Make mempool not drop transactions (#501)

* Rename deliveredrequests to deliveredtxs
* Add methods for querying client progress
* Update mempool-related protobuf definitions
* Re-generate protobufs
* Clean up and add imports for future code
* Adapt mempool transaction lookup to new protobufs
* Make mempool aware of the current epoch

This is required for not emitting the same transactions multiple times
in the same epoch, but still re-emitting transactions
that have not been delivered in a previous epoch.

The main changes to the logic of the mempool itself
are not yet included in this commit to simplify review.
They will follow in the next commit.

* Make mempool not drop transactions

The explanation of how this works is written in the comments
in the beginning of the updated formbatches.go file.

Signed-off-by: Matej Pavlovic <matopavlovic@gmail.com>

pkg/availability/multisigcollector/common/common.go

@@ -4,6 +4,7 @@ import (
 	msctypes "github.com/filecoin-project/mir/pkg/availability/multisigcollector/types"
 	cryptopbtypes "github.com/filecoin-project/mir/pkg/pb/cryptopb/types"
 	trantorpbtypes "github.com/filecoin-project/mir/pkg/pb/trantorpb/types"
+	tt "github.com/filecoin-project/mir/pkg/trantor/types"
 	t "github.com/filecoin-project/mir/pkg/types"
 )
 
@@ -30,6 +31,7 @@ type ModuleConfig struct {
 // All replicas are expected to use identical module parameters.
 type ModuleParams struct {
 	InstanceUID []byte                     // unique identifier for this instance used to prevent replay attacks
+	EpochNr     tt.EpochNr                 // The epoch in which this instance of MultisigCollector operates
 	Membership  *trantorpbtypes.Membership // the list of participating nodes
 	Limit       int                        // the maximum number of certificates to generate before a request is completed
 	MaxRequests int                        // the maximum number of requests to be provided by this module

pkg/availability/multisigcollector/internal/parts/certcreation/certcreation.go

@@ -10,17 +10,16 @@ import (
 	mscpbdsl "github.com/filecoin-project/mir/pkg/pb/availabilitypb/mscpb/dsl"
 	mscpbmsgs "github.com/filecoin-project/mir/pkg/pb/availabilitypb/mscpb/msgs"
 	mscpbtypes "github.com/filecoin-project/mir/pkg/pb/availabilitypb/mscpb/types"
-	cryptopbdsl "github.com/filecoin-project/mir/pkg/pb/cryptopb/dsl"
-	transportpbdsl "github.com/filecoin-project/mir/pkg/pb/transportpb/dsl"
-	tt "github.com/filecoin-project/mir/pkg/trantor/types"
-	"github.com/filecoin-project/mir/pkg/util/membutil"
-	"github.com/filecoin-project/mir/pkg/util/sliceutil"
-
 	apbtypes "github.com/filecoin-project/mir/pkg/pb/availabilitypb/types"
+	cryptopbdsl "github.com/filecoin-project/mir/pkg/pb/cryptopb/dsl"
 	mempooldsl "github.com/filecoin-project/mir/pkg/pb/mempoolpb/dsl"
+	transportpbdsl "github.com/filecoin-project/mir/pkg/pb/transportpb/dsl"
 	trantorpbtypes "github.com/filecoin-project/mir/pkg/pb/trantorpb/types"
+	tt "github.com/filecoin-project/mir/pkg/trantor/types"
 	t "github.com/filecoin-project/mir/pkg/types"
 	"github.com/filecoin-project/mir/pkg/util/maputil"
+	"github.com/filecoin-project/mir/pkg/util/membutil"
+	"github.com/filecoin-project/mir/pkg/util/sliceutil"
 )
 
 // certCreationState represents the state related to this part of the module.
@@ -74,7 +73,7 @@ func IncludeCreatingCertificates(
 			receivedSig: make(map[t.NodeID]bool),
 			sigs:        make(map[t.NodeID][]byte),
 		}
-		mempooldsl.RequestBatch(m, mc.Mempool, &requestBatchFromMempoolContext{reqID})
+		mempooldsl.RequestBatch(m, mc.Mempool, params.EpochNr, &requestBatchFromMempoolContext{reqID})
 		return nil
 	})
 

pkg/availability/multisigcollector/multisigcollector.go

@@ -3,11 +3,10 @@ package multisigcollector
 import (
 	"math"
 
