* ext/stringio/stringio.c (check_modifiable): performance

  improvement.  avoid calling rb_str_modify() twice.

* ext/stringio/stringio.c (strio_ungetc): ditto.

* ext/stringio/stringio.c (strio_putc): ditto.

* ext/stringio/stringio.c (strio_write): ditto, and use
  rb_str_cat() as possible.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@2345 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 15 insertions, 4 deletions

diff --git a/ext/stringio/stringio.c b/ext/stringio/stringio.c
index 27b8aba8ba..11fe8ef455 100644
--- a/ext/stringio/stringio.c
+++ b/ext/stringio/stringio.c
@@ -125,7 +125,6 @@ check_modifiable(ptr)
     if (OBJ_FROZEN(ptr->string)) {
 	rb_raise(rb_eIOError, "not modifiable string");
     }
-    rb_str_modify(ptr->string);
 }
 
 static VALUE strio_s_allocate _((VALUE));
@@ -548,6 +547,7 @@ strio_ungetc(self, ch)
 	if ((unsigned char)RSTRING(ptr->string)->ptr[--ptr->pos] !=
 	    (unsigned char)cc) {
 	    check_modifiable(ptr);
+	    rb_str_modify(ptr->string);
 	    RSTRING(ptr->string)->ptr[ptr->pos] = cc;
 	}
     }
@@ -740,10 +740,18 @@ strio_write(self, str)
     if (ptr->flags & STRIO_APPEND) {
 	ptr->pos = RSTRING(ptr->string)->len;
     }
-    if (ptr->pos + len > RSTRING(ptr->string)->len) {
-	rb_str_resize(ptr->string, ptr->pos + len);
+    if (ptr->pos == RSTRING(ptr->string)->len) {
+	rb_str_cat(ptr->string, RSTRING(str)->ptr, len);
+    }
+    else {
+	if (ptr->pos + len > RSTRING(ptr->string)->len) {
+	    rb_str_resize(ptr->string, ptr->pos + len);
+	}
+	else {
+	    rb_str_modify(ptr->string);
+	}
+	rb_str_update(ptr->string, ptr->pos, len, str);
     }
-    rb_str_update(ptr->string, ptr->pos, len, str);
     ptr->pos += len;
     return LONG2NUM(len);
 }
@@ -768,6 +776,9 @@ strio_putc(self, ch)
     if (ptr->pos >= RSTRING(ptr->string)->len) {
 	rb_str_resize(ptr->string, ptr->pos + 1);
     }
+    else {
+	rb_str_modify(ptr->string);
+    }
     RSTRING(ptr->string)->ptr[ptr->pos++] = c;
     return ch;
 }