compressZlib: don't use a SharedBuffer but a raw u8 * pointer

Remove usage of the SharedBuffer in zlib compression which has two problems:
* We copied the whole memory block to compress it (not good with mapblocks)
* We copied sometimes strings to SharedBuffer to SharedBuffer (2nd time)

Use this method in MapNode::serializeBulk + optimize serialization but merging 3 identical loops in a single loop

1 files changed, 15 insertions, 20 deletions

diff --git a/src/mapnode.cpp b/src/mapnode.cpp
index d835daba2..fd28910ff 100644
--- a/src/mapnode.cpp
+++ b/src/mapnode.cpp
@@ -658,7 +658,7 @@ void MapNode::serializeBulk(std::ostream &os, int version,
 		const MapNode *nodes, u32 nodecount,
 		u8 content_width, u8 params_width, bool compressed)
 {
-	if(!ser_ver_supported(version))
+	if (!ser_ver_supported(version))
 		throw VersionMismatchException("ERROR: MapNode format not supported");
 
 	sanity_check(content_width == 2);
@@ -666,38 +666,33 @@ void MapNode::serializeBulk(std::ostream &os, int version,
 
 	// Can't do this anymore; we have 16-bit dynamically allocated node IDs
 	// in memory; conversion just won't work in this direction.
-	if(version < 24)
+	if (version < 24)
 		throw SerializationError("MapNode::serializeBulk: serialization to "
 				"version < 24 not possible");
 
-	SharedBuffer<u8> databuf(nodecount * (content_width + params_width));
-
-	// Serialize content
-	for(u32 i=0; i<nodecount; i++)
-		writeU16(&databuf[i*2], nodes[i].param0);
+	size_t databuf_size = nodecount * (content_width + params_width);
+	u8 *databuf = new u8[databuf_size];
 
-	// Serialize param1
 	u32 start1 = content_width * nodecount;
-	for(u32 i=0; i<nodecount; i++)
-		writeU8(&databuf[start1 + i], nodes[i].param1);
-
-	// Serialize param2
 	u32 start2 = (content_width + 1) * nodecount;
-	for(u32 i=0; i<nodecount; i++)
+
+	// Serialize content
+	for (u32 i = 0; i < nodecount; i++) {
+		writeU16(&databuf[i * 2], nodes[i].param0);
+		writeU8(&databuf[start1 + i], nodes[i].param1);
 		writeU8(&databuf[start2 + i], nodes[i].param2);
+	}
 
 	/*
 		Compress data to output stream
 	*/
 
-	if(compressed)
-	{
-		compressZlib(databuf, os);
-	}
+	if (compressed)
+		compressZlib(databuf, databuf_size, os);
 	else
-	{
-		os.write((const char*) &databuf[0], databuf.getSize());
-	}
+		os.write((const char*) &databuf[0], databuf_size);
+
+	delete [] databuf;
 }
 
 // Deserialize bulk node data