perf: replace hex with const-hex

Cargo.toml

@@ -118,7 +118,7 @@ bytes = "1.4"
 criterion = "0.5"
 dunce = "1.0"
 eyre = "0.6"
-hex = "0.4"
+hex = { package = "const-hex", version = "1.6", features = ["hex"] }
 hex-literal = "0.4"
 home = "0.5.5"
 Inflector = "0.11"

ethers-contract/ethers-contract-derive/src/event.rs

@@ -340,7 +340,7 @@ fn parse_event_attributes(input: &DeriveInput) -> Result<EthEventAttributes> {
             meta.input.parse::<Token![=]>()?;
             let litstr: LitStr = meta.input.parse()?;
             let s = litstr.value();
-            let b = hex::decode(s.strip_prefix("0x").unwrap_or(&s)).map_err(|e| meta.error(e))?;
+            let b = hex::decode(s).map_err(|e| meta.error(e))?;
             result.signature = Some((b, litstr.span()));
         }
         "anonymous", result.anonymous => { result.anonymous = Some((true, meta.path.span())); }

ethers-core/src/abi/codec.rs

@@ -15,7 +15,7 @@ pub trait AbiEncode {
     where
         Self: Sized,
     {
-        format!("0x{}", hex::encode(self.encode()))
+        hex::encode_prefixed(self.encode())
     }
 }
 

ethers-core/src/types/bytes.rs

@@ -16,6 +16,14 @@ pub struct Bytes(
     pub  bytes::Bytes,
 );
 
+impl hex::FromHex for Bytes {
+    type Error = hex::FromHexError;
+
+    fn from_hex<T: AsRef<[u8]>>(hex: T) -> Result<Self, Self::Error> {
+        hex::decode(hex).map(Into::into)
+    }
+}
+
 impl FromIterator<u8> for Bytes {
     fn from_iter<T: IntoIterator<Item = u8>>(iter: T) -> Self {
         iter.into_iter().collect::<bytes::Bytes>().into()
@@ -197,19 +205,13 @@ impl Decodable for Bytes {
 
 #[derive(Debug, Clone, Error)]
 #[error("Failed to parse bytes: {0}")]
-pub struct ParseBytesError(String);
+pub struct ParseBytesError(hex::FromHexError);
 
 impl FromStr for Bytes {
     type Err = ParseBytesError;
 
     fn from_str(value: &str) -> Result<Self, Self::Err> {
-        if let Some(value) = value.strip_prefix("0x") {
-            hex::decode(value)
-        } else {
-            hex::decode(value)
-        }
-        .map(Into::into)
-        .map_err(|e| ParseBytesError(format!("Invalid hex: {e}")))
+        hex::FromHex::from_hex(value).map_err(ParseBytesError)
     }
 }
 
@@ -218,21 +220,15 @@ where
     S: Serializer,
     T: AsRef<[u8]>,
 {
-    s.serialize_str(&format!("0x{}", hex::encode(x.as_ref())))
+    s.serialize_str(&hex::encode_prefixed(x))
 }
 
 pub fn deserialize_bytes<'de, D>(d: D) -> Result<bytes::Bytes, D::Error>
 where
     D: Deserializer<'de>,
 {
     let value = String::deserialize(d)?;
-    if let Some(value) = value.strip_prefix("0x") {
-        hex::decode(value)
-    } else {
-        hex::decode(&value)
-    }
-    .map(Into::into)
-    .map_err(|e| serde::de::Error::custom(e.to_string()))
+    hex::decode(value).map(Into::into).map_err(serde::de::Error::custom)
 }
 
 #[cfg(test)]

ethers-core/src/types/signature.rs

@@ -64,8 +64,7 @@ pub struct Signature {
 
 impl fmt::Display for Signature {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        let sig = <[u8; 65]>::from(self);
-        write!(f, "{}", hex::encode(&sig[..]))
+        f.write_str(hex::Buffer::<65, false>::new().format(&self.into()))
     }
 }
 
