Another way to store a table to a file
This module takes a Lua table and turns it into binary. Number are stored lossless from the engine.
With version 1.03 there is a secondary arg if you pass true it will read the table as sequential (EVEN WHEN IT IS NOT) and write variables without the key. If you have a sequential table the output will be correct, if you don't have a sequential table the output will be sequential but it will not match your input.
Verion 1.06 adds a CRC check which is enabled by default. You can turn it off with BinaryToTable(tab, false) and TableToBinary(tab, nil, false).
Output from the test.lua:
Results with Ryzen 9 3900x on 32bit srcds (100 loops)
It took util.TableToJSON an average of 0.13179323
It took util.JSONToTable an average of 0.14723701
It took TableToBinary an average of 0.00686151
It took BinaryToTable an average of 0.01347262
TableToBinary without CRC is 19.40 faster than util.TableToJSON
BinaryToTable without CRC is 11.05 faster than util.JSONToTable
TableToBinary with CRC is 19.21 faster than util.TableToJSON
BinaryToTable with CRC is 10.93 faster than util.JSONToTable
TableToBinary produced an output of 839878 Byte
util.TableToJSON produced an output of 1360001 Byte
BinaryToTable is roughly 11X faster than util.JSONToTable Given the near zero difference in CRC and non CRC leave it enabled unless you want to edit the file for some reason.
To compile, download https://github.com/Facepunch/gmod-module-base/tree/development and premake5 https://premake.github.io/ Put the include folder from gmod-module-base in the folder above gm_binarytable, put premake5.exe in the gm_binarytable folder and run BuildProjects.bat. You should know from there.
Please let me know if you encounter any problems. I would also like to know your application for this. Please let me know.
Thank you for using this.
C and C++ use memory to store temporary values. These values are stored in the memory as bits. 8 bits per byte.
You push a table to this module and it does the following:
Get the table
Check what type the first variable is, number, string, Vector, Angle, table.
For numbers it converts it into the smallest possible storage space. Strings get written raw with a length in front of it. Vectors and angles get written raw. With a table we start from the begin and loop it.
Before adding our variable into our output we add a header byte, this contains the type we will write.
We write the variable and we start from the begin until we are done.
This storage method should be lossless as it stores everything. Meaning { Vector() } will be stored like this:
1 byte for our table index type indicator, 1 byte for our table index index, 1 byte for our table key indicator 12 bytes for the Vector and done. 15 bytes in total completely lossless.
for { { Vector() } } it is slightly different but it is about the same.
1 byte key index indicator, 1 byte key index number, 1 byte table start, 1 byte key index indicator, 1 byte key index number, 1 byte values index indicator, 12 bytes value, 1 byte table close. A total of 19 bytes.
At [128] = { Vector() } all that changes is the initial key index number can no longer be stored in a byte but needs 2 bytes changing the size from 19 to 20.
At [32768] = { Vector() } this will be done again but this time it goes from 2 to 4 bytes chaning the size from 20 to 22.
Floating points from Lua that are not in a Vector or Angle will be saved with 8 bytes. This ensures lossless storing.
util.TableToJSON converts floating points into a string meaning 9.99999 will be turned into 10 this modules stores it as its value meaning after you store it and get it back it is still 9.99999. If you need this precision this is the way to go.
By not having to convert anything we can save a lot of time. util.TableToJSON takes 0.4170118 seconds to convert 100000 time { VectorRand() } in a table to a string where TableToBinary takes 0.0635785 seconds. This leaves more time for the server to do other things. Better yet converting it back to a table takes 0.0651309 seconds in this case compared to 0.1256353 with util.JSONToTable.
Trying to convert the Global table crashes the program