Documentation ¶
Index ¶
- func BasicEquality(a, b graph.Value) bool
- func NextUID() uint64
- func OutputQueryShapeForIterator(it graph.Iterator, ts graph.TripleStore, outputMap map[string]interface{})
- func RunIntOp(a int64, op Operator, b int64) bool
- type And
- func (it *And) AddSubIterator(sub graph.Iterator)
- func (it *And) Clone() graph.Iterator
- func (it *And) Close()
- func (it *And) Contains(val graph.Value) bool
- func (it *And) DebugString(indent int) string
- func (it *And) Next() bool
- func (it *And) NextPath() bool
- func (it *And) Optimize() (graph.Iterator, bool)
- func (it *And) Reset()
- func (it *And) Result() graph.Value
- func (it *And) ResultTree() *graph.ResultTree
- func (it *And) Size() (int64, bool)
- func (it *And) Stats() graph.IteratorStats
- func (it *And) SubIterators() []graph.Iterator
- func (it *And) TagResults(dst map[string]graph.Value)
- func (it *And) Tagger() *graph.Tagger
- func (it *And) Type() graph.Type
- func (it *And) UID() uint64
- type Comparison
- func (it *Comparison) Clone() graph.Iterator
- func (it *Comparison) Close()
- func (it *Comparison) Contains(val graph.Value) bool
- func (it *Comparison) DebugString(indent int) string
- func (it *Comparison) Next() bool
- func (it *Comparison) NextPath() bool
- func (it *Comparison) Optimize() (graph.Iterator, bool)
- func (it *Comparison) Reset()
- func (it *Comparison) Result() graph.Value
- func (it *Comparison) ResultTree() *graph.ResultTree
- func (it *Comparison) Size() (int64, bool)
- func (it *Comparison) Stats() graph.IteratorStats
- func (it *Comparison) SubIterators() []graph.Iterator
- func (it *Comparison) TagResults(dst map[string]graph.Value)
- func (it *Comparison) Tagger() *graph.Tagger
- func (it *Comparison) Type() graph.Type
- func (it *Comparison) UID() uint64
- type Equality
- type Fixed
- func (it *Fixed) Add(v graph.Value)
- func (it *Fixed) Clone() graph.Iterator
- func (it *Fixed) Close()
- func (it *Fixed) Contains(v graph.Value) bool
- func (it *Fixed) DebugString(indent int) string
- func (it *Fixed) Next() bool
- func (it *Fixed) NextPath() bool
- func (it *Fixed) Optimize() (graph.Iterator, bool)
- func (it *Fixed) Reset()
- func (it *Fixed) Result() graph.Value
- func (it *Fixed) ResultTree() *graph.ResultTree
- func (it *Fixed) Size() (int64, bool)
- func (it *Fixed) Stats() graph.IteratorStats
- func (it *Fixed) SubIterators() []graph.Iterator
- func (it *Fixed) TagResults(dst map[string]graph.Value)
- func (it *Fixed) Tagger() *graph.Tagger
- func (it *Fixed) Type() graph.Type
- func (it *Fixed) UID() uint64
- type HasA
- func (it *HasA) Clone() graph.Iterator
- func (it *HasA) Close()
- func (it *HasA) Contains(val graph.Value) bool
- func (it *HasA) DebugString(indent int) string
- func (it *HasA) Direction() quad.Direction
- func (it *HasA) Next() bool
- func (it *HasA) NextContains() bool
- func (it *HasA) NextPath() bool
- func (it *HasA) Optimize() (graph.Iterator, bool)
- func (it *HasA) Reset()
- func (it *HasA) Result() graph.Value
- func (it *HasA) ResultTree() *graph.ResultTree
- func (it *HasA) Size() (int64, bool)
- func (it *HasA) Stats() graph.IteratorStats
- func (it *HasA) SubIterators() []graph.Iterator
- func (it *HasA) TagResults(dst map[string]graph.Value)
- func (it *HasA) Tagger() *graph.Tagger
- func (it *HasA) Type() graph.Type
- func (it *HasA) UID() uint64
- type Int64
- func (it *Int64) Clone() graph.Iterator
- func (it *Int64) Close()
- func (it *Int64) Contains(tsv graph.Value) bool
