Crate entidb_sync_engine 

EntiDB Sync Engine

Sync state machine and engine for EntiDB.

This crate provides:

• Sync state machine (idle → pulling → pushing → synced)
• Cursor management
• Conflict detection and resolution
• Retry with exponential backoff
• HTTP transport abstraction
• Database-backed sync applier

Architecture

The sync engine implements a pull-then-push synchronization model:

1. Pull remote changes first (server is authoritative)
2. Apply remote changes locally
3. Push local changes to server

The sync server uses the same EntiDB core as clients, ensuring consistent storage semantics everywhere.

Key Invariants

• Server is authoritative
• Pull always happens before push
• Operations are idempotent
• Sync operations are atomic per batch
• Server uses EntiDB for persistence (no external database)

Structs

DatabaseApplier

A sync applier backed by an EntiDB database.

HttpTransport

HTTP-based sync transport.

LoopbackClient

A loopback HTTP client that routes requests directly to a sync server.

MemorySyncApplier

An in-memory sync applier for testing.

MockTransport

A mock transport for testing.

RetryConfig

Configuration for retry behavior.

SyncConfig

Configuration for sync operations.

SyncCycleResult

Result of a sync cycle.

SyncEngine

The sync engine manages synchronization with a remote server.

SyncStats

Statistics about sync operations.

Enums

SyncError

Errors that can occur during sync operations.

SyncRequest

Request types for sync operations.

SyncResponse

Response types for sync operations.

SyncState

The current state of the sync engine.

Traits

CborDecode

Trait for CBOR decoding.

CborEncode

Trait for CBOR encoding.

HttpClient

HTTP client abstraction.

LoopbackServer

Trait for servers that can handle loopback requests.

SyncApplier

Callback for applying remote operations to the local database.

SyncTransport

A sync transport handles network communication with the sync server.

Type Aliases

SyncResult

Result type for sync operations.