+	"github.com/filecoin-project/mir/pkg/availability/multisigcollector/common"
 	"github.com/filecoin-project/mir/pkg/availability/multisigcollector/internal/parts/batchreconstruction"
 	"github.com/filecoin-project/mir/pkg/availability/multisigcollector/internal/parts/certcreation"
 	"github.com/filecoin-project/mir/pkg/availability/multisigcollector/internal/parts/certverification"
-
-	"github.com/filecoin-project/mir/pkg/availability/multisigcollector/common"
 	"github.com/filecoin-project/mir/pkg/dsl"
 	"github.com/filecoin-project/mir/pkg/factorymodule"
 	"github.com/filecoin-project/mir/pkg/logging"
@@ -24,7 +23,7 @@ type ModuleConfig = common.ModuleConfig
 type ModuleParams = common.ModuleParams
 
 // DefaultParamsTemplate returns the availability module parameters structure partially filled with default values.
-// Fields without a meaningful default value (like InstanceUID and Membership)
+// Fields without a meaningful default value (like InstanceUID, Epoch, and Membership)
 // are left empty (zero values for their corresponding type).
 func DefaultParamsTemplate() ModuleParams {
 	return ModuleParams{
@@ -70,6 +69,7 @@ func NewReconfigurableModule(mc ModuleConfig, paramsTemplate ModuleParams, logge
 				// Fill in instance-specific parameters.
 				moduleParams := paramsTemplate
 				moduleParams.InstanceUID = []byte(mscID)
+				moduleParams.EpochNr = mscParams.Epoch
 				moduleParams.Membership = mscParams.Membership
 				moduleParams.MaxRequests = int(mscParams.MaxRequests)
 				// TODO: Use InstanceUIDs properly.

pkg/batchfetcher/batchfetcher.go

@@ -3,30 +3,28 @@ package batchfetcher
 import (
 	"fmt"
 
-	bfevents "github.com/filecoin-project/mir/pkg/batchfetcher/events"
 	"github.com/filecoin-project/mir/pkg/checkpoint"
+	"github.com/filecoin-project/mir/pkg/clientprogress"
+	"github.com/filecoin-project/mir/pkg/dsl"
+	"github.com/filecoin-project/mir/pkg/events"
 	"github.com/filecoin-project/mir/pkg/logging"
+	"github.com/filecoin-project/mir/pkg/modules"
 	apppbdsl "github.com/filecoin-project/mir/pkg/pb/apppb/dsl"
 	apppbevents "github.com/filecoin-project/mir/pkg/pb/apppb/events"
+	availabilitypbdsl "github.com/filecoin-project/mir/pkg/pb/availabilitypb/dsl"
+	apbtypes "github.com/filecoin-project/mir/pkg/pb/availabilitypb/types"
 	"github.com/filecoin-project/mir/pkg/pb/batchfetcherpb"
+	bfeventstypes "github.com/filecoin-project/mir/pkg/pb/batchfetcherpb/events"
 	checkpointpbtypes "github.com/filecoin-project/mir/pkg/pb/checkpointpb/types"
+	"github.com/filecoin-project/mir/pkg/pb/eventpb"
+	eventpbdsl "github.com/filecoin-project/mir/pkg/pb/eventpb/dsl"
 	eventpbtypes "github.com/filecoin-project/mir/pkg/pb/eventpb/types"
 	isspbdsl "github.com/filecoin-project/mir/pkg/pb/isspb/dsl"
+	mppbdsl "github.com/filecoin-project/mir/pkg/pb/mempoolpb/dsl"
 	"github.com/filecoin-project/mir/pkg/pb/trantorpb"
-	tt "github.com/filecoin-project/mir/pkg/trantor/types"
-
-	availabilitypbdsl "github.com/filecoin-project/mir/pkg/pb/availabilitypb/dsl"
-	apbtypes "github.com/filecoin-project/mir/pkg/pb/availabilitypb/types"
-	bfeventstypes "github.com/filecoin-project/mir/pkg/pb/batchfetcherpb/events"
+	trantorpbdsl "github.com/filecoin-project/mir/pkg/pb/trantorpb/dsl"
 	trantorpbtypes "github.com/filecoin-project/mir/pkg/pb/trantorpb/types"
-
-	eventpbdsl "github.com/filecoin-project/mir/pkg/pb/eventpb/dsl"
-
-	"github.com/filecoin-project/mir/pkg/clientprogress"
-	"github.com/filecoin-project/mir/pkg/dsl"
-	"github.com/filecoin-project/mir/pkg/events"
-	"github.com/filecoin-project/mir/pkg/modules"
-	"github.com/filecoin-project/mir/pkg/pb/eventpb"
+	tt "github.com/filecoin-project/mir/pkg/trantor/types"
 	t "github.com/filecoin-project/mir/pkg/types"
 )
 
