Get rid of BigUInt

Author: Internal-Compiler-Error

Cargo.toml

@@ -20,7 +20,7 @@ path = "src/parser_tester.rs"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-num = { version = "^0.4", features = ["alloc"] }
+num = { version = "^0.4" }
 bendy = { version = "^0.3" }
 juicy_bencode = "^0.1"
 rand = { version = "^0.8", features = ["small_rng"] }

src/dht_service.rs

@@ -194,7 +194,6 @@ mod tests {
         dht_service::DhtV4,
         domain_knowledge::{InfoHash, NodeId},
     };
-    use num::{BigUint, Num};
     use opentelemetry::global;
     use rand::RngCore;
     use std::{net::SocketAddrV4, str::FromStr, sync::Once};
@@ -292,13 +291,7 @@ mod tests {
         )
         .await?;
 
-        let info_hash = BigUint::from_str_radix("233b78ca585fe0a8c9e8eb4bda03f52e8b6f554b", 16).unwrap();
-        let info_hash = info_hash.to_bytes_be();
-
-        let mut stupid = [0u8; 20];
-        stupid.copy_from_slice(&info_hash[0..20]);
-
-        let info_hash = InfoHash(stupid);
+        let info_hash = InfoHash::from_hex_str("233b78ca585fe0a8c9e8eb4bda03f52e8b6f554b");
 
         let client = dht.client();
         let (token, peers) = client.get_peers(info_hash).await?;

src/dht_service/dht_client.rs

@@ -5,8 +5,7 @@ use crate::{
     our_error::{naur, OurError},
     utils::ParSpawnAndAwait,
 };
-use num::BigUint;
-use std::{collections::HashSet, net::SocketAddrV4, ops::BitXor, sync::Arc, time::Duration};
+use std::{collections::HashSet, net::SocketAddrV4, sync::Arc, time::Duration};
 use tokio::time::timeout;
 use tracing::warn;
 use tracing::{instrument, trace};
@@ -118,10 +117,7 @@ impl DhtHandle {
             let mut sorted_by_distance: Vec<_> = returned_nodes
                 .into_iter()
                 .map(|node| {
-                    let node_id = BigUint::from_bytes_be(node.id().as_bytes());
-                    let our_id = BigUint::from_bytes_be(self.our_id.as_bytes());
-                    let distance = our_id.bitxor(node_id);
-
+                    let distance = node.id().dist(&self.our_id);
                     (node, distance)
                 })
                 .collect();

src/domain_knowledge.rs

@@ -3,8 +3,10 @@ use num::{traits::ops::bytes, BigUint};
 use smallvec::SmallVec;
 use std::{fmt::Debug, net::SocketAddrV4};
 
+const NODE_ID_LEN: usize = 20;
+
 #[derive(PartialEq, Eq, Hash, Clone, Copy, PartialOrd, Ord)]
-pub struct NodeId(pub [u8; 20]);
+pub struct NodeId(pub [u8; NODE_ID_LEN]);
 
 impl Debug for NodeId {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
@@ -16,13 +18,13 @@ impl Debug for NodeId {
 }
 
 impl NodeId {
-    /// Panics if the length is not exactly 20
+    /// Panics if the length is not exactly NODE_ID_LEN
     pub fn from_bytes_unchecked(bytes: &[u8]) -> Self {
-        if bytes.len() != 20 {
-            panic!("Node id must be exactly 20 bytes");
+        if bytes.len() != NODE_ID_LEN {
+            panic!("Node id must be exactly {NODE_ID_LEN} bytes");
         }
 
-        let mut arr = [0u8; 20];
+        let mut arr = [0u8; NODE_ID_LEN];
         arr.copy_from_slice(bytes);
         NodeId(arr)
     }
@@ -37,9 +39,9 @@ impl NodeId {
         our_id ^ node_id
     }
 
-    pub fn dist(&self, rhs: &Self) -> [u8; 20] {
-        let mut dist = [0u8; 20];
-        for i in 0..20 {
+    pub fn dist(&self, rhs: &Self) -> [u8; NODE_ID_LEN] {
+        let mut dist = [0u8; NODE_ID_LEN];
+        for i in 0..NODE_ID_LEN {
             dist[i] = self.0[i] ^ rhs.0[i]
         }
         dist
@@ -74,22 +76,42 @@ impl ToBencode for NodeId {
 // }
 
 #[derive(PartialEq, Eq, Hash, Clone, Copy)]
-pub struct InfoHash(pub [u8; 20]);
+pub struct InfoHash(pub [u8; NODE_ID_LEN]);
 
 impl InfoHash {
+    /// Panics if `bytes` is not 20 bytes in length
     pub fn from_bytes_unchecked(bytes: &[u8]) -> Self {
-        if bytes.len() != 20 {
-            panic!("Info hash must be exactly 20 bytes");
+        if bytes.len() != NODE_ID_LEN {
+            panic!("Info hash must be exactly {NODE_ID_LEN} bytes");
         }
 
-        let mut arr = [0u8; 20];
+        let mut arr = [0u8; NODE_ID_LEN];
         arr.copy_from_slice(bytes);
         InfoHash(arr)
     }
 
     pub fn as_bytes(&self) -> &[u8] {
         &self.0
     }
+
+    pub fn from_hex_str(str: &str) -> Self {
+        if str.len() != NODE_ID_LEN * 2 {
+            panic!("Info hash must be exactly {NODE_ID_LEN} bytes");
+        }
+        if !str.is_ascii() {
+            panic!("input has non ascii characters");
+        }
+
+        let mut arr = [0u8; NODE_ID_LEN];
+        let mut i = 0;
+        while i != str.len() {
+            let bytes = &str[i..i + 2];
+            arr[i >> 1] = u8::from_str_radix(bytes, 16).expect("input string must be consist of soley hex digits");
+            i <<= 1;
+        }
+
+        Self(arr)
+    }
 }
 
 impl Debug for InfoHash {