/* hv.h
*
- * Copyright (c) 1991-2003, 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 {
+ /* Keep hent_next first in this structure, because sv_free_arenas take
+ advantage of this to share code between the he arenas and the SV
+ body arenas */
HE *hent_next; /* next entry in chain */
HEK *hent_hek; /* hash key */
- SV *hent_val; /* scalar value that was hashed */
+ union {
+ SV *hent_val; /* scalar value that was hashed */
+ Size_t hent_refcount; /* references for this shared hash key */
+ } he_valu;
};
/* hash key -- defined separately for use as shared pointer */
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 */
+ /* after the \0 there is a byte for flags, such as whether the key
+ is UTF-8 */
+};
+
+struct shared_he {
+ struct he shared_he_he;
+ struct hek shared_he_hek;
+};
+
+/* Subject to change.
+ Don't access this directly.
+*/
+struct xpvhv_aux {
+ HEK *xhv_name; /* name, if a symbol table */
+ AV *xhv_backreferences; /* back references for weak references */
+ 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 */
+ union {
+ NV xnv_nv; /* numeric value, if any */
+ HV * xgv_stash;
+ } xnv_u;
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 */
+ union {
+ IV xivu_iv; /* integer value or pv offset */
+ UV xivu_uv;
+ void * xivu_p1;
+ I32 xivu_i32;
+ HEK * xivu_namehek;
+ } xiv_u;
+ union {
+ MAGIC* xmg_magic; /* linked list of magicalness */
+ HV* xmg_ourstash; /* Stash for our (when SvPAD_OUR is true) */
+ } xmg_u;
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 */
};
+#define xhv_keys xiv_u.xivu_iv
+
+#if 0
+typedef struct xpvhv xpvhv_allocated;
+#else
+typedef struct {
+ STRLEN xhv_fill; /* how full xhv_array currently is */
+ STRLEN xhv_max; /* subscript of last element of xhv_array */
+ union {
+ IV xivu_iv; /* integer value or pv offset */
+ UV xivu_uv;
+ void * xivu_p1;
+ I32 xivu_i32;
+ HEK * xivu_namehek;
+ } xiv_u;
+ union {
+ MAGIC* xmg_magic; /* linked list of magicalness */
+ HV* xmg_ourstash; /* Stash for our (when SvPAD_OUR is true) */
+ } xmg_u;
+ HV* xmg_stash; /* class package */
+} xpvhv_allocated;
+#endif
+
/* hash a key */
/* FYI: This is the "One-at-a-Time" algorithm by Bob Jenkins
* from requirements by Colin Plumb.
/* 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)
+ * a "char" can be either signed or unsigned, 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_tmp = str; \
+ register const char * const 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 * const 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
=head1 Hash Manipulation Functions
=for apidoc Am|char*|HvNAME|HV* stash
-Returns the package name of a stash. See C<SvSTASH>, C<CvSTASH>.
+Returns the package name of a stash, or NULL if C<stash> isn't 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
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
+Returns the key as an C<SV*>, or C<NULL> if the hash entry does not
contain an C<SV*> key.
=for apidoc Am|SV*|HeSVKEY_force|HE* he
#define Nullhv Null(HV*)
-#define HvARRAY(hv) (*(HE***)&((XPVHV*) SvANY(hv))->xhv_array)
+#define HvARRAY(hv) ((hv)->sv_u.svu_hash)
#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
+/* This quite intentionally does no flag checking first. That's your
+ responsibility. */
+#define HvAUX(hv) ((struct xpvhv_aux*)&(HvARRAY(hv)[HvMAX(hv)+1]))
+#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) (SvOOK(hv) ? HvAUX(hv)->xhv_riter : -1)
+#define HvEITER_get(hv) (SvOOK(hv) ? HvAUX(hv)->xhv_eiter : 0)
+#define HvNAME(hv) HvNAME_get(hv)
+/* FIXME - all of these should use a UTF8 aware API, which should also involve
+ getting the length. */
+/* This macro may go away without notice. */
+#define HvNAME_HEK(hv) (SvOOK(hv) ? HvAUX(hv)->xhv_name : 0)
+#define HvNAME_get(hv) ((SvOOK(hv) && (HvAUX(hv)->xhv_name)) \
+ ? HEK_KEY(HvAUX(hv)->xhv_name) : 0)
+#define HvNAMELEN_get(hv) ((SvOOK(hv) && (HvAUX(hv)->xhv_name)) \
+ ? HEK_LEN(HvAUX(hv)->xhv_name) : 0)
/* 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 HvKEYS(hv) HvUSEDKEYS(hv)
+#define HvUSEDKEYS(hv) (HvTOTALKEYS(hv) - HvPLACEHOLDERS_get(hv))
#define HvTOTALKEYS(hv) XHvTOTALKEYS((XPVHV*) SvANY(hv))
-#define HvPLACEHOLDERS(hv) XHvPLACEHOLDERS((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)
* 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 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 HvREHASH(hv) (SvFLAGS(hv) & SVphv_REHASH)
+#define HvREHASH_on(hv) (SvFLAGS(hv) |= SVphv_REHASH)
+#define HvREHASH_off(hv) (SvFLAGS(hv) &= ~SVphv_REHASH)
#define Nullhe Null(HE*)
#define HeNEXT(he) (he)->hent_next
#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 HeVAL(he) (he)->he_valu.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))
+ HeKEY(he) : NULL))
#define HeSVKEY(he) ((HeKEY(he) && \
HeKLEN(he) == HEf_SVKEY) ? \
- HeKEY_sv(he) : Nullsv)
+ HeKEY_sv(he) : NULL)
#define HeSVKEY_force(he) (HeKEY(he) ? \
((HeKLEN(he) == HEf_SVKEY) ? \
#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_UNSHARED 0x08 /* This key isn't a shared hash key. */
#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_REHASH is exempt.
