- added fancy buffer

git-svn-id: http://moon:8086/svn/matlab/trunk@63 801c6759-fa7c-4059-a304-17956f83a07c

ofdm/buffer.m

@@ -0,0 +1,44 @@
+function [buf] = buffer()
+	
+	buf = struct('mem', [], 'ri', 0, 'wi', 0, 'fill', 0, 'obj', @()obj_(), 'len', @()len_(), 'read', @(len)read_(len), 'readAt', @(len, offset)readAt_(len, offset), 'setReadIndex', @(offset)setReadIndex_(offset), 'write', @(x)write_(x));
+
+	function b = obj_()
+		b = buf;
+	end
+
+	function len = len_()
+		len = 0;
+		if (buf.wi > buf.ri)
+			len = buf.wi - buf.ri;
+		end
+	end
+
+	function [x] = readAt_(len, offset)
+		x = [];
+		
+		if (buf.ri+offset) >= 0
+			if (buf.wi-(buf.ri+offset) >= len)
+				x = buf.mem(buf.ri+1+offset:buf.ri+len+offset);
+			end
+		end
+	end
+
+	function [x] = read_(len)
+		x = readAt_(len, 0);
+		if ~isempty(x)
+			buf.ri = buf.ri + len;
+		end
+	end
+
+	function setReadIndex_(offset)
+		buf.ri = offset;
+	end
+
+	function write_(x)
+		len = length(x);
+		buf.mem(buf.wi+1:buf.wi+len,:) = x;
+		buf.fill = buf.fill + len;
+		buf.wi = buf.wi + len;
+	end
+
+end