ipld_nostd/cid/
version.rs

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use {
	super::error::{Error, Result},
	core::convert::TryFrom,
	scale::{Decode, Encode},
};

/// The version of the CID.
#[derive(
	PartialEq, Eq, PartialOrd, Ord, Clone, Copy, Debug, Hash, Decode, Encode,
)]
pub enum Version {
	/// CID version 0.
	V0,
	/// CID version 1.
	V1,
}

impl Version {
	/// Check if the version of `data` string is CIDv0.
	pub fn is_v0_str(data: &str) -> bool {
		// v0 is a Base58Btc encoded sha hash, so it has
		// fixed length and always begins with "Qm"
		data.len() == 46 && data.starts_with("Qm")
	}

	/// Check if the version of `data` bytes is CIDv0.
	pub fn is_v0_binary(data: &[u8]) -> bool {
		data.len() == 34 && data.starts_with(&[0x12, 0x20])
	}
}

/// Convert a number to the matching version, or `Error` if no valid version is
/// matching.
impl TryFrom<u64> for Version {
	type Error = Error;

	fn try_from(raw: u64) -> Result<Self> {
		match raw {
			0 => Ok(Self::V0),
			1 => Ok(Self::V1),
			_ => Err(Error::InvalidCidVersion),
		}
	}
}

impl From<Version> for u64 {
	fn from(ver: Version) -> u64 {
		match ver {
			Version::V0 => 0,
			Version::V1 => 1,
		}
	}
}