perl/hv.h
<<
>>
Prefs
   1/*    hv.h
   2 *
   3 *    Copyright (C) 1991, 1992, 1993, 1996, 1997, 1998, 1999,
   4 *    2000, 2001, 2002, 2003, 2005, 2006, 2007, 2008, by Larry Wall and others
   5 *
   6 *    You may distribute under the terms of either the GNU General Public
   7 *    License or the Artistic License, as specified in the README file.
   8 *
   9 */
  10
  11/* entry in hash value chain */
  12struct he {
  13    /* Keep hent_next first in this structure, because sv_free_arenas take
  14       advantage of this to share code between the he arenas and the SV
  15       body arenas  */
  16    HE          *hent_next;     /* next entry in chain */
  17    HEK         *hent_hek;      /* hash key */
  18    union {
  19        SV      *hent_val;      /* scalar value that was hashed */
  20        Size_t  hent_refcount;  /* references for this shared hash key */
  21    } he_valu;
  22};
  23
  24/* hash key -- defined separately for use as shared pointer */
  25struct hek {
  26    U32         hek_hash;       /* hash of key */
  27    I32         hek_len;        /* length of hash key */
  28    char        hek_key[1];     /* variable-length hash key */
  29    /* the hash-key is \0-terminated */
  30    /* after the \0 there is a byte for flags, such as whether the key
  31       is UTF-8 */
  32};
  33
  34struct shared_he {
  35    struct he shared_he_he;
  36    struct hek shared_he_hek;
  37};
  38
  39/* Subject to change.
  40   Don't access this directly.
  41   Use the funcs in mro.c
  42*/
  43
  44struct mro_alg {
  45    AV *(*resolve)(pTHX_ HV* stash, U32 level);
  46    const char *name;
  47    U16 length;
  48    U16 kflags; /* For the hash API - set HVhek_UTF8 if name is UTF-8 */
  49    U32 hash; /* or 0 */
  50};
  51
  52struct mro_meta {
  53    /* repurposed as a hash holding the different MROs private data. */
  54    AV      *mro_linear_dfs; /* cached dfs @ISA linearization */
  55    /* repurposed as a pointer directly to the current MROs private data.  */
  56    AV      *mro_linear_c3;  /* cached c3 @ISA linearization */
  57    HV      *mro_nextmethod; /* next::method caching */
  58    U32     cache_gen;       /* Bumping this invalidates our method cache */
  59    U32     pkg_gen;         /* Bumps when local methods/@ISA change */
  60    const struct mro_alg *mro_which; /* which mro alg is in use? */
  61    HV      *isa;            /* Everything this class @ISA */
  62};
  63
  64#define MRO_GET_PRIVATE_DATA(smeta, which)                 \
  65    (((smeta)->mro_which && (which) == (smeta)->mro_which) \
  66     ? MUTABLE_SV((smeta)->mro_linear_c3)                  \
  67     : Perl_mro_get_private_data(aTHX_ (smeta), (which)))
  68
  69/* Subject to change.
