lib/perl5/5.6.1/msys/CORE/hv.h

   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