Struct CrdtState 

pub struct CrdtState { /* private fields */ }

A CRDT state for a single tenant/namespace.

Implementations

impl CrdtState

pub fn new(peer_id: u64) -> Result<Self>

Create a new empty state for the given peer.

pub fn upsert( &self, collection: &str, row_id: &str, fields: &[(&str, LoroValue)], ) -> Result<()>

Insert or update a row in a collection.

pub fn delete(&self, collection: &str, row_id: &str) -> Result<()>

Delete a row from a collection.

pub fn clear_collection(&self, collection: &str) -> Result<usize>

Delete all rows in a collection. Returns the number of rows deleted.

pub fn read_row(&self, collection: &str, row_id: &str) -> Option<LoroValue>

Read a single row’s fields as a LoroValue::Map.

Navigates via LoroMap::get() to avoid the expensive recursive get_deep_value() clone on the entire row container.

pub fn read_field( &self, collection: &str, row_id: &str, field: &str, ) -> Option<LoroValue>

Read a single field from a row without cloning the entire row.

This is the fast path for KV-style access where only one field is needed. Avoids allocating a full Map for single-field reads.

Shares the same doc.get_map(collection).get(row_id) lookup pattern as read_row, but returns a single field value instead of the whole row map — different return granularity, intentionally kept separate.

pub fn row_exists(&self, collection: &str, row_id: &str) -> bool

Check if a row exists in a collection.

pub fn collection_names(&self) -> Vec<String>

List all collection names (top-level map keys in the Loro doc).

pub fn row_ids(&self, collection: &str) -> Vec<String>

Get all row IDs in a collection.

pub fn field_value_exists( &self, collection: &str, field: &str, value: &LoroValue, ) -> bool

Check if a value exists for the given field across all rows in a collection. Used for UNIQUE constraint checking.

pub fn export_snapshot(&self) -> Result<Vec<u8>>

Export the current state as bytes for sync.

pub fn import(&self, data: &[u8]) -> Result<()>

Import remote updates.

pub fn doc(&self) -> &LoroDoc

Get the underlying LoroDoc for advanced operations.

pub fn peer_id(&self) -> u64

Peer ID of this state.

pub fn compact_history(&mut self) -> Result<()>

Compact the CRDT history by replacing the internal LoroDoc with a shallow snapshot.

A shallow snapshot contains the current state but discards the full operation history. This is the CRDT equivalent of WAL truncation after checkpoint.

After compaction:

• All current state is preserved (reads return same values).
• New deltas can still be applied and merged.
• Historical operations before the snapshot point are gone.
• Peers that sync after compaction receive a full snapshot instead of incremental deltas (acceptable for long-offline peers).

Call this periodically (e.g., every 30 minutes or when memory pressure exceeds threshold) to prevent unbounded history growth.

pub fn oplog_version_vector(&self) -> VersionVector

Get the current oplog version vector.

pub fn read_at_version( &self, collection: &str, row_id: &str, version: &VersionVector, ) -> Result<Option<LoroValue>>

Read the document state at a historical version.

Uses fork_at to create a lightweight copy at the target version and reads the specified row. Returns None if the row didn’t exist.

Cost: O(oplog_size) for the fork — not for hot-path queries.

pub fn export_updates_since( &self, from_version: &VersionVector, ) -> Result<Vec<u8>>

Export the oplog delta from a version to the current state.

Returns the operations that transform from_version into current state. Used for DIFF rendering and delta sync.

pub fn compact_at_version(&mut self, version: &VersionVector) -> Result<()>

Compact history at a specific version (not just current frontiers).

Discards oplog entries before the target version. Current state and all versions after the target are preserved.

pub fn restore_to_version( &self, collection: &str, row_id: &str, version: &VersionVector, ) -> Result<Vec<u8>>

Restore a document to a historical version by creating a forward delta.

Reads the state at the target version, then generates a new mutation that sets the current state to match the historical state. History is preserved — this is a forward operation, not a rollback.

Returns the delta bytes to be applied through the normal write path.

pub fn estimated_memory_bytes(&self) -> usize

Estimated memory usage of the CRDT state (bytes).

Includes operation history, current state, and internal caches. Use this to decide when to trigger compact_history().