/* Minetest Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com> This program is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ #include "serialization.h" #include "util/serialize.h" #include "zlib.h" /* report a zlib or i/o error */ void zerr(int ret) { dstream<<"zerr: "; switch (ret) { case Z_ERRNO: if (ferror(stdin)) dstream<<"error reading stdin"<<std::endl; if (ferror(stdout)) dstream<<"error writing stdout"<<std::endl; break; case Z_STREAM_ERROR: dstream<<"invalid compression level"<<std::endl; break; case Z_DATA_ERROR: dstream<<"invalid or incomplete deflate data"<<std::endl; break; case Z_MEM_ERROR: dstream<<"out of memory"<<std::endl; break; case Z_VERSION_ERROR: dstream<<"zlib version mismatch!"<<std::endl; break; default: dstream<<"return value = "<<ret<<std::endl; } } void compressZlib(const u8 *data, size_t data_size, std::ostream &os, int level) { z_stream z; const s32 bufsize = 16384; char output_buffer[bufsize]; int status = 0; int ret; z.zalloc = Z_NULL; z.zfree = Z_NULL; z.opaque = Z_NULL; 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_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) { zerr(status); throw SerializationError("compressZlib: deflate failed"); } int count = bufsize - z.avail_out; if(count) os.write(output_buffer, count); // This determines zlib has given all output if(status == Z_STREAM_END) break; } deflateEnd(&z); } void compressZlib(const std::string &data, std::ostream &os, int level) { compressZlib((u8*)data.c_str(), data.size(), os, level); } void decompressZlib(std::istream &is, std::ostream &os, size_t limit) { z_stream z; const s32 bufsize = 16384; char input_buffer[bufsize]; char output_buffer[bufsize]; int status = 0; int ret; int bytes_read = 0; int bytes_written = 0; int input_buffer_len = 0; z.zalloc = Z_NULL; z.zfree = Z_NULL; z.opaque = Z_NULL; 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(;;) { int output_size = bufsize; z.next_out = (Bytef*)output_buffer; z.avail_out = output_size; if (limit) { int limit_remaining = limit - bytes_written; if (limit_remaining <= 0) { // we're aborting ahead of time - throw an error? break; } if (limit_remaining < output_size) { z.avail_out = output_size = limit_remaining; } } if(z.avail_in == 0) { z.next_in = (Bytef*)input_buffer; is.read(input_buffer, bufsize); input_buffer_len = is.gcount(); z.avail_in = input_buffer_len; //dstream<<"read fail="<<is.fail()<<" bad="<<is.bad()<<std::endl; } if(z.avail_in == 0) { //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; bytes_read += is.gcount() - z.avail_in; //dstream<<"bytes_read="<<bytes_read<<std::endl; if(status == Z_NEED_DICT || status == Z_DATA_ERROR || status == Z_MEM_ERROR) { zerr(status); throw SerializationError("decompressZlib: inflate failed"); } int count = output_size - z.avail_out; //dstream<<"count="<<count<<std::endl; if(count) os.write(output_buffer, count); bytes_written += count; 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 is.clear(); // Just in case EOF is set for(u32 i=0; i < z.avail_in; i++) { is.unget(); if(is.fail() || is.bad()) { dstream<<"unget #"<<i<<" failed"<<std::endl; dstream<<"fail="<<is.fail()<<" bad="<<is.bad()<<std::endl; throw SerializationError("decompressZlib: unget failed"); } } break; } } inflateEnd(&z); } void compress(const SharedBuffer<u8> &data, std::ostream &os, u8 version) { if(version >= 11) { 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]; for(u32 i=1; i<data.getSize(); i++) { if( data[i] != current_byte || more_count == 255 ) { // write count and byte os.write((char*)&more_count, 1); os.write((char*)¤t_byte, 1); more_count = 0; current_byte = data[i]; } else { more_count++; } } // write count and byte os.write((char*)&more_count, 1); os.write((char*)¤t_byte, 1); } void decompress(std::istream &is, std::ostream &os, u8 version) { if(version >= 11) { decompressZlib(is, os); return; } // Read length (u32) 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(;;) { u8 more_count=0; u8 byte=0; is.read((char*)&more_count, 1); is.read((char*)&byte, 1); if(is.eof()) throw SerializationError("decompress: stream ended halfway"); for(s32 i=0; i<(u16)more_count+1; i++) os.write((char*)&byte, 1); count += (u16)more_count+1; if(count == len) break; } }