diff --git a/gql/parser.go b/gql/parser.go
index bc63388140dd6b88861fce94a37fb1e04867635b..1e9d86438614b99197fa218bb308a38b376696c0 100644
--- a/gql/parser.go
+++ b/gql/parser.go
@@ -152,7 +152,7 @@ func parseArguments(l *lex.Lexer) (result []pair, rerr error) {
for {
var p pair
- // Get key.
+ // Get key
item := <-l.Items
if item.Typ == itemArgName {
p.Key = item.Val
@@ -164,7 +164,7 @@ func parseArguments(l *lex.Lexer) (result []pair, rerr error) {
return result, fmt.Errorf("Expecting argument name. Got: %v", item)
}
- // Get value.
+ // Get value
item = <-l.Items
if item.Typ == itemArgVal {
p.Val = item.Val
@@ -238,7 +238,6 @@ func godeep(l *lex.Lexer, gq *GraphQuery) error {
return nil
} else if item.Typ == itemLeftRound {
-
args, err := parseArguments(l)
if err != nil {
return err
diff --git a/posting/list.go b/posting/list.go
index 6f7ae0088b2b0fdcc7d99f282f6205fcdb6e799c..e858cf676d64b99a6ed15c1fc496f31130b427f3 100644
--- a/posting/list.go
+++ b/posting/list.go
@@ -720,15 +720,35 @@ func (l *List) LastCompactionTs() time.Time {
return l.lastCompact
}
-func (l *List) GetUids() []uint64 {
+func (l *List) GetUids(offset, count int) []uint64 {
l.wg.Wait()
l.RLock()
defer l.RUnlock()
- result := make([]uint64, l.length())
+ if offset < 0 {
+ glog.WithField("offset", offset).Fatal("Unexpected offset")
+ return make([]uint64, 0)
+ }
+
+ if count < 0 {
+ count = 0 - count
+ offset = l.length() - count
+ }
+
+ if count == 0 {
+ count = l.length() - offset
+
+ } else if count > l.length()-offset {
+ count = l.length() - offset
+ }
+ if count < 0 {
+ count = 0
+ }
+
+ result := make([]uint64, count)
result = result[:0]
var p types.Posting
- for i := 0; i < l.length(); i++ {
+ for i := offset; i < count+offset && i < l.length(); i++ {
if ok := l.get(&p, i); !ok || p.Uid() == math.MaxUint64 {
break
}
diff --git a/posting/list_test.go b/posting/list_test.go
index 824573680a726f867f195df4b88f553974655d2e..79cde4bcbef35fe0dcb99f5287c5e975a3963034 100644
--- a/posting/list_test.go
+++ b/posting/list_test.go
@@ -44,6 +44,32 @@ func checkUids(t *testing.T, l *List, uids ...uint64) error {
return fmt.Errorf("Expected: %v. Got: %v", uids[i], p.Uid())
}
}
+ if len(uids) >= 3 {
+ ruids := l.GetUids(1, 2)
+ if len(ruids) != 2 {
+ return fmt.Errorf("Expected result of length: 2. Got: %v", len(ruids))
+ }
+
+ for i := 0; i < len(ruids); i++ {
+ if ruids[i] != uids[1+i] {
+ return fmt.Errorf("GetUids expected: %v. Got: %v", uids[1+i], ruids[i])
+ }
+ }
+
+ ruids = l.GetUids(1, -2) // offset should be ignored.
+ ulen := len(uids)
+ if ulen > 2 && len(ruids) != 2 {
+ return fmt.Errorf("Expected result of length: 2. Got: %v", len(ruids))
+ }
+
+ for i := 0; i < len(ruids); i++ {
+ if ruids[i] != uids[ulen-2+i] {
+ return fmt.Errorf("GetUids neg count expected: %v. Got: %v",
+ uids[ulen-2+i], ruids[i])
+ }
+ }
+ }
+
return nil
}
diff --git a/query/query.go b/query/query.go
index e06a58761e36128aeb3a81c95a9408f9818e3ebb..ee2643e0364134761b3c55015709a02930e9e3dd 100644
--- a/query/query.go
+++ b/query/query.go
@@ -110,6 +110,8 @@ func (l *Latency) ToMap() map[string]string {
// client convenient formats, like GraphQL / JSON.
type SubGraph struct {
Attr string
+ Count int
+ Offset int
Children []*SubGraph
query []byte
@@ -325,9 +327,14 @@ func (g *SubGraph) PreTraverse() (gr *pb.GraphResponse, rerr error) {
}
func treeCopy(gq *gql.GraphQuery, sg *SubGraph) {
+ // Typically you act on the current node, and leave recursion to deal with
+ // children. But, in this case, we don't want to muck with the current
+ // node, because of the way we're dealing with the root node.
