e$B1sF#$H?=$7$^$9!#e(B
e$B0J2<$N%W%m%0%i%`$,$d$?$iCY$$$G$9!#$^$?!"%a%b%j$rBgNL$K>CHq$7$^$9!#e(B
$ time ./ruby -ve ’
a = [0] * 10000
(1 … 10000).map { a.slice!(0, 1) }
’
ruby 1.9.0 (2008-03-07 revision 15720) [i686-linux]
real 0m10.940s
user 0m4.200s
sys 0m6.710s
e$BG[Ns$N6&M-$,860x$N$h$&$G$9!#e(Ba.slice!(i, n) e$B$Oe(B Ruby
e$B$G=q$/$He(B
t = a[i, n]
a[i, n] = []
return t
e$B$H$$$&Iw$K<BAu$5$l$F$$$F!"e(B
- t = a[i, n] e$B$,e(B a e$B$He(B t e$B$r6&M->uBV$K$9$ke(B
- a[i, n] = [] e$B$,e(B a e$B$re(B rb_ary_modify e$B$9$ke(B
- rb_ary_modify e$B$NCf$Ge(B a e$BA4BN$re(B MEMCPY e$B$9$ke(B
e$B$H$$$&Iw$K<B9T$5$l$^$9!#$3$l$K$h$C$F!"e(B
- 3 e$B$Ne(B MEMCPY e$B$,Kh2se(B O(a.size) e$B$^$k$^$k$+$+$C$FCY$$e(B
- t e$B$,e(B a.size e$B%P%$%H$rL5BL$K3NJ]$7$?$^$^$K$J$je(B (n
e$B$G==J,e(B) e$B!"%a%b%j$r05Gw$9$ke(B
e$B$H$$$&$h$&$K$J$C$F$$$^$9!#e(B
e$BK<AE*$J2r7h$G$O$J$$$G$9$,!"e(Bslice! e$B$KFC2=$7$?e(B 2
e$B$D$N:GE,2=$r$7$F$_$^$7$?!#e(B
- rb_ary_splice e$B$Ge(B rb_ary_modify e$B$9$k$H$-!"I,MW$J$H$3$m$@$1e(B
MEMCPY e$B$9$ke(B - a.slice!(i, n) e$B$Ge(B n e$B$,e(B a.size / 2 e$B$h$j>.$5$$>l9g$Oe(B t
e$B$r6&M-$;$:$K:n$ke(B
e$B%Y%s%A%^!<%/$G$9!#C10L$OIC!#e(B
±---------±------------±----------------------------------------------+
| e$B:GE,2=A0e(B | e$B:GE,2=8ee(B | |
| user sys | user sys | a = [0] * 10000; b = (1 … 10000).map { … } |
±---------±------------±----------------------------------------------+
| 4.2 6.7 | 0.14 0.03 | a.slice!(0, 1) |
| 0.26 6.6 | 0.050 0.030 | t, a = a, a.slice!(0, a.size - 1); t |
±---------±------------±----------------------------------------------+
e$B$J$*!"$3$N:GE,2=$rF~$l$F$b!"0J2<$N%3!<%I$G$O$d$C$Q$jCY$$$G$9!#e(B
e$B$3$l$r2?$H$+$9$k$N$O$$$m$$$m$HLLE]$=$&$G$9!#e(B
a = [0] * 10000
(1 … 10000).map { t = a[0, 1]; a[0, 1] = []; t }
Index: array.c
— array.c (revision 15726)
+++ array.c (working copy)
@@ -647,6 +647,26 @@
}
VALUE
+rb_ary_subseq_copy(VALUE ary, long beg, long len)
+{
- VALUE klass, ary2;
- if (beg > RARRAY_LEN(ary)) return Qnil;
- if (beg < 0 || len < 0) return Qnil;
- if (RARRAY_LEN(ary) < len || RARRAY_LEN(ary) < beg + len) {
- len = RARRAY_LEN(ary) - beg;
- }
- klass = rb_obj_class(ary);
- ary2 = ary_new(klass, len);
- if (len > 0) {
- MEMCPY(RARRAY_PTR(ary2), RARRAY_PTR(ary) + beg, VALUE, len);
- RARRAY(ary2)->len = len;
- }
- return ary2;
+}
+VALUE
rb_ary_subseq(VALUE ary, long beg, long len)
{
VALUE klass, ary2, shared;
@@ -973,8 +993,8 @@
rpl = rb_ary_to_ary(rpl);
rlen = RARRAY_LEN(rpl);
}
- rb_ary_modify(ary);
if (beg >= RARRAY_LEN(ary)) {
-
rb_ary_modify(ary);
len = beg + rlen;
if (len >= ARY_CAPA(ary)) {
RESIZE_CAPA(ary, len);
@@ -993,15 +1013,30 @@
}alen = RARRAY_LEN(ary) + rlen - len;
- if (alen >= ARY_CAPA(ary)) {
-
RESIZE_CAPA(ary, alen);
- rb_ary_modify_check(ary);
- if (ARY_SHARED_P(ary)) {
-
VALUE *ptr; -
ptr = ALLOC_N(VALUE, alen); -
FL_UNSET(ary, ELTS_SHARED); -
MEMCPY(ptr, RARRAY_PTR(ary), VALUE, beg); -
MEMCPY(ptr + beg + rlen, RARRAY_PTR(ary) + beg + len, -
VALUE, RARRAY_LEN(ary) - (beg + len)); -
RARRAY(ary)->aux.capa = RARRAY(ary)->len = alen; -
}RARRAY(ary)->ptr = ptr; - else {
-
if (alen >= ARY_CAPA(ary)) { - RESIZE_CAPA(ary, alen);
-
} -
if (len != rlen) { - MEMMOVE(RARRAY_PTR(ary) + beg + rlen,
-
RARRAY_PTR(ary) + beg + len, -
VALUE, RARRAY_LEN(ary) - (beg + len)); - RARRAY(ary)->len = alen;
-
} - }
- if (len != rlen) {
-
MEMMOVE(RARRAY_PTR(ary) + beg + rlen, RARRAY_PTR(ary) + beg +
len,
-
VALUE, RARRAY_LEN(ary) - (beg + len)); -
RARRAY(ary)->len = alen; - }
if (rlen > 0) {
MEMMOVE(RARRAY_PTR(ary) + beg, RARRAY_PTR(rpl), VALUE, rlen);
}
@@ -1790,7 +1825,12 @@
pos = RARRAY_LEN(ary) + pos;
if (pos < 0) return Qnil;
} - arg2 = rb_ary_subseq(ary, pos, len);
- if (len * 2 < RARRAY_LEN(ary)) {
-
arg2 = rb_ary_subseq_copy(ary, pos, len); - }
- else {
-
arg2 = rb_ary_subseq(ary, pos, len); - }
rb_ary_splice(ary, pos, len, Qundef); /* Qnil/rb_ary_new2(0) */
return arg2;
}