Support for S3 bucket prefixes

crates/utils/src/codec/base32_custom.rs

@@ -57,8 +57,12 @@ impl Base32Writer {
     }
 
     pub fn with_capacity(capacity: usize) -> Self {
+        Self::with_raw_capacity((capacity + 3) / 4 * 5)
+    }
+
+    pub fn with_raw_capacity(capacity: usize) -> Self {
         Base32Writer {
-            result: String::with_capacity((capacity + 3) / 4 * 5),
+            result: String::with_capacity(capacity),
             last_byte: 0,
             pos: 0,
         }
@@ -68,6 +72,10 @@ impl Base32Writer {
         self.result.push(ch);
     }
 
+    pub fn push_string(&mut self, string: &str) {
+        self.result.push_str(string);
+    }
+
     fn push_byte(&mut self, byte: u8, is_remainder: bool) {
         let (ch1, ch2) = match self.pos % 5 {
             0 => ((byte & 0xF8) >> 3, u8::MAX),