/* hv.h
*
- * Copyright (c) 1991-1999, Larry Wall
+ * Copyright (c) 1991-2000, 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;
- HEK *hent_hek;
- SV *hent_val;
+ 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;
- I32 hek_len;
- char hek_key[1];
+ 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 */
IV xhv_keys; /* how many elements in the array */
- double xnv_nv; /* numeric value, if any */
+ NV xnv_nv; /* numeric value, if any */
MAGIC* xmg_magic; /* magic for scalar array */
HV* xmg_stash; /* class package */
char *xhv_name; /* name, if a symbol table */
};
+/* hash a key */
#define PERL_HASH(hash,str,len) \
STMT_START { \
register const char *s_PeRlHaSh = str; \
(hash) = hash_PeRlHaSh + (hash_PeRlHaSh>>5); \
} STMT_END
+/*
+=for apidoc AmU||HEf_SVKEY
+This flag, used in the length slot of hash entries and magic structures,
+specifies the structure contains a C<SV*> pointer where a C<char*> pointer
+is to be expected. (For information only--not to be used).
+
+=for apidoc AmU||Nullhv
+Null HV pointer.
+
+=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 a SV* */
#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) ? \
#define HeSVKEY_force(he) (HeKEY(he) ? \
((HeKLEN(he) == HEf_SVKEY) ? \
HeKEY_sv(he) : \
- sv_2mortal(newSVpv(HeKEY(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 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
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