  70   Don't access this directly.
  71*/
  72
  73struct xpvhv_aux {
  74    HEK         *xhv_name;      /* name, if a symbol table */
  75    AV          *xhv_backreferences; /* back references for weak references */
  76    HE          *xhv_eiter;     /* current entry of iterator */
  77    I32         xhv_riter;      /* current root of iterator */
  78    struct mro_meta *xhv_mro_meta;
  79};
  80
  81/* hash structure: */
  82/* This structure must match the beginning of struct xpvmg in sv.h. */
  83struct xpvhv {
  84    union {
  85        NV      xnv_nv;         /* numeric value, if any */
  86        HV *    xgv_stash;
  87        struct {
  88            U32 xlow;
  89            U32 xhigh;
  90        }       xpad_cop_seq;   /* used by pad.c for cop_sequence */
  91        struct {
  92            U32 xbm_previous;   /* how many characters in string before rare? */
  93            U8  xbm_flags;
  94            U8  xbm_rare;       /* rarest character in string */
  95        }       xbm_s;          /* fields from PVBM */
  96    }           xnv_u;
  97    STRLEN      xhv_fill;       /* how full xhv_array currently is */
  98    STRLEN      xhv_max;        /* subscript of last element of xhv_array */
  99    union {
 100        IV      xivu_iv;        /* integer value or pv offset */
 101        UV      xivu_uv;
 102        void *  xivu_p1;
 103        I32     xivu_i32;
 104        HEK *   xivu_namehek;
 105    }           xiv_u;
 106    union {
 107        MAGIC*  xmg_magic;      /* linked list of magicalness */
 108        HV*     xmg_ourstash;   /* Stash for our (when SvPAD_OUR is true) */
 109    } xmg_u;
 110    HV*         xmg_stash;      /* class package */
 111};
 112
 113#define xhv_keys xiv_u.xivu_iv
 114
 115typedef struct {
 116    STRLEN      xhv_fill;       /* how full xhv_array currently is */
 117    STRLEN      xhv_max;        /* subscript of last element of xhv_array */
 118    union {
 119        IV      xivu_iv;        /* integer value or pv offset */
 120        UV      xivu_uv;
 121        void *  xivu_p1;
 122        I32     xivu_i32;
 123        HEK *   xivu_namehek;
 124    }           xiv_u;
 125    union {
 126        MAGIC*  xmg_magic;      /* linked list of magicalness */
 127        HV*     xmg_ourstash;   /* Stash for our (when SvPAD_OUR is true) */
 128    } xmg_u;
 129    HV*         xmg_stash;      /* class package */
 130} xpvhv_allocated;
 131
 132/* hash a key */
 133/* FYI: This is the "One-at-a-Time" algorithm by Bob Jenkins
 134 * from requirements by Colin Plumb.
 135 * (http://burtleburtle.net/bob/hash/doobs.html) */
 136/* The use of a temporary pointer and the casting games
 137 * is needed to serve the dual purposes of
 138 * (a) the hashed data being interpreted as "unsigned char" (new since 5.8,
 139 *     a "char" can be either signed or unsigned, depending on the compiler)
 140 * (b) catering for old code that uses a "char"
 141 *
 142 * The "hash seed" feature was added in Perl 5.8.1 to perturb the results
 143 * to avoid "algorithmic complexity attacks".
 144 *
 145 * If USE_HASH_SEED is defined, hash randomisation is done by default
 146 * If USE_HASH_SEED_EXPLICIT is defined, hash randomisation is done
 147 * only if the environment variable PERL_HASH_SEED is set.
 148 * For maximal control, one can define PERL_HASH_SEED.
 149 * (see also perl.c:perl_parse()).
 150 */
 151#ifndef PERL_HASH_SEED
 152#   if defined(USE_HASH_SEED) || defined(USE_HASH_SEED_EXPLICIT)
 153#       define PERL_HASH_SEED   PL_hash_seed
 154#   else
 155#       define PERL_HASH_SEED   0
 156#   endif
 157#endif
 158#define PERL_HASH(hash,str,len) \
 159     STMT_START { \
 160        register const char * const s_PeRlHaSh_tmp = str; \
 161        register const unsigned char *s_PeRlHaSh = (const unsigned char *)s_PeRlHaSh_tmp; \
 162        register I32 i_PeRlHaSh = len; \
 163        register U32 hash_PeRlHaSh = PERL_HASH_SEED; \
 164        while (i_PeRlHaSh--) { \
