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@nickbabcock
nickbabcock committed Dec 16, 2023
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93 changes: 15 additions & 78 deletions README.md
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Expand Up @@ -24,7 +24,9 @@ Converters](https://github.com/ParadoxGameConverters) and

## Quick Start

Below is a demonstration on parsing plaintext data using jomini tools.
Below is a demonstration of deserializing plaintext data using serde.
Several additional serde-like attributes are used to reconcile the serde
data model with structure of these files.

```rust
use jomini::{
Expand Down Expand Up @@ -71,9 +73,9 @@ let actual: Model = jomini::text::de::from_windows1252_slice(data)?;
assert_eq!(actual, expected);
```

## Binary Parsing
## Binary Deserialization

Parsing data encoded in the binary format is done in a similar fashion but with a couple extra steps for the caller to supply:
Deserializing data encoded in the binary format is done in a similar fashion but with a couple extra steps for the caller to supply:

- How text should be decoded (typically Windows-1252 or UTF-8)
- How rational (floating point) numbers are decoded
Expand All @@ -84,7 +86,7 @@ Implementors be warned, not only does each Paradox game have a different binary
Below is an example that defines a sample binary format and uses a hashmap token lookup.

```rust
use jomini::{BinaryDeserializer, Encoding, JominiDeserialize, Windows1252Encoding};
use jomini::{Encoding, JominiDeserialize, Windows1252Encoding, binary::BinaryFlavor};
use std::{borrow::Cow, collections::HashMap};

#[derive(JominiDeserialize, PartialEq, Debug)]
Expand Down Expand Up @@ -116,8 +118,7 @@ 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::builder_flavor(BinaryTestFlavor)
.deserialize_slice(&data[..], &map)?;
let actual: MyStruct = BinaryTestFlavor.deserialize_slice(&data[..], &map)?;
assert_eq!(actual, MyStruct { field1: "ENG".to_string() });
```

Expand All @@ -126,59 +127,14 @@ without any duplication.

One can configure the behavior when a token is unknown (ie: fail immediately or try to continue).

### Ondemand Deserialization

The ondemand deserializer is a one-shot deserialization mode is often faster
and more memory efficient as it does not parse the input into an intermediate
tape, and instead deserializes right from the input.

It is instantiated and used similarly to `BinaryDeserializer`

```rust
use jomini::OndemandBinaryDeserializer;
// [...snip code from previous example...]

let actual: MyStruct = OndemandBinaryDeserializer::builder_flavor(BinaryTestFlavor)
.deserialize_slice(&data[..], &map)?;
assert_eq!(actual, MyStruct { field1: "ENG".to_string() });
```

### Direct identifier deserialization with `token` attribute

There may be some performance loss during binary deserialization as
tokens are resolved to strings via a `TokenResolver` and then matched against the
string representations of a struct's fields.

We can fix this issue by directly encoding the expected token value into the struct:

```rust
#[derive(JominiDeserialize, PartialEq, Debug)]
struct MyStruct {
#[jomini(token = 0x2d82)]
field1: String,
}

// Empty token to string resolver
let map = HashMap::<u16, String>::new();

let actual: MyStruct = BinaryDeserializer::builder_flavor(BinaryTestFlavor)
.deserialize_slice(&data[..], &map)?;
assert_eq!(actual, MyStruct { field1: "ENG".to_string() });
```

Couple notes:

- This does not obviate need for the token to string resolver as tokens may be used as values.
- If the `token` attribute is specified on one field on a struct, it must be specified on all fields of that struct.

## Caveats

Caller is responsible for:
Before calling any Jomini API, callers are expected to:

- Determining the correct format (text or binary) ahead of time
- Stripping off any header that may be present (eg: `EU4txt` / `EU4bin`)
- Providing the token resolver for the binary format
- Providing the conversion to reconcile how, for example, a date may be encoded as an integer in
- Determine the correct format (text or binary) ahead of time.
- Strip off any header that may be present (eg: `EU4txt` / `EU4bin`)
- Provide the token resolver for the binary format
- Provide the conversion to reconcile how, for example, a date may be encoded as an integer in
the binary format, but as a string when in plaintext.

## The Mid-level API
Expand All @@ -199,6 +155,9 @@ for (key, _op, value) in reader.fields() {
}
```

For even lower level of parisng, see the respective binary and text
documentation.

The mid-level API also provides the excellent utility of converting the
plaintext Clausewitz format to JSON when the `json` feature is enabled.

Expand All @@ -211,28 +170,6 @@ let actual = reader.json().to_string()?;
assert_eq!(actual, r#"{"foo":"bar"}"#);
```

## One Level Lower

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";

assert_eq!(
TextTape::from_slice(&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.

