Add QMS for IAVL migration query multistore

baseapp/abci.go

@@ -13,20 +13,20 @@
 	"time"
 
 	"github.com/armon/go-metrics"
-	"github.com/gogo/protobuf/proto"
-	abci "github.com/tendermint/tendermint/abci/types"
-	tmproto "github.com/tendermint/tendermint/proto/tendermint/types"
-	"google.golang.org/grpc/codes"
-	grpcstatus "google.golang.org/grpc/status"
-
 	"github.com/cosmos/cosmos-sdk/codec"
 	snapshottypes "github.com/cosmos/cosmos-sdk/snapshots/types"
+	"github.com/cosmos/cosmos-sdk/store/types"
 	"github.com/cosmos/cosmos-sdk/tasks"
 	"github.com/cosmos/cosmos-sdk/telemetry"
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
 	"github.com/cosmos/cosmos-sdk/types/legacytm"
 	"github.com/cosmos/cosmos-sdk/utils"
+	"github.com/gogo/protobuf/proto"
+	abci "github.com/tendermint/tendermint/abci/types"
+	tmproto "github.com/tendermint/tendermint/proto/tendermint/types"
+	"google.golang.org/grpc/codes"
+	grpcstatus "google.golang.org/grpc/status"
 )
 
 // InitChain implements the ABCI interface. It runs the initialization logic
@@ -708,7 +708,8 @@
 // CreateQueryContext creates a new sdk.Context for a query, taking as args
 // the block height and whether the query needs a proof or not.
 func (app *BaseApp) CreateQueryContext(height int64, prove bool) (sdk.Context, error) {
-	if err := checkNegativeHeight(height); err != nil {
+	err := checkNegativeHeight(height)
+	if err != nil {
 		return sdk.Context{}, err
 	}
 
@@ -734,7 +735,13 @@
 			)
 	}
 
-	cacheMS, err := app.cms.CacheMultiStoreWithVersion(height)
+	var cacheMS types.CacheMultiStore
+	if height < app.migrationHeight && app.qms != nil {
+		cacheMS, err = app.qms.CacheMultiStoreWithVersion(height)
+	} else {
+		cacheMS, err = app.cms.CacheMultiStoreWithVersion(height)
+	}
+
 	if err != nil {
 		return sdk.Context{},
 			sdkerrors.Wrapf(
@@ -905,12 +912,25 @@
 }
 
 func handleQueryStore(app *BaseApp, path []string, req abci.RequestQuery) abci.ResponseQuery {
-	// "/store" prefix for store queries
-	queryable, ok := app.cms.(sdk.Queryable)
-	if !ok {
-		return sdkerrors.QueryResultWithDebug(sdkerrors.Wrap(sdkerrors.ErrUnknownRequest, "multistore doesn't support queries"), app.trace)
+
+	var (
+		queryable sdk.Queryable
+		ok        bool
+	)
+	// Check if online migration is enabled for fallback read
+	if req.Height < app.migrationHeight && app.qms != nil {
+		queryable, ok = app.qms.(sdk.Queryable)
+		if !ok {
+			return sdkerrors.QueryResultWithDebug(sdkerrors.Wrap(sdkerrors.ErrUnknownRequest, "multistore doesn't support queries"), app.trace)
+		}
+	} else {
+		queryable, ok = app.cms.(sdk.Queryable)
+		if !ok {
+			return sdkerrors.QueryResultWithDebug(sdkerrors.Wrap(sdkerrors.ErrUnknownRequest, "multistore doesn't support queries"), app.trace)
+		}
 	}
 
+	// "/store" prefix for store queries
 	req.Path = "/" + strings.Join(path[1:], "/")
 
 	if req.Height <= 1 && req.Prove {

baseapp/baseapp.go

@@ -179,9 +179,11 @@ type BaseApp struct { //nolint: maligned
 }
 
 type appStore struct {
-	db          dbm.DB               // common DB backend
-	cms         sdk.CommitMultiStore // Main (uncached) state
-	storeLoader StoreLoader          // function to handle store loading, may be overridden with SetStoreLoader()
+	db              dbm.DB               // common DB backend
+	cms             sdk.CommitMultiStore // Main (uncached) state
+	qms             sdk.MultiStore       // Query multistore used for migration only
+	migrationHeight int64
+	storeLoader     StoreLoader // function to handle store loading, may be overridden with SetStoreLoader()
 
 	// an inter-block write-through cache provided to the context during deliverState
 	interBlockCache sdk.MultiStorePersistentCache

baseapp/options.go

@@ -361,3 +361,13 @@
 	// BaseApp will pass BeginBlock, DeliverTx, and EndBlock requests and responses to the streaming services to update their ABCI context
 	app.abciListeners = append(app.abciListeners, s)
 }
+
+// SetQueryMultiStore set a alternative MultiStore implementation to support online migration fallback read.
+func (app *BaseApp) SetQueryMultiStore(ms sdk.MultiStore) {
+	app.qms = ms
+}
+
+// SetMigrationHeight set the migration height for online migration so that query below this height will still be served from IAVL.
+func (app *BaseApp) SetMigrationHeight(height int64) {
+	app.migrationHeight = height
+}