 165            hash_PeRlHaSh += *s_PeRlHaSh++; \
 166            hash_PeRlHaSh += (hash_PeRlHaSh << 10); \
 167            hash_PeRlHaSh ^= (hash_PeRlHaSh >> 6); \
 168        } \
 169        hash_PeRlHaSh += (hash_PeRlHaSh << 3); \
 170        hash_PeRlHaSh ^= (hash_PeRlHaSh >> 11); \
 171        (hash) = (hash_PeRlHaSh + (hash_PeRlHaSh << 15)); \
 172    } STMT_END
 173
 174/* Only hv.c and mod_perl should be doing this.  */
 175#ifdef PERL_HASH_INTERNAL_ACCESS
 176#define PERL_HASH_INTERNAL(hash,str,len) \
 177     STMT_START { \
 178        register const char * const s_PeRlHaSh_tmp = str; \
 179        register const unsigned char *s_PeRlHaSh = (const unsigned char *)s_PeRlHaSh_tmp; \
 180        register I32 i_PeRlHaSh = len; \
 181        register U32 hash_PeRlHaSh = PL_rehash_seed; \
 182        while (i_PeRlHaSh--) { \
 183            hash_PeRlHaSh += *s_PeRlHaSh++; \
 184            hash_PeRlHaSh += (hash_PeRlHaSh << 10); \
 185            hash_PeRlHaSh ^= (hash_PeRlHaSh >> 6); \
 186        } \
 187        hash_PeRlHaSh += (hash_PeRlHaSh << 3); \
 188        hash_PeRlHaSh ^= (hash_PeRlHaSh >> 11); \
 189        (hash) = (hash_PeRlHaSh + (hash_PeRlHaSh << 15)); \
 190    } STMT_END
 191#endif
 192
 193/*
 194=head1 Hash Manipulation Functions
 195
 196=for apidoc AmU||HEf_SVKEY
 197This flag, used in the length slot of hash entries and magic structures,
 198specifies the structure contains an C<SV*> pointer where a C<char*> pointer
 199is to be expected. (For information only--not to be used).
 200
 201=head1 Handy Values
 202
 203=for apidoc AmU||Nullhv
 204Null HV pointer.
 205
 206=head1 Hash Manipulation Functions
 207
 208=for apidoc Am|char*|HvNAME|HV* stash
 209Returns the package name of a stash, or NULL if C<stash> isn't a stash.
 210See C<SvSTASH>, C<CvSTASH>.
 211
 212=for apidoc Am|void*|HeKEY|HE* he
 213Returns the actual pointer stored in the key slot of the hash entry. The
 214pointer may be either C<char*> or C<SV*>, depending on the value of
 215C<HeKLEN()>.  Can be assigned to.  The C<HePV()> or C<HeSVKEY()> macros are
 216usually preferable for finding the value of a key.
 217
 218=for apidoc Am|STRLEN|HeKLEN|HE* he
 219If this is negative, and amounts to C<HEf_SVKEY>, it indicates the entry
 220holds an C<SV*> key.  Otherwise, holds the actual length of the key.  Can
 221be assigned to. The C<HePV()> macro is usually preferable for finding key
 222lengths.
 223
 224=for apidoc Am|SV*|HeVAL|HE* he
 225Returns the value slot (type C<SV*>) stored in the hash entry.
 226
 227=for apidoc Am|U32|HeHASH|HE* he
 228Returns the computed hash stored in the hash entry.
 229
 230=for apidoc Am|char*|HePV|HE* he|STRLEN len
 231Returns the key slot of the hash entry as a C<char*> value, doing any
 232necessary dereferencing of possibly C<SV*> keys.  The length of the string
 233is placed in C<len> (this is a macro, so do I<not> use C<&len>).  If you do
 234not care about what the length of the key is, you may use the global
 235variable C<PL_na>, though this is rather less efficient than using a local
 236variable.  Remember though, that hash keys in perl are free to contain
 237embedded nulls, so using C<strlen()> or similar is not a good way to find
 238the length of hash keys. This is very similar to the C<SvPV()> macro
 239described elsewhere in this document. See also C<HeUTF8>.
 240
 241If you are using C<HePV> to get values to pass to C<newSVpvn()> to create a
 242new SV, you should consider using C<newSVhek(HeKEY_hek(he))> as it is more
 243efficient.
 244
 245=for apidoc Am|char*|HeUTF8|HE* he|STRLEN len
 246Returns whether the C<char *> value returned by C<HePV> is encoded in UTF-8,
 247doing any necessary dereferencing of possibly C<SV*> keys.  The value returned
 248will be 0 or non-0, not necessarily 1 (or even a value with any low bits set),
 249so B<do not> blindly assign this to a C<bool> variable, as C<bool> may be a
 250typedef for C<char>.