## Write API

There are two targeted use cases for the write API. One is when a text tape is on hand.
Expand Down
62 changes: 59 additions & 3 deletions src/binary/mod.rs
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Expand Up @@ -6,10 +6,66 @@
//!
//! If the serde deserialization API is too high level, one can build
//! abstractions ontop of.
//! - [BinaryTape::from_slice]: Realizes a pseudo AST onto
//! a linear tape. Cleans up and normalizes data.
//! - [TokenReader]: an incremental binary lexer designed for handling large
//! - [BinaryTape::from_slice]: Realizes a pseudo AST onto a linear tape.
//! Cleans up and normalizes data.
//! - [TokenReader]: An incremental binary lexer designed for handling large
//! saves in a memory efficient manner.
//! - [Lexer]: The lowest level, a zero cost binary data scanner over a byte
//! slice.
//!
//! ## Direct identifier deserialization with `token` attribute
//!
//! There may be some performance loss during binary deserialization as
//! tokens are resolved to strings via a `TokenResolver` and then matched against the
//! string representations of a struct's fields.
//!
//! We can fix this issue by directly encoding the expected token value into the struct:
//!
//! ```rust
//! # #[cfg(feature = "derive")] {
//! # use jomini::{Encoding, JominiDeserialize, Windows1252Encoding, binary::BinaryFlavor};
//! # use std::{borrow::Cow, collections::HashMap};
//! #
//! # #[derive(Debug, Default)]
//! # pub struct BinaryTestFlavor;
//! #
//! # impl BinaryFlavor for BinaryTestFlavor {
//! # fn visit_f32(&self, data: [u8; 4]) -> f32 {
//! # f32::from_le_bytes(data)
//! # }
//! #
//! # fn visit_f64(&self, data: [u8; 8]) -> f64 {
//! # f64::from_le_bytes(data)
//! # }
//! # }
//! #
//! # impl Encoding for BinaryTestFlavor {
//! # fn decode<'a>(&self, data: &'a [u8]) -> Cow<'a, str> {
//! # Windows1252Encoding::decode(data)
//! # }
//! # }
//! #
//! # let data = [ 0x82, 0x2d, 0x01, 0x00, 0x0f, 0x00, 0x03, 0x00, 0x45, 0x4e, 0x47 ];
//! #
//! #[derive(JominiDeserialize, PartialEq, Debug)]
//! struct MyStruct {
//! #[jomini(token = 0x2d82)]
//! field1: String,
//! }
//!
//! // Empty token to string resolver
//! let map = HashMap::<u16, String>::new();
//!
//! let actual: MyStruct = BinaryTestFlavor.deserialize_slice(&data[..], &map)?;
//! assert_eq!(actual, MyStruct { field1: "ENG".to_string() });
//! # }
//! # Ok::<(), Box<dyn std::error::Error>>(())
//! ```
//!
//! Couple notes:
//!
//! - This does not obviate need for the token to string resolver as tokens may be used as values.
//! - If the `token` attribute is specified on one field on a struct, it must be specified on all fields of that struct.
/// binary deserialization
#[cfg(feature = "derive")]
Expand Down
94 changes: 11 additions & 83 deletions src/lib.rs
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Expand Up @@ -14,15 +14,17 @@ Converters](https://github.com/ParadoxGameConverters) and
## Features
- ✔ Versatile: Handle both plaintext and binary encoded data
- ✔ Fast: Parse data at 1 GB/s
- ✔ Fast: Parse data at over 1 GB/s
- ✔ Small: Compile with zero dependencies
- ✔ Safe: Extensively fuzzed against potential malicious input
- ✔ Ergonomic: Use [serde](https://serde.rs/derive.html)-like macros to have parsing logic automatically implemented
- ✔ Embeddable: Cross platform native apps, statically compiled services, or in the browser via [Wasm](https://webassembly.org/)
## Quick Start
Below is a demonstration on parsing plaintext data using jomini tools.
Below is a demonstration of deserializing plaintext data using serde.
Several additional serde-like attributes are used to reconcile the serde
data model with structure of these files.
```rust
# #[cfg(feature = "derive")] {
Expand Down Expand Up @@ -129,68 +131,14 @@ without any duplication.
One can configure the behavior when a token is unknown (ie: fail immediately or try to continue).
### Direct identifier deserialization with `token` attribute
There may be some performance loss during binary deserialization as
tokens are resolved to strings via a `TokenResolver` and then matched against the
string representations of a struct's fields.
We can fix this issue by directly encoding the expected token value into the struct:
```rust
