binary-codec 0.4.6

A binary codec for Rust that provides serialization and deserialization of data structures to and from binary formats.
Documentation 
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use crate::{
    BitStreamReader, BitStreamWriter, DeserializationError, SerializationError, SerializerConfig,
};

pub fn get_read_size<'a, T: Clone>(
    stream: &mut BitStreamReader,
    size_key: Option<&str>,
    config: &mut SerializerConfig<T>,
) -> Result<usize, DeserializationError> {
    let size = if let Some(size_key) = size_key {
        if size_key == "__dynamic" {
            return stream.read_dyn_int().map(|v| v as usize);
        }

        config.get_length(size_key).unwrap_or(stream.bytes_left())
    } else {
        stream.bytes_left()
    };

    Ok(size)
}

pub fn write_size<T: Clone>(
    size: usize,
    size_key: Option<&str>,
    stream: &mut BitStreamWriter,
    config: &mut SerializerConfig<T>,
) -> Result<(), SerializationError> {
    if let Some(size_key) = size_key {
        if size_key == "__dynamic" {
            stream.write_dyn_int(size as u128);
            return Ok(());
        }

        if let Some(expected) = config.get_length(size_key) {
            if expected != size {
                return Err(SerializationError::UnexpectedLength(expected, size));
            }
        }
    }

    Ok(())
}

pub fn read_string<T: Clone>(
    stream: &mut BitStreamReader,
    size_key: Option<&str>,
    config: &mut SerializerConfig<T>,
) -> Result<String, DeserializationError> {
    let len = get_read_size(stream, size_key, config)?;
    let slice = stream.read_bytes(len)?;
    let string = String::from_utf8(slice.to_vec()).expect("Not valid UTF-8 bytes to create string");

    Ok(string)
}

pub fn write_string<T: Clone>(
    value: &str,
    size_key: Option<&str>,
    stream: &mut BitStreamWriter,
    config: &mut SerializerConfig<T>,
) -> Result<(), SerializationError> {
    write_size(value.len(), size_key, stream, config)?;
    stream.write_bytes(&value.as_bytes());

    Ok(())
}

pub fn read_object<T, U>(
    stream: &mut BitStreamReader,
    size_key: Option<&str>,
    config: &mut SerializerConfig<U>,
) -> Result<T, DeserializationError>
where
    T: crate::BinaryDeserializer<U>,
    U: Clone,
{
    let len = get_read_size(stream, size_key, config)?;

    // If exact size of buffer is available, don't slice
    if stream.bytes_left() == len {
        T::read_bytes(stream, Some(config))
    } else {
        // Create an isolated slice, because it could be that the object uses a dynamically sized buffer based on bytes left
        let slice = stream.read_bytes(len)?;
        let mut isolated_reader = BitStreamReader::new(slice);

        T::read_bytes(&mut isolated_reader, Some(config))
    }
}

pub fn write_object<T, U>(
    value: &T,
    size_key: Option<&str>,
    stream: &mut BitStreamWriter,
    config: &mut SerializerConfig<U>,
) -> Result<(), SerializationError>
where
    T: crate::BinarySerializer<U>,
    U: Clone,
{
    // If length name is provided, we need to ensure the length matches
    // So we write it to a different buffer
    if size_key.is_some() {
        let mut buffer = Vec::new();
        let mut temp_stream = BitStreamWriter::new(&mut buffer);
        value.write_bytes(&mut temp_stream, Some(config))?;
        write_size(buffer.len(), size_key, stream, config)?;
        stream.write_bytes(&buffer);
        Ok(())
    } else {
        value.write_bytes(stream, Some(config))
    }
}