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

diff --git a/src/mapnode.cpp b/src/mapnode.cpp
index d835daba27f461f0629fe33958dec3d69854254f..fd28910ff6848f00a148bdf8829a8ff5f8daefe7 100644 (file)
--- 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

diff --git a/src/serialization.cpp b/src/serialization.cpp
index d30e83726f307cac9d58f83c6f4f80d93d1ebac3..ac6fc0db2c7da542e2c4875f32eae2862ad6dfac 100644 (file)
--- a/src/serialization.cpp
+++ b/src/serialization.cpp
@@ -27,7 +27,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 
 /* report a zlib or i/o error */
 void zerr(int ret)
-{   
+{
     dstream<<"zerr: ";
     switch (ret) {
     case Z_ERRNO:
@@ -53,7 +53,7 @@ void zerr(int ret)
     }
 }
 
-void compressZlib(SharedBuffer<u8> data, std::ostream &os, int level)
+void compressZlib(const u8 *data, size_t data_size, std::ostream &os, int level)
 {
        z_stream z;
        const s32 bufsize = 16384;
@@ -68,16 +68,16 @@ void compressZlib(SharedBuffer<u8> data, std::ostream &os, int level)
        ret = deflateInit(&z, level);
        if(ret != Z_OK)
                throw SerializationError("compressZlib: deflateInit failed");
-       
+
        // Point zlib to our input buffer
        z.next_in = (Bytef*)&data[0];
-       z.avail_in = data.getSize();
+       z.avail_in = data_size;
        // And get all output
        for(;;)
        {
                z.next_out = (Bytef*)output_buffer;
                z.avail_out = bufsize;
-               
+
                status = deflate(&z, Z_FINISH);
                if(status == Z_NEED_DICT || status == Z_DATA_ERROR
                                || status == Z_MEM_ERROR)
@@ -98,8 +98,7 @@ void compressZlib(SharedBuffer<u8> data, std::ostream &os, int level)
 
 void compressZlib(const std::string &data, std::ostream &os, int level)
 {
-       SharedBuffer<u8> databuf((u8*)data.c_str(), data.size());
-       compressZlib(databuf, os, level);
+       compressZlib((u8*)data.c_str(), data.size(), os, level);
 }
 
 void decompressZlib(std::istream &is, std::ostream &os)
@@ -120,9 +119,9 @@ void decompressZlib(std::istream &is, std::ostream &os)
        ret = inflateInit(&z);
        if(ret != Z_OK)
                throw SerializationError("dcompressZlib: inflateInit failed");
-       
+
        z.avail_in = 0;
-       
+
        //dstream<<"initial fail="<<is.fail()<<" bad="<<is.bad()<<std::endl;
 
        for(;;)
@@ -143,7 +142,7 @@ void decompressZlib(std::istream &is, std::ostream &os)
                        //dstream<<"z.avail_in == 0"<<std::endl;
                        break;
                }
-                       
+
                //dstream<<"1 z.avail_in="<<z.avail_in<<std::endl;
                status = inflate(&z, Z_NO_FLUSH);
                //dstream<<"2 z.avail_in="<<z.avail_in<<std::endl;
@@ -163,7 +162,7 @@ void decompressZlib(std::istream &is, std::ostream &os)
                if(status == Z_STREAM_END)
                {
                        //dstream<<"Z_STREAM_END"<<std::endl;
-                       
+
                        //dstream<<"z.avail_in="<<z.avail_in<<std::endl;
                        //dstream<<"fail="<<is.fail()<<" bad="<<is.bad()<<std::endl;
                        // Unget all the data that inflate didn't take
@@ -178,7 +177,7 @@ void decompressZlib(std::istream &is, std::ostream &os)
                                        throw SerializationError("decompressZlib: unget failed");
                                }
                        }
-                       
+
                        break;
                }
        }
@@ -186,23 +185,23 @@ void decompressZlib(std::istream &is, std::ostream &os)
        inflateEnd(&z);
 }
 
-void compress(SharedBuffer<u8> data, std::ostream &os, u8 version)
+void compress(const SharedBuffer<u8> &data, std::ostream &os, u8 version)
 {
        if(version >= 11)
        {
-               compressZlib(data, os);
+               compressZlib(*data ,data.getSize(), os);
                return;
        }
 
        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];
@@ -242,7 +241,7 @@ void decompress(std::istream &is, std::ostream &os, u8 version)
        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(;;)
@@ -251,7 +250,7 @@ void decompress(std::istream &is, std::ostream &os, u8 version)
                u8 byte=0;
 
                is.read((char*)&more_count, 1);
-               
+
                is.read((char*)&byte, 1);
 
                if(is.eof())

diff --git a/src/serialization.h b/src/serialization.h
index c91c3241f5bd29261d52b60185aae305b988ae59..4e01db40ab1ddff4ba0bb0162a1766952a869776 100644 (file)
--- a/src/serialization.h
+++ b/src/serialization.h
@@ -86,12 +86,12 @@ inline bool ser_ver_supported(s32 v) {
        Misc. serialization functions
 */
 
-void compressZlib(SharedBuffer<u8> data, std::ostream &os, int level = -1);
+void compressZlib(const u8 *data, size_t data_size, std::ostream &os, int level = -1);
 void compressZlib(const std::string &data, std::ostream &os, int level = -1);
 void decompressZlib(std::istream &is, std::ostream &os);
 
 // These choose between zlib and a self-made one according to version
-void compress(SharedBuffer<u8> data, std::ostream &os, u8 version);
+void compress(const SharedBuffer<u8> &data, std::ostream &os, u8 version);
 //void compress(const std::string &data, std::ostream &os, u8 version);
 void decompress(std::istream &is, std::ostream &os, u8 version);