rustcdc 0.2.0

Embeddable Rust CDC library focused on correctness-first capture primitives
Documentation 
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syntax = "proto3";

package rustcdc;

// Canonical CDC event envelope — rustcdc envelope_version=1
//
// Field numbers are stable. New fields will only be added with new tag numbers.
// Consumers MUST ignore unknown fields (standard protobuf behaviour).
//
// Encoding notes:
//   - `before` and `after` carry UTF-8 JSON as raw bytes.
//   - `ts` is milliseconds since Unix epoch (1970-01-01T00:00:00Z).
//   - `envelope_version` is currently always 1.
//
// Usage example (Go):
//   import "github.com/acme/rustcdc/proto/event_pb"
//   e := &event_pb.Event{}
//   proto.Unmarshal(data, e)
//   after := make(map[string]interface{})
//   json.Unmarshal(e.After, &after)

// ─── Operation ────────────────────────────────────────────────────────────────

// CRUD operation that produced this event.
enum Operation {
  // Should never appear in well-formed output.
  OPERATION_UNSPECIFIED = 0;
  // INSERT row.
  INSERT = 1;
  // UPDATE row (after-image; before-image in `before` field).
  UPDATE = 2;
  // DELETE row.
  DELETE = 3;
  // READ during initial snapshot.
  READ = 4;
  // DDL schema change.
  SCHEMA_CHANGE = 5;
  // TRUNCATE table.
  TRUNCATE = 6;
}

// ─── SourceMetadata ───────────────────────────────────────────────────────────

// Identity of the source connector and the event's durable position within it.
message SourceMetadata {
  // Logical connector name (e.g. "postgres", "mysql", "sqlserver").
  string source_name = 1;
  // Source-specific durable position (LSN, GTID, transaction log offset, …).
  string offset = 2;
  // Source timestamp in milliseconds since Unix epoch.
  uint64 timestamp = 3;
}

// ─── SnapshotMetadata ─────────────────────────────────────────────────────────

// Present only during the initial snapshot phase; absent during streaming CDC.
message SnapshotMetadata {
  // Identifier for the snapshot session (uuid or monotonic counter).
  string snapshot_id = 1;
  // Zero-based index of this chunk within the snapshot.
  uint32 chunk_index = 2;
  // True if this is the last chunk for this snapshot session.
  bool is_last_chunk = 3;
}

// ─── TransactionMetadata ──────────────────────────────────────────────────────

// Present when the event participates in a named transaction.
message TransactionMetadata {
  // Source transaction identifier (e.g. XID, GTID numeric component).
  uint64 tx_id = 1;
  // Total number of events committed in this transaction.
  uint32 total_events = 2;
  // Zero-based position of this event within the transaction.
  uint32 event_index = 3;
}

// ─── Event ────────────────────────────────────────────────────────────────────

// A single captured CDC event.
message Event {
  // JSON-encoded before-image of the row. Absent for INSERT events.
  optional bytes before = 1;
  // JSON-encoded after-image of the row. Absent for DELETE events.
  optional bytes after = 2;
  // CRUD operation.
  Operation op = 3;
  // Source connector identity and durable position.
  SourceMetadata source = 4;
  // Event timestamp in milliseconds since Unix epoch.
  uint64 ts = 5;
  // Database schema (namespace) name. Absent when unknown.
  optional string schema = 6;
  // Table name.
  string table = 7;
  // Ordered list of primary key column names.
  repeated string primary_key = 8;
  // Snapshot phase metadata. Absent during streaming CDC.
  SnapshotMetadata snapshot = 9;
  // Transaction metadata. Absent for single-event transactions.
  TransactionMetadata transaction = 10;
  // Canonical envelope schema version. Currently always 1.
  uint32 envelope_version = 11;
}