-
Notifications
You must be signed in to change notification settings - Fork 1.5k
/
outputrdf.go
242 lines (223 loc) · 6.34 KB
/
outputrdf.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
/*
* Copyright 2017-2023 Dgraph Labs, Inc. and Contributors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package query
import (
"bytes"
"fmt"
"strconv"
"github.com/pkg/errors"
"github.com/dgraph-io/dgraph/algo"
"github.com/dgraph-io/dgraph/protos/pb"
"github.com/dgraph-io/dgraph/types"
"github.com/dgraph-io/dgraph/x"
)
// rdfBuilder is used to generate RDF from subgraph.
type rdfBuilder struct {
buf *bytes.Buffer
}
// ToRDF converts the given subgraph list into rdf format.
func ToRDF(l *Latency, sgl []*SubGraph) ([]byte, error) {
b := &rdfBuilder{
buf: &bytes.Buffer{},
}
for _, sg := range sgl {
if err := validateSubGraphForRDF(sg); err != nil {
return nil, err
}
// Skip parent graph. we don't want parent values.
for _, child := range sg.Children {
if err := b.castToRDF(child); err != nil {
return nil, err
}
}
}
return b.buf.Bytes(), nil
}
// castToRDF converts the given subgraph to RDF and appends to the
// output string.
func (b *rdfBuilder) castToRDF(sg *SubGraph) error {
if err := validateSubGraphForRDF(sg); err != nil {
return err
}
if sg.SrcUIDs != nil {
// Get RDF for the given subgraph.
if err := b.rdfForSubgraph(sg); err != nil {
return err
}
}
// Recursively cnvert RDF for the children graph.
for _, child := range sg.Children {
if err := b.castToRDF(child); err != nil {
return err
}
}
return nil
}
// rdfForSubgraph generates RDF and appends to the output parameter.
func (b *rdfBuilder) rdfForSubgraph(sg *SubGraph) error {
// handle the case of recurse queries
// Do not generate RDF if all the children of sg null uidMatrix
nonNullChild := false
for _, ch := range sg.Children {
if len(ch.uidMatrix) != 0 {
nonNullChild = true
}
}
if len(sg.Children) > 0 && !nonNullChild {
return nil
}
for i, uid := range sg.SrcUIDs.Uids {
if sg.Params.IgnoreResult {
// Skip ignored values.
continue
}
if sg.IsInternal() {
if sg.Params.Expand != "" {
continue
}
// Check if we have val for the given uid. If you got uid then populate
// the rdf.
val, ok := sg.Params.UidToVal[uid]
if !ok && val.Value == nil {
continue
}
outputval, err := getObjectVal(val)
if err != nil {
continue
}
b.writeRDF(uid, []byte(sg.aggWithVarFieldName()), outputval)
continue
}
switch {
case len(sg.counts) > 0:
// Add count rdf.
b.rdfForCount(uid, sg.counts[i], sg)
case i < len(sg.uidMatrix) && len(sg.uidMatrix[i].Uids) != 0 && len(sg.Children) > 0:
// Add posting list relation.
b.rdfForUIDList(uid, sg.uidMatrix[i], sg)
case i < len(sg.valueMatrix):
b.rdfForValueList(uid, sg.valueMatrix[i], sg.fieldName())
}
}
return nil
}
func (b *rdfBuilder) writeRDF(subject uint64, predicate []byte, object []byte) {
// add subject
x.Check2(b.buf.Write(x.ToHex(subject, true)))
x.Check(b.buf.WriteByte(' '))
// add predicate
b.writeTriple(predicate)
x.Check(b.buf.WriteByte(' '))
// add object
x.Check2(b.buf.Write(object))
x.Check(b.buf.WriteByte(' '))
x.Check(b.buf.WriteByte('.'))
x.Check(b.buf.WriteByte('\n'))
}
func (b *rdfBuilder) writeTriple(val []byte) {
x.Check(b.buf.WriteByte('<'))
x.Check2(b.buf.Write(val))
x.Check(b.buf.WriteByte('>'))
}
// rdfForCount returns rdf for count fucntion.
func (b *rdfBuilder) rdfForCount(subject uint64, count uint32, sg *SubGraph) {
fieldName := sg.Params.Alias
if fieldName == "" {
fieldName = fmt.Sprintf("count(%s)", sg.Attr)
}
b.writeRDF(subject, []byte(fieldName),
quotedNumber([]byte(strconv.FormatUint(uint64(count), 10))))
}
// rdfForUIDList returns rdf for uid list.
func (b *rdfBuilder) rdfForUIDList(subject uint64, list *pb.List, sg *SubGraph) {
for _, destUID := range list.Uids {
if algo.IndexOf(sg.DestUIDs, destUID) < 0 {
// This uid is filtered.
continue
}
// Build object.
b.writeRDF(subject, []byte(sg.fieldName()), x.ToHex(destUID, true))
}
}
// rdfForValueList returns rdf for the value list.
// Ignore RDF's for the attirbute `uid`.
func (b *rdfBuilder) rdfForValueList(subject uint64, valueList *pb.ValueList, attr string) {
for _, destValue := range valueList.Values {
val, err := convertWithBestEffort(destValue, attr)
if err != nil {
continue
}
outputval, err := getObjectVal(val)
if err != nil {
continue
}
b.writeRDF(subject, []byte(attr), outputval)
}
}
func getObjectVal(v types.Val) ([]byte, error) {
outputval, err := valToBytes(v)
if err != nil {
return nil, err
}
switch v.Tid {
case types.UidID:
return buildTriple(outputval), nil
case types.IntID:
return quotedNumber(outputval), nil
case types.FloatID:
return quotedNumber(outputval), nil
case types.GeoID:
return nil, errors.New("Geo id is not supported in rdf output")
default:
return outputval, nil
}
}
func buildTriple(val []byte) []byte {
buf := make([]byte, 0, 2+len(val))
buf = append(buf, '<')
buf = append(buf, val...)
buf = append(buf, '>')
return buf
}
func validateSubGraphForRDF(sg *SubGraph) error {
if sg.IsGroupBy() {
return errors.New("groupby is not supported in rdf output format")
}
uidCount := sg.Attr == "uid" && sg.Params.DoCount && sg.IsInternal()
if uidCount {
return errors.New("uid count is not supported in the rdf output format")
}
if sg.Params.Normalize {
return errors.New("normalize directive is not supported in the rdf output format")
}
if sg.Params.IgnoreReflex {
return errors.New("ignorereflex directive is not supported in the rdf output format")
}
if sg.SrcFunc != nil && sg.SrcFunc.Name == "checkpwd" {
return errors.New("chkpwd function is not supported in the rdf output format")
}
if sg.Params.Facet != nil && !sg.Params.ExpandAll {
return errors.New("facets are not supported in the rdf output format")
}
return nil
}
func quotedNumber(val []byte) []byte {
tmpVal := make([]byte, 0, len(val)+2)
tmpVal = append(tmpVal, '"')
tmpVal = append(tmpVal, val...)
tmpVal = append(tmpVal, '"')
return tmpVal
}