Patricia#show_nodes uses Ruby IO methods

This allows the output of Patricia#show_nodes to be redirected
to StringIO objects (or anything else that responds to printf).
Since Ruby 1.9 no longer uses stdio, this lets us go through the
normal output stream used by Ruby.

3 files changed, 52 insertions, 6 deletions

diff --git a/ext/rpatricia/extconf.rb b/ext/rpatricia/extconf.rb
index ac42e36..18bb7a7 100755
--- a/ext/rpatricia/extconf.rb
+++ b/ext/rpatricia/extconf.rb
@@ -1,5 +1,5 @@
 #!/usr/bin/env ruby 
 require "mkmf"
 
+have_func("rb_str_set_len", "ruby.h")
 create_makefile("rpatricia")
-
diff --git a/ext/rpatricia/rpatricia.c b/ext/rpatricia/rpatricia.c
index 54ac3ed..fcb544b 100644
--- a/ext/rpatricia/rpatricia.c
+++ b/ext/rpatricia/rpatricia.c
@@ -4,7 +4,6 @@
  */
 
 #include "ruby.h"
-#include <stdio.h> /* printf */
 #include <stdlib.h>
 #include "patricia.h"
 
@@ -142,18 +141,33 @@ p_num_nodes (VALUE self)
   return INT2NUM(n);
 }
 
+/* needed for Ruby 1.8.6, in 1.8.7 and later */
+#ifndef HAVE_RB_STR_SET_LEN
+static void
+rb_str_set_len(VALUE str, long len)
+{
+  RSTRING(str)->len = len;
+  RSTRING(str)->ptr[len] = '\0';
+}
+#endif
+
 static VALUE
 p_print_nodes (VALUE self)
 {
-  int n;
-  char buff[32];
+  ID id_printf = rb_intern("printf");
+  VALUE fmt = rb_str_new2("node: %s\n");
+  VALUE buf = rb_str_buf_new(128);
+  char *cbuf;
   patricia_tree_t *tree;
   patricia_node_t *node;
   Data_Get_Struct(self, patricia_tree_t, tree);
 
   PATRICIA_WALK(tree->head, node) {
-    prefix_toa2x(node->prefix, buff, 1);
-    printf("node: %s\n", buff);
+    rb_str_resize(buf, 128);
+    cbuf = RSTRING_PTR(buf);
+    prefix_toa2x(node->prefix, cbuf, 1);
+    rb_str_set_len(buf, strlen(cbuf));
+    rb_funcall(rb_stdout, id_printf, 2, fmt, buf);
   } PATRICIA_WALK_END;
   return Qtrue;
 }
diff --git a/test/test_show_nodes.rb b/test/test_show_nodes.rb
new file mode 100644
index 0000000..b4aa3a0
--- /dev/null
+++ b/test/test_show_nodes.rb
@@ -0,0 +1,32 @@
+require 'test/unit'
+require 'rpatricia'
+require 'stringio'
+
+class TestShowNodes < Test::Unit::TestCase
+
+  def test_show_nodes
+    t = Patricia.new
+    assert_nothing_raised do
+      t.add("127.0.0.0/24")
+      t.add("192.168.1.0/24")
+      t.add("192.168.2.0/24")
+      t.add("192.168.3.100")
+      t.add("10.0.0.0/8", "pref_10")
+    end
+    begin
+      oldout = $stdout
+      $stdout = tmpout = StringIO.new
+      assert_nothing_raised { t.show_nodes }
+    ensure
+      $stdout = oldout
+    end
+    expect = [
+      "node: 10.0.0.0/8",
+      "node: 127.0.0.0/24",
+      "node: 192.168.1.0/24",
+      "node: 192.168.2.0/24",
+      "node: 192.168.3.100/32"
+    ].join("\n") << "\n"
+    assert_equal expect, tmpout.string
+  end
+end