Function canonicalize

src/context/read_cache.rs:50–69

Sorts JSON object keys recursively so two semantically-equal arg objects hash identically regardless of key insertion order.

(v: &serde_json::Value)

/// Sorts JSON object keys recursively so two semantically-equal arg objects
/// hash identically regardless of key insertion order.
fn canonicalize(v: &serde_json::Value) -> String {
    use serde_json::Value;
    match v {
        Value::Object(map) => {
            let mut entries: Vec<(&String, &Value)> = map.iter().collect();
            entries.sort_by_key(|(k, _)| k.as_str());
            let inner = entries
                .into_iter()
                .map(|(k, v)| format!("\"{k}\":{}", canonicalize(v)))
                .collect::<Vec<_>>()
                .join(",");
            format!("{{{inner}}}")
        }
        Value::Array(items) => {
            let inner = items.iter().map(canonicalize).collect::<Vec<_>>().join(",");
            format!("[{inner}]")
        }
        other => other.to_string(),
    }
}

/// SHA-256 of arbitrary bytes, hex-encoded. Used as the body digest so callers
/// can detect content changes even when only the cache layer changed.