A low level, performance oriented parser for EU4 save files and other PDS developed titles. Consult the write-up for an in-depth look at the Paradox Clausewitz format and the pitfalls that come trying to support all variations. It's extremely difficult to write a robust and fast parser for this format, but jomini accomplishes both tasks.
Jomini is the cornerstone of Rakaly, an EU4 achievement leaderboard and save file analyzer. This library is also powers the Paradox Game Converters and pdxu to parse ironman EU4, CK3, HOI4, and Imperator saves.
Below is a demonstration on parsing plaintext data using jomini tools.
```rust use jomini::{JominiDeserialize, TextDeserializer};
pub struct Model {
human: bool,
first: Option
let data = br#" human = yes forth = 10 core = "HAB" names = { "Johan" "Frederick" } core = FRA "#;
let expected = Model { human: true, first: None, fourth: 10, cores: vec!["HAB".tostring(), "FRA".tostring()], names: vec!["Johan".tostring(), "Frederick".tostring()], };
let actual: Model = TextDeserializer::fromwindows1252slice(data)?; assert_eq!(actual, expected); ```
Parsing data encoded in the binary format is done in a similar fashion but with an extra step. Tokens can be encoded into 16 integers, and so one must provide a map from these integers to their textual representations
```rust use jomini::{JominiDeserialize, BinaryDeserializer}; use std::collections::HashMap;
struct MyStruct { field1: String, }
let data = [ 0x82, 0x2d, 0x01, 0x00, 0x0f, 0x00, 0x03, 0x00, 0x45, 0x4e, 0x47 ];
let mut map = HashMap::new(); map.insert(0x2d82, "field1");
let actual: MyStruct = BinaryDeserializer::fromeu4(&data[..], &map)?; asserteq!(actual, MyStruct { field1: "ENG".to_string() }); ```
When done correctly, one can use the same structure to represent both the plaintext and binary data without any duplication.
One can configure the behavior when a token is unknown (ie: fail immediately or try to continue).
Caller is responsible for:
EU4txt / EU4bin)If the automatic deserialization via JominiDeserialize is too high level, there is a mid-level
api where one can easily iterate through the parsed document and interrogate fields for
their information.
```rust use jomini::TextTape;
let data = b"name=aaa name=bbb core=123 name=ccc name=ddd"; let tape = TextTape::fromslice(data).unwrap(); let mut reader = tape.windows1252reader();
while let Some((key, op, value)) = reader.nextfield() { println!("{:?}={:?}", key.readstr(), value.readstr().unwrap()); } ```
At the lowest layer, one can interact with the raw data directly via TextTape
and BinaryTape.
```rust use jomini::{TextTape, TextToken, Scalar};
let data = b"foo=bar";
asserteq!( TextTape::fromslice(&data[..])?.tokens(), &[ TextToken::Unquoted(Scalar::new(b"foo")), TextToken::Unquoted(Scalar::new(b"bar")), ] ); ```
If one will only use TextTape and BinaryTape then jomini can be compiled without default
features, resulting in a build without dependencies.
There are two targeted use cases for the write API. One is when a text tape is on hand. This is useful when one needs to reformat a document (note that comments are not preserved):
```rust use jomini::{TextTape, TextWriterBuilder};
let tape = TextTape::fromslice(b"hello = world")?;
let mut out: Vec
The writer normalizes any formatting issues. The writer is not able to losslessly write all parsed documents, but these are limited to truly esoteric situations and hope to be resolved in future releases.
The other use case is geared more towards incremental writing that can be found in melters or those crafting documents by hand. These use cases need to manually drive the writer:
rust
use jomini::TextWriterBuilder;
let mut out: Vec<u8> = Vec::new();
let mut writer = TextWriterBuilder::new().from_writer(&mut out);
writer.write_unquoted(b"hello")?;
writer.write_unquoted(b"world")?;
writer.write_unquoted(b"foo")?;
writer.write_unquoted(b"bar")?;
assert_eq!(&out, b"hello=world\nfoo=bar\n");
Due to the nature of Clausewitz being closed source, this library can never guarantee compatibility with Clausewitz. There is no specification of what valid input looks like, and we only have examples that have been collected in the wild. From what we do know, Clausewitz is recklessly flexible: allowing each game object to potentially define its own unique syntax. It is technically possible for us to support these fringe edge cases in search for perfection, but achieving that goal would sacrifice either ergonomics or performance: two pillars that are a must for save game parsing. Until a suitable solution is presented, a workaround would be to preprocess the unique syntax into a more recognizable format.
The good news is that unsupported syntax is typically isolated in a handful of game files.
Known unsupported syntax:
simple_cross_flag = {
pattern = list "christian_emblems_list"
color1 = list "normal_colors"
}
Above is an example of an unmarked list found in CK3. Typically lists are use brackets ({, }) but those are conspicuously missing here.
on_actions = {
faith_holy_order_land_acquisition_pulse
delay = { days = { 5 10 }}
faith_heresy_events_pulse
delay = { days = { 15 20 }}
faith_fervor_events_pulse
}
Alternating value and key value pairs. Makes one wish they used a bit more of a self describing format. We can parse objects or lists that occur at the end of a container, but are unable to repeatedly switch between the two formats.
pride_of_the_fleet = yes definition definition = heavy_cruiser
In this instance, the first definition should be skipped, but skipping an unrecognized or duplicate field is not consistent across game objects, as we can see from the previous examples where one shouldn't skip fields like this.
Benchmarks are ran with the following command:
cargo clean
cargo bench -- '/ck3'
find ./target -wholename "*/new/raw.csv" -print0 | xargs -0 xsv cat rows > assets/jomini-benchmarks.csv
And can be analyzed with the R script found in the assets directory.
Below is a graph generated from benchmarking on an arbitrary computer.
