feat: add a global params store module

tm2/pkg/sdk/params/keeper.go

@@ -0,0 +1,72 @@
+package params
+
+import (
+	"log/slog"
+
+	"github.com/gnolang/gno/tm2/pkg/amino"
+	"github.com/gnolang/gno/tm2/pkg/sdk"
+	"github.com/gnolang/gno/tm2/pkg/store"
+)
+
+const (
+	ModuleName = "params"
+
+	StoreKey = "params"
+
+	// ValueStorePrevfix is "/pv/" for param value.
+	ValueStoreKeyPrefix = "/pv/"
+)
+
+func ValueStoreKey(key string) []byte {
+	return append([]byte(ValueStoreKeyPrefix), []byte(key)...)
+}
+
+// Keeper of the global param store.
+type Keeper struct {
+	key       store.StoreKey
+	keyMapper KeyMapper
+}
+
+// NewKeeper constructs a params keeper
+func NewKeeper(key store.StoreKey, keyMapper KeyMapper) Keeper {
+	return Keeper{
+		key:       key,
+		keyMapper: keyMapper,
+	}
+}
+
+// Logger returns a module-specific logger.
+func (k Keeper) Logger(ctx sdk.Context) *slog.Logger {
+	return ctx.Logger().With("module", ModuleName)
+}
+
+// GetParam gets a param value from the global param store.
+func (k Keeper) GetParam(ctx sdk.Context, key string, target interface{}) (bool, error) {
+	stor := ctx.Store(k.key)
+	if k.keyMapper != nil {
+		key = k.keyMapper.Map(key)
+	}
+
+	bz := stor.Get(ValueStoreKey(key))
+	if bz == nil {
+		return false, nil
+	}
+
+	return true, amino.Unmarshal(bz, target)
+}
+
+// SetParam sets a param value to the global param store.
+func (k Keeper) SetParam(ctx sdk.Context, key string, param interface{}) error {
+	bz, err := amino.Marshal(param)
+	if err != nil {
+		return err
+	}
+
+	stor := ctx.Store(k.key)
+	if k.keyMapper != nil {
+		key = k.keyMapper.Map(key)
+	}
+
+	stor.Set(ValueStoreKey(key), bz)
+	return nil
+}

tm2/pkg/sdk/params/keymapper.go

@@ -0,0 +1,8 @@
+package params
+
+// KeyMapper is used to map one key string to another.
+type KeyMapper interface {
+	// Map does a transformation on an input key to produce the key
+	// appropriate for accessing a param keeper's storage instance.
+	Map(key string) string
+}