X-Git-Url: https://perl5.git.perl.org/perl5.git/blobdiff_plain/8ac04967afa079525f14b42d77496f34f82a67de..bc641c27709fc92be4f44291a8f5fa3a483662fd:/hv.h diff --git a/hv.h b/hv.h index 466f33d..555c6f0 100644 --- a/hv.h +++ b/hv.h @@ -1,92 +1,292 @@ /* hv.h * - * Copyright (c) 1991-1997, Larry Wall + * Copyright (C) 1991, 1992, 1993, 1996, 1997, 1998, 1999, + * 2000, 2001, 2002, 2003, 2005, 2006, 2007, 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. * */ -typedef struct he HE; -typedef struct hek HEK; - +/* entry in hash value chain */ struct he { - HE *hent_next; - HEK *hent_hek; - SV *hent_val; + /* 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 */ + 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 */ 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 */ + /* the hash-key is \0-terminated */ + /* 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; + struct { + U32 xlow; + U32 xhigh; + } xpad_cop_seq; /* used by pad.c for cop_sequence */ + struct { + U32 xbm_previous; /* how many characters in string before rare? */ + U8 xbm_flags; + U8 xbm_rare; /* rarest character in string */ + } xbm_s; /* fields from PVBM */ + } 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 */ - double xnv_nv; /* numeric value, if any */ - 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 + +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; + +/* 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 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 char *s_PeRlHaSh = 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 = 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 * 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; \ - while (i_PeRlHaSh--) \ - hash_PeRlHaSh = hash_PeRlHaSh * 33 + *s_PeRlHaSh++; \ - (hash) = hash_PeRlHaSh + (hash_PeRlHaSh>>5); \ + 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 pointer where a C 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, 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 +pointer may be either C or C, depending on the value of +C. Can be assigned to. The C or C 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, it indicates the entry +holds an C key. Otherwise, holds the actual length of the key. Can +be assigned to. The C macro is usually preferable for finding key +lengths. + +=for apidoc Am|SV*|HeVAL|HE* he +Returns the value slot (type C) 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 value, doing any +necessary dereferencing of possibly C keys. The length of the string +is placed in C (this is a macro, so do I use C<&len>). If you do +not care about what the length of the key is, you may use the global +variable C, 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 or similar is not a good way to find +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 +contain an C key. +=for apidoc Am|SV*|HeSVKEY_force|HE* he +Returns the key as an C. Will create and return a temporary mortal +C if the hash entry contains only a C key. + +=for apidoc Am|SV*|HeSVKEY_set|HE* he|SV* sv +Sets the key to a given C, taking care to set the appropriate flags to +indicate the presence of an C key, and returns the same +C. + +=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 HEf_SVKEY -2 /* hent_key is an SV* */ #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 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 +/* 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) + +/* + * 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) +/* 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) -#ifdef OVERLOAD - -/* 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) -*/ - -#endif /* OVERLOAD */ +#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 @@ -94,21 +294,26 @@ struct xpvhv { #define HeKEY(he) HEK_KEY(HeKEY_hek(he)) #define HeKEY_sv(he) (*(SV**)HeKEY(he)) #define HeKLEN(he) HEK_LEN(HeKEY_hek(he)) -#define HeVAL(he) (he)->hent_val +#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)->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) ? \ 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)) @@ -118,3 +323,128 @@ struct xpvhv { #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_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 */ +#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. */ + +#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: + */