Method create_view_from

atomic-repository/src/repository/views.rs:265–343

Create a new view that inherits changes from another view. This creates a new view and copies all changes from the source view to the new view. The new view will have the same content state as the source view at the time of creation. # Arguments `name` - The name of the new view to create `from_view` - The name of the view to inherit changes from # Errors Returns an error if: - The new view a

(&mut self, name: &str, from_view: &str)

    /// repo.create_view_from("feature", "dev")?;
    /// ```
    pub fn create_view_from(&mut self, name: &str, from_view: &str) -> Result<(), RepositoryError> {
        let mut txn = self
            .pristine
            .write_txn()
            .map_err(|e| RepositoryError::Database(e.to_string()))?;

        // Check if the new view already exists
        if txn
            .get_view(name)
            .map_err(|e| RepositoryError::Database(e.to_string()))?
            .is_some()
        {
            return Err(RepositoryError::ViewAlreadyExists {
                name: name.to_string(),
            });
        }

        // Get the source view
        let source_view = txn
            .get_view(from_view)
            .map_err(|e| RepositoryError::Database(e.to_string()))?
            .ok_or_else(|| RepositoryError::ViewNotFound {
                name: from_view.to_string(),
            })?;

        let source_id = source_view.id;

        // Collect all changes from the source view
        let changes: Vec<(NodeId, Hash)> = {
            let iter = txn
                .iter_changes(&source_view, 0)
                .map_err(|e| RepositoryError::Database(e.to_string()))?;

            let mut result = Vec::new();
            for item in iter {
                let (_seq, node_id, _merkle) =
                    item.map_err(|e| RepositoryError::Database(e.to_string()))?;
                let hash = txn
                    .get_external(node_id)
                    .map_err(|e| RepositoryError::Database(e.to_string()))?
                    .ok_or_else(|| {
                        RepositoryError::Database(format!(
                            "Change {} has no external hash",
                            node_id.0
                        ))
                    })?;
                result.push((node_id, hash));
            }
            result
        };

        // Create the new view as a **Draft** view parented on the
        // source view.  Draft views write edges to GRAPH like all
        // views, but use a change filter for isolation. The parent
        // link means the view chain includes the source's content.
        // Create workspace directory for the new view.
        ensure_workspace_dir(&self.dot_dir, name)?;