1 files changed, 115 insertions, 0 deletions
diff --git a/libraries/logic/GZip.cpp b/libraries/logic/GZip.cpp
new file mode 100644
index 00000000..38605df6
--- /dev/null
+++ b/libraries/logic/GZip.cpp
@@ -0,0 +1,115 @@
+#include "GZip.h"
+#include <zlib.h>
+#include <QByteArray>
+
+bool GZip::unzip(const QByteArray &compressedBytes, QByteArray &uncompressedBytes)
+{
+	if (compressedBytes.size() == 0)
+	{
+		uncompressedBytes = compressedBytes;
+		return true;
+	}
+
+	unsigned uncompLength = compressedBytes.size();
+	uncompressedBytes.clear();
+	uncompressedBytes.resize(uncompLength);
+
+	z_stream strm;
+	memset(&strm, 0, sizeof(strm));
+	strm.next_in = (Bytef *)compressedBytes.data();
+	strm.avail_in = compressedBytes.size();
+
+	bool done = false;
+
+	if (inflateInit2(&strm, (16 + MAX_WBITS)) != Z_OK)
+	{
+		return false;
+	}
+
+	int err = Z_OK;
+
+	while (!done)
+	{
+		// If our output buffer is too small
+		if (strm.total_out >= uncompLength)
+		{
+			uncompressedBytes.resize(uncompLength * 2);
+			uncompLength *= 2;
+		}
+
+		strm.next_out = (Bytef *)(uncompressedBytes.data() + strm.total_out);
+		strm.avail_out = uncompLength - strm.total_out;
+
+		// Inflate another chunk.
+		err = inflate(&strm, Z_SYNC_FLUSH);
+		if (err == Z_STREAM_END)
+			done = true;
+		else if (err != Z_OK)
+		{
+			break;
+		}
+	}
+
+	if (inflateEnd(&strm) != Z_OK || !done)
+	{
+		return false;
+	}
+
+	uncompressedBytes.resize(strm.total_out);
+	return true;
+}
+
+bool GZip::zip(const QByteArray &uncompressedBytes, QByteArray &compressedBytes)
+{
+	if (uncompressedBytes.size() == 0)
+	{
+		compressedBytes = uncompressedBytes;
+		return true;
+	}
+
+	unsigned compLength = std::min(uncompressedBytes.size(), 16);
+	compressedBytes.clear();
+	compressedBytes.resize(compLength);
+
+	z_stream zs;
+	memset(&zs, 0, sizeof(zs));
+
+	if (deflateInit2(&zs, Z_DEFAULT_COMPRESSION, Z_DEFLATED, (16 + MAX_WBITS), 8, Z_DEFAULT_STRATEGY) != Z_OK)
+	{
+		return false;
+	}
+
+	zs.next_in = (Bytef*)uncompressedBytes.data();
+	zs.avail_in = uncompressedBytes.size();
+
+	int ret;
+	compressedBytes.resize(uncompressedBytes.size());
+
+	unsigned offset = 0;
+	unsigned temp = 0;
+	do
+	{
+		auto remaining = compressedBytes.size() - offset;
+		if(remaining < 1)
+		{
+			compressedBytes.resize(compressedBytes.size() * 2);
+		}
+		zs.next_out = (Bytef *) (compressedBytes.data() + offset);
+		temp = zs.avail_out = compressedBytes.size() - offset;
+		ret = deflate(&zs, Z_FINISH);
+		offset += temp - zs.avail_out;
+	} while (ret == Z_OK);
+
+	compressedBytes.resize(offset);
+
+	if (deflateEnd(&zs) != Z_OK)
+	{
+		return false;
+	}
+
+	if (ret != Z_STREAM_END)
+	{
+		return false;
+	}
+	return true;
+}
+\ No newline at end of file