@@ -213,9 +212,7 @@ impl FromStr for Signature {
     type Err = SignatureError;
 
     fn from_str(s: &str) -> Result<Self, Self::Err> {
-        let s = s.strip_prefix("0x").unwrap_or(s);
-        let bytes = hex::decode(s)?;
-        Signature::try_from(&bytes[..])
+        Signature::try_from(&hex::decode(s)?[..])
     }
 }
 

ethers-core/src/types/transaction/eip2718.rs

@@ -662,7 +662,6 @@ impl From<TypedTransaction> for Eip2930TransactionRequest {
 
 #[cfg(test)]
 mod tests {
-    use hex::ToHex;
     use rlp::Decodable;
 
     use super::*;
@@ -859,7 +858,7 @@ mod tests {
         // compare rlp - sighash should then be the same
         let tx_expected_rlp = "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";
         let tx_real_rlp_vec = tx.rlp().to_vec();
-        let tx_real_rlp: String = tx_real_rlp_vec.encode_hex();
+        let tx_real_rlp: String = hex::encode(tx_real_rlp_vec);
         assert_eq!(tx_expected_rlp, tx_real_rlp);
 
         let r =

ethers-providers/src/ext/ens.rs

@@ -112,9 +112,7 @@ mod tests {
     use super::*;
 
     fn assert_hex(hash: H256, val: &str) {
-        let v = if let Some(stripped) = val.strip_prefix("0x") { stripped } else { val };
-
-        assert_eq!(hash.0.to_vec(), hex::decode(v).unwrap());
+        assert_eq!(hash.0.to_vec(), hex::decode(val).unwrap());
     }
 
     #[test]

ethers-providers/src/rpc/provider.rs

@@ -34,7 +34,6 @@ use ethers_core::{
     utils,
 };
 use futures_util::{lock::Mutex, try_join};
-use hex::FromHex;
 use serde::{de::DeserializeOwned, Serialize};
 use std::{
     collections::VecDeque, convert::TryFrom, fmt::Debug, str::FromStr, sync::Arc, time::Duration,
@@ -584,11 +583,10 @@ impl<P: JsonRpcClient> Middleware for Provider<P> {
         let data = utils::serialize(&data.into());
         let from = utils::serialize(from);
 
-        // get the response from `eth_sign` call and trim the 0x-prefix if present.
+        // get the response from `eth_sign` call
         let sig: String = self.request("eth_sign", [from, data]).await?;
-        let sig = sig.strip_prefix("0x").unwrap_or(&sig);
 
-        // decode the signature.
+        // decode the signature
         let sig = hex::decode(sig)?;
         Ok(Signature::try_from(sig.as_slice())
             .map_err(|e| ProviderError::CustomError(e.to_string()))?)
@@ -682,11 +680,17 @@ impl<P: JsonRpcClient> Middleware for Provider<P> {
         let from = utils::serialize(&from);
         let block = utils::serialize(&block.unwrap_or_else(|| BlockNumber::Latest.into()));
 
-        // get the hex encoded value.
+        // get the hex encoded value
         let value: String = self.request("eth_getStorageAt", [from, position, block]).await?;
-        // get rid of the 0x prefix and left pad it with zeroes.
-        let value = format!("{:0>64}", value.replace("0x", ""));
-        Ok(H256::from_slice(&Vec::from_hex(value)?))
+        // decode and left-pad to 32 bytes
+        let bytes = hex::decode(value)?;
+        if bytes.len() > 32 {
+            Err(hex::FromHexError::InvalidStringLength.into())
+        } else {
+            let mut buf = [0; 32];
+            buf[32 - bytes.len()..].copy_from_slice(&bytes);
+            Ok(H256(buf))
+        }
     }
 
     async fn get_code<T: Into<NameOrAddress> + Send + Sync>(

ethers-signers/src/trezor/app.rs

@@ -153,13 +153,10 @@ impl TrezorEthereum {
         derivation: &DerivationType,
     ) -> Result<Address, TrezorError> {
         let mut client = self.get_client(self.session_id.clone())?;
-
         let address_str = client.ethereum_get_address(Self::convert_path(derivation))?;
-
-        let mut address = [0; 20];
-        address.copy_from_slice(&hex::decode(&address_str[2..])?);
-
-        Ok(Address::from(address))
+        let mut address_bytes = [0; 20];
+        hex::decode_to_slice(address_str, &mut address_bytes)?;
+        Ok(address_bytes.into())
     }
 
