1 /* hv.h 2 * 3 * Copyright (c) 1991-2001, Larry Wall 4 * 5 * You may distribute under the terms of either the GNU General Public 6 * License or the Artistic License, as specified in the README file. 7 * 8 */ 9 10 /* typedefs to eliminate some typing */ 11 typedef struct he HE; 12 typedef struct hek HEK; 13 14 /* entry in hash value chain */ 15 struct he { 16 HE *hent_next; /* next entry in chain */ 17 HEK *hent_hek; /* hash key */ 18 SV *hent_val; /* scalar value that was hashed */ 19 }; 20 21 /* hash key -- defined separately for use as shared pointer */ 22 struct hek { 23 U32 hek_hash; /* hash of key */ 24 I32 hek_len; /* length of hash key */ 25 char hek_key[1]; /* variable-length hash key */ 26 }; 27 28 /* hash structure: */ 29 /* This structure must match the beginning of struct xpvmg in sv.h. */ 30 struct xpvhv { 31 char * xhv_array; /* pointer to malloced string */ 32 STRLEN xhv_fill; /* how full xhv_array currently is */ 33 STRLEN xhv_max; /* subscript of last element of xhv_array */ 34 IV xhv_keys; /* how many elements in the array */ 35 NV xnv_nv; /* numeric value, if any */ 36 MAGIC* xmg_magic; /* magic for scalar array */ 37 HV* xmg_stash; /* class package */ 38 39 I32 xhv_riter; /* current root of iterator */ 40 HE *xhv_eiter; /* current entry of iterator */ 41 PMOP *xhv_pmroot; /* list of pm's for this package */ 42 char *xhv_name; /* name, if a symbol table */ 43 }; 44 45 /* hash a key */ 46 #define PERL_HASH(hash,str,len) \ 47 STMT_START { \ 48 register const char *s_PeRlHaSh = str; \ 49 register I32 i_PeRlHaSh = len; \ 50 register U32 hash_PeRlHaSh = 0; \ 51 while (i_PeRlHaSh--) \ 52 hash_PeRlHaSh = hash_PeRlHaSh * 33 + *s_PeRlHaSh++; \ 53 (hash) = hash_PeRlHaSh + (hash_PeRlHaSh>>5); \ 54 } STMT_END 55 56 /* 57 =for apidoc AmU||HEf_SVKEY 58 This flag, used in the length slot of hash entries and magic structures, 59 specifies the structure contains a C<SV*> pointer where a C<char*> pointer 60 is to be expected. (For information only--not to be used). 61 62 =for apidoc AmU||Nullhv 63 Null HV pointer. 64 65 =for apidoc Am|char*|HvNAME|HV* stash 66 Returns the package name of a stash. See C<SvSTASH>, C<CvSTASH>. 67 68 =for apidoc Am|void*|HeKEY|HE* he 69 Returns the actual pointer stored in the key slot of the hash entry. The 70 pointer may be either C<char*> or C<SV*>, depending on the value of 71 C<HeKLEN()>. Can be assigned to. The C<HePV()> or C<HeSVKEY()> macros are 72 usually preferable for finding the value of a key. 73 74 =for apidoc Am|STRLEN|HeKLEN|HE* he 75 If this is negative, and amounts to C<HEf_SVKEY>, it indicates the entry 76 holds an C<SV*> key. Otherwise, holds the actual length of the key. Can 77 be assigned to. The C<HePV()> macro is usually preferable for finding key 78 lengths. 79 80 =for apidoc Am|SV*|HeVAL|HE* he 81 Returns the value slot (type C<SV*>) stored in the hash entry. 82 83 =for apidoc Am|U32|HeHASH|HE* he 84 Returns the computed hash stored in the hash entry. 85 86 =for apidoc Am|char*|HePV|HE* he|STRLEN len 87 Returns the key slot of the hash entry as a C<char*> value, doing any 88 necessary dereferencing of possibly C<SV*> keys. The length of the string 89 is placed in C<len> (this is a macro, so do I<not> use C<&len>). If you do 90 not care about what the length of the key is, you may use the global 91 variable C<PL_na>, though this is rather less efficient than using a local 92 variable. Remember though, that hash keys in perl are free to contain 93 embedded nulls, so using C<strlen()> or similar is not a good way to find 94 the length of hash keys. This is very similar to the C<SvPV()> macro 95 described elsewhere in this document. 