Half finished with serialization routine

This commit is contained in:
2023-04-04 15:24:25 -04:00
parent 074f20f93b
commit bee43ebbd2
3 changed files with 239 additions and 7 deletions

View File

@@ -217,13 +217,16 @@ int LuaTypeTagValue(lua_State *L) { return 0; }
// Lua table types. These deliberately do not overlap // Lua table types. These deliberately do not overlap
// with lua type values. // with lua type values.
// //
#define LUA_TT_GENERAL 16 enum LuaTableType {
#define LUA_TT_REGISTRY 17 LUA_TT_GENERAL = LUA_NUMTAGS,
#define LUA_TT_GLOBALENV 18 LUA_TT_REGISTRY,
#define LUA_TT_TANGIBLE 19 LUA_TT_GLOBALENV,
#define LUA_TT_TANGIBLEMETA 20 LUA_TT_TANGIBLE,
#define LUA_TT_GLOBALDB 21 LUA_TT_TANGIBLEMETA,
#define LUA_TT_CLASS 22 LUA_TT_CLASS,
LUA_TT_SENTINEL
};
// World types enum. // World types enum.

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@@ -0,0 +1,189 @@
#include "serializelua.hpp"
enum PackCodes {
LUA_PK_TRUE = LUA_TT_SENTINEL,
LUA_PK_FALSE,
LUA_PK_REFERENCE,
LUA_PK_ENDTABLE
};
class Deserializer {
LuaVar id_to_value_;
LuaStack LS_;
int next_id_;
eng::string &error_;
StreamBuffer *sb_;
Deserializer(LuaStack &LS0, LuaSlot val, StreamBuffer *sb, eng::string &error) :
LS_(LS0.state(), lookup_, value_to_id_), error_(error) {
next_id_ = 1;
LS_.newtable(id_to_value_);
try {
uint8_t b = sb_->read_uint8();
deserialize_r(b, val);
} catch (StreamEof e) {
error_ = "EOF reached while deserializing data";
LS_.set(val, LuaNil);
}
LS_.result();
}
};
// If the serialize routine encounters an error, it must set the
// error message string. In that case, it is assumed that the contents
// of the serialization buffer is no longer valid and there is no
// requirement to try to keep it valid.
class Serializer {
LuaVar lookup_;
LuaVar value_to_id_;
LuaStack LS_;
int next_id_;
eng::string &error_;
StreamBuffer *sb_;
void serialize_keyvals_r(LuaSlot tab) {
LuaVar key, val;
LuaStack SLS(LS_.state(), key, val);
SLS.getmetatable(val, tab);
if (!LS.isnil(val)) {
error_ = "Cannot serialize metatables";
SLS.result();
return;
}
sb_->pack_uint8(LUA_TT_GENERAL);
SLS.set(key, LuaNil);
while (LS.next(tab, key, val)) {
serialize_r(key);
if (!error_.empty()) {
SLS.result();
return;
}
serialize_r(val);
if (!error_.empty()) {
SLS.result();
return;
}
}
sb_->pack_uint8(LUA_PK_ENDTABLE);
SLS.result();
}
void serialize_r(LuaSlot val) {
int tt = LS_.xtype(val);
switch (tt) {
case LUA_TNIL: {
sb_->pack_uint8(LUA_TNIL);
return;
}
case LUA_TBOOLEAN: {
if (LS_.ckboolean(val)) {
sb_->pack_uint8(LUA_PK_TRUE);
} else {
sb_->pack_uint8(LUA_PK_FALSE);
}
return;
}
case LUA_TLIGHTUSERDATA: {
sb_->pack_uint8(LUA_TLIGHTUSERDATA);
sb_->pack_uint64(LS_.cktoken(val).value);
return;
}
case LUA_TNUMBER: {
sb_->pack_uint8(LUA_TNUMBER);
sb_->pack_double(LS_.cknumber(val));
return;
}
case LUA_TSTRING: {
LS_.rawget(lookup_, value_to_id_, val);
if (!LS_.isnil(lookup_)) {
sb_->pack_uint8(LUA_PK_REFERENCE);
sb_->pack_uint32(LS.ckint(lookup_));
} else {
LS_.rawset(value_to_id_, val, next_id_++);
sb_->pack_uint8(LUA_TSTRING);
