X-Git-Url: https://perl5.git.perl.org/perl5.git/blobdiff_plain/4bb101f2758f169969171dfe6b70f68a406dcc1e..a0714e2c8319bd04d1f7d262de652b6b5ec054f7:/hv.h diff --git a/hv.h b/hv.h index 6a51ca4..9f9c1e3 100644 --- a/hv.h +++ b/hv.h @@ -1,22 +1,24 @@ /* hv.h * * Copyright (C) 1991, 1992, 1993, 1996, 1997, 1998, 1999, - * 2000, 2001, 2002, by Larry Wall and others + * 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 */ @@ -25,28 +27,58 @@ struct hek { 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 */ + NV xnv_nv; /* numeric value, if any */ 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 + union { + IV xivu_iv; /* integer value or pv offset */ + UV xivu_uv; + void * xivu_p1; + } xiv_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 */ }; +#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; + } xiv_u; + MAGIC* xmg_magic; /* magic for scalar array */ + 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. @@ -54,15 +86,31 @@ struct xpvhv { /* 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); \ @@ -73,6 +121,25 @@ struct xpvhv { (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 @@ -89,7 +156,8 @@ Null HV pointer. =head1 Hash Manipulation Functions =for apidoc Am|char*|HvNAME|HV* stash -Returns the package name of a stash. See C, C. +Returns the package name of a stash, or NULL if C isn't a stash. +See C, C. =for apidoc Am|void*|HeKEY|HE* he Returns the actual pointer stored in the key slot of the hash entry. The @@ -121,7 +189,7 @@ the length of hash keys. This is very similar to the C macro described elsewhere in this document. =for apidoc Am|SV*|HeSVKEY|HE* he -Returns the key as an C, or C if the hash entry does not +Returns the key as an C, or C if the hash entry does not contain an C key. =for apidoc Am|SV*|HeSVKEY_force|HE* he @@ -141,32 +209,42 @@ C. #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) @@ -178,6 +256,7 @@ C. * 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) @@ -187,6 +266,10 @@ C. #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)) */ @@ -208,18 +291,19 @@ C. #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) ? \ @@ -238,20 +322,36 @@ C. #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 @@ -264,6 +364,26 @@ C. /* 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) + +/* + * Local variables: + * c-indentation-style: bsd + * c-basic-offset: 4 + * indent-tabs-mode: t + * End: + * + * ex: set ts=8 sts=4 sw=4 noet: + */