X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=ext%2FHash%2FUtil%2FFieldHash%2FFieldHash.xs;h=972f99dad3b3f0e44f40e9ac79f898992cde5c9f;hb=d74d639bc8e61d741d9a79acc1bd92b4db9c8347;hp=14e60f15a5c19b7e788ec211f614a54c1369c41d;hpb=a607227a3e6385121d3bf032568fb6b9c2dd6e68;p=p5sagit%2Fp5-mst-13.2.git

diff --git a/ext/Hash/Util/FieldHash/FieldHash.xs b/ext/Hash/Util/FieldHash/FieldHash.xs
index 14e60f1..972f99d 100644
--- a/ext/Hash/Util/FieldHash/FieldHash.xs
+++ b/ext/Hash/Util/FieldHash/FieldHash.xs
@@ -4,12 +4,13 @@
 
 /* support for Hash::Util::FieldHash, prefix HUF_ */
 
-/* The object registry, a package variable */
-#define HUF_OB_REG "Hash::Util::FieldHash::ob_reg"
+/* A Perl sub that returns a hashref to the object registry */
+#define HUF_OB_REG "Hash::Util::FieldHash::_ob_reg"
 /* Magic cookies to recognize object id's.  Hi, Eva, David */
 #define HUF_COOKIE 2805.1980
 #define HUF_REFADDR_COOKIE 1811.1976
-
+/* Identifier for PERL_MAGIC_ext magic */
+#define HUF_IDCACHE 0x4944
 
 /* For global cache of object registry */
 #define MY_CXT_KEY "Hash::Util::FieldHash::_guts" XS_VERSION
@@ -18,6 +19,29 @@ typedef struct {
 } my_cxt_t;
 START_MY_CXT
 
+/* Inquire the object registry (a lexical hash) from perl */
+HV* HUF_get_ob_reg(void) {
+    dSP;
+    HV* ob_reg = NULL;
+    I32 items;
+    ENTER;
+    SAVETMPS;
+
+    PUSHMARK(SP);
+    items = call_pv(HUF_OB_REG, G_SCALAR|G_NOARGS);
+    SPAGAIN;
+
+    if (items == 1 && TOPs && SvROK(TOPs) && SvTYPE(SvRV(TOPs)) == SVt_PVHV)
+        ob_reg = (HV*)SvRV(POPs);
+    PUTBACK;
+    FREETMPS;
+    LEAVE;
+
+    if (!ob_reg)
+        Perl_die(aTHX_ "Can't get object registry hash");
+    return ob_reg;
+}
+
 /* Deal with global context */
 #define HUF_INIT 1
 #define HUF_CLONE 0
@@ -26,44 +50,49 @@ START_MY_CXT
 void HUF_global(I32 how) {
     if (how == HUF_INIT) {
         MY_CXT_INIT;
-        MY_CXT.ob_reg = get_hv(HUF_OB_REG, 1);
+        MY_CXT.ob_reg = HUF_get_ob_reg();
     } else if (how == HUF_CLONE) {
         MY_CXT_CLONE;
-        MY_CXT.ob_reg = get_hv(HUF_OB_REG, 0);
+        MY_CXT.ob_reg = HUF_get_ob_reg();
     } else if (how == HUF_RESET) {
         dMY_CXT;
-        MY_CXT.ob_reg = get_hv(HUF_OB_REG, 0);
+        MY_CXT.ob_reg = HUF_get_ob_reg();
     }
 }
 
-/* the id as an SV, optionally marked in the nv (unused feature) */
-SV* HUF_id(SV* ref, NV cookie) {
-    SV* id = sv_newmortal();
-    if (cookie == 0 ) {
-        SvUPGRADE(id, SVt_PVIV);
-    } else {
-        SvUPGRADE(id, SVt_PVNV);
-        SvNV_set(id, cookie);
-        SvNOK_on(id);
-    }
-    SvIV_set(id, (IV)SvRV(ref));
-    SvIOK_on(id);
-    return id;
-}
+/* Object id */
 
-/* plain id, only used for field hash entries in field lists */
-SV* HUF_field_id(SV* obj) {
-    return HUF_id(obj, 0.0);
-}
+/* definition of id transformation */
+#define HUF_OBJ_ID(x) newSVuv(PTR2UV(x))
 
