Add Save/SaveReverse and HAS API and split path.go into two files

This commit is contained in:
Barak Michener 2015-06-02 15:27:12 -04:00
parent 34de880945
commit f825fef208
3 changed files with 316 additions and 165 deletions

View file

@ -0,0 +1,262 @@
// 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 path
import (
"github.com/google/cayley/graph"
"github.com/google/cayley/graph/iterator"
"github.com/google/cayley/quad"
)
func isMorphism(nodes ...string) morphism {
return morphism{
Name: "is",
Reversal: func() morphism { return isMorphism(nodes...) },
Apply: func(qs graph.QuadStore, it graph.Iterator) graph.Iterator {
var sub graph.Iterator
if len(nodes) == 0 {
sub = qs.NodesAllIterator()
} else {
fixed := qs.FixedIterator()
for _, n := range nodes {
fixed.Add(qs.ValueOf(n))
}
sub = fixed
}
and := iterator.NewAnd(qs)
and.AddSubIterator(sub)
and.AddSubIterator(it)
return and
},
}
}
func hasMorphism(via interface{}, nodes ...string) morphism {
return morphism{
Name: "has",
Reversal: func() morphism { return hasMorphism(via, nodes...) },
Apply: func(qs graph.QuadStore, it graph.Iterator) graph.Iterator {
var sub graph.Iterator
if len(nodes) == 0 {
sub = qs.NodesAllIterator()
} else {
fixed := qs.FixedIterator()
for _, n := range nodes {
fixed.Add(qs.ValueOf(n))
}
sub = fixed
}
var viaPath *Path
if via != nil {
viaPath = buildViaPath(qs, via)
} else {
viaPath = buildViaPath(qs)
}
subAnd := iterator.NewAnd(qs)
subAnd.AddSubIterator(iterator.NewLinksTo(qs, sub, quad.Object))
subAnd.AddSubIterator(iterator.NewLinksTo(qs, viaPath.BuildIterator(), quad.Predicate))
hasa := iterator.NewHasA(qs, subAnd, quad.Subject)
and := iterator.NewAnd(qs)
and.AddSubIterator(it)
and.AddSubIterator(hasa)
return and
},
}
}
func tagMorphism(tags ...string) morphism {
return morphism{
Name: "tag",
Reversal: func() morphism { return tagMorphism(tags...) },
Apply: func(qs graph.QuadStore, it graph.Iterator) graph.Iterator {
for _, t := range tags {
it.Tagger().Add(t)
}
return it
},
tags: tags,
}
}
func outMorphism(via ...interface{}) morphism {
return morphism{
Name: "out",
Reversal: func() morphism { return inMorphism(via...) },
Apply: func(qs graph.QuadStore, it graph.Iterator) graph.Iterator {
path := buildViaPath(qs, via...)
return inOutIterator(path, it, false)
},
}
}
func inMorphism(via ...interface{}) morphism {
return morphism{
Name: "in",
Reversal: func() morphism { return outMorphism(via...) },
Apply: func(qs graph.QuadStore, it graph.Iterator) graph.Iterator {
path := buildViaPath(qs, via...)
return inOutIterator(path, it, true)
},
}
}
func iteratorMorphism(it graph.Iterator) morphism {
return morphism{
Name: "iterator",
Reversal: func() morphism { return iteratorMorphism(it) },
Apply: func(qs graph.QuadStore, subIt graph.Iterator) graph.Iterator {
and := iterator.NewAnd(qs)
and.AddSubIterator(it)
and.AddSubIterator(subIt)
return and
},
}
}
func andMorphism(p *Path) morphism {
return morphism{
Name: "and",
Reversal: func() morphism { return andMorphism(p) },
Apply: func(qs graph.QuadStore, it graph.Iterator) graph.Iterator {
subIt := p.BuildIteratorOn(qs)
and := iterator.NewAnd(qs)
and.AddSubIterator(it)
