https://github.com/banyc/field_block

A definition language for buffer parsing. No code gen. Restrict business code to outside of the codec.
https://github.com/banyc/field_block

codec network parsing runtime zero-copy

Last synced: about 2 hours ago
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A definition language for buffer parsing. No code gen. Restrict business code to outside of the codec.

• Host: GitHub
• URL: https://github.com/banyc/field_block
• Owner: Banyc
• License: mit
• Created: 2022-09-28T14:39:25.000Z (about 2 years ago)
• Default Branch: master
• Last Pushed: 2022-10-02T14:54:03.000Z (about 2 years ago)
• Last Synced: 2024-10-21T01:37:03.296Z (29 days ago)
• Topics: codec, network, parsing, runtime, zero-copy
• Language: Rust
• Homepage:
• Size: 47.9 KB
• Stars: 0
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# Field Block

A definition language for buffer parsing.

## Usage

Adding this crate to a project:

```bash

cargo add field_block

```

Defining fields for a buffer:

```rust

fn get_block() -> Block {

    let mut block = Block::new();

    block.add_field(

        Name::FixedVarInt, //

        Def::VarInt(U64::Fixed(0xdeadbeef)),

    );

    block.add_field(

        Name::VarInt, //

        Def::VarInt(U64::Var),

    );

    block.add_field(

        Name::BytesFixedLen, //

        Def::Bytes(Len::Fixed(1)),

    );

    block.add_field(

        Name::BytesVarLen, //

        Def::Bytes(Len::Var),

    );

    block.add_field(

        Name::FixedBytes, //

        Def::FixedBytes(vec![0xba, 0xad, 0xf0, 0x0d]),

    );

    block

}

#[derive(Debug, PartialEq, Eq, Hash, Clone)]

enum Name {

    FixedVarInt,

    VarInt,

    BytesFixedLen,

    BytesVarLen,

    FixedBytes,

}

impl FieldName for Name {}

```

Encoding a buffer:

```rust

let block = get_block();

let mut values = HashMap::new();

values.insert(Name::VarInt, Val::VarInt(0x1234));

let vec = vec![1];

values.insert(Name::BytesFixedLen, Val::Bytes(&vec));

let vec = vec![1, 2, 3];

values.insert(Name::BytesVarLen, Val::Bytes(&vec));

let mut vec = vec![0; 1024];

let end = block.to_bytes(&values, &mut vec).unwrap();

```

Decoding a buffer:

```rust

let block = get_block();

let vec = vec![0 | 0xc0, 0, 0, 0, 0xde, 0xad, 0xbe, 0xef, 0x12 | 0x40, 0x34, 1, 3, 1, 2, 3, 0xba, 0xad, 0xf0, 0x0d];

let mut values = HashMap::new();

let end = block.to_values(&vec, &mut values).unwrap();

let ValInfo { value, pos } = values.get(&Name::VarInt).unwrap();

let value = value.varint().unwrap();

println!("Field VarInt has a value {} at pos {}", value, pos);

```

See unit tests for examples.