- func (it *Int64) DebugString(indent int) string
- func (it *Int64) Next() bool
- func (it *Int64) NextPath() bool
- func (it *Int64) Optimize() (graph.Iterator, bool)
- func (it *Int64) Reset()
- func (it *Int64) Result() graph.Value
- func (it *Int64) ResultTree() *graph.ResultTree
- func (it *Int64) Size() (int64, bool)
- func (it *Int64) Stats() graph.IteratorStats
- func (it *Int64) SubIterators() []graph.Iterator
- func (it *Int64) TagResults(dst map[string]graph.Value)
- func (it *Int64) Tagger() *graph.Tagger
- func (it *Int64) Type() graph.Type
- func (it *Int64) UID() uint64
- type Keyer
- type Link
- type LinksTo
- func (it *LinksTo) Clone() graph.Iterator
- func (it *LinksTo) Close()
- func (it *LinksTo) Contains(val graph.Value) bool
- func (it *LinksTo) DebugString(indent int) string
- func (it *LinksTo) Direction() quad.Direction
- func (it *LinksTo) Next() bool
- func (it *LinksTo) NextPath() bool
- func (it *LinksTo) Optimize() (graph.Iterator, bool)
- func (it *LinksTo) Reset()
- func (it *LinksTo) Result() graph.Value
- func (it *LinksTo) ResultTree() *graph.ResultTree
- func (it *LinksTo) Size() (int64, bool)
- func (it *LinksTo) Stats() graph.IteratorStats
- func (it *LinksTo) SubIterators() []graph.Iterator
- func (it *LinksTo) TagResults(dst map[string]graph.Value)
- func (it *LinksTo) Tagger() *graph.Tagger
- func (it *LinksTo) Type() graph.Type
- func (it *LinksTo) UID() uint64
- type Materialize
- func (it *Materialize) Clone() graph.Iterator
- func (it *Materialize) Close()
- func (it *Materialize) Contains(v graph.Value) bool
- func (it *Materialize) DebugString(indent int) string
- func (it *Materialize) Next() bool
- func (it *Materialize) NextPath() bool
- func (it *Materialize) Optimize() (graph.Iterator, bool)
- func (it *Materialize) Reset()
- func (it *Materialize) Result() graph.Value
- func (it *Materialize) ResultTree() *graph.ResultTree
- func (it *Materialize) Size() (int64, bool)
- func (it *Materialize) Stats() graph.IteratorStats
- func (it *Materialize) SubIterators() []graph.Iterator
- func (it *Materialize) TagResults(dst map[string]graph.Value)
- func (it *Materialize) Tagger() *graph.Tagger
- func (it *Materialize) Type() graph.Type
- func (it *Materialize) UID() uint64
- type Node
- type Null
- func (it *Null) Clone() graph.Iterator
- func (it *Null) Close()
- func (it *Null) Contains(graph.Value) bool
- func (it *Null) DebugString(indent int) string
- func (it *Null) Next() bool
- func (it *Null) NextPath() bool
- func (it *Null) Optimize() (graph.Iterator, bool)
- func (it *Null) Reset()
- func (it *Null) Result() graph.Value
- func (it *Null) ResultTree() *graph.ResultTree
- func (it *Null) Size() (int64, bool)
- func (it *Null) Stats() graph.IteratorStats
- func (it *Null) SubIterators() []graph.Iterator
- func (it *Null) TagResults(dst map[string]graph.Value)
- func (it *Null) Tagger() *graph.Tagger
- func (it *Null) Type() graph.Type
- func (it *Null) UID() uint64
- type Operator
- type Optional
- func (it *Optional) Clone() graph.Iterator
- func (it *Optional) Close()
- func (it *Optional) Contains(val graph.Value) bool
- func (it *Optional) DebugString(indent int) string
- func (it *Optional) NextPath() bool
- func (it *Optional) Optimize() (graph.Iterator, bool)
- func (it *Optional) Reset()
- func (it *Optional) Result() graph.Value
- func (it *Optional) ResultTree() *graph.ResultTree
- func (it *Optional) Size() (int64, bool)
- func (it *Optional) Stats() graph.IteratorStats
- func (it *Optional) SubIterators() []graph.Iterator
