Remove LinRead map and sequencing from the Go client.

Author: manishrjain

client.go

@@ -19,19 +19,13 @@ package dgo
 import (
 	"context"
 	"math/rand"
-	"sync"
 
 	"github.com/dgraph-io/dgo/protos/api"
-	"github.com/dgraph-io/dgo/y"
-	"github.com/gogo/protobuf/proto"
 )
 
 // Dgraph is a transaction aware client to a set of dgraph server instances.
 type Dgraph struct {
 	dc []api.DgraphClient
-
-	mu      sync.Mutex
-	linRead *api.LinRead
 }
 
 // NewDgraphClient creates a new Dgraph for interacting with the Dgraph store connected to in
@@ -42,25 +36,12 @@ type Dgraph struct {
 // A single client is thread safe for sharing with multiple go routines.
 func NewDgraphClient(clients ...api.DgraphClient) *Dgraph {
 	dg := &Dgraph{
-		dc:      clients,
-		linRead: &api.LinRead{},
+		dc: clients,
 	}
 
 	return dg
 }
 
-func (d *Dgraph) mergeLinRead(src *api.LinRead) {
-	d.mu.Lock()
-	defer d.mu.Unlock()
-	y.MergeLinReads(d.linRead, src)
-}
-
-func (d *Dgraph) getLinRead() *api.LinRead {
-	d.mu.Lock()
-	defer d.mu.Unlock()
-	return proto.Clone(d.linRead).(*api.LinRead)
-}
-
 // By setting various fields of api.Operation, Alter can be used to do the
 // following:
 //

txn.go

@@ -46,26 +46,23 @@ var (
 type Txn struct {
 	context *api.TxnContext
 
-	finished   bool
-	mutated    bool
-	sequencing api.LinRead_Sequencing
+	finished bool
+	mutated  bool
 
 	dg *Dgraph
 	dc api.DgraphClient
 }
 
 func (txn *Txn) Sequencing(sequencing api.LinRead_Sequencing) {
-	txn.sequencing = sequencing
+	// Sequencing is no longer used.
 }
 
 // NewTxn creates a new transaction.
 func (d *Dgraph) NewTxn() *Txn {
 	txn := &Txn{
-		dg: d,
-		dc: d.anyClient(),
-		context: &api.TxnContext{
-			LinRead: d.getLinRead(),
-		},
+		dg:      d,
+		dc:      d.anyClient(),
+		context: &api.TxnContext{},
 	}
 	return txn
 }
@@ -88,9 +85,7 @@ func (txn *Txn) QueryWithVars(ctx context.Context, q string,
 		Query:   q,
 		Vars:    vars,
 		StartTs: txn.context.StartTs,
-		LinRead: txn.context.LinRead,
 	}
-	req.LinRead.Sequencing = txn.sequencing
 	resp, err := txn.dc.Query(ctx, req)
 	if err == nil {
 		if err := txn.mergeContext(resp.GetTxn()); err != nil {
@@ -105,9 +100,6 @@ func (txn *Txn) mergeContext(src *api.TxnContext) error {
 		return nil
 	}
 
-	y.MergeLinReads(txn.context.LinRead, src.LinRead)
-	txn.dg.mergeLinRead(src.LinRead) // Also merge it with client.
-
 	if txn.context.StartTs == 0 {
 		txn.context.StartTs = src.StartTs
 	}

y/y.go

@@ -20,27 +20,9 @@ package y
 
 import (
 	"errors"
-
-	"github.com/dgraph-io/dgo/protos/api"
 )
 
 var (
 	ErrAborted  = errors.New("Transaction has been aborted. Please retry.")
 	ErrConflict = errors.New("Conflicts with pending transaction. Please abort.")
 )
-
-func MergeLinReads(dst *api.LinRead, src *api.LinRead) {
-	if src == nil || src.Ids == nil {
-		return
-	}
-	if dst.Ids == nil {
-		dst.Ids = make(map[uint32]uint64)
-	}
-	for gid, sid := range src.Ids {
-		if did, has := dst.Ids[gid]; has && did >= sid {
-			// do nothing.
-		} else {
-			dst.Ids[gid] = sid
-		}
-	}
-}