This is a live mirror of the Perl 5 development currently hosted at https://github.com/perl/perl5
No need to create a new magic vtable if it's all 0 pointers.
[perl5.git] / hv.c
diff --git a/hv.c b/hv.c
index 118439a..8552cd2 100644 (file)
--- a/hv.c
+++ b/hv.c
@@ -71,7 +71,8 @@ S_new_he(pTHX)
     LOCK_SV_MUTEX;
     if (!*root)
        S_more_he(aTHX);
-    he = *root;
+    he = (HE*) *root;
+    assert(he);
     *root = HeNEXT(he);
     UNLOCK_SV_MUTEX;
     return he;
@@ -103,7 +104,7 @@ S_save_hek_flags(const char *str, I32 len, U32 hash, int flags)
     HEK_KEY(hek)[len] = 0;
     HEK_LEN(hek) = len;
     HEK_HASH(hek) = hash;
-    HEK_FLAGS(hek) = (unsigned char)flags_masked;
+    HEK_FLAGS(hek) = (unsigned char)flags_masked | HVhek_UNSHARED;
 
     if (flags & HVhek_FREEKEY)
        Safefree(str);
@@ -435,6 +436,8 @@ S_hv_fetch_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
        return NULL;
 
     if (keysv) {
+       if (SvSMAGICAL(hv) && SvGMAGICAL(hv))
+           keysv = hv_magic_uvar_xkey(hv, keysv, action);
        if (flags & HVhek_FREEKEY)
            Safefree(key);
        key = SvPV_const(keysv, klen);
@@ -447,12 +450,12 @@ S_hv_fetch_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
     xhv = (XPVHV*)SvANY(hv);
     if (SvMAGICAL(hv)) {
        if (SvRMAGICAL(hv) && !(action & (HV_FETCH_ISSTORE|HV_FETCH_ISEXISTS))) {
-           if (mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv)) {
-               sv = sv_newmortal();
+           MAGIC *regdata = NULL;
+           if (mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv)
+               || (regdata = mg_find((SV*)hv, PERL_MAGIC_regdata_names))) {
 
                /* XXX should be able to skimp on the HE/HEK here when
                   HV_FETCH_JUST_SV is true.  */
-
                if (!keysv) {
                    keysv = newSVpvn(key, klen);
                    if (is_utf8) {
@@ -461,7 +464,16 @@ S_hv_fetch_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
                } else {
                    keysv = newSVsv(keysv);
                }
-               mg_copy((SV*)hv, sv, (char *)keysv, HEf_SVKEY);
+               if (regdata) {
+                   sv = Perl_reg_named_buff_sv(aTHX_ keysv);
+                   if (!sv) {
+                       SvREFCNT_dec(keysv);
+                       return 0;
+                   }
+               } else {
+                   sv = sv_newmortal();
+                   mg_copy((SV*)hv, sv, (char *)keysv, HEf_SVKEY);
+               }
 
                /* grab a fake HE/HEK pair from the pool or make a new one */
                entry = PL_hv_fetch_ent_mh;
@@ -964,6 +976,8 @@ S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
        return NULL;
 
     if (keysv) {
+       if (SvSMAGICAL(hv) && SvGMAGICAL(hv))
+           keysv = hv_magic_uvar_xkey(hv, keysv, -1);
        if (k_flags & HVhek_FREEKEY)
            Safefree(key);
        key = SvPV_const(keysv, klen);
@@ -1491,6 +1505,39 @@ Perl_newHVhv(pTHX_ HV *ohv)
     return hv;
 }
 