-/* object id (may be different in future) */
 SV* HUF_obj_id(SV* obj) {
-    return HUF_id(obj, 0.0);
+    SV *item = SvRV(obj);
+    MAGIC *mg;
+    SV *id;
+
+    /* Get cached object ID, if it exists */
+    if (SvTYPE(item) >= SVt_PVMG) {
+        for ( mg = SvMAGIC(item); mg; mg = mg->mg_moremagic ) {
+            if ((mg->mg_type == PERL_MAGIC_ext) &&
+                (mg->mg_private == HUF_IDCACHE)
+            ) {
+                return mg->mg_obj;
+            }
+        }
+    }
+
+    /* Create an object ID, cache it */
+    id = HUF_OBJ_ID(item);
+    mg = sv_magicext(item, id, PERL_MAGIC_ext, NULL, NULL, 0);
+    mg->mg_private = HUF_IDCACHE;
+
+    /* Return the object ID */
+    return id;
 }
 
 /* set up uvar magic for any sv */
 void HUF_add_uvar_magic(
-    SV* sv,                    /* the sv to enchant, visible to * get/set */
+    SV* sv,                    /* the sv to enchant, visible to get/set */
     I32(* val)(pTHX_ IV, SV*), /* "get" function */
     I32(* set)(pTHX_ IV, SV*), /* "set" function */
     I32 index,                 /* get/set will see this */
@@ -85,7 +114,8 @@ AV* HUF_get_trigger_content(SV* trigger) {
 }
 
 /* Delete an object from all field hashes it may occur in.  Also delete
- * the object's entry from the object registry.
+ * the object's entry from the object registry.  This function goes in
+ * the uf_set field of the uvar magic of a trigger.
  */
 I32 HUF_destroy_obj(pTHX_ IV index, SV* trigger) {
     /* Do nothing if the weakref wasn't undef'd.  Also don't bother
@@ -104,17 +134,19 @@ I32 HUF_destroy_obj(pTHX_ IV index, SV* trigger) {
         }
         /* make it safe in case we must run in global clenaup, after all */
         if (PL_in_clean_all)
-            HUF_global(HUF_RESET);
+            HUF_global(HUF_RESET); /* shoudn't be needed */
         hv_delete_ent(MY_CXT.ob_reg, ob_id, G_DISCARD, 0);
     }
     return 0;
 }
 
-/* Create a trigger for an object.  The trigger is a magical weak ref
- * that fires when the weak ref expires.  it holds the original id of
- * the object, and a list of field hashes from which the object may
- * have to be deleted.  The trigger is stored in the object registry
- * and also deleted when the object expires.
+/* Create a trigger for an object.  The trigger is a magical SV
+ * that holds a weak ref to the object.  The magic fires when the object
+ * expires and takes care of garbage collection in registred hashes.
+ * For that purpose, the magic structure holds the original id of
+ * the object, and a list (a hash, really) of hashes from which the
+ * object may * have to be deleted.  The trigger is stored in the
+ * object registry and is also deleted when the object expires.
  */
 SV* HUF_new_trigger(SV* obj, SV* ob_id) {
     dMY_CXT;
@@ -138,41 +170,68 @@ SV* HUF_ask_trigger(SV* ob_id) {
 }
 
 /* get the trigger for an object, creating it if necessary */
-SV* HUF_get_trigger(SV* obj, SV* ob_id) {
+SV* HUF_get_trigger0(SV* obj, SV* ob_id) {
     SV* trigger;
     if (!(trigger = HUF_ask_trigger(ob_id)))
         trigger = HUF_new_trigger(obj, ob_id);
     return trigger;
 }
 
-/* mark an object (trigger) as having been used with a field */
+SV* HUF_get_trigger(SV* obj, SV* ob_id) {
+    SV* trigger = HUF_ask_trigger(ob_id);
+    if (!trigger)
+        trigger = HUF_new_trigger(obj, ob_id);
+    return( trigger);
+}
+
+/* mark an object (trigger) as having been used with a field
+   (a clenup-liability)
+*/
 void HUF_mark_field(SV* trigger, SV* field) {
     AV* cont = HUF_get_trigger_content(trigger);
     HV* field_tab = (HV*) *av_fetch(cont, 1, 0);
     SV* field_ref = newRV_inc(field);
-    SV* field_id = HUF_field_id(field_ref);
-    hv_store_ent(field_tab, field_id, field_ref, 0);
+    UV field_addr = PTR2UV(field);
+    hv_store(field_tab, (char *)&field_addr, sizeof(field_addr), field_ref, 0);
 }
 