96 97 =for apidoc Am|SV*|HeSVKEY|HE* he 98 Returns the key as an C<SV*>, or C<Nullsv> if the hash entry does not 99 contain an C<SV*> key. 100 101 =for apidoc Am|SV*|HeSVKEY_force|HE* he 102 Returns the key as an C<SV*>. Will create and return a temporary mortal 103 C<SV*> if the hash entry contains only a C<char*> key. 104 105 =for apidoc Am|SV*|HeSVKEY_set|HE* he|SV* sv 106 Sets the key to a given C<SV*>, taking care to set the appropriate flags to 107 indicate the presence of an C<SV*> key, and returns the same 108 C<SV*>. 109 110 =cut 111 */ 112 113 /* these hash entry flags ride on hent_klen (for use only in magic/tied HVs) */ 114 #define HEf_SVKEY -2 /* hent_key is a SV* */ 115 116 117 #define Nullhv Null(HV*) 118 #define HvARRAY(hv) ((HE**)((XPVHV*) SvANY(hv))->xhv_array) 119 #define HvFILL(hv) ((XPVHV*) SvANY(hv))->xhv_fill 120 #define HvMAX(hv) ((XPVHV*) SvANY(hv))->xhv_max 121 #define HvKEYS(hv) ((XPVHV*) SvANY(hv))->xhv_keys 122 #define HvRITER(hv) ((XPVHV*) SvANY(hv))->xhv_riter 123 #define HvEITER(hv) ((XPVHV*) SvANY(hv))->xhv_eiter 124 #define HvPMROOT(hv) ((XPVHV*) SvANY(hv))->xhv_pmroot 125 #define HvNAME(hv) ((XPVHV*) SvANY(hv))->xhv_name 126 127 #define HvSHAREKEYS(hv) (SvFLAGS(hv) & SVphv_SHAREKEYS) 128 #define HvSHAREKEYS_on(hv) (SvFLAGS(hv) |= SVphv_SHAREKEYS) 129 #define HvSHAREKEYS_off(hv) (SvFLAGS(hv) &= ~SVphv_SHAREKEYS) 130 131 #define HvLAZYDEL(hv) (SvFLAGS(hv) & SVphv_LAZYDEL) 132 #define HvLAZYDEL_on(hv) (SvFLAGS(hv) |= SVphv_LAZYDEL) 133 #define HvLAZYDEL_off(hv) (SvFLAGS(hv) &= ~SVphv_LAZYDEL) 134 135 /* Maybe amagical: */ 136 /* #define HV_AMAGICmb(hv) (SvFLAGS(hv) & (SVpgv_badAM | SVpgv_AM)) */ 137 138 #define HV_AMAGIC(hv) (SvFLAGS(hv) & SVpgv_AM) 139 #define HV_AMAGIC_on(hv) (SvFLAGS(hv) |= SVpgv_AM) 140 #define HV_AMAGIC_off(hv) (SvFLAGS(hv) &= ~SVpgv_AM) 141 142 /* 143 #define HV_AMAGICbad(hv) (SvFLAGS(hv) & SVpgv_badAM) 144 #define HV_badAMAGIC_on(hv) (SvFLAGS(hv) |= SVpgv_badAM) 145 #define HV_badAMAGIC_off(hv) (SvFLAGS(hv) &= ~SVpgv_badAM) 146 */ 147 148 #define Nullhe Null(HE*) 149 #define HeNEXT(he) (he)->hent_next 150 #define HeKEY_hek(he) (he)->hent_hek 151 #define HeKEY(he) HEK_KEY(HeKEY_hek(he)) 152 #define HeKEY_sv(he) (*(SV**)HeKEY(he)) 153 #define HeKLEN(he) HEK_LEN(HeKEY_hek(he)) 154 #define HeVAL(he) (he)->hent_val 155 #define HeHASH(he) HEK_HASH(HeKEY_hek(he)) 156 #define HePV(he,lp) ((HeKLEN(he) == HEf_SVKEY) ? \ 157 SvPV(HeKEY_sv(he),lp) : \ 158 (((lp = HeKLEN(he)) >= 0) ? \ 159 HeKEY(he) : Nullch)) 160 161 #define HeSVKEY(he) ((HeKEY(he) && \ 162 HeKLEN(he) == HEf_SVKEY) ? \ 163 HeKEY_sv(he) : Nullsv) 164 165 #define HeSVKEY_force(he) (HeKEY(he) ? \ 166 ((HeKLEN(he) == HEf_SVKEY) ? \ 167 HeKEY_sv(he) : \ 168 sv_2mortal(newSVpvn(HeKEY(he), \ 169 HeKLEN(he)))) : \ 170 &PL_sv_undef) 171 #define HeSVKEY_set(he,sv) ((HeKLEN(he) = HEf_SVKEY), (HeKEY_sv(he) = sv)) 172 173 #define Nullhek Null(HEK*) 174 #define HEK_BASESIZE STRUCT_OFFSET(HEK, hek_key[0]) 175 #define HEK_HASH(hek) (hek)->hek_hash 176 #define HEK_LEN(hek) (hek)->hek_len 177 #define HEK_KEY(hek) (hek)->hek_key 178 179 /* calculate HV array allocation */ 180 #if defined(STRANGE_MALLOC) || defined(MYMALLOC) 181 # define PERL_HV_ARRAY_ALLOC_BYTES(size) ((size) * sizeof(HE*)) 182 #else 183 # define MALLOC_OVERHEAD 16 184 # define PERL_HV_ARRAY_ALLOC_BYTES(size) \ 185 (((size) < 64) \ 186 ? (size) * sizeof(HE*) \ 187 : (size) * sizeof(HE*) * 2 - MALLOC_OVERHEAD) 188 #endif 189