+/* A rather specialised version of newHVhv for copying %^H, ensuring all the
+   magic stays on it.  */
+HV *
+Perl_hv_copy_hints_hv(pTHX_ HV *const ohv)
+{
+    HV * const hv = newHV();
+    STRLEN hv_fill;
+
+    if (ohv && (hv_fill = HvFILL(ohv))) {
+       STRLEN hv_max = HvMAX(ohv);
+       HE *entry;
+       const I32 riter = HvRITER_get(ohv);
+       HE * const eiter = HvEITER_get(ohv);
+
+       while (hv_max && hv_max + 1 >= hv_fill * 2)
+           hv_max = hv_max / 2;
+       HvMAX(hv) = hv_max;
+
+       hv_iterinit(ohv);
+       while ((entry = hv_iternext_flags(ohv, 0))) {
+           SV *const sv = newSVsv(HeVAL(entry));
+           sv_magic(sv, NULL, PERL_MAGIC_hintselem,
+                    (char *)newSVhek (HeKEY_hek(entry)), HEf_SVKEY);
+           hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
+                          sv, HeHASH(entry), HeKFLAGS(entry));
+       }
+       HvRITER_set(ohv, riter);
+       HvEITER_set(ohv, eiter);
+    }
+    hv_magic(hv, NULL, PERL_MAGIC_hints);
+    return hv;
+}
+
 void
 Perl_hv_free_ent(pTHX_ HV *hv, register HE *entry)
 {
@@ -1559,8 +1606,8 @@ Perl_hv_clear(pTHX_ HV *hv)
                    if (HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
                        SV* const keysv = hv_iterkeysv(entry);
                        Perl_croak(aTHX_
-       "Attempt to delete readonly key '%"SVf"' from a restricted hash",
-                                  keysv);
+                                  "Attempt to delete readonly key '%"SVf"' from a restricted hash",
+                                  (void*)keysv);
                    }
                    SvREFCNT_dec(HeVAL(entry));
                    HeVAL(entry) = &PL_sv_placeholder;
@@ -1574,8 +1621,7 @@ Perl_hv_clear(pTHX_ HV *hv)
     hfreeentries(hv);
     HvPLACEHOLDERS_set(hv, 0);
     if (HvARRAY(hv))
-       (void)memzero(HvARRAY(hv),
-                     (xhv->xhv_max+1 /* HvMAX(hv)+1 */) * sizeof(HE*));
+       Zero(HvARRAY(hv), xhv->xhv_max+1 /* HvMAX(hv)+1 */, HE*);
 
     if (SvRMAGICAL(hv))
        mg_clear((SV*)hv);
@@ -1886,7 +1932,17 @@ Perl_hv_iterinit(pTHX_ HV *hv)
     } else {
        hv_auxinit(hv);
     }
-
+    if (SvMAGICAL(hv) && SvRMAGICAL(hv)) {
+        MAGIC *mg = mg_find((SV*)hv, PERL_MAGIC_regdata_names);
+        if ( mg ) {
+             if (PL_curpm) {
+                const REGEXP * const rx = PM_GETRE(PL_curpm);
+                if (rx && rx->paren_names) {
+                    (void)hv_iterinit(rx->paren_names);
+                } 
+            } 
+        }
+    }
     /* used to be xhv->xhv_fill before 5.004_65 */
     return HvTOTALKEYS(hv);
 }
@@ -2041,6 +2097,7 @@ Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
 
     if (!hv)
        Perl_croak(aTHX_ "Bad hash");
+
     xhv = (XPVHV*)SvANY(hv);
 
     if (!SvOOK(hv)) {
@@ -2052,8 +2109,85 @@ Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
     iter = HvAUX(hv);
 
     oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
+    if (SvMAGICAL(hv) && SvRMAGICAL(hv) &&
+           (mg = mg_find((SV*)hv, PERL_MAGIC_regdata_names)))
+    {
+       SV * key;
+       SV *val = NULL;
+       REGEXP * rx;
+       if (!PL_curpm)
+           return NULL;
+       rx = PM_GETRE(PL_curpm);
+       if (rx && rx->paren_names) {
+           hv = rx->paren_names;
+       } else {
+           return NULL;
+       }
 