-#define HV_FETCH_ISSTORE   0x01
-#define HV_FETCH_ISEXISTS  0x02
-#define HV_FETCH_LVALUE    0x04
-#define HV_FETCH_JUST_SV   0x08
-
-#define HUF_WOULD_CREATE_KEY(x) ((x) != -1 && ((x) & (HV_FETCH_ISSTORE | HV_FETCH_LVALUE)))
+/* Determine, from the value of action, whether this call may create a new
+ * hash key */
+#define HUF_WOULD_CREATE_KEY(x) ((x) != HV_DELETE && ((x) & (HV_FETCH_ISSTORE | HV_FETCH_LVALUE)))
 
-/* The key exchange function.  It communicates with S_hv_magic_uvar_xkey
+/* The key exchange functions.  They communicate with S_hv_magic_uvar_xkey
  * in hv.c */
-I32 HUF_watch_key(pTHX_ IV action, SV* field) {
+I32 HUF_watch_key_safe(pTHX_ IV action, SV* field) {
     MAGIC* mg = mg_find(field, PERL_MAGIC_uvar);
-    SV* keysv = mg->mg_obj;
-    if (keysv && SvROK(keysv)) {
-        SV* ob_id = HUF_obj_id(keysv);
-        mg->mg_obj = ob_id; /* key replacement */
-        if (HUF_WOULD_CREATE_KEY(action)) {
-            SV* trigger = HUF_get_trigger(keysv, ob_id);
-            HUF_mark_field(trigger, field);
+    SV* keysv;
+    if (mg && (keysv = mg->mg_obj)) {
+        if (SvROK(keysv)) { /* ref key */
+            SV* ob_id = HUF_obj_id(keysv);
+            mg->mg_obj = ob_id; /* key replacement */
+            if (HUF_WOULD_CREATE_KEY(action)) {
+                SV* trigger = HUF_get_trigger(keysv, ob_id);
+                HUF_mark_field(trigger, field);
+            }
+        } else if (HUF_WOULD_CREATE_KEY(action)) { /* string key */
+            /* registered as object id? */
+            SV* trigger;
+            if ( trigger = HUF_ask_trigger(keysv))
+                HUF_mark_field( trigger, field);
         }
+    } else {
+        Perl_die(aTHX_ "Rogue call of 'HUF_watch_key_safe'");
+    }
+    return 0;
+}
+
+I32 HUF_watch_key_id(pTHX_ IV action, SV* field) {
+    MAGIC* mg = mg_find(field, PERL_MAGIC_uvar);
+    SV* keysv;
+    if (mg && (keysv = mg->mg_obj)) {
+        if (SvROK(keysv)) /* ref key */
+            mg->mg_obj = HUF_obj_id(keysv); /* key replacement */
+    } else {
+        Perl_die(aTHX_ "Rogue call of 'HUF_watch_key_id'");
     }
     return 0;
 }
@@ -181,17 +240,40 @@ I32 HUF_watch_key(pTHX_ IV action, SV* field) {
 int HUF_get_status(HV* hash) {
     int ans = 0;
     if (hash && (SvTYPE(hash) == SVt_PVHV)) {
-        dMY_CXT;
         MAGIC* mg;
         struct ufuncs* uf;
-        ans = (mg = mg_find((SV*)hash, PERL_MAGIC_uvar)) &&
+        if ((mg = mg_find((SV*)hash, PERL_MAGIC_uvar)) &&
             (uf = (struct ufuncs *)mg->mg_ptr) &&
-            (uf->uf_val == &HUF_watch_key) &&
-            (uf->uf_set == NULL);
+            (uf->uf_set == NULL)
+        ) {
+            ans = HUF_func_2mode(uf->uf_val);
+        }
     }
     return ans;
 }
 
+int HUF_func_2mode( I32(* val)(pTHX_ IV, SV*)) {
+    int ans = 0;
+    if (val == &HUF_watch_key_id)
+        ans = 1;
+    if (val == &HUF_watch_key_safe)
+        ans = 2;
+    return(ans);
+}
+
+I32(* HUF_mode_2func( int mode))(pTHX_ IV, SV*) {
+    I32(* ans)(pTHX_ IV, SV*) = NULL;
+    switch (mode) {
+        case 1:
+            ans = &HUF_watch_key_id;
+            break;
+        case 2:
+            ans = &HUF_watch_key_safe;
+            break;
+    }
+    return(ans);
+}
+
 /* Thread support.  These routines are called by CLONE (and nothing else) */
 
