minetest/src/serialization.cpp

382 lines
8.4 KiB
C++

/*
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 "log.h"
#include "util/serialize.h"
#include <zlib.h>
#include <zstd.h>
/* report a zlib or i/o error */
static 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;
}
}
// Make sure that z is deleted in case of exception
template <int (*F)(z_stream*)>
class ZlibAutoDeleter {
public:
ZlibAutoDeleter(z_stream *ptr) : ptr_(ptr) {}
~ZlibAutoDeleter() { F(ptr_); }
private:
z_stream *ptr_;
};
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");
ZlibAutoDeleter<deflateEnd> deleter(&z);
// 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;
}
}
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_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");
ZlibAutoDeleter<inflateEnd> deleter(&z);
z.avail_in = 0;
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;
}
if(z.avail_in == 0)
{
break;
}
status = inflate(&z, Z_NO_FLUSH);
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;
if(count)
os.write(output_buffer, count);
bytes_written += count;
if(status == Z_STREAM_END)
{
// 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;
}
}
}
struct ZSTD_Deleter {
void operator() (ZSTD_CStream* cstream) {
ZSTD_freeCStream(cstream);
}
void operator() (ZSTD_DStream* dstream) {
ZSTD_freeDStream(dstream);
}
};
void compressZstd(const u8 *data, size_t data_size, std::ostream &os, int level)
{
// reusing the context is recommended for performance
// it will be destroyed when the thread ends
thread_local std::unique_ptr<ZSTD_CStream, ZSTD_Deleter> stream(ZSTD_createCStream());
ZSTD_initCStream(stream.get(), level);
const size_t bufsize = 16384;
char output_buffer[bufsize];
ZSTD_inBuffer input = { data, data_size, 0 };
ZSTD_outBuffer output = { output_buffer, bufsize, 0 };
while (input.pos < input.size) {
size_t ret = ZSTD_compressStream(stream.get(), &output, &input);
if (ZSTD_isError(ret)) {
dstream << ZSTD_getErrorName(ret) << std::endl;
throw SerializationError("compressZstd: failed");
}
if (output.pos) {
os.write(output_buffer, output.pos);
output.pos = 0;
}
}
size_t ret;
do {
ret = ZSTD_endStream(stream.get(), &output);
if (ZSTD_isError(ret)) {
dstream << ZSTD_getErrorName(ret) << std::endl;
throw SerializationError("compressZstd: failed");
}
if (output.pos) {
os.write(output_buffer, output.pos);
output.pos = 0;
}
} while (ret != 0);
}
void decompressZstd(std::istream &is, std::ostream &os)
{
// reusing the context is recommended for performance
// it will be destroyed when the thread ends
thread_local std::unique_ptr<ZSTD_DStream, ZSTD_Deleter> stream(ZSTD_createDStream());
ZSTD_initDStream(stream.get());
const size_t bufsize = 16384;
char output_buffer[bufsize];
char input_buffer[bufsize];
ZSTD_outBuffer output = { output_buffer, bufsize, 0 };
ZSTD_inBuffer input = { input_buffer, 0, 0 };
size_t ret;
do
{
if (input.size == input.pos) {
is.read(input_buffer, bufsize);
input.size = is.gcount();
input.pos = 0;
}
ret = ZSTD_decompressStream(stream.get(), &output, &input);
if (ZSTD_isError(ret)) {
dstream << ZSTD_getErrorName(ret) << std::endl;
throw SerializationError("decompressZstd: failed");
}
if (output.pos) {
os.write(output_buffer, output.pos);
output.pos = 0;
}
} while (ret != 0);
// Unget all the data that ZSTD_decompressStream didn't take
is.clear(); // Just in case EOF is set
for (u32 i = 0; i < input.size - input.pos; i++) {
is.unget();
if (is.fail() || is.bad())
throw SerializationError("decompressZstd: unget failed");
}
}
void compress(const u8 *data, u32 size, std::ostream &os, u8 version, int level)
{
if(version >= 29)
{
// map the zlib levels [0,9] to [1,10]. -1 becomes 0 which indicates the default (currently 3)
compressZstd(data, size, os, level + 1);
return;
}
if(version >= 11)
{
compressZlib(data, size, os, level);
return;
}
if(size == 0)
return;
// Write length (u32)
u8 tmp[4];
writeU32(tmp, size);
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<size; i++)
{
if(
data[i] != current_byte
|| more_count == 255
)
{
// write count and byte
os.write((char*)&more_count, 1);
os.write((char*)&current_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*)&current_byte, 1);
}
void decompress(std::istream &is, std::ostream &os, u8 version)
{
if(version >= 29)
{
decompressZstd(is, os);
return;
}
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;
}
}