-    if ((mg = SvTIED_mg((SV*)hv, PERL_MAGIC_tied))) {
+        key =  sv_newmortal();
+        if (entry) {
+            sv_setsv(key, HeSVKEY_force(entry));
+            SvREFCNT_dec(HeSVKEY(entry));       /* get rid of previous key */
+        }
+        else {
+            char *k;
+            HEK *hek;
+
+            /* one HE per MAGICAL hash */
+            iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
+            Zero(entry, 1, HE);
+            Newxz(k, HEK_BASESIZE + sizeof(SV*), char);
+            hek = (HEK*)k;
+            HeKEY_hek(entry) = hek;
+            HeKLEN(entry) = HEf_SVKEY;
+        }
+        {
+            while (!val) {
+                HE *temphe = hv_iternext_flags(hv,flags);
+                if (temphe) {
+                    IV i;
+                    IV parno = 0;
+                    SV* sv_dat = HeVAL(temphe);
+                    I32 *nums = (I32*)SvPVX(sv_dat);
+                    for ( i = 0; i < SvIVX(sv_dat); i++ ) {
+                        if ((I32)(rx->lastcloseparen) >= nums[i] &&
+                            rx->startp[nums[i]] != -1 &&
+                            rx->endp[nums[i]] != -1) 
+                        {
+                            parno = nums[i];
+                            break;
+                        }
+                    }
+                    if (parno) {
+                        GV *gv_paren;
+                        STRLEN len;
+                        SV *sv = sv_newmortal();
+                        const char* pvkey = HePV(temphe, len);
+                        
+                        Perl_sv_setpvf(aTHX_ sv, "%"IVdf,(IV)parno);
+                        gv_paren = Perl_gv_fetchsv(aTHX_ sv, GV_ADD, SVt_PVGV);
+                        Perl_sv_setpvn(aTHX_ key, pvkey, len);
+                        val = GvSVn(gv_paren);
+                    } 
+                } else {
+                    break;
+                }
+            }
+        }
+        if (val && SvOK(key)) {
+            /* force key to stay around until next time */
+            HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
+            HeVAL(entry) = SvREFCNT_inc_simple_NN(val); 
+            return entry;               /* beware, hent_val is not set */
+        }
+        if (HeVAL(entry))
+            SvREFCNT_dec(HeVAL(entry));
+        Safefree(HeKEY_hek(entry));
+        del_HE(entry);
+        iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
+        return NULL;
+    
+    } else if ((mg = SvTIED_mg((SV*)hv, PERL_MAGIC_tied))) {
        SV * const key = sv_newmortal();
        if (entry) {
            sv_setsv(key, HeSVKEY_force(entry));
@@ -2084,7 +2218,7 @@ Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
        iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
        return NULL;
     }
-#ifdef DYNAMIC_ENV_FETCH  /* set up %ENV for iteration */
+#if defined(DYNAMIC_ENV_FETCH) && !defined(__riscos__)  /* set up %ENV for iteration */
     if (!entry && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
        prime_env_iter();
 #ifdef VMS
@@ -2274,7 +2408,6 @@ S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
     HE *entry;
     register HE **oentry;
     HE **first;
-    bool found = 0;
     bool is_utf8 = FALSE;
     int k_flags = 0;
     const char * const save = str;
@@ -2323,10 +2456,8 @@ S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
     if (he) {
        const HE *const he_he = &(he->shared_he_he);
         for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
-            if (entry != he_he)
-                continue;
-            found = 1;
-            break;
+            if (entry == he_he)
+                break;
         }
     } else {
         const int flags_masked = k_flags & HVhek_MASK;
@@ -2339,13 +2470,12 @@ S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
                 continue;
             if (HeKFLAGS(entry) != flags_masked)
                 continue;
-            found = 1;
             break;
         }
     }
 
-    if (found) {
-        if (--he->shared_he_he.he_valu.hent_refcount == 0) {
+    if (entry) {
+        if (--entry->he_valu.hent_refcount == 0) {
             *oentry = HeNEXT(entry);
             if (!*first) {
                /* There are now no entries in our slot.  */
@@ -2357,7 +2487,7 @@ S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
     }
 
     UNLOCK_STRTAB_MUTEX;
-    if (!found && ckWARN_d(WARN_INTERNAL))
+    if (!entry && ckWARN_d(WARN_INTERNAL))
        Perl_warner(aTHX_ packWARN(WARN_INTERNAL),
                     "Attempt to free non-existent shared string '%s'%s"
                     pTHX__FORMAT,
@@ -2482,6 +2612,24 @@ S_share_hek_flags(pTHX_ const char *str, I32 len, register U32 hash, int flags)
     return HeKEY_hek(entry);
 }
 
