use map instead of list for keys/preds

Author: NamanJain8

dgraph/cmd/alpha/http.go

@@ -26,7 +26,6 @@ import (
 	"io/ioutil"
 	"mime"
 	"net/http"
-	"sort"
 	"strconv"
 	"strings"
 	"time"
@@ -422,12 +421,10 @@ func mutationHandler(w http.ResponseWriter, r *http.Request) {
 		Txn:     resp.Txn,
 		Latency: resp.Latency,
 	}
-	sort.Strings(e.Txn.Keys)
-	sort.Strings(e.Txn.Preds)
 
 	// Don't send keys array which is part of txn context if its commit immediately.
 	if req.CommitNow {
-		e.Txn.Keys = e.Txn.Keys[:0]
+		e.Txn.Keys = nil
 	}
 
 	response := map[string]interface{}{}
@@ -533,10 +530,10 @@ func handleCommit(startTs uint64, reqText []byte) (map[string]interface{}, error
 	}
 
 	if useList {
-		tc.Keys = reqList
+		tc.Keys = x.ListToMap(reqList)
 	} else {
-		tc.Keys = reqMap["keys"]
-		tc.Preds = reqMap["preds"]
+		tc.Keys = x.ListToMap(reqMap["keys"])
+		tc.Preds = x.ListToMap(reqMap["preds"])
 	}
 
 	cts, err := worker.CommitOverNetwork(context.Background(), tc)
@@ -550,7 +547,7 @@ func handleCommit(startTs uint64, reqText []byte) (map[string]interface{}, error
 	e := query.Extensions{
 		Txn: resp.Txn,
 	}
-	e.Txn.Keys = e.Txn.Keys[:0]
+	e.Txn.Keys = make(map[string]bool)
 	response := map[string]interface{}{}
 	response["extensions"] = e
 	mp := map[string]interface{}{}

dgraph/cmd/alpha/http_test.go

@@ -232,8 +232,8 @@ func mutationWithTs(m, t string, isJson bool, commitNow bool, ts uint64) (
 		return mr, err
 	}
 
-	mr.keys = r.Extensions.Txn.Keys
-	mr.preds = r.Extensions.Txn.Preds
+	mr.keys = x.MapToList(r.Extensions.Txn.Keys)
+	mr.preds = x.MapToList(r.Extensions.Txn.Preds)
 	mr.startTs = r.Extensions.Txn.StartTs
 	sort.Strings(mr.preds)
 

dgraph/cmd/zero/oracle.go

@@ -83,7 +83,7 @@ func (o *Oracle) hasConflict(src *api.TxnContext) bool {
 	if src.StartTs < o.startTxnTs {
 		return true
 	}
-	for _, k := range src.Keys {
+	for k := range src.Keys {
 		ki, err := strconv.ParseUint(k, 36, 64)
 		if err != nil {
 			glog.Errorf("Got error while parsing conflict key %q: %v\n", k, err)
@@ -139,7 +139,7 @@ func (o *Oracle) commit(src *api.TxnContext) error {
 	// We store src.Keys as string to ensure compatibility with all the various language clients we
 	// have. But, really they are just uint64s encoded as strings. We use base 36 during creation of
 	// these keys in FillContext in posting/mvcc.go.
-	for _, k := range src.Keys {
+	for k := range src.Keys {
 		ki, err := strconv.ParseUint(k, 36, 64)
 		if err != nil {
 			glog.Errorf("Got error while parsing conflict key %q: %v\n", k, err)
@@ -367,12 +367,7 @@ func (s *Server) commit(ctx context.Context, src *api.TxnContext) error {
 
 	checkPreds := func() error {
 		// Check if any of these tablets is being moved. If so, abort the transaction.
-		preds := make(map[string]struct{})
-
-		for _, k := range src.Preds {
-			preds[k] = struct{}{}
-		}
-		for pkey := range preds {
+		for pkey := range src.Preds {
 			splits := strings.Split(pkey, "-")
 			if len(splits) < 2 {
 				return errors.Errorf("Unable to find group id in %s", pkey)

edgraph/server.go

@@ -595,7 +595,7 @@ func (s *Server) doMutate(ctx context.Context, qc *queryContext, resp *api.Respo
 		if resp.Txn == nil {
 			return errors.Wrapf(err, "Txn Context is nil")
 		}
-		resp.Txn.Keys = resp.Txn.Keys[:0]
+		resp.Txn.Keys = make(map[string]bool)
 		resp.Txn.CommitTs = qc.req.StartTs
 		return err
 	}
@@ -649,7 +649,7 @@ func (s *Server) doMutate(ctx context.Context, qc *queryContext, resp *api.Respo
 	}
 
