Use a HEK to store the GV's name, rather than a malloc()ed string.

Saves 1 word in each GV (no more strlen), and will also save the memory
used by the string itself, as the HEK will exist already due to the
key used by the symbol table for this GV.

p4raw-id: //depot/perl@27379

diff --git a/gv.c b/gv.c
index f6c2087ce61ffef61db7266f9fc63140ddbeb546..8b3b099f3299b6aa0ffe855866b3e478323f793f 100644 (file)
--- a/gv.c
+++ b/gv.c
@@ -2107,11 +2107,15 @@ void
 Perl_gv_name_set(pTHX_ GV *gv, const char *name, U32 len, U32 flags)
 {
     dVAR;
+    U32 hash;
 
     PERL_UNUSED_ARG(flags);
 
-    GvXPVGV(gv)->xgv_name = name ? savepvn(name, len) : NULL;
-    GvXPVGV(gv)->xgv_namelen = len;
+    if (len > I32_MAX)
+       Perl_croak(aTHX_ "panic: gv name too long (%"UVuf")", (UV) len);
+
+    PERL_HASH(hash, name, len);
+    GvXPVGV(gv)->xgv_namehek = name ? share_hek(name, len, hash) : 0;
 }
 
 /*

diff --git a/gv.h b/gv.h
index de8ec52dd89b16bc9b1a1c018e23f16b34369a66..c4e26c3024a30e20e520460cdafda347ba10bc68 100644 (file)
--- a/gv.h
+++ b/gv.h
@@ -43,26 +43,22 @@ struct gp {
            assert(SvTYPE(_gv) == SVt_PVGV || SvTYPE(_gv) >= SVt_PVLV); \
            &(GvXPVGV(_gv)->xnv_u.xgv_stash);                           \
         }))
-#  define GvNAME_get(gv)                                               \
-       ({ GV * const zzzz = (GV *) (gv);                               \
+#  define GvNAME_HEK(gv)                                               \
+       (*({ GV * const zzzz = (GV *) (gv);                             \
           assert(isGV_with_GP(zzzz));                                  \
           assert(SvTYPE(zzzz) == SVt_PVGV || SvTYPE(zzzz) >= SVt_PVLV); \
-          0 + (GvXPVGV(zzzz)->xgv_name);                               \
-        })
-#  define GvNAMELEN_get(gv)                                            \
-       ({ GV * const glank = (GV *) (gv);                              \
-          assert(isGV_with_GP(glank));                         \
-          assert(SvTYPE(glank) == SVt_PVGV || SvTYPE(glank) >= SVt_PVLV); \
-          0 + (GvXPVGV(glank)->xgv_namelen);                           \
-        })
+          &(GvXPVGV(zzzz)->xgv_namehek);                               \
+        }))
 #else
 #  define GvGP(gv)     ((gv)->sv_u.svu_gp)
 #  define GvFLAGS(gv)  (GvXPVGV(gv)->xpv_cur)
 #  define GvSTASH(gv)  (GvXPVGV(gv)->xnv_u.xgv_stash)
-#  define GvNAME_get(gv)       (0 + GvXPVGV(gv)->xgv_name)
-#  define GvNAMELEN_get(gv)    (0 + GvXPVGV(gv)->xgv_namelen)
+#  define GvNAME_HEK(gv)       (GvXPVGV(gv)->xgv_namehek)
 #endif
 
+#define GvNAME_get(gv)         (GvNAME_HEK(gv) ? HEK_KEY(GvNAME_HEK(gv)) : 0)
+#define GvNAMELEN_get(gv)      (GvNAME_HEK(gv) ? HEK_LEN(GvNAME_HEK(gv)) : 0)
+
 #define GvNAME(gv)     GvNAME_get(gv)
 #define GvNAMELEN(gv)  GvNAMELEN_get(gv)
 

diff --git a/sv.c b/sv.c
index 74e6a8bf9ae06fac9787a18f0a520a2d765a75b6..17d8cc20692b6551db0f8e015ec29d829ca7eed6 100644 (file)
--- a/sv.c
+++ b/sv.c
@@ -3216,7 +3216,7 @@ S_glob_assign_glob(pTHX_ SV *dstr, SV *sstr, const int dtype)
        GvSTASH(dstr) = GvSTASH(sstr);
        if (GvSTASH(dstr))
            Perl_sv_add_backref(aTHX_ (SV*)GvSTASH(dstr), dstr);
-       gv_name_set(dstr, name, len, 0);
+       gv_name_set((GV *)dstr, name, len, 0);
        SvFAKE_on(dstr);        /* can coerce to non-glob */
     }
 
@@ -5111,7 +5111,9 @@ Perl_sv_clear(pTHX_ register SV *sv)
        goto freescalar;
     case SVt_PVGV:
        gp_free((GV*)sv);
-       Safefree(GvNAME(sv));
+       if (GvNAME_HEK(sv)) {
+           unshare_hek(GvNAME_HEK(sv));
+       }
        /* If we're in a stash, we don't own a reference to it. However it does
           have a back reference to us, which needs to be cleared.  */
        if (GvSTASH(sv))
@@ -7715,7 +7717,9 @@ S_sv_unglob(pTHX_ SV *sv)
        GvSTASH(sv) = NULL;
     }
     GvMULTI_off(sv);
-    Safefree(GvNAME(sv));
+    if (GvNAME_HEK(sv)) {
+       unshare_hek(GvNAME_HEK(sv));
+    }
     SvSCREAM_off(sv);
 
     /* need to keep SvANY(sv) in the right arena */
@@ -9836,7 +9840,8 @@ Perl_sv_dup(pTHX_ const SV *sstr, CLONE_PARAMS* param)
                    LvTARG(dstr) = sv_dup_inc(LvTARG(dstr), param);
                break;
            case SVt_PVGV:
-               GvXPVGV(dstr)->xgv_name = SAVEPVN(GvNAME(dstr), GvNAMELEN(dstr));
+               if (GvNAME_HEK(dstr))
+                   GvNAME_HEK(dstr) = hek_dup(GvNAME_HEK(dstr), param);
 
                /* Don't call sv_add_backref here as it's going to be created
                   as part of the magic cloning of the symbol table.  */

diff --git a/sv.h b/sv.h
index 50f11e0e13c4aeefa74435364b1b1f5c3f0ac9b5..7a63afc1edbaa7426fa095766a22846bd7aa23a4 100644 (file)
--- a/sv.h
+++ b/sv.h
@@ -487,8 +487,7 @@ struct xpvlv {
     HV*                xmg_stash;      /* class package */
 
     /* a full glob fits into this */
-    char*      xgv_name;
-    STRLEN     xgv_namelen;
+    HEK *      xgv_namehek;
 
     STRLEN     xlv_targoff;
     STRLEN     xlv_targlen;
@@ -516,8 +515,7 @@ struct xpvgv {
     } xmg_u;
     HV*                xmg_stash;      /* class package */
 
-    char*      xgv_name;
-    STRLEN     xgv_namelen;
+    HEK *      xgv_namehek;
 };
 
 struct xpvbm {