1 files changed, 54 insertions, 0 deletions
diff --git a/source/StringCompression.cpp b/source/StringCompression.cpp
new file mode 100644
index 000000000..d21248fac
--- /dev/null
+++ b/source/StringCompression.cpp
@@ -0,0 +1,54 @@
+
+// StringCompression.cpp
+
+// Implements the wrapping functions for compression and decompression using AString as their data
+
+#include "Globals.h"
+#include "StringCompression.h"
+#include "zlib.h"
+
+
+
+
+
+/// Compresses a_Data into a_Compressed; return Z_XXX error constants same as zlib's compress2()
+int CompressString(const char * a_Data, int a_Length, AString & a_Compressed)
+{
+	uLongf CompressedSize = compressBound(a_Length);
+	
+	// HACK: We're assuming that AString returns its internal buffer in its data() call and we're overwriting that buffer!
+	// It saves us one allocation and one memcpy of the entire compressed data
+	// It may not work on some STL implementations! (Confirmed working on MSVC 2008 & 2010)
+	a_Compressed.resize(CompressedSize);
+	int errorcode = compress2( (Bytef*)a_Compressed.data(), &CompressedSize, (const Bytef*)a_Data, a_Length, Z_DEFAULT_COMPRESSION);
+	if (errorcode != Z_OK)
+	{
+		return errorcode;
+	}
+	a_Compressed.resize(CompressedSize);
+	return Z_OK;
+}
+
+
+
+
+
+/// Uncompresses a_Data into a_Decompressed; returns Z_XXX error constants same as zlib's decompress()
+int UncompressString(const char * a_Data, int a_Length, AString & a_Uncompressed, int a_UncompressedSize)
+{
+	// HACK: We're assuming that AString returns its internal buffer in its data() call and we're overwriting that buffer!
+	// It saves us one allocation and one memcpy of the entire compressed data
+	// It may not work on some STL implementations! (Confirmed working on MSVC 2008 & 2010)
+	a_Uncompressed.resize(a_UncompressedSize);
+	int errorcode = uncompress((Bytef*)a_Uncompressed.data(), (uLongf *)&a_UncompressedSize, (const Bytef*)a_Data, a_Length);
+	if (errorcode != Z_OK)
+	{
+		return errorcode;
+	}
+	a_Uncompressed.resize(a_UncompressedSize);
+	return Z_OK;
+}
+
+
+
+