 	// CommitNow was true, no need to send keys.
-	resp.Txn.Keys = resp.Txn.Keys[:0]
+	resp.Txn.Keys = make(map[string]bool)
 	resp.Txn.CommitTs = cts
 	calculateMutationMetrics()
 	return nil

go.mod

@@ -5,6 +5,7 @@ go 1.12
 // replace github.com/dgraph-io/badger/v2 => /home/mrjn/go/src/github.com/dgraph-io/badger
 // replace github.com/dgraph-io/ristretto => /home/mrjn/go/src/github.com/dgraph-io/ristretto
 // replace github.com/dgraph-io/roaring => /home/mrjn/go/src/github.com/dgraph-io/roaring
+replace github.com/dgraph-io/dgo/v200 => /home/algod/go/src/github.com/dgraph-io/dgo
 
 require (
 	contrib.go.opencensus.io/exporter/jaeger v0.1.0

posting/lists.go

@@ -241,7 +241,9 @@ func (lc *LocalCache) fillPreds(ctx *api.TxnContext, gid uint32) {
 		// Also send the group id that the predicate was being served by. This is useful when
 		// checking if Zero should allow a commit during a predicate move.
 		predKey := fmt.Sprintf("%d-%s", gid, pk.Attr)
-		ctx.Preds = append(ctx.Preds, predKey)
+		if ctx.Preds == nil {
+			ctx.Preds = make(map[string]bool)
+		}
+		ctx.Preds[predKey] = true
 	}
-	ctx.Preds = x.Unique(ctx.Preds)
 }

posting/mvcc.go

@@ -212,9 +212,11 @@ func (txn *Txn) FillContext(ctx *api.TxnContext, gid uint32) {
 		// should be done by sending a list of mutating predicates to Zero,
 		// along with the keys to be used for conflict detection.
 		fps := strconv.FormatUint(key, 36)
-		ctx.Keys = append(ctx.Keys, fps)
+		if ctx.Keys == nil {
+			ctx.Keys = make(map[string]bool)
+		}
+		ctx.Keys[fps] = true
 	}
-	ctx.Keys = x.Unique(ctx.Keys)
 
 	txn.Unlock()
 	txn.Update()

worker/mutation.go

@@ -688,8 +688,18 @@ func MutateOverNetwork(ctx context.Context, m *pb.Mutations) (*api.TxnContext, e
 			e = res.err
 		}
 		if res.ctx != nil {
-			tctx.Keys = append(tctx.Keys, res.ctx.Keys...)
-			tctx.Preds = append(tctx.Preds, res.ctx.Preds...)
+			if tctx.Keys == nil {
+				tctx.Keys = make(map[string]bool)
+			}
+			for key := range res.ctx.Keys {
+				tctx.Keys[key] = true
+			}
+			if tctx.Preds == nil {
+				tctx.Preds = make(map[string]bool)
+			}
+			for pred := range res.ctx.Preds {
+				tctx.Preds[pred] = true
+			}
 		}
 	}
 	close(resCh)

x/x.go

@@ -632,6 +632,25 @@ func Unique(a []string) []string {
 	return a[:idx]
 }
 
+func MapToList(mp map[string]bool) []string {
+	if mp == nil {
+		return nil
+	}
+	list := make([]string, 0, len(mp))
+	for k := range mp {
+		list = append(list, k)
+	}
+	return list
+}
+
+func ListToMap(list []string) map[string]bool {
+	mp := make(map[string]bool)
+	for _, k := range list {
+		mp[k] = true
+	}
+	return mp
+}
+
 // ReadLine reads a single line from a buffered reader. The line is read into the
 // passed in buffer to minimize allocations. This is the preferred
 // method for loading long lines which could be longer than the buffer