parsing blobs as either hex, of comma-separated decimal lists

eqlabs · Mar 18, 2024 · 6c21352 · 6c21352
1 parent 7e37172
commit 6c21352
Showing 1 changed file with 49 additions and 12 deletions.
diff --git a/state-reconstruct-fetcher/src/types/v3.rs b/state-reconstruct-fetcher/src/types/v3.rs
@@ -197,18 +197,7 @@ async fn get_blob(
             Ok(response) => match response.text().await {
                 Ok(text) => match get_blob_data(&text) {
                     Ok(data) => {
-                        let plain = if let Some(p) = data.strip_prefix("0x") {
-                            p
-                        } else {
-                            &data
-                        };
-                        match hex::decode(plain) {
-                            Ok(bytes) => return Ok(bytes),
-                            Err(e) => {
-                                tracing::warn!("Cannot parse {}: {:?}", plain, e);
-                                return Err(ParseError::BlobFormatError("not hex".to_string()));
-                            }
-                        }
+                        return parse_blob_data(&data);
                     }
                     Err(e) => {
                         tracing::error!("failed parsing response of {url}");
@@ -258,3 +247,51 @@ fn get_blob_data(json_str: &str) -> Result<String, ParseError> {
         Err(ParseError::BlobFormatError("not JSON".to_string()))
     }
 }
+
+fn parse_blob_data(value_str: &str) -> Result<Vec<u8>, ParseError> {
+    if let Some(plain) = value_str.strip_prefix("0x") {
+        match hex::decode(plain) {
+            Ok(bytes) => Ok(bytes),
+            Err(e) => {
+                tracing::warn!("Cannot parse {}: {:?}", plain, e);
+                Err(ParseError::BlobFormatError("not hex".to_string()))
+            }
+        }
+    } else {
+        // assume comma-separated decimal bytes; arguably there's
+        // nothing stopping the server from using hexadecimals with a
+        // separator, but that format hadn't been seen yet
+        let mut a = Vec::new();
+        for s in value_str.split(',') {
+            match s.parse::<u8>() {
+                Ok(c) => {
+                    a.push(c);
+                }
+                Err(e) => {
+                    tracing::warn!("Cannot parse {} in {}: {:?}", s, value_str, e);
+                    return Err(ParseError::BlobFormatError("not byte".to_string()));
+                }
+            }
+        }
+        Ok(a)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_parse_blob_data() {
+        let value_str = "87,104,179,182,167,219,86,210,29,26,191,244,13,65";
+
+        match parse_blob_data(value_str) {
+            Ok(a) => {
+                assert_eq!(a.len(), 14);
+            }
+            Err(e) => {
+                panic!("parsing failed: {:?}", e);
+            }
+        }
+    }
+}