384 lines
11 KiB
Go
384 lines
11 KiB
Go
// Copyright 2014 The Cayley Authors. All rights reserved.
|
|
//
|
|
// 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 gremlin
|
|
|
|
import (
|
|
"strconv"
|
|
|
|
"github.com/barakmich/glog"
|
|
"github.com/robertkrimen/otto"
|
|
|
|
"github.com/google/cayley/graph"
|
|
"github.com/google/cayley/graph/iterator"
|
|
"github.com/google/cayley/quad"
|
|
)
|
|
|
|
func propertiesOf(obj *otto.Object, name string) []string {
|
|
val, _ := obj.Get(name)
|
|
if val.IsUndefined() {
|
|
return nil
|
|
}
|
|
export, _ := val.Export()
|
|
return export.([]string)
|
|
}
|
|
|
|
func buildIteratorTree(obj *otto.Object, ts graph.TripleStore) graph.Iterator {
|
|
if !isVertexChain(obj) {
|
|
return iterator.NewNull()
|
|
}
|
|
return buildIteratorTreeHelper(obj, ts, iterator.NewNull())
|
|
}
|
|
|
|
func stringsFrom(obj *otto.Object) []string {
|
|
var output []string
|
|
lengthValue, _ := obj.Get("length")
|
|
length, _ := lengthValue.ToInteger()
|
|
ulength := uint32(length)
|
|
for i := uint32(0); i < ulength; i++ {
|
|
name := strconv.FormatInt(int64(i), 10)
|
|
value, err := obj.Get(name)
|
|
if err != nil || !value.IsString() {
|
|
continue
|
|
}
|
|
output = append(output, value.String())
|
|
}
|
|
return output
|
|
}
|
|
|
|
func buildIteratorFromValue(val otto.Value, ts graph.TripleStore) graph.Iterator {
|
|
if val.IsNull() || val.IsUndefined() {
|
|
return ts.NodesAllIterator()
|
|
}
|
|
if val.IsPrimitive() {
|
|
thing, _ := val.Export()
|
|
switch v := thing.(type) {
|
|
case string:
|
|
it := ts.FixedIterator()
|
|
it.Add(ts.ValueOf(v))
|
|
return it
|
|
default:
|
|
glog.Errorln("Trying to build unknown primitive value.")
|
|
}
|
|
}
|
|
switch val.Class() {
|
|
case "Object":
|
|
return buildIteratorTree(val.Object(), ts)
|
|
case "Array":
|
|
// Had better be an array of strings
|
|
strings := stringsFrom(val.Object())
|
|
it := ts.FixedIterator()
|
|
for _, x := range strings {
|
|
it.Add(ts.ValueOf(x))
|
|
}
|
|
return it
|
|
case "Number":
|
|
fallthrough
|
|
case "Boolean":
|
|
fallthrough
|
|
case "Date":
|
|
fallthrough
|
|
case "String":
|
|
it := ts.FixedIterator()
|
|
it.Add(ts.ValueOf(val.String()))
|
|
return it
|
|
default:
|
|
glog.Errorln("Trying to handle unsupported Javascript value.")
