned to. The C<HePV()> or C<HeSVKEY()> macros are
	132	usually preferable for finding the value of a key.
	133
	134	=for apidoc Am\|STRLEN\|HeKLEN\|HE* he
	135	If this is negative, and amounts to C<HEf_SVKEY>, it indicates the entry
	136	holds an C<SV*> key. Otherwise, holds the actual length of the key. Can
	137	be assigned to. The C<HePV()> macro is usually preferable for finding key
	138	lengths.
	139
	140	=for apidoc Am\|SV\|HeVAL\|HE he
	141	Returns the value slot (type C<SV*>) stored in the hash entry.
	142
	143	=for apidoc Am\|U32\|HeHASH\|HE* he
	144	Returns the computed hash stored in the hash entry.
	145
	146	=for apidoc Am\|char\|HePV\|HE he\|STRLEN len
	147	Returns the key slot of the hash entry as a C<char*> value, doing any
	148	necessary dereferencing of possibly C<SV*> keys. The length of the string
	149	is placed in C<len> (this is a macro, so do I<not> use C<&len>). If you do
	150	not care about what the length of the key is, you may use the global
	151	variable C<PL_na>, though this is rather less efficient than using a local
	152	variable. Remember though, that hash keys in perl are free to contain
	153	embedded nulls, so using C<strlen()> or similar is not a good way to find
	154	the length of hash keys. This is very similar to the C<SvPV()> macro
	155	described elsewhere in this document.
	156
	157	=for apidoc Am\|SV\|HeSVKEY\|HE he
	158	Returns the key as an C<SV*>, or C<Nullsv> if the hash entry does not
	159	contain an C<SV*> key.
	160
	161	=for apidoc Am\|SV\|HeSVKEY_force\|HE he
	162	Returns the key as an C<SV*>. Will create and return a temporary mortal
	163	C<SV> if the hash entry contains only a C<char> key.
	164
	165	=for apidoc Am\|SV\|HeSVKEY_set\|HE he\|SV* sv
	166	Sets the key to a given C<SV*>, taking care to set the appropriate flags to
	167	indicate the presence of an C<SV*> key, and returns the same
	168	C<SV*>.
	169
	170	=cut
	171	*/
bf6bd887	172
bf5b86ae	173	/* these hash entry flags ride on hent_klen (for use only in magic/tied HVs) */
d1be9408	174	#define HEf_SVKEY -2 /* hent_key is an SV* */
bf6bd887	175
bf6bd887	176
79072805	177	#define Nullhv Null(HV*)
4efcf9a2	178	#define HvARRAY(hv) ((HE*)&((XPVHV) SvANY(hv))->xhv_array)
79072805	179	#define HvFILL(hv) ((XPVHV*) SvANY(hv))->xhv_fill
463ee0b2	180	#define HvMAX(hv) ((XPVHV*) SvANY(hv))->xhv_max
79072805	181	#define HvRITER(hv) ((XPVHV*) SvANY(hv))->xhv_riter
	182	#define HvEITER(hv) ((XPVHV*) SvANY(hv))->xhv_eiter
	183	#define HvPMROOT(hv) ((XPVHV*) SvANY(hv))->xhv_pmroot
	184	#define HvNAME(hv) ((XPVHV*) SvANY(hv))->xhv_name
a0d0e21e	185
8aacddc1	186	/* the number of keys (including any placeholers) */
	187	#define XHvTOTALKEYS(xhv) ((xhv)->xhv_keys)
	188
	189	/* The number of placeholders in the enumerated-keys hash */
205c8ad3	190	#define XHvPLACEHOLDERS(xhv) ((xhv)->xhv_placeholders)
8aacddc1	191
dd2710a1	192	/* the number of keys that exist() (i.e. excluding placeholders) */
dd2710a1	193	#define XHvUSEDKEYS(xhv) (XHvTOTALKEYS(xhv) - (IV)XHvPLACEHOLDERS(xhv))
8aacddc1	194
	195	/*
	196	* HvKEYS gets the number of keys that actually exist(), and is provided
	197	* for backwards compatibility with old XS code. The core uses HvUSEDKEYS
	198	* (keys, excluding placeholdes) and HvTOTALKEYS (including placeholders)
	199	*/
	200	#define HvKEYS(hv) XHvUSEDKEYS((XPVHV*) SvANY(hv))
	201	#define HvUSEDKEYS(hv) XHvUSEDKEYS((XPVHV*) SvANY(hv))
	202	#define HvTOTALKEYS(hv) XHvTOTALKEYS((XPVHV*) SvANY(hv))
	203	#define HvPLACEHOLDERS(hv) XHvPLACEHOLDERS((XPVHV*) SvANY(hv))
	204
bf6bd887	205	#define HvSHAREKEYS(hv) (SvFLAGS(hv) & SVphv_SHAREKEYS)
	206	#define HvSHAREKEYS_on(hv) (SvFLAGS(hv) \|= SVphv_SHAREKEYS)
	207	#define HvSHAREKEYS_off(hv) (SvFLAGS(hv) &= ~SVphv_SHAREKEYS)
	208
19692e8d	209	/* This is an optimisation flag. It won't be set if all hash keys have a 0
	210	* flag. Currently the only flags relate to utf8.