 251
 252=for apidoc Am|SV*|HeSVKEY|HE* he
 253Returns the key as an C<SV*>, or C<NULL> if the hash entry does not
 254contain an C<SV*> key.
 255
 256=for apidoc Am|SV*|HeSVKEY_force|HE* he
 257Returns the key as an C<SV*>.  Will create and return a temporary mortal
 258C<SV*> if the hash entry contains only a C<char*> key.
 259
 260=for apidoc Am|SV*|HeSVKEY_set|HE* he|SV* sv
 261Sets the key to a given C<SV*>, taking care to set the appropriate flags to
 262indicate the presence of an C<SV*> key, and returns the same
 263C<SV*>.
 264
 265=cut
 266*/
 267
 268/* these hash entry flags ride on hent_klen (for use only in magic/tied HVs) */
 269#define HEf_SVKEY       -2      /* hent_key is an SV* */
 270
 271
 272#define Nullhv Null(HV*)
 273#define HvARRAY(hv)     ((hv)->sv_u.svu_hash)
 274#define HvFILL(hv)      ((XPVHV*)  SvANY(hv))->xhv_fill
 275#define HvMAX(hv)       ((XPVHV*)  SvANY(hv))->xhv_max
 276/* This quite intentionally does no flag checking first. That's your
 277   responsibility.  */
 278#define HvAUX(hv)       ((struct xpvhv_aux*)&(HvARRAY(hv)[HvMAX(hv)+1]))
 279#define HvRITER(hv)     (*Perl_hv_riter_p(aTHX_ MUTABLE_HV(hv)))
 280#define HvEITER(hv)     (*Perl_hv_eiter_p(aTHX_ MUTABLE_HV(hv)))
 281#define HvRITER_set(hv,r)       Perl_hv_riter_set(aTHX_ MUTABLE_HV(hv), r)
 282#define HvEITER_set(hv,e)       Perl_hv_eiter_set(aTHX_ MUTABLE_HV(hv), e)
 283#define HvRITER_get(hv) (SvOOK(hv) ? HvAUX(hv)->xhv_riter : -1)
 284#define HvEITER_get(hv) (SvOOK(hv) ? HvAUX(hv)->xhv_eiter : NULL)
 285#define HvNAME(hv)      HvNAME_get(hv)
 286
 287/* Checking that hv is a valid package stash is the
 288   caller's responsibility */
 289#define HvMROMETA(hv) (HvAUX(hv)->xhv_mro_meta \
 290                       ? HvAUX(hv)->xhv_mro_meta \
 291                       : Perl_mro_meta_init(aTHX_ hv))
 292
 293/* FIXME - all of these should use a UTF8 aware API, which should also involve
 294   getting the length. */
 295/* This macro may go away without notice.  */
 296#define HvNAME_HEK(hv) (SvOOK(hv) ? HvAUX(hv)->xhv_name : NULL)
 297#define HvNAME_get(hv)  ((SvOOK(hv) && (HvAUX(hv)->xhv_name)) \
 298                         ? HEK_KEY(HvAUX(hv)->xhv_name) : NULL)
 299#define HvNAMELEN_get(hv)       ((SvOOK(hv) && (HvAUX(hv)->xhv_name)) \
 300                                 ? HEK_LEN(HvAUX(hv)->xhv_name) : 0)
 301
 302/* the number of keys (including any placeholers) */
 303#define XHvTOTALKEYS(xhv)       ((xhv)->xhv_keys)
 304
 305/*
 306 * HvKEYS gets the number of keys that actually exist(), and is provided
 307 * for backwards compatibility with old XS code. The core uses HvUSEDKEYS
 308 * (keys, excluding placeholdes) and HvTOTALKEYS (including placeholders)
 309 */
 310#define HvKEYS(hv)              HvUSEDKEYS(hv)
 311#define HvUSEDKEYS(hv)          (HvTOTALKEYS(hv) - HvPLACEHOLDERS_get(hv))
 312#define HvTOTALKEYS(hv)         XHvTOTALKEYS((XPVHV*)  SvANY(hv))
 313#define HvPLACEHOLDERS(hv)      (*Perl_hv_placeholders_p(aTHX_ MUTABLE_HV(hv)))
 314#define HvPLACEHOLDERS_get(hv)  (SvMAGIC(hv) ? Perl_hv_placeholders_get(aTHX_ (HV *)hv) : 0)
 315#define HvPLACEHOLDERS_set(hv,p)        Perl_hv_placeholders_set(aTHX_ MUTABLE_HV(hv), p)
 316
 317#define HvSHAREKEYS(hv)         (SvFLAGS(hv) & SVphv_SHAREKEYS)
 318#define HvSHAREKEYS_on(hv)      (SvFLAGS(hv) |= SVphv_SHAREKEYS)
 319#define HvSHAREKEYS_off(hv)     (SvFLAGS(hv) &= ~SVphv_SHAREKEYS)
 320
 321/* This is an optimisation flag. It won't be set if all hash keys have a 0
 322 * flag. Currently the only flags relate to utf8.
