Mod «Save File Compression» for Rimworld (v1.2 - 1.6)

Use compression to save your game

Vanilla's game save files are stored in plain text, so editing your save file is easy, but they can get to hundred(s) of Megabytes in size.
With this mod, they get shrunk to anywhere from 20% to 5% of the size of vanilla, saving your hard drive space. It can also speed up your saving process in some computers.
This mod does not simply repack the vanilla save file as a zip. Instead it intercepts the game's saving process itself, so as the game attempts to write save data, the data are intercepted, compressed and written to disk all at the same time.

There were many other mods that has done this before, but my mod has these differences/advantages:
1. Supports Zstandard compression format, which is much faster and result in smaller files than deflate which other mods support.
2. Can read save files from vanilla and all other save file compression mods that I've seen.
3. Supports 1.2-1.6 using the exact same common compression/decompression library, so likely long term stable.
4. Free and open source.

During normal gameplay:

This mod has no performance impact since no code is run.

When saving game:

If you have a slow hard drive (such as a mechanical hard drive) this mod can speed up your saving process by having less data to write to your hard drive.
In other computers, the bottleneck is the game itself preparing the data to be saved; then the mod neither speed up nor slow down the saving speed.
(This is unlikely) If you find that saving the game seem to take longer, you can decrease the compression level in the mod settings to speed it up.
You can configure the level of compression in the mod's settings, lower number is faster, while higher number result in smaller files.


This mod had no issue in my own 800+ mod list, so it's probably going to be compatible with your mods.
Support RimWorld 1.2-1.6 and all DLCs. Will most likely support future RimWorld versions when they come out.
RimWorld 1.1 and below won't be supported due to lack of Harmony2 support.

Confirmed compatible with:
RimSaves

The following mods have built-in compatibility patches:
Better ModMismatch Window

These mods are similar in function to this mod, so they can't be loaded together; this mod can read saves produced by them.
Savegame Compressor [1.1 - 1.4]
Savegame Compressor (Continued)
RimKeeper - Save Compressor
RWS Compressor

This mod is safe to add mid-save.
If you remove the mod mid-save, you would need to manually extract (uncompress) the save files to be able to load them:
1. When using ZStandard compression format, you can use 7-Zip-zstd[github.com] (not the standard 7-Zip) to extract into vanilla's plain text save file (don't forget the ".rws" file affix).
2. When using Gzip compression format, most decompression software can extract the compressed game file into vanilla's plain text save file, and some text editors such as Kate can edit the compressed file directly without extracting first.
3. Alternatively, you can set the mod setting to disable compression and manually re-save the games so you can load the saves after removing this mod.

Languages

Has built-in support for: English, Chinese (Simplified/Traditional)
Let me know if you make a translation mod for this mod, so that I can add your translation mod here too.


1. Some formats (raw deflate, ZStandard) do not save information about its uncompressed size, so you might not be able to read the uncompressed size of the save file. However, this will NOT brick your save and you can still load the game normally.
2. This mod does not currently support batch compressing/uncompressing saves, you may want to use an external tool such as 7-Zip-zstd to do that.
3. Only save games (and not scnearios/ideology presets from the Ideology DLC/gene presets from the Biotech DLC, etc.) are compressed, this is done on purpose for mod compatibility, and the other files tend to be very small anyways.
4. Sometimes saves manually compressed to ZStandard format using third party software would fails to load, I am not sure why; therefore when manually compressing your save game, Gzip is preferred over ZStandard.
5. The mod Savegame Shrinker's UI buttons may block some informational text from this mod; it does not impact gameplay or saving/loading games.
6. The Gzip format may show incorrect size if a single uncompressed save file get over 4GB in size; however, I've never seen a save file that large.