From c8431a63e8b94ac57d506e2af8738b189f578617 Mon Sep 17 00:00:00 2001
From: Pawan Rawal <pawan0201@gmail.com>
Date: Thu, 28 Apr 2016 10:21:40 +0530
Subject: [PATCH] Added helper methods for protocol buffer response.
Parsing and modifying the subgraph returned in the response. Provided helper
methods for the response.
---
client/client.go | 105 ++++++++++++++++++++++++++++++++++++------
client/client_test.go | 70 +++++++++++++++++-----------
2 files changed, 135 insertions(+), 40 deletions(-)
diff --git a/client/client.go b/client/client.go
index 41e7f304..58dfdb32 100644
--- a/client/client.go
+++ b/client/client.go
@@ -18,25 +18,104 @@ package client
import "github.com/dgraph-io/dgraph/query/pb"
-func NumChildren(resp *pb.GraphResponse) int {
- return len(resp.Children)
+type Entity struct {
+ Attribute string
+ values map[string][]byte
+ gr *pb.GraphResponse // Reference to iteratively build the entity
+ uid uint64
+ children []*Entity
}
-func HasValue(resp *pb.GraphResponse) bool {
- for _, val := range resp.Result.Values {
- if len(val) > 0 {
- return true
+// This function performs a binary search on the uids slice and returns the
+// index at which it finds the uid, else returns -1
+func search(uid uint64, uids []uint64) int {
+ low, mid, high := 0, 0, len(uids)-1
+ for low <= high {
+ mid = (low + high) / 2
+ if uids[mid] == uid {
+ return mid
+ } else if uids[mid] > uid {
+ high = mid - 1
+ } else {
+ low = mid + 1
}
}
- return false
+ return -1
}
-func Values(resp *pb.GraphResponse) []string {
- values := []string{}
- for _, val := range resp.Result.Values {
- if len(val) > 0 {
- values = append(values, string(val))
+// This method populates the values and children for an entity
+func (e *Entity) populate() {
+ m := make(map[string][]byte)
+ for _, grChild := range e.gr.Children {
+ // Index of the uid of the parent node in the query uids of the child. This
+ // is used to get the appropriate value or uidlist for the child.
+ // TODO(pawan) - Log error if i == -1
+ i := search(e.uid, grChild.Query.Uids)
+ // This means its a leaf node
+ if len(grChild.Children) == 0 {
+ m[grChild.Attribute] = grChild.Result.Values[i]
+ } else {
+ // An entity would have as many children as the length of UidList for its
+ // child node.
+ for _, uid := range grChild.Result.Uidmatrix[i].Uids {
+ cEntity := new(Entity)
+ cEntity.gr = grChild
+ cEntity.Attribute = grChild.Attribute
+ cEntity.uid = uid
+ e.children = append(e.children, cEntity)
+ }
}
}
- return values
+ e.values = m
+}
+
+// This method is used to initialize the root entity
+func NewEntity(root *pb.GraphResponse) *Entity {
+ e := new(Entity)
+ e.Attribute = root.Attribute
+ e.uid = root.Result.Uidmatrix[0].Uids[0]
+ e.gr = root
+ e.populate()
+ return e
+}
+
+// This method returns the list of properties for an entity.
+func (e *Entity) Properties() []string {
+ properties := make([]string, len(e.values))
+ i := 0
+ for k := range e.values {
+ properties[i] = k
+ i++
+ }
+ return properties
+}
+
+// This method returns whether a property exists for an entity or not.
+func (e *Entity) HasValue(property string) bool {
+ _, ok := e.values[property]
+ return ok
+}
+
+// This method returns the value corresponding to a property if one exists.
+func (e *Entity) Value(property string) []byte {
+ val, _ := e.values[property]
+ return val
+}
+
+// This method populates the children for an entity and returns them.
+func (e *Entity) Children() []*Entity {
+ for _, child := range e.children {
+ // This makes sure that children are populated only once.
+ // TODO(pawan) - Discuss with Manish if it makes sense to have a flag for
+ // this.