- func (it *Optional) TagResults(dst map[string]graph.Value)
- func (it *Optional) Tagger() *graph.Tagger
- func (it *Optional) Type() graph.Type
- func (it *Optional) UID() uint64
- type Or
- func (it *Or) AddSubIterator(sub graph.Iterator)
- func (it *Or) Clone() graph.Iterator
- func (it *Or) Close()
- func (it *Or) Contains(val graph.Value) bool
- func (it *Or) DebugString(indent int) string
- func (it *Or) Next() bool
- func (it *Or) NextPath() bool
- func (it *Or) Optimize() (graph.Iterator, bool)
- func (it *Or) Reset()
- func (it *Or) Result() graph.Value
- func (it *Or) ResultTree() *graph.ResultTree
- func (it *Or) Size() (int64, bool)
- func (it *Or) Stats() graph.IteratorStats
- func (it *Or) SubIterators() []graph.Iterator
- func (it *Or) TagResults(dst map[string]graph.Value)
- func (it *Or) Tagger() *graph.Tagger
- func (it *Or) Type() graph.Type
- func (it *Or) UID() uint64
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func BasicEquality ¶
Define an equality function of purely ==, which works for native types.
func OutputQueryShapeForIterator ¶
func OutputQueryShapeForIterator(it graph.Iterator, ts graph.TripleStore, outputMap map[string]interface{})
Types ¶
type And ¶
type And struct {
// contains filtered or unexported fields
}
The And iterator. Consists of a number of subiterators, the primary of which will be Next()ed if next is called.
func (*And) AddSubIterator ¶
Add a subiterator to this And iterator.
The first iterator that is added becomes the primary iterator. This is important. Calling Optimize() is the way to change the order based on subiterator statistics. Without Optimize(), the order added is the order used.
func (*And) Close ¶
func (it *And) Close()
Close this iterator, and, by extension, close the subiterators. Close should be idempotent, and it follows that if it's subiterators follow this contract, the And follows the contract.
func (*And) DebugString ¶
Prints information about this iterator.
func (*And) Next ¶
Returns advances the And iterator. Because the And is the intersection of its subiterators, it must choose one subiterator to produce a candidate, and check this value against the subiterators. A productive choice of primary iterator is therefore very important.
func (*And) NextPath ¶ added in v0.4.0
An And has no NextPath of its own -- that is, there are no other values which satisfy our previous result that are not the result itself. Our subiterators might, however, so just pass the call recursively.
func (*And) Optimize ¶
Optimizes the And, by picking the most efficient way to Next() and Contains() its subiterators. For SQL fans, this is equivalent to JOIN.
func (*And) ResultTree ¶
func (it *And) ResultTree() *graph.ResultTree
DEPRECATED Returns the ResultTree for this iterator, recurses to it's subiterators.
func (*And) Size ¶
Returns the approximate size of the And iterator. Because we're dealing with an intersection, we know that the largest we can be is the size of the smallest iterator. This is the heuristic we shall follow. Better heuristics welcome.
func (*And) Stats ¶
func (it *And) Stats() graph.IteratorStats
and.Stats() lives here in and-iterator-optimize.go because it may in the future return different statistics based on how it is optimized. For now, however, it's pretty static.
func (*And) SubIterators ¶
Returns a slice of the subiterators, in order (primary iterator first).
func (*And) TagResults ¶
An extended TagResults, as it needs to add it's own results and recurse down it's subiterators.