+ // So, we work on the children, and then recurse for grand children.
for _, gchild := range gq.Children {
dst := new(SubGraph)
dst.Attr = gchild.Attr
+ dst.Count = gchild.First
sg.Children = append(sg.Children, dst)
treeCopy(gchild, dst)
}
@@ -394,14 +401,14 @@ func newGraph(euid uint64, exid string) (*SubGraph, error) {
sg.Attr = "_root_"
sg.result = b.Bytes[b.Head():]
// Also add query for consistency and to allow for ToJson() later.
- sg.query = createTaskQuery(sg.Attr, []uint64{euid})
+ sg.query = createTaskQuery(sg, []uint64{euid})
return sg, nil
}
// createTaskQuery generates the query buffer.
-func createTaskQuery(attr string, sorted []uint64) []byte {
+func createTaskQuery(sg *SubGraph, sorted []uint64) []byte {
b := flatbuffers.NewBuilder(0)
- ao := b.CreateString(attr)
+ ao := b.CreateString(sg.Attr)
task.QueryStartUidsVector(b, len(sorted))
for i := len(sorted) - 1; i >= 0; i-- {
@@ -412,6 +419,8 @@ func createTaskQuery(attr string, sorted []uint64) []byte {
task.QueryStart(b)
task.QueryAddAttr(b, ao)
task.QueryAddUids(b, vend)
+ task.QueryAddCount(b, int32(sg.Count))
+
qend := task.QueryEnd(b)
b.Finish(qend)
return b.Bytes[b.Head():]
@@ -531,7 +540,7 @@ func ProcessGraph(sg *SubGraph, rch chan error, td time.Duration) {
childchan := make(chan error, len(sg.Children))
for i := 0; i < len(sg.Children); i++ {
child := sg.Children[i]
- child.query = createTaskQuery(child.Attr, sorted)
+ child.query = createTaskQuery(child, sorted)
go ProcessGraph(child, childchan, timeleft)
}
diff --git a/task.fbs b/task.fbs
index 2e3acbb08719ae83954a5b6c0620f3a9aca6406b..3e6f687d1a077760c72ac05c20e312c5fc55603b 100644
--- a/task.fbs
+++ b/task.fbs
@@ -3,6 +3,8 @@ namespace task;
table Query {
attr:string;
uids:[ulong];
+ count:int;
+ offset:int;
}
table Value {
diff --git a/task/Query.go b/task/Query.go
index 9a2b8e25d4af593d1828ed2f60b400c9dd53f3bd..d28c04a77ca5f8789b980ac748ca3a57e6df45ff 100644
--- a/task/Query.go
+++ b/task/Query.go
@@ -39,9 +39,27 @@ func (rcv *Query) UidsLength() int {
return 0
}
-func QueryStart(builder *flatbuffers.Builder) { builder.StartObject(2) }
+func (rcv *Query) Count() int32 {
+ o := flatbuffers.UOffsetT(rcv._tab.Offset(8))
+ if o != 0 {
+ return rcv._tab.GetInt32(o + rcv._tab.Pos)
+ }
+ return 0
+}
+
+func (rcv *Query) Offset() int32 {
+ o := flatbuffers.UOffsetT(rcv._tab.Offset(10))
+ if o != 0 {
+ return rcv._tab.GetInt32(o + rcv._tab.Pos)
+ }
+ return 0
+}
+
+func QueryStart(builder *flatbuffers.Builder) { builder.StartObject(4) }
func QueryAddAttr(builder *flatbuffers.Builder, attr flatbuffers.UOffsetT) { builder.PrependUOffsetTSlot(0, flatbuffers.UOffsetT(attr), 0) }
func QueryAddUids(builder *flatbuffers.Builder, uids flatbuffers.UOffsetT) { builder.PrependUOffsetTSlot(1, flatbuffers.UOffsetT(uids), 0) }
func QueryStartUidsVector(builder *flatbuffers.Builder, numElems int) flatbuffers.UOffsetT { return builder.StartVector(8, numElems, 8)
}
+func QueryAddCount(builder *flatbuffers.Builder, count int32) { builder.PrependInt32Slot(2, count, 0) }
+func QueryAddOffset(builder *flatbuffers.Builder, offset int32) { builder.PrependInt32Slot(3, offset, 0) }
func QueryEnd(builder *flatbuffers.Builder) flatbuffers.UOffsetT { return builder.EndObject() }
diff --git a/worker/task.go b/worker/task.go
index e6e2f7eee6ec431171e4f690cb076a983dc0b9be..358fe322371ea9e7a89620707bba201f7a08edf8 100644
--- a/worker/task.go
+++ b/worker/task.go
@@ -94,7 +94,7 @@ func processTask(query []byte) (result []byte, rerr error) {
task.ValueAddVal(b, valoffset)
voffsets[i] = task.ValueEnd(b)
- ulist := pl.GetUids()
+ ulist := pl.GetUids(int(q.Offset()), int(q.Count()))
uoffsets[i] = x.UidlistOffset(b, ulist)
}
task.ResultStartValuesVector(b, len(voffsets))