Merge branch 'mk/merkle_tree' into ft_merkle_root

src/merkle_tree.cairo

@@ -21,33 +21,30 @@ pub fn merkle_root(ref txids: Array<u256>) -> u256 {
     merkle_root(ref next_txids)
 }
 
-
 #[cfg(test)]
 mod tests {
     use super::{merkle_root};
     use starknet::core::types::FieldElement;
 
     #[test]
     fn test_merkle_root() {
-
-         let txids =  array![0x50ba87bdd484f07c8c55f76a22982f987c0465fdc345381b4634a70dc0ea0b38_u256,
+         let txids =  array![
+          0x50ba87bdd484f07c8c55f76a22982f987c0465fdc345381b4634a70dc0ea0b38_u256,
           0x96b8787b1e3abed802cff132c891c2e511edd200b08baa9eb7d8942d7c5423c6_u256, 
           0x65e5a4862b807c83b588e0f4122d4ca2d46691d17a1ec1ebce4485dccc3380d4_u256,
           0x1ee9441ddde02f8ffb910613cd509adbc21282c6e34728599f3ae75e972fb815_u256,
           0xec950fc02f71fc06ed71afa4d2c49fcba04777f353a001b0bba9924c63cfe712_u256,
           0x5d874040a77de7182f7a68bf47c02898f519cb3b58092b79fa2cff614a0f4d50_u256,
-          0x0a1c958af3e30ad07f659f44f708f8648452d1427463637b9039e5b721699615_256,
+          0x0a1c958af3e30ad07f659f44f708f8648452d1427463637b9039e5b721699615_u256,
           0xd94d24d2dcaac111f5f638983122b0e55a91aeb999e0e4d58e0952fa346a1711_u256,
           0xc4709bc9f860e5dff01b5fc7b53fb9deecc622214aba710d495bccc7f860af4a_u256,
           0xd4ed5f5e4334c0a4ccce6f706f3c9139ac0f6d2af3343ad3fae5a02fee8df542_u256,
           0xb5aed07505677c8b1c6703742f4558e993d7984dc03d2121d3712d81ee067351_u256,
           0xf9a14bf211c857f61ff9a1de95fc902faebff67c5d4898da8f48c9d306f1f80f_u256
           ];
 
-        let expected_merkle_root = "0x50ba87bdd484f07c8c55f76a22982f987c0465fdc345381b4634a70dc0ea0b38_u256";
+        let expected_merkle_root = 0x50ba87bdd484f07c8c55f76a22982f987c0465fdc345381b4634a70dc0ea0b38_u256;
 
         assert_eq!(merkle_root(txids), expected_merkle_root);
     }
 }
-
-

src/validation.cairo

@@ -1,5 +1,5 @@
 use super::merkle_tree::merkle_root;
-use super::utils::{shl, shr, double_sha256};
+use super::utils::{shl, shr};
 use super::state::{Block, ChainState, Transaction, UtreexoState};
 
 const MAX_TARGET: u256 = 0x00000000FFFF0000000000000000000000000000000000000000000000000000;
@@ -102,6 +102,40 @@ fn adjust_difficulty(self: @ChainState, block: @Block) -> (u32, u32) {
     (*self.current_target, *self.epoch_start_time)
 }
 
+// Helper functions
+pub fn bits_to_target(bits: u32) -> Result<u256, felt252> {
+    // Extract exponent and mantissa
+    let exponent: u32 = (bits / 0x1000000);
+    let mantissa: u32 = bits & 0x00FFFFFF;
+
+    // Check if mantissa is valid (should be less than 0x1000000)
+    if mantissa > 0x7FFFFF && exponent != 0 {
+        return Result::Err('Invalid mantissa');
+    }
+
+    // Calculate the full target value
+    let mut target: u256 = mantissa.into();
+
+    if exponent == 0 {
+        // Special case: exponent 0 means we use the mantissa as-is
+        return Result::Ok(target);
+    } else if exponent <= 3 {
+        // For exponents 1, 2, and 3, divide by 256^(3 - exponent) i.e right shift
+        let shift = 8 * (3 - exponent);
+        target = shr(target, shift);
+    } else {
+        let shift = 8 * (exponent - 3);
+        target = shl(target, shift);
+    }
+
+    // Ensure the target doesn't exceed the maximum allowed value
+    if target > MAX_TARGET {
+        return Result::Err('Target exceeds maximum');
+    }
+
+    Result::Ok(target)
+}
+
 pub fn target_to_bits(target: u256) -> Result<u32, felt252> {
     if target == 0 {
         return Result::Err('Target is zero');