feat: add middleware and signer traits (#18)

* feat: add middleware and signer traits

* wip

* wip

* feat: MainPod traits

src/lib.rs

@@ -1,121 +1,5 @@
-use hex::{FromHex, FromHexError};
-use plonky2::field::goldilocks_field::GoldilocksField;
-use plonky2::field::types::{Field, PrimeField64};
-use plonky2::hash::poseidon::PoseidonHash;
-use plonky2::plonk::config::{Hasher, PoseidonGoldilocksConfig};
-use std::cmp::Ordering;
-use std::fmt;
-
 pub mod backend;
+pub mod backends;
 pub mod frontend;
 pub mod merkletree;
-
-pub type F = GoldilocksField;
-/// C is the Plonky2 config used in POD2 to work with Plonky2 recursion.
-pub type C = PoseidonGoldilocksConfig;
-/// D defines the extension degree of the field used in the Plonky2 proofs (quadratic extension).
-pub const D: usize = 2;
-
-#[derive(Clone, Copy, Debug, Default, Hash, PartialEq, Eq)]
-pub struct Hash(pub [F; 4]);
-pub const NULL: Hash = Hash([F::ZERO, F::ZERO, F::ZERO, F::ZERO]);
-
-impl fmt::Display for Hash {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        let v0 = self.0[0].to_canonical_u64();
-        for i in 0..4 {
-            write!(f, "{:02x}", (v0 >> (i * 8)) & 0xff)?;
-        }
-        write!(f, "…")
-    }
-}
-
-impl FromHex for Hash {
-    type Error = FromHexError;
-
-    fn from_hex<T: AsRef<[u8]>>(hex: T) -> Result<Self, Self::Error> {
-        // In little endian
-        let bytes = <[u8; 32]>::from_hex(hex)?;
-        let mut buf: [u8; 8] = [0; 8];
-        let mut inner = [F::ZERO; 4];
-        for i in 0..4 {
-            buf.copy_from_slice(&bytes[8 * i..8 * (i + 1)]);
-            inner[i] = F::from_canonical_u64(u64::from_le_bytes(buf));
-        }
-        Ok(Self(inner))
-    }
-}
-
-impl Ord for Hash {
-    fn cmp(&self, other: &Self) -> Ordering {
-        self.to_string().cmp(&other.to_string())
-    }
-}
-impl PartialOrd for Hash {
-    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
-        Some(self.cmp(other))
-    }
-}
-
-#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, Default)]
-pub struct PodId(pub Hash);
-pub const SELF: PodId = PodId(Hash([F::ONE, F::ZERO, F::ZERO, F::ZERO]));
-
-impl fmt::Display for PodId {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        if *self == SELF {
-            write!(f, "self")
-        } else if self.0 == NULL {
-            write!(f, "null")
-        } else {
-            write!(f, "{}", self.0)
-        }
-    }
-}
-
-pub fn hash_str(s: &str) -> Hash {
-    let mut input = s.as_bytes().to_vec();
-    input.push(1); // padding
-                   // Merge 7 bytes into 1 field, because the field is slightly below 64 bits
-    let input: Vec<F> = input
-        .chunks(7)
-        .map(|bytes| {
-            let mut v: u64 = 0;
-            for b in bytes.iter().rev() {
-                v <<= 8;
-                v += *b as u64;
-            }
-            F::from_canonical_u64(v)
-        })
-        .collect();
-    Hash(PoseidonHash::hash_no_pad(&input).elements)
-}
-
-#[derive(Clone, Debug, Copy)]
-pub struct Params {
-    pub max_input_signed_pods: usize,
-    pub max_input_main_pods: usize,
-    pub max_statements: usize,
-    pub max_signed_pod_values: usize,
-    pub max_public_statements: usize,
-    pub max_statement_args: usize,
-}
-
-impl Params {
-    pub fn max_priv_statements(&self) -> usize {
-        self.max_statements - self.max_public_statements
-    }
-}
-
-impl Default for Params {
-    fn default() -> Self {
-        Self {
-            max_input_signed_pods: 3,
-            max_input_main_pods: 3,
-            max_statements: 20,
-            max_signed_pod_values: 8,
-            max_public_statements: 10,
-            max_statement_args: 5,
-        }
-    }
-}
+pub mod middleware;