From 4e249fb3fbf75f0359758760d88e22aa5b14533c Mon Sep 17 00:00:00 2001
From: Perttu Ahola <celeron55@gmail.com>
Date: Sat, 27 Nov 2010 01:02:21 +0200
Subject: Initial files

---
 src/serialization.cpp | 77 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 77 insertions(+)
 create mode 100644 src/serialization.cpp

(limited to 'src/serialization.cpp')

diff --git a/src/serialization.cpp b/src/serialization.cpp
new file mode 100644
index 000000000..72f675594
--- /dev/null
+++ b/src/serialization.cpp
@@ -0,0 +1,77 @@
+/*
+(c) 2010 Perttu Ahola <celeron55@gmail.com>
+*/
+
+#include "serialization.h"
+#include "utility.h"
+
+void compress(SharedBuffer<u8> data, std::ostream &os, u8 version)
+{
+	if(data.getSize() == 0)
+		return;
+
+	// Write length (u32)
+
+	u8 tmp[4];
+	writeU32(tmp, data.getSize());
+	os.write((char*)tmp, 4);
+	
+	// We will be writing 8-bit pairs of more_count and byte
+	u8 more_count = 0;
+	u8 current_byte = data[0];
+	for(u32 i=1; i<data.getSize(); i++)
+	{
+		if(
+			data[i] != current_byte
+			|| more_count == 255
+		)
+		{
+			// write count and byte
+			os.write((char*)&more_count, 1);
+			os.write((char*)&current_byte, 1);
+			more_count = 0;
+			current_byte = data[i];
+		}
+		else
+		{
+			more_count++;
+		}
+	}
+	// write count and byte
+	os.write((char*)&more_count, 1);
+	os.write((char*)&current_byte, 1);
+}
+
+void decompress(std::istream &is, std::ostream &os, u8 version)
+{
+	// Read length (u32)
+
+	u8 tmp[4];
+	is.read((char*)tmp, 4);
+	u32 len = readU32(tmp);
+	
+	// We will be reading 8-bit pairs of more_count and byte
+	u32 count = 0;
+	for(;;)
+	{
+		u8 more_count=0;
+		u8 byte=0;
+
+		is.read((char*)&more_count, 1);
+		
+		is.read((char*)&byte, 1);
+
+		if(is.eof())
+			throw SerializationError("decompress: stream ended halfway");
+
+		for(s32 i=0; i<(u16)more_count+1; i++)
+			os.write((char*)&byte, 1);
+
+		count += (u16)more_count+1;
+
+		if(count == len)
+			break;
+	}
+}
+
+
-- 
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