feat: Flag for LazyBufferTime (#1797)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

- **New Features**
- Introduced a new command-line flag `--rollkit.lazy_buffer_time` to
enhance transaction accumulation timing in lazy mode.
- Added default configuration for `LazyBufferTime`, allowing users to
specify additional wait time for transactions.

These updates provide users with improved configurability and potential
performance benefits when managing transaction processing.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Author: yarikbratashchuk

cmd/rollkit/docs/rollkit_start.md

@@ -41,6 +41,7 @@ rollkit start [flags]
       --rollkit.da_start_height uint                    starting DA block height (for syncing)
       --rollkit.lazy_aggregator                         wait for transactions, don't build empty blocks
       --rollkit.lazy_block_time duration                block time (for lazy mode) (default 1m0s)
+      --rollkit.lazy_buffer_time duration               additional time to wait to accumulate transactions in lazy mode (default 1s)
       --rollkit.light                                   run light client
       --rollkit.max_pending_blocks uint                 limit of blocks pending DA submission (0 for no limit)
       --rollkit.trusted_hash string                     initial trusted hash to start the header exchange service

config/config.go

@@ -40,6 +40,8 @@ const (
 	FlagDAMempoolTTL = "rollkit.da_mempool_ttl"
 	// FlagLazyBlockTime is a flag for specifying the block time in lazy mode
 	FlagLazyBlockTime = "rollkit.lazy_block_time"
+	// FlagLazyBufferTime is a flag for specifying the additional time to wait to accumulate transactions in lazy mode
+	FlagLazyBufferTime = "rollkit.lazy_buffer_time"
 )
 
 // NodeConfig stores Rollkit node configuration.
@@ -138,6 +140,7 @@ func (nc *NodeConfig) GetViperConfig(v *viper.Viper) error {
 	nc.MaxPendingBlocks = v.GetUint64(FlagMaxPendingBlocks)
 	nc.DAMempoolTTL = v.GetUint64(FlagDAMempoolTTL)
 	nc.LazyBlockTime = v.GetDuration(FlagLazyBlockTime)
+	nc.LazyBufferTime = v.GetDuration(FlagLazyBufferTime)
 	return nil
 }
 
@@ -161,4 +164,5 @@ func AddFlags(cmd *cobra.Command) {
 	cmd.Flags().Uint64(FlagMaxPendingBlocks, def.MaxPendingBlocks, "limit of blocks pending DA submission (0 for no limit)")
 	cmd.Flags().Uint64(FlagDAMempoolTTL, def.DAMempoolTTL, "number of DA blocks until transaction is dropped from the mempool")
 	cmd.Flags().Duration(FlagLazyBlockTime, def.LazyBlockTime, "block time (for lazy mode)")
+	cmd.Flags().Duration(FlagLazyBufferTime, def.LazyBufferTime, "additional time to wait to accumulate transactions in lazy mode")
 }

config/defaults.go

@@ -26,6 +26,7 @@ var DefaultNodeConfig = NodeConfig{
 		DABlockTime:    15 * time.Second,
 		LazyAggregator: false,
 		LazyBlockTime:  60 * time.Second,
+		LazyBufferTime: 1 * time.Second,
 	},
 	DAAddress:       "http://localhost:26658",
 	DAGasPrice:      -1,