# #[cfg(feature = "derive")] {
# use jomini::{Encoding, JominiDeserialize, Windows1252Encoding, binary::BinaryFlavor};
# use std::{borrow::Cow, collections::HashMap};
#
# #[derive(Debug, Default)]
# pub struct BinaryTestFlavor;
#
# impl BinaryFlavor for BinaryTestFlavor {
# fn visit_f32(&self, data: [u8; 4]) -> f32 {
# f32::from_le_bytes(data)
# }
#
# fn visit_f64(&self, data: [u8; 8]) -> f64 {
# f64::from_le_bytes(data)
# }
# }
#
# impl Encoding for BinaryTestFlavor {
# fn decode<'a>(&self, data: &'a [u8]) -> Cow<'a, str> {
# Windows1252Encoding::decode(data)
# }
# }
#
# let data = [ 0x82, 0x2d, 0x01, 0x00, 0x0f, 0x00, 0x03, 0x00, 0x45, 0x4e, 0x47 ];
#
#[derive(JominiDeserialize, PartialEq, Debug)]
struct MyStruct {
#[jomini(token = 0x2d82)]
field1: String,
}
// Empty token to string resolver
let map = HashMap::<u16, String>::new();
let actual: MyStruct = BinaryTestFlavor.deserialize_slice(&data[..], &map)?;
assert_eq!(actual, MyStruct { field1: "ENG".to_string() });
# }
# Ok::<(), Box<dyn std::error::Error>>(())
```
Couple notes:
- This does not obviate need for the token to string resolver as tokens may be used as values.
- If the `token` attribute is specified on one field on a struct, it must be specified on all fields of that struct.
## Caveats
Caller is responsible for:
Before calling any Jomini API, callers are expected to:
- Determining the correct format (text or binary) ahead of time
- Stripping off any header that may be present (eg: `EU4txt` / `EU4bin`)
- Providing the token resolver for the binary format
- Providing the conversion to reconcile how, for example, a date may be encoded as an integer in
- Determine the correct format (text or binary) ahead of time.
- Strip off any header that may be present (eg: `EU4txt` / `EU4bin`)
- Provide the token resolver for the binary format
- Provide the conversion to reconcile how, for example, a date may be encoded as an integer in
the binary format, but as a string when in plaintext.
## The Mid-level API
Expand All @@ -211,6 +159,8 @@ for (key, _op, value) in reader.fields() {
}
```
For even lower level of parisng, see the respective [binary] and [text] module documentation.
*/
#![cfg_attr(
feature = "json",
Expand All @@ -234,28 +184,6 @@ assert_eq!(actual, r#"{"foo":"bar"}"#);
"##
)]
/*!
## One Level Lower
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";
assert_eq!(
TextTape::from_slice(&data[..])?.tokens(),
&[
TextToken::Unquoted(Scalar::new(b"foo")),
TextToken::Unquoted(Scalar::new(b"bar")),
]
);
# Ok::<(), Box<dyn std::error::Error>>(())
```
If one will only use `TextTape` and `BinaryTape` then `jomini` can be compiled without default
features, resulting in a build without dependencies.
## Write API
Expand Down
10 changes: 8 additions & 2 deletions src/text/de.rs
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Expand Up @@ -123,7 +123,10 @@ where
TextDeserializer::from_windows1252_slice(data)?.deserialize()
}

/// Convenience method for deserializing streaming windows1252 data into a Rust value
/// (**Experimental**) Create a Windows1252 text value from a reader
///
/// Considered experimental as it uses a [TokenReader] under the hood, which
/// uses a different parsing routine geared toward save files.
pub fn from_windows1252_reader<T, R>(reader: R) -> Result<T, Error>
where
T: DeserializeOwned,
Expand Down Expand Up @@ -779,7 +782,10 @@ enum TextDeserializerKind<'a, 'b, E> {
}

impl TextDeserializer<'_, '_, Windows1252Encoding> {
/// Create a Windows1252 text deserializer over a reader
/// (**Experimental**) Create a Windows1252 text deserializer over a reader
///
/// Considered experimental as it uses a [TokenReader] under the hood, which
/// uses a different parsing routine geared toward save files.
pub fn from_windows1252_reader<R>(reader: R) -> TextReaderDeserializer<R, Windows1252Encoding>
where
R: Read,
Expand Down
7 changes: 2 additions & 5 deletions src/text/mod.rs
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Expand Up @@ -11,11 +11,8 @@
//! abstractions ontop of:
//! - [TextTape::from_slice]: Realizes a pseudo AST onto
//! a linear tape. Cleans up and normalizes data.
//! - [TokenReader]: (**experimental** unlike the [binary
//! equivalent](crate::binary::TokenReader)) an incremental text lexer
//! designed for handling large saves in a memory efficient manner. It can
//! lex game files, but the best API for exposing esoteric game file syntax
//! has not yet been developed.
//! - [TokenReader]: (**experimental**) an incremental text lexer
//! designed for handling large saves in a memory efficient manner.
//!
//! Some additional APIs are available to make working with a [TextTape] more
//! ergonomic for DOM-like use cases.
Expand Down
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