-/* $RCSfile: hash.h,v $$Revision: 4.1 $$Date: 92/08/07 18:21:52 $
+/* hv.h
*
- * Copyright (c) 1991, Larry Wall
+ * Copyright (c) 1991-2001, 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.
*
- * $Log: hash.h,v $
- * Revision 4.1 92/08/07 18:21:52 lwall
- *
- * Revision 4.0.1.2 91/11/05 17:24:31 lwall
- * patch11: random cleanup
- *
- * Revision 4.0.1.1 91/06/07 11:10:33 lwall
- * patch4: new copyright notice
- *
- * Revision 4.0 91/03/20 01:22:38 lwall
- * 4.0 baseline.
- *
*/
+/* typedefs to eliminate some typing */
typedef struct he HE;
+typedef struct hek HEK;
+/* entry in hash value chain */
struct he {
- HE *hent_next;
- char *hent_key;
- SV *hent_val;
- U32 hent_hash;
- I32 hent_klen;
+ 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 */
+};
+
+/* 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 */
- STRLEN xhv_keys; /* how many elements in the array */
- double xnv_nv; /* numeric value, if any */
+ 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 */
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) */
+#define PERL_HASH(hash,str,len) \
+ STMT_START { \
+ register const char *s_PeRlHaSh = str; \
+ 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 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 HvKEYS(hv) ((XPVHV*) SvANY(hv))->xhv_keys
#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 placeholers) */
+#define XHvUSEDKEYS(xhv) (XHvTOTALKEYS(xhv) - 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)
+
+#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 HeKLEN_UTF8(he) (HeKUTF8(he) ? -HeKLEN(he) : HeKLEN(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_UTF8(hek) (*(HEK_KEY(hek)+HEK_LEN(hek)))
+
+/* 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
+
+/* 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)