[Params, Clients] add generic ParamsQuerier

pkg/client/interface.go

@@ -1,3 +1,4 @@
+//go:generate mockgen -destination=../../testutil/mockclient/grpc_conn_mock.go -package=mockclient github.com/cosmos/gogoproto/grpc ClientConn
 //go:generate mockgen -destination=../../testutil/mockclient/events_query_client_mock.go -package=mockclient . Dialer,Connection,EventsQueryClient
 //go:generate mockgen -destination=../../testutil/mockclient/block_client_mock.go -package=mockclient . Block,BlockClient
 //go:generate mockgen -destination=../../testutil/mockclient/delegation_client_mock.go -package=mockclient . DelegationClient
@@ -380,3 +381,15 @@ type HistoricalQueryCache[T any] interface {
 	// SetAsOfVersion adds or updates a value at a specific version number.
 	SetAsOfVersion(key string, value T, version int64) error
 }
+
+// ParamsQuerier represents a generic querier for module parameters.
+// This interface should be implemented by any module-specific querier
+// that needs to access and cache on-chain parameters.
+type ParamsQuerier[P cosmostypes.Msg] interface {
+	// GetParams queries the chain for the current module parameters, where
+	// P is the params type of a given module (e.g. sharedtypes.Params).
+	GetParams(ctx context.Context) (P, error)
+	// GetParamsAtHeight returns the parameters as they were at the specified
+	// height, where M is the params type of a given module (e.g. sharedtypes.Params).
+	GetParamsAtHeight(ctx context.Context, height int64) (P, error)
+}

pkg/client/query/options.go

@@ -0,0 +1,52 @@
+package query
+
+import (
+	sdkerrors "cosmossdk.io/errors"
+
+	"github.com/pokt-network/poktroll/pkg/client/query/cache"
+)
+
+const (
+	defaultPruneOlderThan = 100
+	defaultMaxKeys        = 1000
+)
+
+// paramsQuerierConfig is the configuration for parameter queriers. It is intended
+// to be configured via ParamsQuerierOptionFn functions.
+type paramsQuerierConfig struct {
+	// CacheOpts are the options passed to create the params cache
+	CacheOpts []cache.QueryCacheOptionFn
+	// ModuleName is used for logging and error context
+	ModuleName string
+	// ModuleParamError is the base error type for parameter query errors
+	ModuleParamError *sdkerrors.Error
+}
+
+// ParamsQuerierOptionFn is a function which receives a paramsQuerierConfig for configuration.
+type ParamsQuerierOptionFn func(*paramsQuerierConfig)
+
+// DefaultParamsQuerierConfig returns the default configuration for parameter queriers
+func DefaultParamsQuerierConfig() *paramsQuerierConfig {
+	return &paramsQuerierConfig{
+		CacheOpts: []cache.QueryCacheOptionFn{
+			cache.WithHistoricalMode(defaultPruneOlderThan),
+			cache.WithMaxKeys(defaultMaxKeys),
+			cache.WithEvictionPolicy(cache.FirstInFirstOut),
+		},
+	}
+}
+
+// WithModuleInfo sets the module name and param error for the querier.
+func WithModuleInfo(moduleName string, moduleParamError *sdkerrors.Error) ParamsQuerierOptionFn {
+	return func(cfg *paramsQuerierConfig) {
+		cfg.ModuleName = moduleName
+		cfg.ModuleParamError = moduleParamError
+	}
+}
+
+// WithQueryCacheOptions is used to configure the params HistoricalQueryCache.
+func WithQueryCacheOptions(opts ...cache.QueryCacheOptionFn) ParamsQuerierOptionFn {
+	return func(cfg *paramsQuerierConfig) {
+		cfg.CacheOpts = append(cfg.CacheOpts, opts...)
+	}
+}