|
|
return iterator.NewNull()
|
|
}
|
|
}
|
|
|
|
func buildInOutIterator(obj *otto.Object, ts graph.TripleStore, base graph.Iterator, isReverse bool) graph.Iterator {
|
|
argList, _ := obj.Get("_gremlin_values")
|
|
if argList.Class() != "GoArray" {
|
|
glog.Errorln("How is arglist not an array? Return nothing.", argList.Class())
|
|
return iterator.NewNull()
|
|
}
|
|
argArray := argList.Object()
|
|
lengthVal, _ := argArray.Get("length")
|
|
length, _ := lengthVal.ToInteger()
|
|
var predicateNodeIterator graph.Iterator
|
|
if length == 0 {
|
|
predicateNodeIterator = ts.NodesAllIterator()
|
|
} else {
|
|
zero, _ := argArray.Get("0")
|
|
predicateNodeIterator = buildIteratorFromValue(zero, ts)
|
|
}
|
|
if length >= 2 {
|
|
var tags []string
|
|
one, _ := argArray.Get("1")
|
|
if one.IsString() {
|
|
tags = append(tags, one.String())
|
|
} else if one.Class() == "Array" {
|
|
tags = stringsFrom(one.Object())
|
|
}
|
|
for _, tag := range tags {
|
|
predicateNodeIterator.Tagger().Add(tag)
|
|
}
|
|
}
|
|
|
|
in, out := quad.Subject, quad.Object
|
|
if isReverse {
|
|
in, out = out, in
|
|
}
|
|
lto := iterator.NewLinksTo(ts, base, in)
|
|
and := iterator.NewAnd()
|
|
and.AddSubIterator(iterator.NewLinksTo(ts, predicateNodeIterator, quad.Predicate))
|
|
and.AddSubIterator(lto)
|
|
return iterator.NewHasA(ts, and, out)
|
|
}
|
|
|
|
func buildIteratorTreeHelper(obj *otto.Object, ts graph.TripleStore, base graph.Iterator) graph.Iterator {
|
|
var it graph.Iterator = base
|
|
|
|
// TODO: Better error handling
|
|
var subIt graph.Iterator
|
|
if prev, _ := obj.Get("_gremlin_prev"); !prev.IsObject() {
|
|
subIt = base
|
|
} else {
|
|
subIt = buildIteratorTreeHelper(prev.Object(), ts, base)
|
|
}
|
|
|
|
stringArgs := propertiesOf(obj, "string_args")
|
|
val, _ := obj.Get("_gremlin_type")
|
|
switch val.String() {
|
|
case "vertex":
|
|
if len(stringArgs) == 0 {
|
|
it = ts.NodesAllIterator()
|
|
} else {
|
|
fixed := ts.FixedIterator()
|
|
for _, name := range stringArgs {
|
|
fixed.Add(ts.ValueOf(name))
|
|
}
|
|
it = fixed
|
|
}
|
|
case "tag":
|
|
it = subIt
|
|
for _, tag := range stringArgs {
|
|
it.Tagger().Add(tag)
|
|
}
|
|
case "save":
|
|
all := ts.NodesAllIterator()
|
|
if len(stringArgs) > 2 || len(stringArgs) == 0 {
|
|
return iterator.NewNull()
|
|
}
|
|
if len(stringArgs) == 2 {
|
|
all.Tagger().Add(stringArgs[1])
|
|
} else {
|
|
all.Tagger().Add(stringArgs[0])
|
|
}
|
|
predFixed := ts.FixedIterator()
|
|
predFixed.Add(ts.ValueOf(stringArgs[0]))
|
|
subAnd := iterator.NewAnd()
|
|
subAnd.AddSubIterator(iterator.NewLinksTo(ts, predFixed, quad.Predicate))
|
|
subAnd.AddSubIterator(iterator.NewLinksTo(ts, all, quad.Object))
|
|
hasa := iterator.NewHasA(ts, subAnd, quad.Subject)
|
|
and := iterator.NewAnd()
|
|
and.AddSubIterator(hasa)
|
|
and.AddSubIterator(subIt)
|
|
it = and
|
|
case "saver":
|
|
all := ts.NodesAllIterator()
|
|
if len(stringArgs) > 2 || len(stringArgs) == 0 {
|
|
return iterator.NewNull()
|
|
}
|
|
if len(stringArgs) == 2 {
|
|
all.Tagger().Add(stringArgs[1])
|
|
} else {
|
|
all.Tagger().Add(stringArgs[0])
|
|
}
|
|
predFixed := ts.FixedIterator()
|
|
predFixed.Add(ts.ValueOf(stringArgs[0]))
|
|
subAnd := iterator.NewAnd()