 /* Fix entries for one object in all field hashes */
@@ -204,11 +286,11 @@ void HUF_fix_trigger(SV* trigger, SV* new_id) {
     hv_iterinit(field_tab);
     while (ent = hv_iternext(field_tab)) {
         SV* field_ref = HeVAL(ent);
-        SV* field_id = HUF_field_id(field_ref);
         HV* field = (HV*)SvRV(field_ref);
+        UV field_addr = PTR2UV(field);
         SV* val;
         /* recreate field tab entry */
-        hv_store_ent(new_tab, field_id, SvREFCNT_inc(field_ref), 0);
+        hv_store(new_tab, (char *)&field_addr, sizeof(field_addr), SvREFCNT_inc(field_ref), 0);
         /* recreate field entry, if any */
         if (val = hv_delete_ent(field, old_id, 0, 0))
             hv_store_ent(field, new_id, SvREFCNT_inc(val), 0);
@@ -221,7 +303,7 @@ void HUF_fix_trigger(SV* trigger, SV* new_id) {
 /* Go over object registry and fix all objects.  Also fix the object
  * registry.
  */
-void HUF_fix_objects() {
+void HUF_fix_objects(void) {
     dMY_CXT;
     I32 i, len;
     HE* ent;
@@ -233,7 +315,20 @@ void HUF_fix_objects() {
     for (i = 0; i <= len; ++i) {
         SV* old_id = *av_fetch(oblist, i, 0);
         SV* trigger = hv_delete_ent(MY_CXT.ob_reg, old_id, 0, 0);
-        SV* new_id = HUF_obj_id(trigger);
+        SV* obj = SvRV(trigger);
+        MAGIC *mg;
+
+        SV* new_id = HUF_OBJ_ID(obj);
+
+        /* Replace cached object ID with this new one */
+        for (mg = SvMAGIC(obj); mg; mg = mg->mg_moremagic) {
+            if ((mg->mg_type == PERL_MAGIC_ext) &&
+                    (mg->mg_private == HUF_IDCACHE)
+                ) {
+                mg->mg_obj = new_id;
+            }
+        }
+
         HUF_fix_trigger(trigger, new_id);
         hv_store_ent(MY_CXT.ob_reg, new_id, SvREFCNT_inc(trigger), 0);
     }
@@ -265,9 +360,10 @@ CODE:
         (field = (HV*)SvRV(href)) &&
         SvTYPE(field) == SVt_PVHV
     ) {
+        
         HUF_add_uvar_magic(
             SvRV(href),
-            &HUF_watch_key,
+            HUF_mode_2func( mode),
             NULL,
             0,
             NULL
@@ -278,23 +374,58 @@ OUTPUT:
     RETVAL
 
 void
-CLONE(char* class)
+id(SV* ref)
+PPCODE:
+    if (SvROK(ref)) {
+        XPUSHs(HUF_obj_id(ref));
+    } else {
+        XPUSHs(ref);
+    }
+
+SV*
+id_2obj(SV* id)
+PROTOTYPE: $
 CODE:
-    if (0 == strcmp(class, "Hash::Util::FieldHash")) {
-        HUF_global(HUF_CLONE);
-        HUF_fix_objects();
+    SV* obj = HUF_ask_trigger(id);
+    if (obj) {
+        RETVAL = newRV_inc(SvRV(obj));
+    } else {
+        RETVAL = &PL_sv_undef;
     }
+OUTPUT:
+    RETVAL
 
 SV*
-_get_obj_id(SV* obj)
+register(SV* obj, ...)
+PROTOTYPE: $@
 CODE:
+    SV* trigger;
+    int i;
     RETVAL = NULL;
-    if (SvROK(obj))
-        RETVAL = HUF_obj_id(obj);
+    if (!SvROK(obj)) {
+        Perl_die(aTHX_ "Attempt to register a non-ref");
+    } else {
+        RETVAL = newRV_inc(SvRV(obj));
+    }
+    trigger = HUF_get_trigger(obj, HUF_obj_id(obj));
+    for (i = 1; i < items; ++ i) {
+        SV* field_ref = POPs;
+        if (SvROK(field_ref) && (SvTYPE(SvRV(field_ref)) == SVt_PVHV)) {
+            HUF_mark_field(trigger, SvRV(field_ref));
+        }
+    }
 OUTPUT:
     RETVAL
 
-SV*
+void
+CLONE(char* classname)
+CODE:
+    if (0 == strcmp(classname, "Hash::Util::FieldHash")) {
+        HUF_global(HUF_CLONE);
+        HUF_fix_objects();
+    }
+
+void
 _active_fields(SV* obj)
 PPCODE:
     if (SvROK(obj)) {