migration routers

sei-db/state_db/sc/migration/dual_write_router.go

@@ -0,0 +1,102 @@
+package migration
+
+import (
+	"fmt"
+
+	ics23 "github.com/confio/ics23/go"
+	"github.com/sei-protocol/sei-chain/sei-db/proto"
+	db "github.com/tendermint/tm-db"
+)
+
+var _ Router = (*TestOnlyDualWriteRouter)(nil)
+
+// A router that dual-writes traffic, sending each batch of changesets to both backends. Read
+// requests, requests for proofs, and requests for iteration are not dual-written, and are instead
+// served exclusively by the primary backend.
+//
+// CRITICAL: this is a test-only router and should never be deployed to production machines.
+type TestOnlyDualWriteRouter struct {
+	primary   *Route
+	secondary DBWriter
+}
+
+// Create a new test-only dual-write router.
+//
+// CRITICAL: this is a test-only router and should never be deployed to production machines.
+func NewTestOnlyDualWriteRouter(
+	// Read, proof, and iteration traffic is served by this route, and writes are also sent here.
+	// Module names associated with this route are ignored; this route forwards all regardless of the module names.
+	primary *Route,
+	// Write traffic is dual-written and also sent here. Reads, proofs, and iteration are not sent here.
+	secondary DBWriter,
+) (*TestOnlyDualWriteRouter, error) {
+
+	if primary == nil {
+		return nil, fmt.Errorf("primary must not be nil")
+	}
+	if primary.proofBuilder == nil {
+		return nil, fmt.Errorf("primary proof builder must not be nil")
+	}
+	if primary.iteratorBuilder == nil {
+		return nil, fmt.Errorf("primary iterator builder must not be nil")
+	}
+	if secondary == nil {
+		return nil, fmt.Errorf("secondary must not be nil")
+	}
+
+	return &TestOnlyDualWriteRouter{primary: primary, secondary: secondary}, nil
+}
+
+func (t *TestOnlyDualWriteRouter) ApplyChangeSets(changesets []*proto.NamedChangeSet) error {
+	err := t.primary.writer(changesets)
+	if err != nil {
+		return fmt.Errorf("primary writer: %w", err)
+	}
+
+	err = t.secondary(changesets)
+	if err != nil {
+		return fmt.Errorf("secondary writer: %w", err)
+	}
+
+	return nil
+}
+
+func (t *TestOnlyDualWriteRouter) GetProof(store string, key []byte) (*ics23.CommitmentProof, error) {
+	proof, err := t.primary.proofBuilder(store, key)
+	if err != nil {
+		return nil, fmt.Errorf("primary proof builder: %w", err)
+	}
+	return proof, nil
+}
+
+func (t *TestOnlyDualWriteRouter) Iterator(
+	store string,
+	start []byte,
+	end []byte,
+	ascending bool,
+) (db.Iterator, error) {
+	iterator, err := t.primary.iteratorBuilder(store, start, end, ascending)
+	if err != nil {
+		return nil, fmt.Errorf("primary iterator builder: %w", err)
+	}
+	return iterator, nil
+}
+
+func (t *TestOnlyDualWriteRouter) Read(store string, key []byte) ([]byte, bool, error) {
+	value, found, err := t.primary.reader(store, key)
+	if err != nil {
+		return nil, false, fmt.Errorf("primary reader: %w", err)
+	}
+	return value, found, nil
+}
+
+// BuildRoute returns a Route that dispatches the given module names to
+// this DualWriteRouter. Reads, writes, iteration and proof requests
+// for those modules will all flow through this dual-write router.
+//
+// Module names must be unique; NewRoute's validation rules apply. The
+// returned Route may be passed to NewModuleRouter alongside other
+// Routes to compose multi-database setups.
+func (t *TestOnlyDualWriteRouter) BuildRoute(moduleNames ...string) (*Route, error) { // TODO LLM you need to write a unit test for this
+	return NewRoute(t.Read, t.ApplyChangeSets, t.Iterator, t.GetProof, moduleNames...)
+}