	211	* Hence it won't be set if all keys are 8 bit only. It will be set if any key
	212	* is utf8 (including 8 bit keys that were entered as utf8, and need upgrading
	213	* when retrieved during iteration. It may still be set when there are no longer
	214	* any utf8 keys.
	215	*/
	216	#define HvHASKFLAGS(hv) (SvFLAGS(hv) & SVphv_HASKFLAGS)
	217	#define HvHASKFLAGS_on(hv) (SvFLAGS(hv) \|= SVphv_HASKFLAGS)
	218	#define HvHASKFLAGS_off(hv) (SvFLAGS(hv) &= ~SVphv_HASKFLAGS)
574c8022	219
bf5b86ae	220	#define HvLAZYDEL(hv) (SvFLAGS(hv) & SVphv_LAZYDEL)
	221	#define HvLAZYDEL_on(hv) (SvFLAGS(hv) \|= SVphv_LAZYDEL)
	222	#define HvLAZYDEL_off(hv) (SvFLAGS(hv) &= ~SVphv_LAZYDEL)
	223
4b5190b5	224	#define HvREHASH(hv) (SvFLAGS(hv) & SVphv_REHASH)
	225	#define HvREHASH_on(hv) (SvFLAGS(hv) \|= SVphv_REHASH)
	226	#define HvREHASH_off(hv) (SvFLAGS(hv) &= ~SVphv_REHASH)
	227
a0d0e21e	228	/* Maybe amagical: */
	229	/* #define HV_AMAGICmb(hv) (SvFLAGS(hv) & (SVpgv_badAM \| SVpgv_AM)) */
	230
	231	#define HV_AMAGIC(hv) (SvFLAGS(hv) & SVpgv_AM)
	232	#define HV_AMAGIC_on(hv) (SvFLAGS(hv) \|= SVpgv_AM)
	233	#define HV_AMAGIC_off(hv) (SvFLAGS(hv) &= ~SVpgv_AM)
	234
	235	/*
	236	#define HV_AMAGICbad(hv) (SvFLAGS(hv) & SVpgv_badAM)
	237	#define HV_badAMAGIC_on(hv) (SvFLAGS(hv) \|= SVpgv_badAM)
	238	#define HV_badAMAGIC_off(hv) (SvFLAGS(hv) &= ~SVpgv_badAM)
	239	*/
bf6bd887	240
	241	#define Nullhe Null(HE*)
	242	#define HeNEXT(he) (he)->hent_next
ff68c719	243	#define HeKEY_hek(he) (he)->hent_hek
ff68c719	244	#define HeKEY(he) HEK_KEY(HeKEY_hek(he))
bbce6d69	245	#define HeKEY_sv(he) ((SV*)HeKEY(he))
ff68c719	246	#define HeKLEN(he) HEK_LEN(HeKEY_hek(he))
da58a35d	247	#define HeKUTF8(he) HEK_UTF8(HeKEY_hek(he))
19692e8d	248	#define HeKWASUTF8(he) HEK_WASUTF8(HeKEY_hek(he))
4b5190b5	249	#define HeKREHASH(he) HEK_REHASH(HeKEY_hek(he))
da58a35d	250	#define HeKLEN_UTF8(he) (HeKUTF8(he) ? -HeKLEN(he) : HeKLEN(he))
19692e8d	251	#define HeKFLAGS(he) HEK_FLAGS(HeKEY_hek(he))
bf6bd887	252	#define HeVAL(he) (he)->hent_val
ff68c719	253	#define HeHASH(he) HEK_HASH(HeKEY_hek(he))
1e422769	254	#define HePV(he,lp) ((HeKLEN(he) == HEf_SVKEY) ? \
	255	SvPV(HeKEY_sv(he),lp) : \
	256	(((lp = HeKLEN(he)) >= 0) ? \
	257	HeKEY(he) : Nullch))
	258
bbce6d69	259	#define HeSVKEY(he) ((HeKEY(he) && \
	260	HeKLEN(he) == HEf_SVKEY) ? \
	261	HeKEY_sv(he) : Nullsv)
	262