 323 * Hence it won't be set if all keys are 8 bit only. It will be set if any key
 324 * is utf8 (including 8 bit keys that were entered as utf8, and need upgrading
 325 * when retrieved during iteration. It may still be set when there are no longer
 326 * any utf8 keys.
 327 * See HVhek_ENABLEHVKFLAGS for the trigger.
 328 */
 329#define HvHASKFLAGS(hv)         (SvFLAGS(hv) & SVphv_HASKFLAGS)
 330#define HvHASKFLAGS_on(hv)      (SvFLAGS(hv) |= SVphv_HASKFLAGS)
 331#define HvHASKFLAGS_off(hv)     (SvFLAGS(hv) &= ~SVphv_HASKFLAGS)
 332
 333#define HvLAZYDEL(hv)           (SvFLAGS(hv) & SVphv_LAZYDEL)
 334#define HvLAZYDEL_on(hv)        (SvFLAGS(hv) |= SVphv_LAZYDEL)
 335#define HvLAZYDEL_off(hv)       (SvFLAGS(hv) &= ~SVphv_LAZYDEL)
 336
 337#define HvREHASH(hv)            (SvFLAGS(hv) & SVphv_REHASH)
 338#define HvREHASH_on(hv)         (SvFLAGS(hv) |= SVphv_REHASH)
 339#define HvREHASH_off(hv)        (SvFLAGS(hv) &= ~SVphv_REHASH)
 340
 341#define Nullhe Null(HE*)
 342#define HeNEXT(he)              (he)->hent_next
 343#define HeKEY_hek(he)           (he)->hent_hek
 344#define HeKEY(he)               HEK_KEY(HeKEY_hek(he))
 345#define HeKEY_sv(he)            (*(SV**)HeKEY(he))
 346#define HeKLEN(he)              HEK_LEN(HeKEY_hek(he))
 347#define HeKUTF8(he)  HEK_UTF8(HeKEY_hek(he))
 348#define HeKWASUTF8(he)  HEK_WASUTF8(HeKEY_hek(he))
 349#define HeKREHASH(he)  HEK_REHASH(HeKEY_hek(he))
 350#define HeKLEN_UTF8(he)  (HeKUTF8(he) ? -HeKLEN(he) : HeKLEN(he))
 351#define HeKFLAGS(he)  HEK_FLAGS(HeKEY_hek(he))
 352#define HeVAL(he)               (he)->he_valu.hent_val
 353#define HeHASH(he)              HEK_HASH(HeKEY_hek(he))
 354#define HePV(he,lp)             ((HeKLEN(he) == HEf_SVKEY) ?            \
 355                                 SvPV(HeKEY_sv(he),lp) :                \
 356                                 ((lp = HeKLEN(he)), HeKEY(he)))
 357#define HeUTF8(he)              ((HeKLEN(he) == HEf_SVKEY) ?            \
 358                                 SvUTF8(HeKEY_sv(he)) :                 \
 359                                 (U32)HeKUTF8(he))
 360
 361#define HeSVKEY(he)             ((HeKEY(he) &&                          \
 362                                  HeKLEN(he) == HEf_SVKEY) ?            \
 363                                 HeKEY_sv(he) : NULL)
 364
 365#define HeSVKEY_force(he)       (HeKEY(he) ?                            \
 366                                 ((HeKLEN(he) == HEf_SVKEY) ?           \
 367                                  HeKEY_sv(he) :                        \
 368                                  newSVpvn_flags(HeKEY(he),             \
 369                                                 HeKLEN(he), SVs_TEMP)) : \