+STATIC SV *
+S_hv_magic_uvar_xkey(pTHX_ HV* hv, SV* keysv, int action)
+{
+    MAGIC* mg;
+    if ((mg = mg_find((SV*)hv, PERL_MAGIC_uvar))) {
+       struct ufuncs * const uf = (struct ufuncs *)mg->mg_ptr;
+       if (uf->uf_set == NULL) {
+           SV* obj = mg->mg_obj;
+           mg->mg_obj = keysv;         /* pass key */
+           uf->uf_index = action;      /* pass action */
+           magic_getuvar((SV*)hv, mg);
+           keysv = mg->mg_obj;         /* may have changed */
+           mg->mg_obj = obj;
+       }
+    }
+    return keysv;
+}
+
 I32 *
 Perl_hv_placeholders_p(pTHX_ HV *hv)
 {
@@ -2523,6 +2671,52 @@ Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
     /* else we don't need to add magic to record 0 placeholders.  */
 }
 
+SV *
+S_refcounted_he_value(pTHX_ const struct refcounted_he *he)
+{
+    dVAR;
+    SV *value;
+    switch(he->refcounted_he_data[0] & HVrhek_typemask) {
+    case HVrhek_undef:
+       value = newSV(0);
+       break;
+    case HVrhek_delete:
+       value = &PL_sv_placeholder;
+       break;
+    case HVrhek_IV:
+       value = (he->refcounted_he_data[0] & HVrhek_UV)
+           ? newSVuv(he->refcounted_he_val.refcounted_he_u_iv)
+           : newSViv(he->refcounted_he_val.refcounted_he_u_uv);
+       break;
+    case HVrhek_PV:
+       /* Create a string SV that directly points to the bytes in our
+          structure.  */
+       value = newSV(0);
+       sv_upgrade(value, SVt_PV);
+       SvPV_set(value, (char *) he->refcounted_he_data + 1);
+       SvCUR_set(value, he->refcounted_he_val.refcounted_he_u_len);
+       /* This stops anything trying to free it  */
+       SvLEN_set(value, 0);
+       SvPOK_on(value);
+       SvREADONLY_on(value);
+       if (he->refcounted_he_data[0] & HVrhek_UTF8)
+           SvUTF8_on(value);
+       break;
+    default:
+       Perl_croak(aTHX_ "panic: refcounted_he_value bad flags %x",
+                  he->refcounted_he_data[0]);
+    }
+    return value;
+}
+
+#ifdef USE_ITHREADS
+/* A big expression to find the key offset */
+#define REF_HE_KEY(chain) \
+       ((((chain->refcounted_he_data[0] & HVrhek_typemask) == HVrhek_PV) \
+           ? chain->refcounted_he_val.refcounted_he_u_len + 1 : 0)       \
+        + 1 + chain->refcounted_he_data)
+#endif
+
 /*
 =for apidoc refcounted_he_chain_2hv
 
@@ -2534,6 +2728,7 @@ in C<struct refcounted_he *>.
 HV *
 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain)
 {
+    dVAR;
     HV *hv = newHV();
     U32 placeholders = 0;
     /* We could chase the chain once to get an idea of the number of keys,
@@ -2548,24 +2743,56 @@ Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain)
     }
 
     while (chain) {
-       const U32 hash = HEK_HASH(chain->refcounted_he_he.hent_hek);
+#ifdef USE_ITHREADS
+       U32 hash = chain->refcounted_he_hash;
+#else
+       U32 hash = HEK_HASH(chain->refcounted_he_hek);
+#endif
        HE **oentry = &((HvARRAY(hv))[hash & max]);
        HE *entry = *oentry;
+       SV *value;
 
        for (; entry; entry = HeNEXT(entry)) {
            if (HeHASH(entry) == hash) {
-               goto next_please;
+               /* We might have a duplicate key here.  If so, entry is older
+                  than the key we've already put in the hash, so if they are
+                  the same, skip adding entry.  */
+#ifdef USE_ITHREADS
+               const STRLEN klen = HeKLEN(entry);
+               const char *const key = HeKEY(entry);
+               if (klen == chain->refcounted_he_keylen
+                   && (!!HeKUTF8(entry)
+                       == !!(chain->refcounted_he_data[0] & HVhek_UTF8))
+                   && memEQ(key, REF_HE_KEY(chain), klen))
+                   goto next_please;
+#else
+               if (HeKEY_hek(entry) == chain->refcounted_he_hek)
+                   goto next_please;
+               if (HeKLEN(entry) == HEK_LEN(chain->refcounted_he_hek)
+                   && HeKUTF8(entry) == HEK_UTF8(chain->refcounted_he_hek)
+                   && memEQ(HeKEY(entry), HEK_KEY(chain->refcounted_he_hek),
+                            HeKLEN(entry)))
+                   goto next_please;
+#endif
            }
        }
        assert (!entry);
        entry = new_HE();
 
