/* hv.h
*
- * Copyright (c) 1991-2001, 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.
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: */
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 */
+ /* list of pm's for this package is now stored in symtab magic. */
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) */
+/* 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 const 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 = 0; \
+ register U32 hash_PeRlHaSh = PERL_HASH_SEED; \
while (i_PeRlHaSh--) { \
hash_PeRlHaSh += *s_PeRlHaSh++; \
hash_PeRlHaSh += (hash_PeRlHaSh << 10); \
(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 = 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>.
#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 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.
+ * 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 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) ? \
#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)))
+#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 */
-#if defined(STRANGE_MALLOC) || defined(MYMALLOC)
+#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
: (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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