Struct AttachRegistry 

pub struct AttachRegistry { /* private fields */ }

Live set of attachments keyed by alias. Thread-safe via an internal Mutex; all operations are serial, which matches the rest of the engine’s single-connection model.

The registry holds user-attached databases — the default persistent database is attached directly by crate::engine::Engine and isn’t tracked here. Replay-on-reconnect only re-issues the user attaches; the engine re-attaches persistent itself when it’s reconstructed.

Implementations

impl AttachRegistry

pub fn new() -> Self

pub fn attach( &self, engine: &Engine, req: AttachRequest, ) -> Result<AttachedDb, McpError>

Attach a database into the current engine’s connection and store it in the registry. Caller is responsible for read-only enforcement (--read-only + writable: true combination).

Errors

• Returns ErrorCode::InvalidArgument if the alias fails validate_alias, if the alias is already in use, or if on_missing=Create is combined with writable=false.
• Returns ErrorCode::FileNotFound when on_missing=Error and the target .hyper path does not exist.
• Returns ErrorCode::InternalError if the registry mutex is poisoned (bubbled up from AttachRegistry::lock).
• Propagates any error from the underlying ATTACH DATABASE (and the optional CREATE DATABASE IF NOT EXISTS) executed on the engine’s connection — surfaced through the ? operator in the body.

pub fn detach(&self, engine: &Engine, alias: &str) -> Result<bool, McpError>

Detach the alias from the current connection and drop it from the registry. Returns Ok(false) if the alias was not present.

When the detachment leaves the registry empty, restores the connection’s default schema_search_path so unqualified name resolution returns to the single-database mode Hyper uses on a fresh connection.

Errors

• Returns ErrorCode::InternalError if the registry mutex is poisoned.
• Propagates any error from the DETACH DATABASE statement executed via engine.execute_command. A failure to reset the schema_search_path afterwards is logged but NOT surfaced as an error — the detach itself already succeeded.

pub fn list(&self) -> Vec<AttachedDb>

Read-only snapshot of the current registry. Order matches the insertion order of still-live entries.

pub fn get(&self, alias: &str) -> Option<AttachedDb>

Lookup by alias (case-insensitive). None if absent.

Aliases are stored lowercased (see AttachRegistry::attach), so any caller supplying a mixed-case alias still finds the stored entry.

pub fn replay_all(&self, engine: &Engine) -> Result<(), McpError>

Re-issue ATTACH DATABASE for every tracked entry. Used after crate::server::HyperMcpServer’s with_engine rebuilds a fresh Engine following a ConnectionLost error.

Attachments that fail to replay (file moved, corrupted, held by another process) are dropped from the registry with a WARN log so the rest of the session can continue — a single stale entry should not poison the whole reconnect path.

Errors

Returns ErrorCode::InternalError if the registry mutex is poisoned. Per-entry replay failures are logged and swallowed — the method only returns Err for errors that prevent it from running at all.

Trait Implementations

impl Debug for AttachRegistry

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for AttachRegistry

fn default() -> Self

Returns the “default value” for a type.