 370                                 &PL_sv_undef)
 371#define HeSVKEY_set(he,sv)      ((HeKLEN(he) = HEf_SVKEY), (HeKEY_sv(he) = sv))
 372
 373#define Nullhek Null(HEK*)
 374#define HEK_BASESIZE            STRUCT_OFFSET(HEK, hek_key[0])
 375#define HEK_HASH(hek)           (hek)->hek_hash
 376#define HEK_LEN(hek)            (hek)->hek_len
 377#define HEK_KEY(hek)            (hek)->hek_key
 378#define HEK_FLAGS(hek)  (*((unsigned char *)(HEK_KEY(hek))+HEK_LEN(hek)+1))
 379
 380#define HVhek_UTF8      0x01 /* Key is utf8 encoded. */
 381#define HVhek_WASUTF8   0x02 /* Key is bytes here, but was supplied as utf8. */
 382#define HVhek_REHASH    0x04 /* This key is in an hv using a custom HASH . */
 383#define HVhek_UNSHARED  0x08 /* This key isn't a shared hash key. */
 384#define HVhek_FREEKEY   0x100 /* Internal flag to say key is malloc()ed.  */
 385#define HVhek_PLACEHOLD 0x200 /* Internal flag to create placeholder.
 386                               * (may change, but Storable is a core module) */
 387#define HVhek_KEYCANONICAL 0x400 /* Internal flag - key is in canonical form.
 388                                    If the string is UTF-8, it cannot be
 389                                    converted to bytes. */
 390#define HVhek_MASK      0xFF
 391
 392/* Which flags enable HvHASKFLAGS? Somewhat a hack on a hack, as
 393   HVhek_REHASH is only needed because the rehash flag has to be duplicated
 394   into all keys as hv_iternext has no access to the hash flags. At this
 395   point Storable's tests get upset, because sometimes hashes are "keyed"
 396   and sometimes not, depending on the order of data insertion, and whether
 397   it triggered rehashing. So currently HVhek_REHASH is exempt.
 398   Similarly UNSHARED
 399*/
 400   
 401#define HVhek_ENABLEHVKFLAGS    (HVhek_MASK & ~(HVhek_REHASH|HVhek_UNSHARED))
 402
 403#define HEK_UTF8(hek)           (HEK_FLAGS(hek) & HVhek_UTF8)
 404#define HEK_UTF8_on(hek)        (HEK_FLAGS(hek) |= HVhek_UTF8)
 405#define HEK_UTF8_off(hek)       (HEK_FLAGS(hek) &= ~HVhek_UTF8)
 406#define HEK_WASUTF8(hek)        (HEK_FLAGS(hek) & HVhek_WASUTF8)
 407#define HEK_WASUTF8_on(hek)     (HEK_FLAGS(hek) |= HVhek_WASUTF8)
 408#define HEK_WASUTF8_off(hek)    (HEK_FLAGS(hek) &= ~HVhek_WASUTF8)
 409#define HEK_REHASH(hek)         (HEK_FLAGS(hek) & HVhek_REHASH)
 410#define HEK_REHASH_on(hek)      (HEK_FLAGS(hek) |= HVhek_REHASH)
 411
 412/* calculate HV array allocation */
 413#ifndef PERL_USE_LARGE_HV_ALLOC
 414/* Default to allocating the correct size - default to assuming that malloc()
 415   is not broken and is efficient at allocating blocks sized at powers-of-two.
