Function load_change_data

atomic-cli/src/commands/push/helpers.rs:172–204

Load and serialize change data from the repository. Loads the change from the repository and serializes it to bytes suitable for uploading to a remote. # Arguments `repo` - The repository to load from `hash` - The hash of the change to load # Returns The serialized change data as bytes. # Errors Returns `CliError::ChangeNotFound` if the change doesn't exist, or `CliError::Internal` if seria

(repo: &Repository, hash: &Hash)

/// Returns `CliError::ChangeNotFound` if the change doesn't exist,
/// or `CliError::Internal` if serialization fails.
pub fn load_change_data(repo: &Repository, hash: &Hash) -> CliResult<Bytes> {
    // Read the raw V3 change file from disk instead of deserializing and
    // re-serializing.  This is faster, uses less memory, and — critically —
    // preserves the exact bytes that produced the content hash.  Re-serializing
    // can produce different bytes (field ordering, padding) which would break
    // hash verification on the server.
    let change_path = repo.change_store().change_path(hash);
    if change_path.exists() {
        let data = std::fs::read(&change_path).map_err(|e| {
            CliError::Internal(anyhow::anyhow!(
                "Failed to read change file {:?}: {}",
                change_path,
                e
            ))
        })?;
        return Ok(Bytes::from(data));
    }

    // Fallback: deserialize + re-serialize (legacy path for changes
    // whose on-disk file was cleaned up or doesn't exist).
    let change = repo
        .load_change(hash)
        .map_err(|_| CliError::ChangeNotFound {
            hash: hash.to_base32(),
        })?;

    let mut buffer = Vec::new();
    change
        .serialize(&mut buffer)
        .map_err(|e| CliError::Internal(anyhow::anyhow!("Failed to serialize change: {}", e)))?;

    Ok(Bytes::from(buffer))
}

// Delta Transfer Protocol