	263	#define HeSVKEY_force(he) (HeKEY(he) ? \
	264	((HeKLEN(he) == HEf_SVKEY) ? \
	265	HeKEY_sv(he) : \
79cb57f6	266	sv_2mortal(newSVpvn(HeKEY(he), \
bbce6d69	267	HeKLEN(he)))) : \
3280af22	268	&PL_sv_undef)
1e422769	269	#define HeSVKEY_set(he,sv) ((HeKLEN(he) = HEf_SVKEY), (HeKEY_sv(he) = sv))
bbce6d69	270
ff68c719	271	#define Nullhek Null(HEK*)
71be2cbc	272	#define HEK_BASESIZE STRUCT_OFFSET(HEK, hek_key[0])
ff68c719	273	#define HEK_HASH(hek) (hek)->hek_hash
	274	#define HEK_LEN(hek) (hek)->hek_len
	275	#define HEK_KEY(hek) (hek)->hek_key
19692e8d	276	#define HEK_FLAGS(hek) (((unsigned char )(HEK_KEY(hek))+HEK_LEN(hek)+1))
	277
	278	#define HVhek_UTF8 0x01 /* Key is utf8 encoded. */
	279	#define HVhek_WASUTF8 0x02 /* Key is bytes here, but was supplied as utf8. */
4b5190b5	280	#define HVhek_REHASH 0x04 /* This key is in an hv using a custom HASH . */
19692e8d	281	#define HVhek_FREEKEY 0x100 /* Internal flag to say key is malloc()ed. */
e16e2ff8	282	#define HVhek_PLACEHOLD 0x200 /* Internal flag to create placeholder.
e16e2ff8	283	* (may change, but Storable is a core module) */
19692e8d	284	#define HVhek_MASK 0xFF
	285
	286	#define HEK_UTF8(hek) (HEK_FLAGS(hek) & HVhek_UTF8)
	287	#define HEK_UTF8_on(hek) (HEK_FLAGS(hek) \|= HVhek_UTF8)
	288	#define HEK_UTF8_off(hek) (HEK_FLAGS(hek) &= ~HVhek_UTF8)
	289	#define HEK_WASUTF8(hek) (HEK_FLAGS(hek) & HVhek_WASUTF8)
	290	#define HEK_WASUTF8_on(hek) (HEK_FLAGS(hek) \|= HVhek_WASUTF8)
	291	#define HEK_WASUTF8_off(hek) (HEK_FLAGS(hek) &= ~HVhek_WASUTF8)
4b5190b5	292	#define HEK_REHASH(hek) (HEK_FLAGS(hek) & HVhek_REHASH)
4b5190b5	293	#define HEK_REHASH_on(hek) (HEK_FLAGS(hek) \|= HVhek_REHASH)
d18c6117	294
5cbe4eec	295	/* calculate HV array allocation */
d18c6117	296	#if defined(STRANGE_MALLOC) \|\| defined(MYMALLOC)
	297	# define PERL_HV_ARRAY_ALLOC_BYTES(size) ((size) * sizeof(HE*))
	298	#else
	299	# define MALLOC_OVERHEAD 16
	300	# define PERL_HV_ARRAY_ALLOC_BYTES(size) \
	301	(((size) < 64) \
	302	? (size) * sizeof(HE*) \
	303	: (size) * sizeof(HE) 2 - MALLOC_OVERHEAD)
	304	#endif
37d85e3a	305
e16e2ff8	306	/* Flags for hv_iternext_flags. */
	307	#define HV_ITERNEXT_WANTPLACEHOLDERS 0x01 /* Don't skip placeholders. */
	308
37d85e3a	309	/* available as a function in hv.c */
	310	#define Perl_sharepvn(sv, len, hash) HEK_KEY(share_hek(sv, len, hash))
	311	#define sharepvn(sv, len, hash) Perl_sharepvn(sv, len, hash)