@@ -80,6 +78,10 @@ func NewModule(mc ModuleConfig, epochNr tt.EpochNr, clientProgress *clientprogre
 		epochNr = newEpochNr
 		output.Enqueue(&outputItem{
 			event: apppbevents.NewEpoch(mc.Destination, epochNr, protocolModule).Pb(),
+			f: func(_ *eventpb.Event) {
+				clientProgress.GarbageCollect()
+				mppbdsl.NewEpoch(m, mc.Mempool, epochNr, trantorpbtypes.ClientProgressFromPb(clientProgress.Pb()))
+			},
 		})
 		output.Flush(m)
 		return nil
@@ -141,10 +143,10 @@ func NewModule(mc ModuleConfig, epochNr tt.EpochNr, clientProgress *clientprogre
 			// At the time of forwarding, submit the client progress to the checkpointing protocol.
 			f: func(_ *eventpb.Event) {
 				clientProgress.GarbageCollect()
-				dsl.EmitEvent(m, bfevents.ClientProgress(
+				trantorpbdsl.ClientProgress(m,
 					mc.Checkpoint.Then(t.ModuleID(fmt.Sprintf("%v", epochNr))),
-					clientProgress.Pb(),
-				))
+					trantorpbtypes.ClientProgressFromPb(clientProgress.Pb()).Progress,
+				)
 			},
 		})
 		output.Flush(m)

pkg/batchfetcher/config.go

@@ -9,4 +9,5 @@ type ModuleConfig struct {
 	Availability t.ModuleID // ID of the factory module containing the availability modules.
 	Checkpoint   t.ModuleID // ID of the checkpoint factory module to which to submit client progress.
 	Destination  t.ModuleID // ID of the module to deliver the produced event stream to (usually the application).
+	Mempool      t.ModuleID // ID of the mempool module to send updates on client progress to.
 }

pkg/clientprogress/clientprogress.go

@@ -19,6 +19,13 @@ func NewClientProgress(logger logging.Logger) *ClientProgress {
 	}
 }
 
+func (cp *ClientProgress) Contains(clID tt.ClientID, txNo tt.TxNo) bool {
+	if _, ok := cp.ClientTrackers[clID]; !ok {
+		return false
+	}
+	return cp.ClientTrackers[clID].Contains(txNo)
+}
+
 func (cp *ClientProgress) Add(clID tt.ClientID, txNo tt.TxNo) bool {
 	if _, ok := cp.ClientTrackers[clID]; !ok {
 		cp.ClientTrackers[clID] = EmptyDeliveredTXs(logging.Decorate(cp.logger, "", "clID", clID))

pkg/clientprogress/deliveredrequests.go → pkg/clientprogress/deliveredtxs.go

@@ -39,44 +39,55 @@ func DeliveredTXsFromPb(pb *trantorpb.DeliveredTXs, logger logging.Logger) *Deli
 	return dr
 }
 
+// Contains returns true if the given txNo has already been added.
+func (dt *DeliveredTXs) Contains(txNo tt.TxNo) bool {
+
+	if txNo < dt.lowWM {
+		return true
+	}
+
+	_, alreadyPresent := dt.delivered[txNo]
+	return alreadyPresent
+}
+
 // Add adds a transaction number that is considered delivered to the DeliveredTXs.
 // Returns true if the transaction number has been added now (after not being previously present).
 // Returns false if the transaction number has already been added before the call to Add.
-func (dr *DeliveredTXs) Add(txNo tt.TxNo) bool {
+func (dt *DeliveredTXs) Add(txNo tt.TxNo) bool {
 
-	if txNo < dr.lowWM {
-		dr.logger.Log(logging.LevelDebug, "Transaction number below client's watermark window.",
-			"lowWM", dr.lowWM, "txNo", txNo)
+	if txNo < dt.lowWM {
+		dt.logger.Log(logging.LevelDebug, "Transaction number below client's watermark window.",
+			"lowWM", dt.lowWM, "txNo", txNo)
 		return false
 	}
 
-	_, alreadyPresent := dr.delivered[txNo]
-	dr.delivered[txNo] = struct{}{}
+	_, alreadyPresent := dt.delivered[txNo]
+	dt.delivered[txNo] = struct{}{}
 	return !alreadyPresent
 }
 
 // GarbageCollect reduces the memory footprint of the DeliveredTXs
 // by deleting a contiguous prefix of delivered transaction numbers
 // and increasing the low watermark accordingly.
 // Returns the new low watermark.
-func (dr *DeliveredTXs) GarbageCollect() tt.TxNo {
+func (dt *DeliveredTXs) GarbageCollect() tt.TxNo {
 
-	for _, ok := dr.delivered[dr.lowWM]; ok; _, ok = dr.delivered[dr.lowWM] {
-		delete(dr.delivered, dr.lowWM)
-		dr.lowWM++
+	for _, ok := dt.delivered[dt.lowWM]; ok; _, ok = dt.delivered[dt.lowWM] {
+		delete(dt.delivered, dt.lowWM)
+		dt.lowWM++
 	}
 