+ if len(child.children) == 0 && child.values == nil {
+ child.populate()
+ }
+ }
+ return e.children
+}
+
+// This method returns the number of children for an entity.
+func (e *Entity) NumChildren() int {
+ return len(e.children)
}
diff --git a/client/client_test.go b/client/client_test.go
index 345f62ac..21ab8372 100644
--- a/client/client_test.go
+++ b/client/client_test.go
@@ -142,43 +142,59 @@ func TestQuery(t *testing.T) {
return
}
- if NumChildren(resp) != 4 {
- t.Errorf("Expected 4 children, Got: %v", NumChildren(resp))
+ root := NewEntity(resp)
+
+ if root.Attribute != "_root_" {
+ t.Errorf("Expected attribute _root_, Got: %v", root.Attribute)
}
- if HasValue(resp) {
- t.Errorf("Expected HasValue to return false, Got: true")
+ if len(root.Properties()) != 3 {
+ t.Errorf("Expected 3 properties for entity, Got: %v",
+ len(root.Properties()))
}
-
- child := resp.Children[0]
- if child.Attribute != "name" {
- t.Errorf("Expected attribute name, Got: %v", child.Attribute)
+ if !root.HasValue("name") {
+ t.Errorf("Expected entity to have value for name, Got: false")
+ }
+ if root.HasValue("names") {
+ t.Errorf("Expected entity to not have value for names, Got: true")
}
- if !HasValue(child) {
- t.Errorf("Expected HasValue to return true, Got: false")
+ if string(root.Value("name")) != "Michonne" {
+ t.Errorf("Expected value for name to be Michonne, Got: %v",
+ string(root.Value("name")))
}
- if Values(child)[0] != "Michonne" {
- t.Errorf("Expected Value to return Michonee, Got %v", Values(child)[0])
+ if len(root.Value("names")) != 0 {
+ t.Errorf("Expected values for names to return empty byte slice, Got: len",
+ len(root.Value("names")))
+ }
+ if root.NumChildren() != 5 {
+ t.Errorf("Expected entity to have 5 children, Got: %v", root.NumChildren())
}
- child = resp.Children[3]
- if child.Attribute != "friend" {
- t.Errorf("Expected attribute friend, Got: %v", child.Attribute)
+ child := root.Children()[0]
+ if !child.HasValue("name") {
+ t.Errorf("Expected entity to have value for name, Got: false")
}
- if NumChildren(child) != 1 {
- t.Errorf("Expected 1 child, Got: %v", NumChildren(child))
+ if string(child.Value("name")) != "Rick Grimes" {
+ t.Errorf("Expected child to have name value Rick Grimes, Got: ",
+ string(child.Value("name")))
}
- if HasValue(child) {
- t.Errorf("Expected HasValue to return false, Got: true")
+ child = root.Children()[1]
+ if string(child.Value("name")) != "Glenn Rhee" {
+ t.Errorf("Expected child to have name value Glenn Rhee, Got: ",
+ string(child.Value("name")))
}
-
- child = child.Children[0]
- if child.Attribute != "name" {
- t.Errorf("Expected attribute name, Got: %v", child.Attribute)
+ child = root.Children()[2]
+ if string(child.Value("name")) != "Daryl Dixon" {
+ t.Errorf("Expected child to have name value Daryl Dixon, Got: ",
+ string(child.Value("name")))
}
- if !HasValue(child) {
- t.Errorf("Expected HasValue to return true, Got: false")
+ child = root.Children()[3]
+ if string(child.Value("name")) != "Andrea" {
+ t.Errorf("Expected child to have name value Andrea, Got: ",
+ string(child.Value("name")))
}
- if len(Values(child)) != 4 {
- t.Errorf("Expected 4 Values. Got: %v", len(Values(child)))
+ child = root.Children()[4]
+ if string(child.Value("name")) != "" {
+ t.Errorf("Expected child to have name empty name value, Got: ",
+ string(child.Value("name")))
}
}
--
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