add WithLeaves

trie/nodes.proto

@@ -32,6 +32,12 @@ message Bitmap {
 // Since 0.5.10
 message Nodes {
 
+    // WithLeaves indicates whether to store leaf values(as an index).
+    // Otherwise, it is a "filter" which can only provide existence information
+    // but not location information.
+    //
+    // Since 0.5.10
+    bool WithLeaves = 8;
 
     // WithPrefixContent indicates whether full inner prefixes are stored or only the
     // lengths of inner prefix are stored.
@@ -97,6 +103,7 @@ message Nodes {
     int32 InnerPrefixCnt = 16;
 
 
+
     // NodeTypeBM is a bitmap in which a "1" indicates the i-th node is an inner
     // node, otherwise it is a leaf.
     //

trie/slimtrie_create.go

@@ -36,6 +36,8 @@ type creator struct {
 	bigCnt  int32
 	nodeCnt int32
 
+	withLeaves bool
+
 	// options
 
 	option Opt
@@ -68,14 +70,16 @@ type creator struct {
 	innerBMCnt []map[uint64]int32
 }
 
-func newCreator(n int, opt Opt) *creator {
+func newCreator(n int, withLeaves bool, opt Opt) *creator {
 
 	c := &creator{
 
 		isBig:   true,
 		bigCnt:  0,
 		nodeCnt: 0,
 
+		withLeaves: withLeaves,
+
 		option: opt,
 
 		innerIndexes: make([]int32, 0, n),
@@ -205,7 +209,10 @@ func (c *creator) addLeaf(nid int32, v interface{}) {
 
 	c.nodeCnt++
 
-	c.leaves = append(c.leaves, v)
+	if c.withLeaves {
+		c.leaves = append(c.leaves, v)
+	}
+
 }
 
 // counterElt stores an at most 17 bit bitmap and how many times it is used.
@@ -303,6 +310,7 @@ func (c *creator) build(e encode.Encoder) *SlimTrie {
 		BigInnerCnt:       c.bigCnt,
 		WithPrefixContent: c.option.CompleteInner,
 		WithLeafPrefix:    c.option.CompleteLeaf,
+		WithLeaves:        c.withLeaves,
 	}
 
 	// Mapping most used 17-bit bitmap inner node to short inner node.
@@ -376,7 +384,9 @@ func (c *creator) build(e encode.Encoder) *SlimTrie {
 	}
 
 	// TODO separate leaf init
-	ns.initLeaves(c.leaves, e)
+	if c.withLeaves {
+		ns.initLeaves(c.leaves, e)
+	}
 
 	if c.option.CompleteLeaf {
 		ns.LeafPrefixBM = newBM(c.leafPrefixIndexes, int32(len(c.leaves)), "r64")
@@ -395,11 +405,6 @@ func (c *creator) build(e encode.Encoder) *SlimTrie {
 // TODO filter mode: CompleteInner
 func newSlimTrie(e encode.Encoder, keys []string, values interface{}, opt Opt) (*SlimTrie, error) {
 
-	// filter mode
-	if values == nil {
-		e = encode.Dummy{}
-	}
-
 	n := len(keys)
 	if n == 0 {
 		return &SlimTrie{encoder: e, nodes: &Nodes{}}, nil
@@ -429,7 +434,7 @@ func newSlimTrie(e encode.Encoder, keys []string, values interface{}, opt Opt) (
 	})
 
 	sb := sigbits.New(keys)
-	c := newCreator(n, opt)
+	c := newCreator(n, values != nil, opt)
 
 	queue := make([]subset, 0, n*2)
 	queue = append(queue, subset{0, int32(n), 0})
@@ -442,13 +447,11 @@ func newSlimTrie(e encode.Encoder, keys []string, values interface{}, opt Opt) (
 		// single key, it is a leaf
 		if e-s == 1 {
 			must.Be.True(tokeep[s])
-			var v interface{}
 			if values == nil {
-				v = nil
+				c.addLeaf(nid, nil)
 			} else {
-				v = getV(rvals, int(s))
+				c.addLeaf(nid, getV(rvals, s))
 			}
-			c.addLeaf(nid, v)
 			c.setLeafPrefix(nid, keys[s], o.fromKeyBit)
 			continue
 		}
@@ -579,7 +582,7 @@ func newValueToKeep(keys []string, values interface{}) []bool {
 		prev := getV(rvals, 0)
 
 		for i := 1; i < n; i++ {
-			v := getV(rvals, i)
+			v := getV(rvals, int32(i))
 			tokeep[i] = prev != v
 			prev = v
 		}
@@ -588,11 +591,11 @@ func newValueToKeep(keys []string, values interface{}) []bool {
 	return tokeep
 }
 
-func getV(reflectSlice reflect.Value, i int) interface{} {
+func getV(reflectSlice reflect.Value, i int32) interface{} {
 	if reflectSlice.IsNil() {
 		return nil
 	}
-	return reflectSlice.Index(i).Interface()
+	return reflectSlice.Index(int(i)).Interface()
 }
 
 func (ns *Nodes) initLeaves(elts interface{}, e encode.Encoder) {

trie/slimtrie_marshal.go

@@ -129,7 +129,7 @@ func before000510ToNewChildrenArray(st *SlimTrie, ver string, ch *array.Bitmap16
 		}
 
 		// before 0.5.10 it stores steps only, no prefix
-		c := newCreator(64, Opt{})
+		c := newCreator(64, true, Opt{})
 
 		// before 0.5.10 there is no big inner
 		c.isBig = false

trie/slimtrie_query.go

@@ -562,6 +562,10 @@ func (st *SlimTrie) getLeaf(nodeid int32) interface{} {
 
 func (st *SlimTrie) getIthLeaf(ith int32) interface{} {
 
+	if !st.nodes.WithLeaves {
+		return nil
+	}
+
 	eltsize := st.encoder.GetEncodedSize(nil)
 	stIdx := ith * int32(eltsize)