-       HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_he.hent_hek);
-
-       HeVAL(entry) = chain->refcounted_he_he.he_valu.hent_val;
-       if (HeVAL(entry) == &PL_sv_placeholder)
+#ifdef USE_ITHREADS
+       HeKEY_hek(entry)
+           = share_hek_flags(REF_HE_KEY(chain),
+                             chain->refcounted_he_keylen,
+                             chain->refcounted_he_hash,
+                             (chain->refcounted_he_data[0]
+                              & (HVhek_UTF8|HVhek_WASUTF8)));
+#else
+       HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_hek);
+#endif
+       value = refcounted_he_value(chain);
+       if (value == &PL_sv_placeholder)
            placeholders++;
-       SvREFCNT_inc_void_NN(HeVAL(entry));
+       HeVAL(entry) = value;
 
        /* Link it into the chain.  */
        HeNEXT(entry) = *oentry;
@@ -2578,7 +2805,7 @@ Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain)
        HvTOTALKEYS(hv)++;
 
     next_please:
-       chain = (struct refcounted_he *) chain->refcounted_he_he.hent_next;
+       chain = chain->refcounted_he_next;
     }
 
     if (placeholders) {
@@ -2590,20 +2817,76 @@ Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain)
        flags, but it's probably not worth it, as this per-hash flag is only
        really meant as an optimisation for things like Storable.  */
     HvHASKFLAGS_on(hv);
-#ifdef DEBUGGING
-    Perl_hv_assert(aTHX_ hv);
-#endif
+    DEBUG_A(Perl_hv_assert(aTHX_ hv));
 
     return hv;
 }
 
+SV *
+Perl_refcounted_he_fetch(pTHX_ const struct refcounted_he *chain, SV *keysv,
+                        const char *key, STRLEN klen, int flags, U32 hash)
+{
+    dVAR;
+    /* Just to be awkward, if you're using this interface the UTF-8-or-not-ness
+       of your key has to exactly match that which is stored.  */
+    SV *value = &PL_sv_placeholder;
+    bool is_utf8;
+
+    if (keysv) {
+       if (flags & HVhek_FREEKEY)
+           Safefree(key);
+       key = SvPV_const(keysv, klen);
+       flags = 0;
+       is_utf8 = (SvUTF8(keysv) != 0);
+    } else {
+       is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
+    }
+
+    if (!hash) {
+       if (keysv && (SvIsCOW_shared_hash(keysv))) {
+            hash = SvSHARED_HASH(keysv);
+        } else {
+            PERL_HASH(hash, key, klen);
+        }
+    }
+
+    for (; chain; chain = chain->refcounted_he_next) {
+#ifdef USE_ITHREADS
+       if (hash != chain->refcounted_he_hash)
+           continue;
+       if (klen != chain->refcounted_he_keylen)
+           continue;
+       if (memNE(REF_HE_KEY(chain),key,klen))
+           continue;
+       if (!!is_utf8 != !!(chain->refcounted_he_data[0] & HVhek_UTF8))
+           continue;
+#else
+       if (hash != HEK_HASH(chain->refcounted_he_hek))
+           continue;
+       if (klen != (STRLEN)HEK_LEN(chain->refcounted_he_hek))
+           continue;
+       if (memNE(HEK_KEY(chain->refcounted_he_hek),key,klen))
+           continue;
+       if (!!is_utf8 != !!HEK_UTF8(chain->refcounted_he_hek))
+           continue;
+#endif
+
+       value = sv_2mortal(refcounted_he_value(chain));
+       break;
+    }
+
+    if (flags & HVhek_FREEKEY)
+       Safefree(key);
+
+    return value;
+}
+
 /*
 =for apidoc refcounted_he_new
 
-Creates a new C<struct refcounted_he>. Assumes ownership of one reference
-to I<value>. As S<key> is copied into a shared hash key, all references remain
-the property of the caller. The C<struct refcounted_he> is returned with a
-reference count of 1.
+Creates a new C<struct refcounted_he>. As S<key> is copied, and value is
+stored in a compact form, all references remain the property of the caller.
+The C<struct refcounted_he> is returned with a reference count of 1.
 
