[gzip] do not initialize deflator if gzip is not enabled for tunnel

Signed-off-by: R4SAS <r4sas@i2pmail.org>

libi2pd/Datagram.cpp

@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2013-2020, The PurpleI2P Project
+* Copyright (c) 2013-2021, The PurpleI2P Project
 *
 * This file is part of Purple i2pd project and licensed under BSD3
 *
@@ -21,6 +21,9 @@ namespace datagram
 	DatagramDestination::DatagramDestination (std::shared_ptr<i2p::client::ClientDestination> owner, bool gzip):
 		m_Owner (owner), m_Receiver (nullptr), m_RawReceiver (nullptr), m_Gzip (gzip)
 	{
+		if (m_Gzip)
+			m_Deflator.reset (new i2p::data::GzipDeflator);
+
 		auto identityLen = m_Owner->GetIdentity ()->GetFullLen ();
 		m_From.resize (identityLen);
 		m_Owner->GetIdentity ()->ToBuffer (m_From.data (), identityLen);
@@ -152,11 +155,16 @@ namespace datagram
 		const std::vector<std::pair<const uint8_t *, size_t> >& payloads,
 		uint16_t fromPort, uint16_t toPort, bool isRaw, bool checksum)
 	{
+		size_t size;
 		auto msg = m_I2NPMsgsPool.AcquireShared ();
 		uint8_t * buf = msg->GetPayload ();
 		buf += 4; // reserve for length
-		size_t size = m_Gzip ? m_Deflator.Deflate (payloads, buf, msg->maxLen - msg->len) :
-			i2p::data::GzipNoCompression (payloads, buf, msg->maxLen - msg->len);
+
+		if (m_Gzip && m_Deflator)
+			size = m_Deflator->Deflate (payloads, buf, msg->maxLen - msg->len);
+		else
+			size = i2p::data::GzipNoCompression (payloads, buf, msg->maxLen - msg->len);
+
 		if (size)
 		{
 			htobe32buf (msg->GetPayload (), size); // length

libi2pd/Datagram.h

@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2013-2020, The PurpleI2P Project
+* Copyright (c) 2013-2021, The PurpleI2P Project
 *
 * This file is part of Purple i2pd project and licensed under BSD3
 *
@@ -164,7 +164,7 @@ namespace datagram
 			std::map<uint16_t, Receiver> m_ReceiversByPorts;
 
 			i2p::data::GzipInflator m_Inflator;
-			i2p::data::GzipDeflator m_Deflator;
+			std::unique_ptr<i2p::data::GzipDeflator> m_Deflator;
 			std::vector<uint8_t> m_From, m_Signature;
 			i2p::util::MemoryPool<I2NPMessageBuffer<I2NP_MAX_MESSAGE_SIZE> > m_I2NPMsgsPool;
 	};

libi2pd/Streaming.cpp

@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2013-2020, The PurpleI2P Project
+* Copyright (c) 2013-2021, The PurpleI2P Project
 *
 * This file is part of Purple i2pd project and licensed under BSD3
 *
@@ -1040,6 +1040,8 @@ namespace stream
 		m_Owner (owner), m_LocalPort (localPort), m_Gzip (gzip),
 		m_PendingIncomingTimer (m_Owner->GetService ())
 	{
+		if (m_Gzip)
+			m_Deflator.reset (new i2p::data::GzipDeflator);
 	}
 
 	StreamingDestination::~StreamingDestination ()
@@ -1296,13 +1298,17 @@ namespace stream
 	std::shared_ptr<I2NPMessage> StreamingDestination::CreateDataMessage (
 		const uint8_t * payload, size_t len, uint16_t toPort, bool checksum)
 	{
+		size_t size;
 		auto msg = m_I2NPMsgsPool.AcquireShared ();
 		uint8_t * buf = msg->GetPayload ();
 		buf += 4; // reserve for lengthlength
 		msg->len += 4;
-		size_t size = (!m_Gzip || len <= i2p::stream::COMPRESSION_THRESHOLD_SIZE)?
-			i2p::data::GzipNoCompression (payload, len, buf, msg->maxLen - msg->len):
-			m_Deflator.Deflate (payload, len, buf, msg->maxLen - msg->len);
+
+		if (m_Gzip && m_Deflator)
+			size = m_Deflator->Deflate (payload, len, buf, msg->maxLen - msg->len);
+		else
+			size = i2p::data::GzipNoCompression (payload, len, buf, msg->maxLen - msg->len);
+
 		if (size)
 		{
 			htobe32buf (msg->GetPayload (), size); // length

libi2pd/Streaming.h

@@ -312,7 +312,7 @@ namespace stream
 		public:
 
 			i2p::data::GzipInflator m_Inflator;
-			i2p::data::GzipDeflator m_Deflator;
+			std::unique_ptr<i2p::data::GzipDeflator> m_Deflator;
 
 			// for HTTP only
 			const decltype(m_Streams)& GetStreams () const { return m_Streams; };