|
|
subAnd.AddSubIterator(iterator.NewLinksTo(ts, predFixed, quad.Predicate))
|
|
subAnd.AddSubIterator(iterator.NewLinksTo(ts, all, quad.Subject))
|
|
hasa := iterator.NewHasA(ts, subAnd, quad.Object)
|
|
and := iterator.NewAnd()
|
|
and.AddSubIterator(hasa)
|
|
and.AddSubIterator(subIt)
|
|
it = and
|
|
case "has":
|
|
fixed := ts.FixedIterator()
|
|
if len(stringArgs) < 2 {
|
|
return iterator.NewNull()
|
|
}
|
|
for _, name := range stringArgs[1:] {
|
|
fixed.Add(ts.ValueOf(name))
|
|
}
|
|
predFixed := ts.FixedIterator()
|
|
predFixed.Add(ts.ValueOf(stringArgs[0]))
|
|
subAnd := iterator.NewAnd()
|
|
subAnd.AddSubIterator(iterator.NewLinksTo(ts, predFixed, quad.Predicate))
|
|
subAnd.AddSubIterator(iterator.NewLinksTo(ts, fixed, quad.Object))
|
|
hasa := iterator.NewHasA(ts, subAnd, quad.Subject)
|
|
and := iterator.NewAnd()
|
|
and.AddSubIterator(hasa)
|
|
and.AddSubIterator(subIt)
|
|
it = and
|
|
case "morphism":
|
|
it = base
|
|
case "and":
|
|
arg, _ := obj.Get("_gremlin_values")
|
|
firstArg, _ := arg.Object().Get("0")
|
|
if !isVertexChain(firstArg.Object()) {
|
|
return iterator.NewNull()
|
|
}
|
|
argIt := buildIteratorTree(firstArg.Object(), ts)
|
|
|
|
and := iterator.NewAnd()
|
|
and.AddSubIterator(subIt)
|
|
and.AddSubIterator(argIt)
|
|
it = and
|
|
case "back":
|
|
arg, _ := obj.Get("_gremlin_back_chain")
|
|
argIt := buildIteratorTree(arg.Object(), ts)
|
|
and := iterator.NewAnd()
|
|
and.AddSubIterator(subIt)
|
|
and.AddSubIterator(argIt)
|
|
it = and
|
|
case "is":
|
|
fixed := ts.FixedIterator()
|
|
for _, name := range stringArgs {
|
|
fixed.Add(ts.ValueOf(name))
|
|
}
|
|
and := iterator.NewAnd()
|
|
and.AddSubIterator(fixed)
|
|
and.AddSubIterator(subIt)
|
|
it = and
|
|
case "or":
|
|
arg, _ := obj.Get("_gremlin_values")
|
|
firstArg, _ := arg.Object().Get("0")
|
|
if !isVertexChain(firstArg.Object()) {
|
|
return iterator.NewNull()
|
|
}
|
|
argIt := buildIteratorTree(firstArg.Object(), ts)
|
|
|
|
or := iterator.NewOr()
|
|
or.AddSubIterator(subIt)
|
|
or.AddSubIterator(argIt)
|
|
it = or
|
|
case "both":
|
|
// Hardly the most efficient pattern, but the most general.
|
|
// Worth looking into an Optimize() optimization here.
|
|
clone := subIt.Clone()
|
|
it1 := buildInOutIterator(obj, ts, subIt, false)
|
|
it2 := buildInOutIterator(obj, ts, clone, true)
|
|
|
|
or := iterator.NewOr()
|
|
or.AddSubIterator(it1)
|
|
or.AddSubIterator(it2)
|
|
it = or
|
|
case "out":
|
|
it = buildInOutIterator(obj, ts, subIt, false)
|
|
case "follow":
|
|
// Follow a morphism
|
|
arg, _ := obj.Get("_gremlin_values")
|
|
firstArg, _ := arg.Object().Get("0")
|
|
if isVertexChain(firstArg.Object()) {
|
|
return iterator.NewNull()
|
|
}
|
|
it = buildIteratorTreeHelper(firstArg.Object(), ts, subIt)
|
|
case "followr":
|
|
// Follow a morphism
|
|
arg, _ := obj.Get("_gremlin_followr")
|
|
if isVertexChain(arg.Object()) {
|
|
return iterator.NewNull()
|
|
}
|
|
it = buildIteratorTreeHelper(arg.Object(), ts, subIt)
|
|
case "in":
|
|
it = buildInOutIterator(obj, ts, subIt, true)
|
|
case "not":
|
|
// Not is implemented as the difference between the primary iterator
|
|
// and the iterator chain composed of (primaryIt->Follow->FollowR).