 416*/   
 417#  define PERL_HV_ARRAY_ALLOC_BYTES(size) ((size) * sizeof(HE*))
 418#else
 419#  define MALLOC_OVERHEAD 16
 420#  define PERL_HV_ARRAY_ALLOC_BYTES(size) \
 421                        (((size) < 64)                                  \
 422                         ? (size) * sizeof(HE*)                         \
 423                         : (size) * sizeof(HE*) * 2 - MALLOC_OVERHEAD)
 424#endif
 425
 426/* Flags for hv_iternext_flags.  */
 427#define HV_ITERNEXT_WANTPLACEHOLDERS    0x01    /* Don't skip placeholders.  */
 428
 429#define hv_iternext(hv) hv_iternext_flags(hv, 0)
 430#define hv_magic(hv, gv, how) sv_magic(MUTABLE_SV(hv), MUTABLE_SV(gv), how, NULL, 0)
 431
 432/* available as a function in hv.c */
 433#define Perl_sharepvn(sv, len, hash) HEK_KEY(share_hek(sv, len, hash))
 434#define sharepvn(sv, len, hash)      Perl_sharepvn(sv, len, hash)
 435
 436#define share_hek_hek(hek)                                              \
 437    (++(((struct shared_he *)(((char *)hek)                             \
 438                              - STRUCT_OFFSET(struct shared_he,         \
 439                                              shared_he_hek)))          \
 440        ->shared_he_he.he_valu.hent_refcount),                          \
 441     hek)
 442
 443#define hv_store_ent(hv, keysv, val, hash)                              \
 444    ((HE *) hv_common((hv), (keysv), NULL, 0, 0, HV_FETCH_ISSTORE,      \
 445                      (val), (hash)))
 446
 447#define hv_exists_ent(hv, keysv, hash)                                  \
 448    (hv_common((hv), (keysv), NULL, 0, 0, HV_FETCH_ISEXISTS, 0, (hash)) \
 449     ? TRUE : FALSE)
 450#define hv_fetch_ent(hv, keysv, lval, hash)                             \
 451    ((HE *) hv_common((hv), (keysv), NULL, 0, 0,                        \
 452                      ((lval) ? HV_FETCH_LVALUE : 0), NULL, (hash)))
 453#define hv_delete_ent(hv, key, flags, hash)                             \
 454    (MUTABLE_SV(hv_common((hv), (key), NULL, 0, 0, (flags) | HV_DELETE, \
 455                          NULL, (hash))))
 456
 457#define hv_store_flags(hv, key, klen, val, hash, flags)                 \
 458    ((SV**) hv_common((hv), NULL, (key), (klen), (flags),               \
 459                      (HV_FETCH_ISSTORE|HV_FETCH_JUST_SV), (val),       \
 460                      (hash)))
 461
 462#define hv_store(hv, key, klen, val, hash)                              \
 463    ((SV**) hv_common_key_len((hv), (key), (klen),                      \
 464                              (HV_FETCH_ISSTORE|HV_FETCH_JUST_SV),      \
 465                              (val), (hash)))
 466
 467#define hv_exists(hv, key, klen)                                        \
 468    (hv_common_key_len((hv), (key), (klen), HV_FETCH_ISEXISTS, NULL, 0) \
 469     ? TRUE : FALSE)
 470
 471#define hv_fetch(hv, key, klen, lval)                                   \
 472    ((SV**) hv_common_key_len((hv), (key), (klen), (lval)               \
 473                              ? (HV_FETCH_JUST_SV | HV_FETCH_LVALUE)    \
 474                              : HV_FETCH_JUST_SV, NULL, 0))
 475
 476#define hv_delete(hv, key, klen, flags)                                 \
 477    (MUTABLE_SV(hv_common_key_len((hv), (key), (klen),                  \
 478                                  (flags) | HV_DELETE, NULL, 0)))
 479
 480/* This refcounted he structure is used for storing the hints used for lexical
 481   pragmas. Without threads, it's basically struct he + refcount.