and.AddSubIterator(subIt)
return and
},
}
}
func orMorphism(p *Path) morphism {
return morphism{
Name: "or",
Reversal: func() morphism { return orMorphism(p) },
Apply: func(qs graph.QuadStore, it graph.Iterator) graph.Iterator {
subIt := p.BuildIteratorOn(qs)
and := iterator.NewOr()
and.AddSubIterator(it)
and.AddSubIterator(subIt)
return and
},
}
}
func followMorphism(p *Path) morphism {
return morphism{
Name: "follow",
Reversal: func() morphism { return followMorphism(p.Reverse()) },
Apply: func(qs graph.QuadStore, base graph.Iterator) graph.Iterator {
return p.Morphism()(qs, base)
},
}
}
func exceptMorphism(p *Path) morphism {
return morphism{
Name: "except",
Reversal: func() morphism { return exceptMorphism(p) },
Apply: func(qs graph.QuadStore, base graph.Iterator) graph.Iterator {
subIt := p.BuildIteratorOn(qs)
notIt := iterator.NewNot(subIt, qs.NodesAllIterator())
and := iterator.NewAnd(qs)
and.AddSubIterator(base)
and.AddSubIterator(notIt)
return and
},
}
}
func saveMorphism(via interface{}, tag string) morphism {
return morphism{
Name: "save",
Reversal: func() morphism { return saveMorphism(via, tag) },
Apply: func(qs graph.QuadStore, it graph.Iterator) graph.Iterator {
return buildSave(qs, via, tag, it, false)
},
tags: []string{tag},
}
}
func saveReverseMorphism(via interface{}, tag string) morphism {
return morphism{
Name: "saver",
Reversal: func() morphism { return saveReverseMorphism(via, tag) },
Apply: func(qs graph.QuadStore, it graph.Iterator) graph.Iterator {
return buildSave(qs, via, tag, it, true)
},
tags: []string{tag},
}
}
func buildSave(qs graph.QuadStore, via interface{}, tag string, it graph.Iterator, reverse bool) graph.Iterator {
all := qs.NodesAllIterator()
all.Tagger().Add(tag)
node, allDir := quad.Subject, quad.Object
var viaPath *Path
if via != nil {
viaPath = buildViaPath(qs, via)
} else {
viaPath = buildViaPath(qs)
}
if reverse {
node, allDir = allDir, node
}
lto := iterator.NewLinksTo(qs, all, allDir)
subAnd := iterator.NewAnd(qs)
subAnd.AddSubIterator(iterator.NewLinksTo(qs, viaPath.BuildIterator(), quad.Predicate))
subAnd.AddSubIterator(lto)
hasa := iterator.NewHasA(qs, subAnd, node)
and := iterator.NewAnd(qs)
and.AddSubIterator(hasa)
and.AddSubIterator(it)
return and
}
func inOutIterator(viaPath *Path, it graph.Iterator, reverse bool) graph.Iterator {
in, out := quad.Subject, quad.Object
if reverse {
in, out = out, in
}
lto := iterator.NewLinksTo(viaPath.qs, it, in)
and := iterator.NewAnd(viaPath.qs)
and.AddSubIterator(iterator.NewLinksTo(viaPath.qs, viaPath.BuildIterator(), quad.Predicate))
and.AddSubIterator(lto)
return iterator.NewHasA(viaPath.qs, and, out)
}
func buildViaPath(qs graph.QuadStore, via ...interface{}) *Path {
if len(via) == 0 {
return PathFromIterator(qs, qs.NodesAllIterator())
} else if len(via) == 1 {
v := via[0]
switch p := v.(type) {
case *Path:
return p
case string:
return StartPath(qs, p)
default:
panic("Invalid type passed to buildViaPath.")
}
}
var strings []string
for _, s := range via {
if str, ok := s.(string); ok {
strings = append(strings, str)
} else {
panic("Non-string type passed to long Via path")
}
}
return StartPath(qs, strings...)
}