type Comparison ¶
type Comparison struct {
// contains filtered or unexported fields
}
func NewComparison ¶
func NewComparison(sub graph.Iterator, op Operator, val interface{}, ts graph.TripleStore) *Comparison
func (*Comparison) Clone ¶
func (it *Comparison) Clone() graph.Iterator
func (*Comparison) Close ¶
func (it *Comparison) Close()
func (*Comparison) DebugString ¶
func (it *Comparison) DebugString(indent int) string
Prints the value-comparison and its subiterator.
func (*Comparison) Next ¶
func (it *Comparison) Next() bool
func (*Comparison) NextPath ¶ added in v0.4.0
func (it *Comparison) NextPath() bool
func (*Comparison) Optimize ¶
func (it *Comparison) Optimize() (graph.Iterator, bool)
There's nothing to optimize, locally, for a value-comparison iterator. Replace the underlying iterator if need be. potentially replace it.
func (*Comparison) Reset ¶
func (it *Comparison) Reset()
func (*Comparison) Result ¶
func (it *Comparison) Result() graph.Value
func (*Comparison) Size ¶
func (it *Comparison) Size() (int64, bool)
func (*Comparison) Stats ¶
func (it *Comparison) Stats() graph.IteratorStats
We're only as expensive as our subiterator. Again, optimized value comparison iterators should do better.
func (*Comparison) SubIterators ¶
func (it *Comparison) SubIterators() []graph.Iterator
No subiterators.
func (*Comparison) TagResults ¶
func (it *Comparison) TagResults(dst map[string]graph.Value)
If we failed the check, then the subiterator should not contribute to the result set. Otherwise, go ahead and tag it.
func (*Comparison) Tagger ¶
func (it *Comparison) Tagger() *graph.Tagger
func (*Comparison) Type ¶
func (it *Comparison) Type() graph.Type
Registers the value-comparison iterator.
func (*Comparison) UID ¶
func (it *Comparison) UID() uint64
type Fixed ¶
type Fixed struct {
// contains filtered or unexported fields
}
A Fixed iterator consists of it's values, an index (where it is in the process of Next()ing) and an equality function.
func NewFixedIteratorWithCompare ¶
Creates a new Fixed iterator with a custom comparitor.
func (*Fixed) Add ¶
Add a value to the iterator. The array now contains this value. TODO(barakmich): This ought to be a set someday, disallowing repeated values.
func (*Fixed) Contains ¶
Check if the passed value is equal to one of the values stored in the iterator.
func (*Fixed) DebugString ¶
Print some information about the iterator.
func (*Fixed) Optimize ¶
Optimize() for a Fixed iterator is simple. Returns a Null iterator if it's empty (so that other iterators upstream can treat this as null) or there is no optimization.
func (*Fixed) Stats ¶
func (it *Fixed) Stats() graph.IteratorStats
As we right now have to scan the entire list, Next and Contains are linear with the size. However, a better data structure could remove these limits.
type HasA ¶
type HasA struct {
// contains filtered or unexported fields
}
A HasA consists of a reference back to the graph.TripleStore that it references, a primary subiterator, a direction in which the triples for that subiterator point, and a temporary holder for the iterator generated on Contains().
func NewHasA ¶
Construct a new HasA iterator, given the triple subiterator, and the triple direction for which it stands.
func (*HasA) Close ¶
func (it *HasA) Close()
Close the subiterator, the result iterator (if any) and the HasA.
func (*HasA) Contains ¶
Check a value against our internal iterator. In order to do this, we must first open a new iterator of "triples that have `val` in our direction", given to us by the triple store, and then Next() values out of that iterator and Contains() them against our subiterator.
func (*HasA) DebugString ¶
Print some information about this iterator.
func (*HasA) Next ¶
Next advances the iterator. This is simpler than Contains. We have a subiterator we can get a value from, and we can take that resultant triple, pull our direction out of it, and return that.
func (*HasA) NextContains ¶
NextContains() is shared code between Contains() and GetNextResult() -- calls next on the result iterator (a triple iterator based on the last checked value) and returns true if another match is made.