+ Similarly UNSHARED
+*/
+
+#define HVhek_ENABLEHVKFLAGS (HVhek_MASK & ~(HVhek_REHASH|HVhek_UNSHARED))
+
#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
/* Flags for hv_iternext_flags. */
#define HV_ITERNEXT_WANTPLACEHOLDERS 0x01 /* Don't skip placeholders. */
+#define hv_iternext(hv) hv_iternext_flags(hv, 0)
+#define hv_magic(hv, gv, how) sv_magic((SV*)(hv), (SV*)(gv), how, NULL, 0)
+
/* 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)
+
+#define share_hek_hek(hek) \
+ (++(((struct shared_he *)(((char *)hek) \
+ - STRUCT_OFFSET(struct shared_he, \
+ shared_he_hek))) \
+ ->shared_he_he.he_valu.hent_refcount), \
+ hek)
+
+/* This refcounted he structure is used for storing the hints used for lexical
+ pragmas. Without threads, it's basically struct he + refcount.
+ With threads, life gets more complex as the structure needs to be shared
+ between threads (because it hangs from OPs, which are shared), hence the
+ alternate definition and mutex. */
+
+#ifdef PERL_CORE
+
+/* Gosh. This really isn't a good name any longer. */
+struct refcounted_he {
+ struct refcounted_he *refcounted_he_next; /* next entry in chain */
+#ifdef USE_ITHREADS
+ U32 refcounted_he_hash;
+ U32 refcounted_he_keylen;
+#else
+ HEK *refcounted_he_hek; /* hint key */
+#endif
+ U32 refcounted_he_refcnt; /* reference count */
+ union {
+ IV refcounted_he_u_iv;
+ UV refcounted_he_u_uv;
+ STRLEN refcounted_he_u_len;
+ } refcounted_he_val;
+ /* First byte is flags. Then NUL-terminated value. Then for ithreads,
+ non-NUL terminated key. */
+ char refcounted_he_data[1];
+};
+
+/* Flag bits are HVhek_UTF8, HVhek_WASUTF8, then */
+#define HVrhek_undef 0x00 /* Value is undef. */
+#define HVrhek_PV 0x10 /* Value is a string. */
+#define HVrhek_IV 0x20 /* Value is IV/UV. */
+#define HVrhek_delete 0x30 /* Value is placeholder - signifies delete. */
+#define HVrhek_typemask 0x30
+#define HVrhek_UTF8 0x40 /* string value is utf8. */
+#define HVrhek_UV 0x40 /* integer value is UV. */
+
+# ifdef USE_ITHREADS
+# define HINTS_REFCNT_LOCK MUTEX_LOCK(&PL_hints_mutex)
+# define HINTS_REFCNT_UNLOCK MUTEX_UNLOCK(&PL_hints_mutex)
+# else
+# define HINTS_REFCNT_LOCK NOOP
+# define HINTS_REFCNT_UNLOCK NOOP
+# endif
+#endif
+
+#ifdef USE_ITHREADS
+# define HINTS_REFCNT_INIT MUTEX_INIT(&PL_hints_mutex)
+# define HINTS_REFCNT_TERM MUTEX_DESTROY(&PL_hints_mutex)
+#else
+# define HINTS_REFCNT_INIT NOOP
+# define HINTS_REFCNT_TERM NOOP
+#endif
+
+/*
+ * Local variables:
+ * c-indentation-style: bsd
+ * c-basic-offset: 4
+ * indent-tabs-mode: t
+ * End:
+ *
+ * ex: set ts=8 sts=4 sw=4 noet:
+ */