 =cut
 */
@@ -2611,19 +2894,92 @@ reference count of 1.
 struct refcounted_he *
 Perl_refcounted_he_new(pTHX_ struct refcounted_he *const parent,
                       SV *const key, SV *const value) {
+    dVAR;
     struct refcounted_he *he;
+    STRLEN key_len;
+    const char *key_p = SvPV_const(key, key_len);
+    STRLEN value_len = 0;
+    const char *value_p = NULL;
+    char value_type;
+    char flags;
+    STRLEN key_offset;
     U32 hash;
-    STRLEN len;
-    const char *p = SvPV_const(key, len);
+    bool is_utf8 = SvUTF8(key) ? TRUE : FALSE;
+
+    if (SvPOK(value)) {
+       value_type = HVrhek_PV;
+    } else if (SvIOK(value)) {
+       value_type = HVrhek_IV;
+    } else if (value == &PL_sv_placeholder) {
+       value_type = HVrhek_delete;
+    } else if (!SvOK(value)) {
+       value_type = HVrhek_undef;
+    } else {
+       value_type = HVrhek_PV;
+    }
+
+    if (value_type == HVrhek_PV) {
+       value_p = SvPV_const(value, value_len);
+       key_offset = value_len + 2;
+    } else {
+       value_len = 0;
+       key_offset = 1;
+    }
+    flags = value_type;
+
+#ifdef USE_ITHREADS
+    he = (struct refcounted_he*)
+       PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
+                            + key_len
+                            + key_offset);
+#else
+    he = (struct refcounted_he*)
+       PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
+                            + key_offset);
+#endif
+
 
-    PERL_HASH(hash, p, len);
+    he->refcounted_he_next = parent;
 
-    Newx(he, 1, struct refcounted_he);
+    if (value_type == HVrhek_PV) {
+       Copy(value_p, he->refcounted_he_data + 1, value_len + 1, char);
+       he->refcounted_he_val.refcounted_he_u_len = value_len;
+       if (SvUTF8(value)) {
+           flags |= HVrhek_UTF8;
+       }
+    } else if (value_type == HVrhek_IV) {
+       if (SvUOK(value)) {
+           he->refcounted_he_val.refcounted_he_u_uv = SvUVX(value);
+           flags |= HVrhek_UV;
+       } else {
+           he->refcounted_he_val.refcounted_he_u_iv = SvIVX(value);
+       }
+    }
 
-    he->refcounted_he_he.hent_next = (HE *)parent;
-    he->refcounted_he_he.he_valu.hent_val = value;
-    he->refcounted_he_he.hent_hek
-       = share_hek(p, SvUTF8(key) ? -(I32)len : len, hash);
+    if (is_utf8) {
+       /* Hash keys are always stored normalised to (yes) ISO-8859-1.
+          As we're going to be building hash keys from this value in future,
+          normalise it now.  */
+       key_p = (char*)bytes_from_utf8((const U8*)key_p, &key_len, &is_utf8);
+       flags |= is_utf8 ? HVhek_UTF8 : HVhek_WASUTF8;
+    }
+    PERL_HASH(hash, key_p, key_len);
+
+#ifdef USE_ITHREADS
+    he->refcounted_he_hash = hash;
+    he->refcounted_he_keylen = key_len;
+    Copy(key_p, he->refcounted_he_data + key_offset, key_len, char);
+#else
+    he->refcounted_he_hek = share_hek_flags(key_p, key_len, hash, flags);
+#endif
+
+    if (flags & HVhek_WASUTF8) {
+       /* If it was downgraded from UTF-8, then the pointer returned from
+          bytes_from_utf8 is an allocated pointer that we must free.  */
+       Safefree(key_p);
+    }
+
+    he->refcounted_he_data[0] = flags;
     he->refcounted_he_refcnt = 1;
 
     return he;
@@ -2641,95 +2997,29 @@ and C<refcounted_he_free> iterates onto the parent node.
 