func (*HasA) Optimize ¶
Pass the Optimize() call along to the subiterator. If it becomes Null, then the HasA becomes Null (there are no triples that have any directions).
func (*HasA) ResultTree ¶
func (it *HasA) ResultTree() *graph.ResultTree
DEPRECATED Return results in a ResultTree.
func (*HasA) Stats ¶
func (it *HasA) Stats() graph.IteratorStats
GetStats() returns the statistics on the HasA iterator. This is curious. Next cost is easy, it's an extra call or so on top of the subiterator Next cost. ContainsCost involves going to the graph.TripleStore, iterating out values, and hoping one sticks -- potentially expensive, depending on fanout. Size, however, is potentially smaller. we know at worst it's the size of the subiterator, but if there are many repeated values, it could be much smaller in totality.
func (*HasA) SubIterators ¶
Return our sole subiterator.
func (*HasA) TagResults ¶
Pass the TagResults down the chain.
type Int64 ¶
type Int64 struct {
// contains filtered or unexported fields
}
An All iterator across a range of int64 values, from `max` to `min`.
func (*Int64) Contains ¶
Contains() for an Int64 is merely seeing if the passed value is withing the range, assuming the value is an int64.
func (*Int64) DebugString ¶
Prints the All iterator as just an "all".
func (*Int64) Next ¶
Next() on an Int64 all iterator is a simple incrementing counter. Return the next integer, and mark it as the result.
func (*Int64) Size ¶
The number of elements in an Int64 is the size of the range. The size is exact.
func (*Int64) Stats ¶
func (it *Int64) Stats() graph.IteratorStats
Stats for an Int64 are simple. Super cheap to do any operation, and as big as the range.
func (*Int64) TagResults ¶
Fill the map based on the tags assigned to this iterator.
type Keyer ¶ added in v0.4.0
type Keyer interface {
Key() interface{}
}
Keyer provides a method for comparing types that are not otherwise comparable. The Key method must return a dynamic type that is comparable according to the Go language specification. The returned value must be unique for each receiver value.
type LinksTo ¶
type LinksTo struct {
// contains filtered or unexported fields
}
A LinksTo has a reference back to the graph.TripleStore (to create the iterators for each node) the subiterator, and the direction the iterator comes from. `next_it` is the tempoarary iterator held per result in `primary_it`.
func NewLinksTo ¶
Construct a new LinksTo iterator around a direction and a subiterator of nodes.
func (*LinksTo) Contains ¶
If it checks in the right direction for the subiterator, it is a valid link for the LinksTo.
func (*LinksTo) NextPath ¶ added in v0.4.0
We won't ever have a new result, but our subiterators might.
func (*LinksTo) Stats ¶
func (it *LinksTo) Stats() graph.IteratorStats
Return a guess as to how big or costly it is to next the iterator.
func (*LinksTo) SubIterators ¶
Return a list containing only our subiterator.
func (*LinksTo) TagResults ¶
Tag these results, and our subiterator's results.
type Materialize ¶ added in v0.4.0
type Materialize struct {
// contains filtered or unexported fields
}
func NewMaterialize ¶ added in v0.4.0
func NewMaterialize(sub graph.Iterator) *Materialize
func (*Materialize) Clone ¶ added in v0.4.0
func (it *Materialize) Clone() graph.Iterator
func (*Materialize) Close ¶ added in v0.4.0
func (it *Materialize) Close()
func (*Materialize) DebugString ¶ added in v0.4.0
func (it *Materialize) DebugString(indent int) string
Print some information about the iterator.
func (*Materialize) Next ¶ added in v0.4.0
func (it *Materialize) Next() bool
func (*Materialize) NextPath ¶ added in v0.4.0
func (it *Materialize) NextPath() bool
func (*Materialize) Optimize ¶ added in v0.4.0
func (it *Materialize) Optimize() (graph.Iterator, bool)
func (*Materialize) Reset ¶ added in v0.4.0
func (it *Materialize) Reset()
func (*Materialize) Result ¶ added in v0.4.0
func (it *Materialize) Result() graph.Value
func (*Materialize) ResultTree ¶ added in v0.4.0
func (it *Materialize) ResultTree() *graph.ResultTree
DEPRECATED
func (*Materialize) Size ¶ added in v0.4.0
func (it *Materialize) Size() (int64, bool)
Size is the number of values stored, if we've got them all. Otherwise, guess based on the size of the subiterator.
