Binmarshal

Pack and unpack structs and enums into and out of binary data streams.

Add to your project

cargo add binmarshal

Packing Structs and Enums

use binmarshal::*;

#[derive(Debug, Clone, BinMarshal)]
#[marshal(tag_type = u8)]
enum MyEnum {
  #[marshal(tag = "0")]
  Variant1,
  #[marshal(tag = "1")]
  Variant2 {
    #[marshal(bits = 4)]
    a: u8,
    #[marshal(align = 1)]
    b: u16,
    c: LengthTaggedVec<u8, i32>
  }
}

fn main() {
  let v = MyEnum::Variant2 {
    a: 13,
    b: 5192,
    c: LengthTaggedVec::new(vec![ -12, -242, 12034 ])
  };

  // Packing
  let mut bytes = [0u8; 256];
  let mut writer = BufferBitWriter::new(&mut bytes);
  v.write(&mut writer, ());
  let slice = writer.slice();   // Gives you a &[u8] reference of the appropriate length, as a subset of "bytes"

  // Unpacking
  let v = MyEnum::read(&mut BitView::new(slice), ()).unwrap();
}

Using Context

Context allows you to pass variables between structs and enums, primarily for tagging enums. If you are using tagged enums with context, you must call .update() prior to writing.

use binmarshal::*;

#[derive(Clone)]
struct MyContext {
  tag: u8
}

#[derive(Debug, Clone, BinMarshal)]
#[marshal(ctx = MyContext, tag_type = u8, tag = "ctx.tag")]
enum MyEnum {
  #[marshal(tag = "1")]
  Variant1,
  #[marshal(tag = "2")]
  Variant2,
}

#[derive(Debug, Clone, BinMarshal)]
struct MyStruct {
  variant: u8,
  #[marshal(ctx = "construct", ctx_member(field = "tag", member = "variant"))]
  inner: MyEnum
}

Examples

More complex examples are provided under examples