 void
 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
+    PERL_UNUSED_CONTEXT;
+
     while (he) {
        struct refcounted_he *copy;
+       U32 new_count;
 
-       if (--he->refcounted_he_refcnt)
+       HINTS_REFCNT_LOCK;
+       new_count = --he->refcounted_he_refcnt;
+       HINTS_REFCNT_UNLOCK;
+       
+       if (new_count) {
            return;
+       }
 
-       unshare_hek_or_pvn (he->refcounted_he_he.hent_hek, 0, 0, 0);
-       SvREFCNT_dec(he->refcounted_he_he.he_valu.hent_val);
+#ifndef USE_ITHREADS
+       unshare_hek_or_pvn (he->refcounted_he_hek, 0, 0, 0);
+#endif
        copy = he;
-       he = (struct refcounted_he *) he->refcounted_he_he.hent_next;
-       Safefree(copy);
+       he = he->refcounted_he_next;
+       PerlMemShared_free(copy);
     }
 }
 
-
-/*
-=for apidoc refcounted_he_dup
-
-Duplicates the C<struct refcounted_he *> for a new thread.
-
-=cut
-*/
-
-#if defined(USE_ITHREADS)
-struct refcounted_he *
-Perl_refcounted_he_dup(pTHX_ const struct refcounted_he *const he,
-                       CLONE_PARAMS* param)
-{
-    struct refcounted_he *copy;
-
-    if (!he)
-       return NULL;
-
-    /* look for it in the table first */
-    copy = (struct refcounted_he *)ptr_table_fetch(PL_ptr_table, he);
-    if (copy)
-       return copy;
-
-    /* create anew and remember what it is */
-    Newx(copy, 1, struct refcounted_he);
-    ptr_table_store(PL_ptr_table, he, copy);
-
-    copy->refcounted_he_he.hent_next
-       = (HE *)Perl_refcounted_he_dup(aTHX_
-                                      (struct refcounted_he *)
-                                      he->refcounted_he_he.hent_next,
-                                      param);
-    copy->refcounted_he_he.he_valu.hent_val
-       = SvREFCNT_inc(sv_dup(he->refcounted_he_he.he_valu.hent_val, param));
-    copy->refcounted_he_he.hent_hek
-       = hek_dup(he->refcounted_he_he.hent_hek, param);
-    copy->refcounted_he_refcnt = he->refcounted_he_refcnt;
-    return copy;
-}
-
-/*
-=for apidoc refcounted_he_copy
-
-Copies a chain of C<struct refcounted_he *>. Used by C<pp_entereval>.
-
-=cut
-*/
-
-struct refcounted_he *
-Perl_refcounted_he_copy(pTHX_ const struct refcounted_he * he)
-{
-    struct refcounted_he *copy;
-    HEK *hek;
-    /* This is much easier to express recursively than iteratively.  */
-    if (!he)
-       return NULL;
-
-    Newx(copy, 1, struct refcounted_he);
-    copy->refcounted_he_he.hent_next
-       = (HE *)Perl_refcounted_he_copy(aTHX_
-                                      (struct refcounted_he *)
-                                      he->refcounted_he_he.hent_next);
-    copy->refcounted_he_he.he_valu.hent_val
-       = newSVsv(he->refcounted_he_he.he_valu.hent_val);
-    hek = he->refcounted_he_he.hent_hek;
-    copy->refcounted_he_he.hent_hek
-       = share_hek(HEK_KEY(hek),
-                   HEK_UTF8(hek) ? -(I32)HEK_LEN(hek) : HEK_LEN(hek),
-                   HEK_HASH(hek));
-    copy->refcounted_he_refcnt = 1;
-    return copy;
-}
-#endif
-
 /*
 =for apidoc hv_assert
 
