/* hv.h
*
- * Copyright (c) 1991-1994, Larry Wall
+ * 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.
*
*/
+/* 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 */
+ /* the hash-key is \0-terminated */
+ /* after the \0 there is a byte for flags, such as whether the key
+ is UTF-8 */
+};
+
+
+/* Subject to change.
+ Don't access this directly.
+*/
+struct xpvhv_aux {
+ char *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 {
- char * xhv_array; /* pointer to malloced string */
+ IV for_rent;
STRLEN xhv_fill; /* how full xhv_array currently is */
STRLEN xhv_max; /* subscript of last element of xhv_array */
- I32 xhv_keys; /* how many elements in the array */
- double xnv_nv; /* numeric value, if any */
+ union {
+ NV xnvu_nv; /* numeric value, if any */
+ struct {
+ void *xnv_p1;
+ union {
+ void *xnv_p2;
+ IV xnv_i2; /* how many elements in the array */
+ } xnv_u2;
+ } xnv_s;
+ } xnv_u;
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 */
+ /* list of pm's for this package is now stored in symtab magic. */
};
+#define xhv_aux xnv_u.xnv_s.xnv_p1
+#define xhv_keys xnv_u.xnv_s.xnv_u2.xnv_i2
+
+
+/* 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 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 char *s_PeRlHaSh = str; \
+ 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 = 0; \
- while (i_PeRlHaSh--) \
- hash_PeRlHaSh = hash_PeRlHaSh * 33 + *s_PeRlHaSh++; \
- (hash) = hash_PeRlHaSh; \
+ 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. 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.
-/* these hash entry flags ride on hent_klen */
+=for apidoc Am|SV*|HeVAL|HE* he
+Returns the value slot (type C<SV*>) stored in the hash entry.
-#define HEf_LAZYDEL -1 /* entry must be deleted during next iter step */
-#define HEf_SVKEY -2 /* hent_key is a SV* (only for magic/tied HVs) */
+=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***)&((hv)->sv_u.sv_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
+#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) (((XPVHV *)SvANY(hv))->xhv_aux ? \
+ ((struct xpvhv_aux*)((XPVHV *)SvANY(hv))->xhv_aux)->xhv_riter : -1)
+#define HvEITER_get(hv) (((XPVHV *)SvANY(hv))->xhv_aux ? \
+ ((struct xpvhv_aux *)((XPVHV *)SvANY(hv))->xhv_aux)->xhv_eiter : 0)
+#define HvNAME(hv) (*Perl_hv_name_p(aTHX_ (HV*)hv))
+/* FIXME - all of these should use a UTF8 aware API, which should also involve
+ getting the length. */
+#define HvNAME_get(hv) (((XPVHV *)SvANY(hv))->xhv_aux ? \
+ ((struct xpvhv_aux *)((XPVHV *)SvANY(hv))->xhv_aux)->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)
-#ifdef OVERLOAD
+/* 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_badAMAGIC_off(hv) (SvFLAGS(hv) &= ~SVpgv_badAM)
*/
-#endif /* OVERLOAD */
-
#define Nullhe Null(HE*)
#define HeNEXT(he) (he)->hent_next
-#define HeKEY(he) (he)->hent_key
-#define HeKLEN(he) (he)->hent_klen
+#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) (he)->hent_hash
-#define HePV(he) ((he)->hent_klen == HEf_SVKEY) ? \
- SvPV((SV*)((he)->hent_key),na) : \
- (he)->hent_key))
-#define HeSVKEY(he) (((he)->hent_key && \
- (he)->hent_klen == HEf_SVKEY) ? \
- (SV*)((he)->hent_key) : Nullsv)
-
-#define HeSVKEY_force(he) ((he)->hent_key ? \
- (((he)->hent_klen == HEf_SVKEY) ? \
- (SV*)((he)->hent_key) : \
- sv_2mortal(newSVpv((he)->hent_key, \
- (he)->hent_klen))) : \
- &sv_undef)
+#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)
+
+/*
+ * Local variables:
+ * c-indentation-style: bsd
+ * c-basic-offset: 4
+ * indent-tabs-mode: t
+ * End:
+ *
+ * ex: set ts=8 sts=4 sw=4 noet:
+ */
https://perl5.git.perl.org / perl5.git / blobdiff