From 49e6c8f56d89681f20836a14480959fa89d24e26 Mon Sep 17 00:00:00 2001
From: Tilman Sauerbeck <tilman@code-monkey.de>
Date: Sat, 30 Apr 2005 13:15:19 +0000
Subject: [PATCH] Re-implemented Stream#serialize and Chunk#serialize in C.

---
 ChangeLog  |  4 ++-
 ext/ext.c  | 90 +++++++++++++++++++++++++++++++++++++++++++++++++++++-
 lib/eet.rb | 16 ++--------
 3 files changed, 94 insertions(+), 16 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index f124ff3..9d70b36 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,9 +1,11 @@
 --
-$Id: ChangeLog 33 2005-04-30 11:10:16Z tilman $
+$Id: ChangeLog 34 2005-04-30 13:15:19Z tilman $
 ++
 
 2005-04-30 Tilman Sauerbeck (tilman at code-monkey de)
         * lib/eet.rb: Tweaked Stream#serialize for performance
+        * lib/eet.rb, ext/ext.c: Re-implemented Stream#serialize and
+          Chunk#serialize in C
 
 2005-04-19 Tilman Sauerbeck (tilman at code-monkey de)
         * Rakefile: Code cleanup
diff --git a/ext/ext.c b/ext/ext.c
index d85cd56..31becea 100644
--- a/ext/ext.c
+++ b/ext/ext.c
@@ -1,5 +1,5 @@
 /*
- * $Id: ext.c 31 2005-04-12 19:03:50Z tilman $
+ * $Id: ext.c 34 2005-04-30 13:15:19Z tilman $
  *
  * Copyright (c) 2005 Tilman Sauerbeck (tilman at code-monkey de)
  *
@@ -35,6 +35,15 @@
 	if (!*(ef)) \
 		rb_raise (rb_eIOError, "closed stream");
 
+#ifdef WORDS_BIGENDIAN
+# define BSWAP32(x) \
+	((((x) & 0xff000000) >> 24) | (((x) & 0x00ff0000) >> 8) | \
+	(((x) & 0x0000ff00) << 8) | (((x) & 0x000000ff) << 24))
+#else /* !WORDS_BIGENDIAN */
+# define BSWAP16(x) (x)
+# define BSWAP32(x) (x)
+#endif /* WORDS_BIGENDIAN */
+
 static VALUE c_close (VALUE self);
 
 static void
@@ -419,6 +428,79 @@ c_write_image (int argc, VALUE *argv, VALUE self)
 		return INT2FIX (n);
 }
 
+static VALUE
+stream_serialize (VALUE self)
+{
+	VALUE ret;
+	struct RArray *stream;
+	static ID id_serialize;
+	long i;
+
+	ret = rb_str_new2 ("");
+
+	stream = RARRAY (self);
+	if (!stream->len)
+		return ret;
+
+	if (!id_serialize)
+		id_serialize = rb_intern ("serialize");
+
+	for (i = 0; i < stream->len; i++) {
+		VALUE str = rb_funcall (stream->ptr[i], id_serialize, 0, NULL);
+
+		rb_str_append (ret, str);
+	}
+
+	return ret;
+}
+
+static VALUE
+chunk_serialize (VALUE self)
+{
+	VALUE tmp, ret;
+	unsigned int size, buf_len;
+	unsigned char *buf;
+	struct RString *tag, *data;
+	static ID id_tag, id_data;
+
+	if (!id_tag)
+		id_tag = rb_intern ("@tag");
+
+	if (!id_data)
+		id_data = rb_intern ("@data");
+
+	tmp = rb_ivar_get (self, id_tag);
+	StringValue (tmp);
+	tag = RSTRING (tmp);
+
+	tmp = rb_ivar_get (self, id_data);
+	StringValue (tmp);
+	data = RSTRING (tmp);
+
+	buf_len = 9 + tag->len + data->len;
+	ret = rb_str_buf_new (buf_len);
+
+	buf = RSTRING (ret)->ptr;
+	RSTRING (ret)->len = buf_len;
+
+	memcpy (buf, "CHnK", 4);
+	buf += 4;
+
+	size = tag->len + data->len + 1;
+	size = BSWAP32 (size);
+	memcpy (buf, &size, 4);
+	buf += 4;
+
+	memcpy (buf, tag->ptr, tag->len);
+	buf += tag->len;
+
+	*buf++ = 0;
+
+	memcpy (buf, data->ptr, data->len);
+
+	return ret;
+}
+
 void
 Init_eet_ext ()
 {
@@ -437,4 +519,10 @@ Init_eet_ext ()
 	rb_define_method (c, "write", c_write, -1);
 	rb_define_method (c, "read_image", c_read_image, 1);
 	rb_define_method (c, "write_image", c_write_image, -1);
+
+	c = rb_define_class_under (m, "Stream", rb_cArray);
+	rb_define_method (c, "serialize", stream_serialize, 0);
+
+	c = rb_define_class_under (m, "Chunk", rb_cObject);
+	rb_define_method (c, "serialize", chunk_serialize, 0);
 }
diff --git a/lib/eet.rb b/lib/eet.rb
index ddac645..8a94984 100644
--- a/lib/eet.rb
+++ b/lib/eet.rb
@@ -1,5 +1,5 @@
 #--
-# $Id: eet.rb 33 2005-04-30 11:10:16Z tilman $
+# $Id: eet.rb 34 2005-04-30 13:15:19Z tilman $
 #
 # Copyright (c) 2005 Tilman Sauerbeck (tilman at code-monkey de)
 #
@@ -166,10 +166,6 @@ module Eet
 			super(chunk.nil? ? 0 : 1, chunk)
 		end
 
-		def serialize
-			map { |c| c.serialize }.join
-		end
-
 		def Stream.deserialize(data)
 			data = data.to_str.dup
 			s = Stream.new
@@ -194,21 +190,13 @@ module Eet
 			@tag = tag.to_str.dup.freeze
 			@data = data.to_str.dup.freeze
 
-			@size = @tag.length + 1 + @data.length
-
 			# libeet uses a signed 32bit integer to store the
 			# chunk size, so make sure we don't overflow it
-			if @size >= (1 << 31)
+			if (@tag.length + 1 + @data.length) >= (1 << 31)
 				raise(ArgumentError, "tag or data too long")
 			end
 		end
 
-		def serialize
-			buf = "CHnK"
-			buf << [@size].pack("V")
-			buf << @tag << "\0" << @data
-		end
-
 		def Chunk.deserialize(data)
 			if data.length < 8 || data[0, 4] != "CHnK"
 				raise(ChunkError, "invalid data")
-- 
2.30.2