 482   With threads, life gets more complex as the structure needs to be shared
 483   between threads (because it hangs from OPs, which are shared), hence the
 484   alternate definition and mutex.  */
 485
 486struct refcounted_he;
 487
 488#ifdef PERL_CORE
 489
 490/* Gosh. This really isn't a good name any longer.  */
 491struct refcounted_he {
 492    struct refcounted_he *refcounted_he_next;   /* next entry in chain */
 493#ifdef USE_ITHREADS
 494    U32                   refcounted_he_hash;
 495    U32                   refcounted_he_keylen;
 496#else
 497    HEK                  *refcounted_he_hek;    /* hint key */
 498#endif
 499    union {
 500        IV                refcounted_he_u_iv;
 501        UV                refcounted_he_u_uv;
 502        STRLEN            refcounted_he_u_len;
 503        void             *refcounted_he_u_ptr;  /* Might be useful in future */
 504    } refcounted_he_val;
 505    U32                   refcounted_he_refcnt; /* reference count */
 506    /* First byte is flags. Then NUL-terminated value. Then for ithreads,
 507       non-NUL terminated key.  */
 508    char                  refcounted_he_data[1];
 509};
 510
 511/* Flag bits are HVhek_UTF8, HVhek_WASUTF8, then */
 512#define HVrhek_undef    0x00 /* Value is undef. */
 513#define HVrhek_delete   0x10 /* Value is placeholder - signifies delete. */
 514#define HVrhek_IV       0x20 /* Value is IV. */
 515#define HVrhek_UV       0x30 /* Value is UV. */
 516#define HVrhek_PV       0x40 /* Value is a (byte) string. */
 517#define HVrhek_PV_UTF8  0x50 /* Value is a (utf8) string. */
 518/* Two spare. As these have to live in the optree, you can't store anything
 519   interpreter specific, such as SVs. :-( */
 520#define HVrhek_typemask 0x70
 521
 522#ifdef USE_ITHREADS
 523/* A big expression to find the key offset */
 524#define REF_HE_KEY(chain)                                               \
 525        ((((chain->refcounted_he_data[0] & 0x60) == 0x40)               \
 526            ? chain->refcounted_he_val.refcounted_he_u_len + 1 : 0)     \
 527         + 1 + chain->refcounted_he_data)
 528#endif
 529
 530#  ifdef USE_ITHREADS
 531#    define HINTS_REFCNT_LOCK           MUTEX_LOCK(&PL_hints_mutex)
 532#    define HINTS_REFCNT_UNLOCK         MUTEX_UNLOCK(&PL_hints_mutex)
 533#  else
 534#    define HINTS_REFCNT_LOCK           NOOP
 535#    define HINTS_REFCNT_UNLOCK         NOOP
 536#  endif
 537#endif
 538
 539#ifdef USE_ITHREADS
 540#  define HINTS_REFCNT_INIT             MUTEX_INIT(&PL_hints_mutex)
 541#  define HINTS_REFCNT_TERM             MUTEX_DESTROY(&PL_hints_mutex)
 542#else
 543#  define HINTS_REFCNT_INIT             NOOP
 544#  define HINTS_REFCNT_TERM             NOOP
 545#endif
 546
 547/* Hash actions
 548 * Passed in PERL_MAGIC_uvar calls
 549 */
 550#define HV_DISABLE_UVAR_XKEY    0x01
 551/* We need to ensure that these don't clash with G_DISCARD, which is 2, as it
 552   is documented as being passed to hv_delete().  */
 553#define HV_FETCH_ISSTORE        0x04
 554#define HV_FETCH_ISEXISTS       0x08
 555#define HV_FETCH_LVALUE         0x10
 556#define HV_FETCH_JUST_SV        0x20
 557#define HV_DELETE               0x40
 558
 559/*
 560=for apidoc newHV
 561
 562Creates a new HV.  The reference count is set to 1.
 563
 564=cut
 565*/
 566
 567#define newHV() MUTABLE_HV(newSV_type(SVt_PVHV))
 568
 569/*
 570 * Local variables:
 571 * c-indentation-style: bsd
 572 * c-basic-offset: 4
 573 * indent-tabs-mode: t
 574 * End:
 575 *
 576 * ex: set ts=8 sts=4 sw=4 noet:
 577 */
 578
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.