pkg/client/query/paramsquerier.go

@@ -0,0 +1,148 @@
+package query
+
+import (
+	"context"
+	"errors"
+
+	"cosmossdk.io/depinject"
+	cosmostypes "github.com/cosmos/cosmos-sdk/types"
+	gogogrpc "github.com/cosmos/gogoproto/grpc"
+
+	"github.com/pokt-network/poktroll/pkg/client"
+	"github.com/pokt-network/poktroll/pkg/client/query/cache"
+	"github.com/pokt-network/poktroll/pkg/polylog"
+)
+
+// abstractParamsQuerier is NOT intended to be used for anything except the
+// compile-time interface compliance assertion that immediately follows.
+type abstractParamsQuerier = cachedParamsQuerier[cosmostypes.Msg, paramsQuerierIface[cosmostypes.Msg]]
+
+var _ client.ParamsQuerier[cosmostypes.Msg] = (*abstractParamsQuerier)(nil)
+
+// paramsQuerierIface is an interface which generated query clients MUST implement
+// to be compatible with the cachedParamsQuerier.
+//
+// DEV_NOTE: It is mainly required due to syntactic constraints imposed by the generics
+// (i.e. otherwise, P here MUST be a value type, and there's no way to express that Q
+// (below) SHOULD be in terms of the concrete type of P in NewCachedParamsQuerier).
+type paramsQuerierIface[P cosmostypes.Msg] interface {
+	GetParams(context.Context) (P, error)
+}
+
+// NewCachedParamsQuerier creates a new, generic, params querier with the given
+// concrete query client constructor and the configuration which results from
+// applying the given options.
+func NewCachedParamsQuerier[P cosmostypes.Msg, Q paramsQuerierIface[P]](
+	deps depinject.Config,
+	queryClientConstructor func(conn gogogrpc.ClientConn) Q,
+	opts ...ParamsQuerierOptionFn,
+) (_ client.ParamsQuerier[P], err error) {
+	cfg := DefaultParamsQuerierConfig()
+	for _, opt := range opts {
+		opt(cfg)
+	}
+
+	paramsCache, err := cache.NewInMemoryCache[P](cfg.CacheOpts...)
+	if err != nil {
+		return nil, err
+	}
+
+	querier := &cachedParamsQuerier[P, Q]{
+		config:      cfg,
+		paramsCache: paramsCache,
+	}
+
+	if err = depinject.Inject(
+		deps,
+		&querier.clientConn,
+	); err != nil {
+		return nil, err
+	}
+
+	querier.queryClient = queryClientConstructor(querier.clientConn)
+
+	return querier, nil
+}
+
+// cachedParamsQuerier provides a generic implementation of cached param querying.
+// It handles parameter caching and chain querying in a generic way, where
+// P is a pointer type of the parameters, and Q is the interface type of the
+// corresponding query client.
+type cachedParamsQuerier[P cosmostypes.Msg, Q paramsQuerierIface[P]] struct {
+	clientConn  gogogrpc.ClientConn
+	queryClient Q
+	paramsCache client.HistoricalQueryCache[P]
+	config      *paramsQuerierConfig
+}
+
+// GetParams returns the latest cached params, if any; otherwise, it queries the
+// current on-chain params and caches them.
+func (bq *cachedParamsQuerier[P, Q]) GetParams(ctx context.Context) (P, error) {
+	logger := polylog.Ctx(ctx).With(
+		"module", bq.config.ModuleName,
+		"method", "GetParams",
+	)
+
+	// Check the cache first.
+	var paramsZero P
+	cached, err := bq.paramsCache.Get("params")
+	switch {
+	case err == nil:
+		logger.Debug().Msgf("params cache hit")
+		return cached, nil
+	case !errors.Is(err, cache.ErrCacheMiss):
+		return paramsZero, err
+	}
+
+	logger.Debug().Msgf("%s", err)
+
+	// Query on-chain on cache miss.
+	params, err := bq.queryClient.GetParams(ctx)
+	if err != nil {
+		if bq.config.ModuleParamError != nil {
+			return paramsZero, bq.config.ModuleParamError.Wrap(err.Error())
+		}
+		return paramsZero, err
+	}
+
+	// Update the cache.
+	if err = bq.paramsCache.Set("params", params); err != nil {
+		return paramsZero, err
+	}
+
+	return params, nil
+}
+
+// GetParamsAtHeight returns parameters as they were as of the given height, **if
+// that height is present in the cache**. Otherwise, it queries the current params
+// and returns them.
+//
+// TODO_MAINNET(@bryanchriswhite): Once on-chain historical data is available,
+// update this to query for the historical params, rather than returning the
+// current params, if the case of a cache miss.
+func (bq *cachedParamsQuerier[P, Q]) GetParamsAtHeight(ctx context.Context, height int64) (P, error) {
+	logger := polylog.Ctx(ctx).With(
+		"module", bq.config.ModuleName,
+		"method", "GetParamsAtHeight",
+		"height", height,
+	)
+
+	// Try to get from cache at specific height
+	cached, err := bq.paramsCache.GetAtHeight("params", height)
+	switch {
+	case err == nil:
+		logger.Debug().Msg("params cache hit")
+		return cached, nil
+	case !errors.Is(err, cache.ErrCacheMiss):
+		return cached, err
+	}
+
+	logger.Debug().Msgf("%s", err)
+
+	// TODO_MAINNET(@bryanchriswhite): Implement querying historical params from chain
+	err = cache.ErrCacheMiss.Wrapf("TODO: on-chain historical data not implemented")
+	logger.Error().Msgf("%s", err)
+
+	// Meanwhile, return current params as fallback. 😬
+	return bq.GetParams(ctx)
+}