@@ -2743,63 +3033,62 @@ Check that a hash is in an internally consistent state.
 void
 Perl_hv_assert(pTHX_ HV *hv)
 {
-  dVAR;
-  HE* entry;
-  int withflags = 0;
-  int placeholders = 0;
-  int real = 0;
-  int bad = 0;
-  const I32 riter = HvRITER_get(hv);
-  HE *eiter = HvEITER_get(hv);
-
-  (void)hv_iterinit(hv);
-
-  while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
-    /* sanity check the values */
-    if (HeVAL(entry) == &PL_sv_placeholder) {
-      placeholders++;
-    } else {
-      real++;
-    }
-    /* sanity check the keys */
-    if (HeSVKEY(entry)) {
-      /*EMPTY*/ /* Don't know what to check on SV keys.  */
-    } else if (HeKUTF8(entry)) {
-      withflags++;
-       if (HeKWASUTF8(entry)) {
-        PerlIO_printf(Perl_debug_log,
-                      "hash key has both WASUFT8 and UTF8: '%.*s'\n",
-                      (int) HeKLEN(entry),  HeKEY(entry));
-        bad = 1;
-       }
-    } else if (HeKWASUTF8(entry)) {
-      withflags++;
-    }
-  }
-  if (!SvTIED_mg((SV*)hv, PERL_MAGIC_tied)) {
-    if (HvUSEDKEYS(hv) != real) {
-      PerlIO_printf(Perl_debug_log, "Count %d key(s), but hash reports %d\n",
-                   (int) real, (int) HvUSEDKEYS(hv));
-      bad = 1;
-    }
-    if (HvPLACEHOLDERS_get(hv) != placeholders) {
-      PerlIO_printf(Perl_debug_log,
-                   "Count %d placeholder(s), but hash reports %d\n",
-                   (int) placeholders, (int) HvPLACEHOLDERS_get(hv));
-      bad = 1;
-    }
-  }
-  if (withflags && ! HvHASKFLAGS(hv)) {
-    PerlIO_printf(Perl_debug_log,
-                 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
-                 withflags);
-    bad = 1;
-  }
-  if (bad) {
-    sv_dump((SV *)hv);
-  }
-  HvRITER_set(hv, riter);              /* Restore hash iterator state */
-  HvEITER_set(hv, eiter);
+    dVAR;
+    HE* entry;
+    int withflags = 0;
+    int placeholders = 0;
+    int real = 0;
+    int bad = 0;
+    const I32 riter = HvRITER_get(hv);
+    HE *eiter = HvEITER_get(hv);
+
+    (void)hv_iterinit(hv);
+
+    while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
+       /* sanity check the values */
+       if (HeVAL(entry) == &PL_sv_placeholder)
+           placeholders++;
+       else
+           real++;
+       /* sanity check the keys */
+       if (HeSVKEY(entry)) {
+           NOOP;   /* Don't know what to check on SV keys.  */
+       } else if (HeKUTF8(entry)) {
+           withflags++;
+           if (HeKWASUTF8(entry)) {
+               PerlIO_printf(Perl_debug_log,
+                           "hash key has both WASUFT8 and UTF8: '%.*s'\n",
+                           (int) HeKLEN(entry),  HeKEY(entry));
+               bad = 1;
+           }
+       } else if (HeKWASUTF8(entry))
+           withflags++;
+    }
+    if (!SvTIED_mg((SV*)hv, PERL_MAGIC_tied)) {
+       static const char bad_count[] = "Count %d %s(s), but hash reports %d\n";
+       const int nhashkeys = HvUSEDKEYS(hv);
+       const int nhashplaceholders = HvPLACEHOLDERS_get(hv);
+
+       if (nhashkeys != real) {
+           PerlIO_printf(Perl_debug_log, bad_count, real, "keys", nhashkeys );
+           bad = 1;
+       }
+       if (nhashplaceholders != placeholders) {
+           PerlIO_printf(Perl_debug_log, bad_count, placeholders, "placeholder", nhashplaceholders );
+           bad = 1;
+       }
+    }
+    if (withflags && ! HvHASKFLAGS(hv)) {
+       PerlIO_printf(Perl_debug_log,
+                   "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
+                   withflags);
+       bad = 1;
+    }
+    if (bad) {
+       sv_dump((SV *)hv);
+    }
+    HvRITER_set(hv, riter);            /* Restore hash iterator state */
+    HvEITER_set(hv, eiter);
 }
 
 #endif