     /// Signs an Ethereum transaction (requires confirmation on the Trezor)

ethers-signers/src/trezor/types.rs

@@ -40,11 +40,11 @@ pub enum TrezorError {
     FeaturesError,
     #[error("Not able to unpack value for TrezorTransaction.")]
     DataError,
-    #[error(transparent)]
     /// Error when converting from a hex string
-    HexError(#[from] hex::FromHexError),
     #[error(transparent)]
+    HexError(#[from] hex::FromHexError),
     /// Error when converting a semver requirement
+    #[error(transparent)]
     SemVerError(#[from] semver::Error),
     /// Error when signing EIP712 struct with not compatible Trezor ETH app
     #[error("Trezor ethereum app requires at least version: {0:?}")]
@@ -79,7 +79,7 @@ impl TrezorTransaction {
         let to: String = match tx.to() {
             Some(v) => match v {
                 NameOrAddress::Name(_) => return Err(TrezorError::NoENSSupport),
-                NameOrAddress::Address(value) => format!("0x{}", hex::encode(value)),
+                NameOrAddress::Address(value) => hex::encode_prefixed(value),
             },
             // Contract Creation
             None => "".to_string(),
@@ -113,7 +113,7 @@ impl TrezorTransaction {
 
                 let mut access_list: Vec<Trezor_AccessListItem> = Vec::new();
                 for item in &eip1559_tx.access_list.0 {
-                    let address: String = format!("0x{}", hex::encode(item.address));
+                    let address: String = hex::encode_prefixed(item.address);
                     let mut storage_keys: Vec<Vec<u8>> = Vec::new();
 
                     for key in &item.storage_keys {

ethers-signers/src/wallet/private_key.rs

@@ -154,8 +154,7 @@ impl FromStr for Wallet<SigningKey> {
     type Err = WalletError;
 
     fn from_str(src: &str) -> Result<Self, Self::Err> {
-        let src = src.strip_prefix("0x").or_else(|| src.strip_prefix("0X")).unwrap_or(src);
-        let src = hex::decode(src)?;
+        let src = hex::decode(src.strip_prefix("0X").unwrap_or(src))?;
 
         if src.len() != 32 {
             return Err(WalletError::HexError(hex::FromHexError::InvalidStringLength))

ethers-solc/src/artifacts/serde_helpers.rs

@@ -7,27 +7,15 @@ pub fn deserialize_bytes<'de, D>(d: D) -> Result<Bytes, D::Error>
 where
     D: Deserializer<'de>,
 {
-    String::deserialize(d)?.parse::<Bytes>().map_err(|e| serde::de::Error::custom(e.to_string()))
+    String::deserialize(d)?.parse::<Bytes>().map_err(serde::de::Error::custom)
 }
 
 pub fn deserialize_opt_bytes<'de, D>(d: D) -> Result<Option<Bytes>, D::Error>
 where
     D: Deserializer<'de>,
 {
     let value = Option::<String>::deserialize(d)?;
-    if let Some(value) = value {
-        Ok(Some(
-            if let Some(value) = value.strip_prefix("0x") {
-                hex::decode(value)
-            } else {
-                hex::decode(&value)
-            }
-            .map_err(|e| serde::de::Error::custom(e.to_string()))?
-            .into(),
-        ))
-    } else {
-        Ok(None)
-    }
+    value.as_deref().map(str::parse).transpose().map_err(serde::de::Error::custom)
 }
 
 pub fn default_for_null<'de, D, T>(deserializer: D) -> Result<T, D::Error>

ethers-solc/src/utils.rs

@@ -283,9 +283,11 @@ pub fn library_fully_qualified_placeholder(name: impl AsRef<str>) -> String {
 
 /// Returns the library hash placeholder as `$hex(library_hash(name))$`
 pub fn library_hash_placeholder(name: impl AsRef<[u8]>) -> String {
-    let hash = library_hash(name);
-    let placeholder = hex::encode(hash);
-    format!("${placeholder}$")
+    let mut s = String::with_capacity(34 + 2);
+    s.push('$');
+    s.push_str(hex::Buffer::<17, false>::new().format(&library_hash(name)));
+    s.push('$');
+    s
 }
 
 /// Returns the library placeholder for the given name