sb_->pack_string(LS_.ckstring(val));
}
return;
}
case LUA_TTABLE: {
// LS.xtype should never return LUA_TTABLE.
error_ = "Bad xtype in serialization";
return;
}
case LUA_TFUNCTION: {
error_ = "Cannot serialize closures";
return;
}
case LUA_TUSERDATA: {
error_ = "Cannot serialize userdata";
return;
}
case LUA_TTHREAD: {
error_ = "Cannot serialize coroutines";
return;
}
case LUA_TT_GENERAL: {
LS_.rawget(lookup_, value_to_id_, val);
if (!LS_.isnil(lookup_)) {
sb_->pack_uint8(LUA_PK_REFERENCE);
sb_->pack_uint32(LS.ckint(lookup_));
} else {
LS_.rawset(value_to_id_, val, next_id_++);
serialize_table_r(val);
}
return;
}
case LUA_TT_REGISTRY: {
error_ = "Pointer to registry found in serialization, shouldn't happen";
return;
}
case LUA_TT_GLOBALENV: {
sb_->pack_uint8(LUA_TT_GLOBALENV);
return;
}
case LUA_TT_TANGIBLE: {
sb_->pack_uint8(LUA_TT_TANGIBLE);
sb_->pack_int64(LS_.tanid(val));
return;
}
case LUA_TT_TANGIBLEMETA: {
error_ = "Pointer to a tangible metatable found in serialization, shouldn't happen";
return;
}
case LUA_TT_CLASS: {
sb_->pack_uint8(LUA_TT_CLASS);
sb_->pack_string(LS_.classname(val));
return;
}
default: {
error_ = "Unrecognized xtype in serialization";
return;
}
}
Serializer(LuaStack &LS0, LuaSlot val, StreamBuffer *sb, eng::string &error) :
LS_(LS0.state(), lookup_, value_to_id_), error_(error) {
next_id_ = 1;
LS_.newtable(value_to_id_);
serialize_r(val);
LS_.result();
}
};
eng::string serialize_lua(LuaStack &LS0, LuaSlot val, StreamBuffer *sb) {
eng::string error;
Serializer sz(LS0, val, sb, error);
return error;
};
eng::string deserialize_lua(LuaStack &LS0, LuaSlot val, StreamBuffer *sb) {
eng::string error;
Deserializer dsz(LS0, val, sb, error);
if (!error_.empty()) {
LS0.set(val, LuaNil);
}
return error;
}

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@@ -0,0 +1,40 @@
////////////////////////////////////////////////////////////
//
// This module contains routines to serialize and deserialize
// lua data structures. These routines can handle cyclic data
// structures.
//
// These routines are used for some specific difference
// transmission cases, but they're not the heart of the lua
// difference transmission system.
//
////////////////////////////////////////////////////////////
#ifndef SERIALIZELUA_HPP
#define SERIALIZELUA_HPP
#include "luastack.hpp"
#include "streambuffer.hpp"
// serialize_lua
//
// Serialize a value from the LuaSlot and store it in the StreamBuffer.
// On success, returns empty string.
//
// If there is an error, returns an error message. In this case, the
// streambuffer contains garbage.
//
eng::string serialize_lua(LuaStack &LS0, LuaSlot val, StreamBuffer *sb);
// deserialize_lua
//
// Deserialize a value from the StreamBuffer and store it in the LuaSlot.
// On success, returns empty string.
//
// If there is an error, returns an error message. In this case, the
// streambuffer is likely only partially consumed.
//
eng::string deserialize_lua(LuaStack &LS0, LuaSlot val, StreamBuffer *sb);
#endif // SERIALIZELUA_HPP