-	return dr.lowWM
+	return dt.lowWM
 }
 
-func (dr *DeliveredTXs) Pb() *trantorpb.DeliveredTXs {
-	delivered := make([]uint64, len(dr.delivered))
-	for i, txNo := range maputil.GetSortedKeys(dr.delivered) {
+func (dt *DeliveredTXs) Pb() *trantorpb.DeliveredTXs {
+	delivered := make([]uint64, len(dt.delivered))
+	for i, txNo := range maputil.GetSortedKeys(dt.delivered) {
 		delivered[i] = txNo.Pb()
 	}
 
 	return &trantorpb.DeliveredTXs{
-		LowWm:     dr.lowWM.Pb(),
+		LowWm:     dt.lowWM.Pb(),
 		Delivered: delivered,
 	}
 }

pkg/iss/iss.go

@@ -20,10 +20,6 @@ import (
 	es "github.com/go-errors/errors"
 	"google.golang.org/protobuf/proto"
 
-	cvpbdsl "github.com/filecoin-project/mir/pkg/pb/checkpointpb/chkpvalidatorpb/dsl"
-
-	"github.com/filecoin-project/mir/pkg/orderers/common"
-
 	"github.com/filecoin-project/mir/pkg/checkpoint"
 	"github.com/filecoin-project/mir/pkg/clientprogress"
 	"github.com/filecoin-project/mir/pkg/crypto"
@@ -33,11 +29,13 @@ import (
 	"github.com/filecoin-project/mir/pkg/logging"
 	"github.com/filecoin-project/mir/pkg/modules"
 	"github.com/filecoin-project/mir/pkg/orderers"
+	"github.com/filecoin-project/mir/pkg/orderers/common"
 	apppbdsl "github.com/filecoin-project/mir/pkg/pb/apppb/dsl"
 	"github.com/filecoin-project/mir/pkg/pb/availabilitypb"
 	apbdsl "github.com/filecoin-project/mir/pkg/pb/availabilitypb/dsl"
 	mscpbtypes "github.com/filecoin-project/mir/pkg/pb/availabilitypb/mscpb/types"
 	apbtypes "github.com/filecoin-project/mir/pkg/pb/availabilitypb/types"
+	cvpbdsl "github.com/filecoin-project/mir/pkg/pb/checkpointpb/chkpvalidatorpb/dsl"
 	chkppbdsl "github.com/filecoin-project/mir/pkg/pb/checkpointpb/dsl"
 	chkppbmsgs "github.com/filecoin-project/mir/pkg/pb/checkpointpb/msgs"
 	checkpointpbtypes "github.com/filecoin-project/mir/pkg/pb/checkpointpb/types"
@@ -629,6 +627,7 @@ func (iss *ISS) initAvailability() {
 		&factorypbtypes.GeneratorParams{
 			Type: &factorypbtypes.GeneratorParams_MultisigCollector{
 				MultisigCollector: &mscpbtypes.InstanceParams{
+					Epoch:       iss.epoch.Nr(),
 					Membership:  iss.memberships[0],
 					MaxRequests: uint64(iss.Params.SegmentLength)},
 			},

pkg/mempool/simplemempool/common/common.go

@@ -4,7 +4,9 @@ import (
 	"time"
 
 	trantorpbtypes "github.com/filecoin-project/mir/pkg/pb/trantorpb/types"
+	tt "github.com/filecoin-project/mir/pkg/trantor/types"
 	t "github.com/filecoin-project/mir/pkg/types"
+	"github.com/filecoin-project/mir/pkg/util/indexedlist"
 )
 
 // ModuleConfig sets the module ids. All replicas are expected to use identical module configurations.
@@ -40,6 +42,10 @@ type ModuleParams struct {
 }
 
 // State represents the common state accessible to all parts of the module implementation.
+// TODO: Consider moving this definition inside the `internal` subdirectory, as it is only used by the mempool.
 type State struct {
-	TxByID map[string]*trantorpbtypes.Transaction
+	// All the transactions in the mempool.
+	// Incoming transactions that have not yet been delivered are added to this list.
+	// They are removed upon delivery.
+	Transactions *indexedlist.IndexedList[tt.TxID, *trantorpbtypes.Transaction]
 }

pkg/mempool/simplemempool/internal/parts/formbatchesext/formbatches.go

@@ -21,7 +21,7 @@ func IncludeBatchCreation(
 		return nil
 	})
 
-	mpdsl.UponRequestBatch(m, func(origin *mppbtypes.RequestBatchOrigin) error {
+	mpdsl.UponRequestBatch(m, func(_ tt.EpochNr, origin *mppbtypes.RequestBatchOrigin) error {
 		txs := fetchTransactions()
 		mpdsl.RequestTransactionIDs(m, mc.Self, txs, &requestTxIDsContext{
 			txs:    txs,