datse/src/server/data.rs

//! Data structures for the in-memory map.
use super::*;
use std::{
    collections::HashMap,
    borrow::Cow,
    error,
    fmt,
};
use generational_arena::{
    Arena, Index,
};
use bitflags::bitflags;
use cryptohelpers::{
    rsa::{
	RsaPublicKey, RsaPrivateKey,
	Signature,
    },
    aes::{self, AesKey,},
    sha256::Sha256Hash,
};
use tokio::io::{
    AsyncRead, AsyncWrite,
};

/// An absolute (nested) index
#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
pub struct AbsoluteIndex(Vec<Index>);

/// Possible value types of the data map
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub enum Data
{
    Byte(u8),
    Char(char),
    Bool(bool),

    /// Signed integer
    SI(i64),
    /// Unsigned integer
    UI(u64),
    /// Floating-point integer
    FI(f64),

    /// A UTF-8 text string
    Text(String),
    /// A binary blob
    Binary(Vec<u8>),

    /// A reference index to an item within the same `Datamap` as this one.
    RelativeRef(Index),
    /// A reference to an item N deep within nested `Map` elements.
    ///
    /// The first `Index` specifies the `Map` data item at the root `Datamap` that contains the next, et cetera. The pointed to value is the last index.
    AbsoluteRef(AbsoluteIndex),

    /// A list of atoms
    List(Vec<Atom>),
    /// Another datamap
    Map(Datamap),

    /// An AES key
    AesKey(AesKey),
    /// An RSA keypair
    RsaKeypair(RsaPrivateKey, RsaPublicKey),
    /// An RSA private key
    RsaPrivate(RsaPrivateKey),
    /// An RSA public key
    RsaPublic(RsaPublicKey),

    /// A SHA256 hash
    Hash(Sha256Hash),

    /// A unique ID
    Uuid(uuid::Uuid),

    /// An RSA signature
    Signature(Signature),

    /// Nothing
    Null,
}

/// An entry that may or may not be encrypted
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub enum MaybeEncrypted
{
    /// This is an encrypted serialized `Data`.
    Encrypted(Vec<u8>),
    /// An unencrypted `Data`
    Unencrypted(Data),
}

submod!(encryption; "impl for `MaybeEncrypted`. \
		     Other `Data` encryption helpers");

bitflags! {
    /// And additional metadata for values
    #[derive(Serialize, Deserialize)]
    struct Tags: u16
    {
	/// Default
	const NONE =      0;
	/// This value should be cloned on write unless specified elsewhere.
	const COW =       1<<0;
	/// This should not show up in searches.
	const HIDDEN =    1<<1;
	/// Versioning is enabled for this value.
	///
	/// When it is deleted, it should instead be moved away into a sperate entry.
	const VERSIONED = 1<<2;
    }
}

/// Information about a map entry.
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub struct Info
{
    alt_name: Option<(String, String)>,
    
    created: u64,
    modified: u64,

    tags: Tags,

    /// Events to be emitted to `State` when this element does something.
    ///
    /// Can be used for monitoring or logging and such.
    hooks: event::Hooks,

    owner: Option<Vec<user::EntityID>>, //starts as the user that created (i.e. same as `created_by`), or `None` if ownership is disabled
    signed: Option<Vec<Signature>>,

    perms: user::Permissions,

    created_by: user::UserID,
    log: Vec<event::InBandEvent>,
}

/// The root data containing map
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct Datamap
{
    data: Arena<Atom>,
    ident: HashMap<Identifier, Index>,
}

impl PartialEq for Datamap
{
    fn eq(&self, other: &Self) -> bool
    {
	self.ident == other.ident && {
	    for (v1, v2) in self.ident.iter().map(|(_, v)| (self.data.get(*v), other.data.get(*v)))
	    {
		if v1 != v2 {
		    return false;
		}
	    }
	    true
	}
    }
}

/// A value in a datamap, contains the information about the value and the value itself.
///
/// May also contain previous versions of this atom.
///
/// # Note
/// `Atom` boxes most of itself. It's not needed to box `Atom` itself.
// Box these first two together, since they are hueg.
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub struct Atom(Box<(MaybeEncrypted, Info)>, Vec<Atom>);

/// An identifier for an item in a `Datamap`, or an item nested within many `Datamap`s.
#[derive(Debug, Clone, Ord, PartialOrd, Eq, PartialEq, Hash, Serialize, Deserialize)]
pub struct Identifier(String);

#[cfg(test)]
mod tests
{
    #[test]
    fn data_me_sync()
    {
	let data = super::Data::SI(-120);
	let aes = super::aes::AesKey::generate().unwrap();

	println!("Data: {:?}", data);
	let enc = super::MaybeEncrypted::new_encrypted(data.clone(), &aes).expect("Couldn't encrypt");
	println!("M/Enc: {:?}", enc);
	let dec = enc.clone().into_unencrypted(Some(&aes)).expect("Couldn't decrypt");
	println!("M/Dec: {:?}", dec);
	let out = dec.into_data(Some(&aes)).unwrap();

	assert_eq!(data, out);
    }
}