v0.3.12-pre.004

crates/ksp-raw-transaction-lib/src/signature.rs

@@ -1,5 +1,5 @@
 // file: crates/ksp-raw-transaction-lib/src/signature.rs
-// version: 3
+// version: 4
 
 use base64::Engine; // rust-rules: trait-import
 
@@ -8,6 +8,35 @@ pub const MAX_RAW_TRANSACTION_SIGNATURE_TEXT_BYTES: usize = 88;
 /// Minimum UTF-8 byte length admitted for one textual Base58 Solana transaction signature.
 pub const MIN_RAW_TRANSACTION_SIGNATURE_TEXT_BYTES: usize = 64;
 
+/// Encodes one canonical 64-byte Solana transaction signature as bounded Base58 text.
+#[must_use]
+pub fn format_raw_transaction_signature(signature: &ksp_store_api::RawTransactionSignature) -> std::string::String {
+    const ALPHABET: &[u8; 58] = b"123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz";
+    let bytes = signature.as_bytes();
+    let leading_zeroes = bytes.iter().take_while(|byte| return **byte == 0).count();
+    let mut digits = std::vec::Vec::with_capacity(crate::MAX_RAW_TRANSACTION_SIGNATURE_TEXT_BYTES);
+    for byte in bytes {
+        let mut carry = u32::from(*byte);
+        for digit in &mut digits {
+            let expanded = (u32::from(*digit) * 256) + carry;
+            *digit = (expanded % 58) as u8;
+            carry = expanded / 58;
+        }
+        while carry != 0 {
+            digits.push((carry % 58) as u8);
+            carry /= 58;
+        }
+    }
+    let mut output = std::string::String::with_capacity(leading_zeroes + digits.len());
+    for _ in 0..leading_zeroes {
+        output.push('1');
+    }
+    for digit in digits.iter().rev() {
+        output.push(char::from(ALPHABET[usize::from(*digit)]));
+    }
+    return output;
+}
+
 /// Parses one bounded Base58 Solana transaction signature to exactly 64 canonical bytes.
 pub fn parse_raw_transaction_signature(value: &str) -> ksp_core_lib::Result<ksp_store_api::RawTransactionSignature> {
     let text = value.as_bytes();