X-Git-Url: https://perl5.git.perl.org/perl5.git/blobdiff_plain/79072805bf63abe5b5978b5928ab00d360ea3e7f..7bde033ebff0a0b90536713c20543166fab1b660:/hv.h diff --git a/hv.h b/hv.h index eb3c050..c43fc57 100644 --- a/hv.h +++ b/hv.h @@ -1,82 +1,276 @@ -/* $RCSfile: hash.h,v $$Revision: 4.1 $$Date: 92/08/07 18:21:52 $ +/* hv.h * - * Copyright (c) 1991, Larry Wall + * Copyright (C) 1991, 1992, 1993, 1996, 1997, 1998, 1999, + * 2000, 2001, 2002, 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. * - * $Log: hash.h,v $ - * Revision 4.1 92/08/07 18:21:52 lwall - * - * Revision 4.0.1.2 91/11/05 17:24:31 lwall - * patch11: random cleanup - * - * Revision 4.0.1.1 91/06/07 11:10:33 lwall - * patch4: new copyright notice - * - * Revision 4.0 91/03/20 01:22:38 lwall - * 4.0 baseline. - * */ -#define FILLPCT 80 /* don't make greater than 99 */ -#define DBM_CACHE_MAX 63 /* cache 64 entries for dbm file */ - /* (resident array acts as a write-thru cache)*/ - -#define COEFFSIZE (16 * 8) /* size of coeff array */ - +/* 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; - I32 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 + UTF8 */ }; +/* hash structure: */ +/* This structure must match the beginning of struct xpvmg in sv.h. */ struct xpvhv { - char * xpv_pv; /* pointer to malloced string */ - STRLEN xpv_cur; /* length of xp_pv as a C string */ - STRLEN xpv_len; /* allocated size */ - STRLEN xof_off; /* ptr is incremented by offset */ - double xnv_nv; /* numeric value, if any */ + char * xhv_array; /* pointer to malloced string */ + 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 */ HV* xmg_stash; /* class package */ - MAGIC* xhv_magic; /* magic for elements */ - - HE **xhv_array; - I32 xhv_max; /* subscript of last element of xhv_array */ - I32 xhv_dosplit; /* how full to get before splitting */ - I32 xhv_fill; /* how full xhv_array currently is */ 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 */ -#ifdef SOME_DBM -#ifdef HAS_GDBM - GDBM_FILE xhv_dbm; -#else -#ifdef HAS_NDBM - DBM *xhv_dbm; +}; + +/* 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 defined(USE_HASH_SEED) || defined(USE_HASH_SEED_EXPLICIT) +# define PERL_HASH_SEED PL_hash_seed #else - I32 xhv_dbm; -#endif -#endif +# define PERL_HASH_SEED 0 #endif - unsigned char xhv_coeffsize; /* is 0 for symbol tables */ -}; +#define PERL_HASH(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 = 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 + +/* +=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. 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 an SV* */ + #define Nullhv Null(HV*) -#define HvMAGIC(hv) ((XPVHV*) SvANY(hv))->xhv_magic -#define HvARRAY(hv) ((XPVHV*) SvANY(hv))->xhv_array -#define HvMAX(hv) ((XPVHV*) SvANY(hv))->xhv_max -#define HvDOSPLIT(hv) ((XPVHV*) SvANY(hv))->xhv_dosplit +#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 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 HvDBM(hv) ((XPVHV*) SvANY(hv))->xhv_dbm -#define HvCOEFFSIZE(hv) ((XPVHV*) SvANY(hv))->xhv_coeffsize + +/* 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. + */ +#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) + +/* 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 Nullhe Null(HE*) +#define HeNEXT(he) (he)->hent_next +#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 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) ? \ + 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_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 + +#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) + +/* calculate HV array allocation */ +#if defined(STRANGE_MALLOC) || defined(MYMALLOC) +# 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)