|
|
|
|
// Arguments for follow iterator
|
|
arg, _ := obj.Get("_gremlin_values")
|
|
firstArg, _ := arg.Object().Get("0")
|
|
if isVertexChain(firstArg.Object()) {
|
|
return iterator.NewNull()
|
|
}
|
|
|
|
// Arguments for followR iterator
|
|
revArg, _ := obj.Get("_gremlin_followr")
|
|
if isVertexChain(revArg.Object()) {
|
|
return iterator.NewNull()
|
|
}
|
|
|
|
// Build the primaryIt->Follow iterator
|
|
followIt := buildIteratorTreeHelper(firstArg.Object(), ts, subIt)
|
|
// Build the primaryIt->Follow->FollowR iterator
|
|
forbiddenIt := buildIteratorTreeHelper(revArg.Object(), ts, followIt)
|
|
|
|
it = iterator.NewNot(subIt, forbiddenIt)
|
|
case "loop":
|
|
arg, _ := obj.Get("_gremlin_values")
|
|
firstArg, _ := arg.Object().Get("0")
|
|
secondArg, _ := arg.Object().Get("1")
|
|
thirdArg, _ := arg.Object().Get("2")
|
|
|
|
// Parse the loop iterating sequence
|
|
if isVertexChain(firstArg.Object()) {
|
|
return iterator.NewNull()
|
|
}
|
|
|
|
// Create the loop iterator: first, create an entry point iterator.
|
|
loopEntryIt := iterator.NewEntryPoint(subIt)
|
|
// Then create a loop iterator on top of the entry point.
|
|
loopIt := buildIteratorTreeHelper(firstArg.Object(), ts, loopEntryIt)
|
|
|
|
// Parse the number of loops to execute.
|
|
// bounded=false means it will loop until no more results are produced.
|
|
noLoops := 0
|
|
bounded := false
|
|
if secondArg.IsNumber() {
|
|
if no, err := secondArg.ToInteger(); err == nil {
|
|
noLoops = int(no)
|
|
bounded = true
|
|
} else {
|
|
return iterator.NewNull()
|
|
}
|
|
} else if secondArg.IsBoolean() {
|
|
if boolVal, err := secondArg.ToBoolean(); err == nil && boolVal {
|
|
bounded = false
|
|
} else {
|
|
return iterator.NewNull()
|
|
}
|
|
} else {
|
|
thirdArg = secondArg
|
|
}
|
|
|
|
// If the number of loops is le 0, the loop is unbounded
|
|
if noLoops <= 0 {
|
|
bounded = false
|
|
} else {
|
|
bounded = true
|
|
}
|
|
|
|
// Create the filter iterator
|
|
filterEntryIt := iterator.NewEntryPoint(nil)
|
|
var filterIt graph.Iterator
|
|
if thirdArg.IsNull() || thirdArg.IsUndefined() {
|
|
// There is no filter morphism, use the entry point as a filter.
|
|
filterIt = filterEntryIt
|
|
} else if isVertexChain(thirdArg.Object()) {
|
|
return iterator.NewNull()
|
|
} else {
|
|
// There is a filter morphism, create the filter iterator based on the entry point.
|
|
filterIt = buildIteratorTreeHelper(thirdArg.Object(), ts, filterEntryIt)
|
|
}
|
|
|
|
it = iterator.NewLoop(ts, subIt, loopIt, filterIt, loopEntryIt, filterEntryIt, noLoops, bounded)
|
|
}
|
|
return it
|
|
}
|