From b654e0719a6d87f51c8b680e53347e4f5de8a54e Mon Sep 17 00:00:00 2001 From: nobu Date: Sat, 14 Jun 2014 01:55:25 +0000 Subject: [PATCH] array.c: non-recursive rcombinate0 * array.c (rcombinate0): remove recursion, by looping with indexes stored in `p`. git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46428 b2dd03c8-39d4-4d8f-98ff-823fe69b080e --- ChangeLog | 5 ++++- array.c | 33 ++++++++++++++++++++------------- test/ruby/test_array.rb | 6 ++++++ 3 files changed, 30 insertions(+), 14 deletions(-) diff --git a/ChangeLog b/ChangeLog index 251bd357a0..0dcd5f97df 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,4 +1,7 @@ -Sat Jun 14 10:53:49 2014 Nobuyoshi Nakada +Sat Jun 14 10:54:08 2014 Nobuyoshi Nakada + + * array.c (rcombinate0): remove recursion, by looping with indexes + stored in `p`. * array.c (rpermute0): remove recursion, by looping with indexes stored in `p`. diff --git a/array.c b/array.c index 8322c294f2..28fd109285 100644 --- a/array.c +++ b/array.c @@ -5087,18 +5087,25 @@ rb_ary_repeated_permutation(VALUE ary, VALUE num) } static void -rcombinate0(long n, long r, long *p, long index, long rest, VALUE values) +rcombinate0(const long n, const long r, long *const p, const long rest, const VALUE values) { - if (rest > 0) { - for (; index < n; ++index) { - p[r-rest] = index; - rcombinate0(n, r, p, index, rest-1, values); + long i = 0, index = 0; + + p[index] = i; + for (;;) { + if (++index < r-1) { + p[index] = i; + continue; } - } - else { - if (!yield_indexed_values(values, r, p)) { - rb_raise(rb_eRuntimeError, "repeated combination reentered"); + for (; i < n; ++i) { + p[index] = i; + if (!yield_indexed_values(values, r, p)) { + rb_raise(rb_eRuntimeError, "repeated combination reentered"); + } } + do { + if (index <= 0) return; + } while ((i = ++p[--index]) >= n); } } @@ -5163,13 +5170,13 @@ rb_ary_repeated_combination(VALUE ary, VALUE num) /* yield nothing */ } else { - volatile VALUE t0 = tmpbuf(n, sizeof(long)); - long *p = (long*)RSTRING_PTR(t0); + volatile VALUE t0; + long *p = ALLOCV_N(long, t0, n); VALUE ary0 = ary_make_shared_copy(ary); /* private defensive copy of ary */ RBASIC_CLEAR_CLASS(ary0); - rcombinate0(len, n, p, 0, n, ary0); /* compute and yield repeated combinations */ - tmpbuf_discard(t0); + rcombinate0(len, n, p, n, ary0); /* compute and yield repeated combinations */ + ALLOCV_END(t0); RBASIC_SET_CLASS_RAW(ary0, rb_cArray); } return ary; diff --git a/test/ruby/test_array.rb b/test/ruby/test_array.rb index b9b2d5f88b..d728bb78f0 100644 --- a/test/ruby/test_array.rb +++ b/test/ruby/test_array.rb @@ -1815,6 +1815,12 @@ class TestArray < Test::Unit::TestCase a = @cls[0, 1, 2, 3, 4][1, 4].repeated_combination(2) assert_empty(a.reject {|x| !x.include?(0)}) + + assert_separately([], <<-"end;") # do + assert_nothing_raised(SystemStackError) do + assert_equal(:ok, Array.new(100_000, nil).repeated_combination(500_000) {break :ok}) + end + end; end def test_take