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/* hv.h
*
* Copyright (c) 1991-2002, Larry Wall
*
* 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
UTF8 */
};
/* 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"
*/
#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 = 0; \
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
/*
=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)
/* 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 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_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)
/* 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)
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