func (*Materialize) Stats ¶ added in v0.4.0
func (it *Materialize) Stats() graph.IteratorStats
The entire point of Materialize is to amortize the cost by putting it all up front.
func (*Materialize) SubIterators ¶ added in v0.4.0
func (it *Materialize) SubIterators() []graph.Iterator
func (*Materialize) TagResults ¶ added in v0.4.0
func (it *Materialize) TagResults(dst map[string]graph.Value)
func (*Materialize) Tagger ¶ added in v0.4.0
func (it *Materialize) Tagger() *graph.Tagger
func (*Materialize) Type ¶ added in v0.4.0
func (it *Materialize) Type() graph.Type
Register this iterator as a Materialize iterator.
func (*Materialize) UID ¶ added in v0.4.0
func (it *Materialize) UID() uint64
type Null ¶
type Null struct {
// contains filtered or unexported fields
}
Here we define the simplest iterator -- the Null iterator. It contains nothing. It is the empty set. Often times, queries that contain one of these match nothing, so it's important to give it a special iterator.
func (*Null) Optimize ¶
A good iterator will close itself when it returns true. Null has nothing it needs to do.
func (*Null) ResultTree ¶
func (it *Null) ResultTree() *graph.ResultTree
func (*Null) Stats ¶
func (it *Null) Stats() graph.IteratorStats
A null iterator costs nothing. Use it!
func (*Null) SubIterators ¶
func (*Null) TagResults ¶
Fill the map based on the tags assigned to this iterator.
type Optional ¶
type Optional struct {
// contains filtered or unexported fields
}
An optional iterator has the sub-constraint iterator we wish to be optional and whether the last check we received was true or false.
func (*Optional) Contains ¶
Contains() is the real hack of this iterator. It always returns true, regardless of whether the subiterator matched. But we keep track of whether the subiterator matched for results purposes.
func (*Optional) DebugString ¶
Prints the optional and it's subiterator.
func (*Optional) NextPath ¶ added in v0.4.0
An optional iterator only has a next result if, (a) last time we checked we had any results whatsoever, and (b) there was another subresult in our optional subbranch.
func (*Optional) Optimize ¶
There's nothing to optimize for an optional. Optimize the subiterator and potentially replace it.
func (*Optional) Stats ¶
func (it *Optional) Stats() graph.IteratorStats
We're only as expensive as our subiterator. Except, we can't be nexted.
func (*Optional) SubIterators ¶
No subiterators.
func (*Optional) TagResults ¶
If we failed the check, then the subiterator should not contribute to the result set. Otherwise, go ahead and tag it.
type Or ¶
type Or struct {
// contains filtered or unexported fields
}
func NewShortCircuitOr ¶
func NewShortCircuitOr() *Or
func (*Or) AddSubIterator ¶
Add a subiterator to this Or graph.iterator. Order matters.
func (*Or) Close ¶
func (it *Or) Close()
Close this graph.iterator, and, by extension, close the subiterators. Close should be idempotent, and it follows that if it's subiterators follow this contract, the And follows the contract.
func (*Or) DebugString ¶
Prints information about this graph.iterator.
func (*Or) Next ¶
Next advances the Or graph.iterator. Because the Or is the union of its subiterators, it must produce from all subiterators -- unless it it shortcircuiting, in which case, it is the first one that returns anything.
func (*Or) NextPath ¶ added in v0.4.0
An Or has no NextPath of its own -- that is, there are no other values which satisfy our previous result that are not the result itself. Our subiterators might, however, so just pass the call recursively. In the case of shortcircuiting, only allow new results from the currently checked graph.iterator
func (*Or) ResultTree ¶
func (it *Or) ResultTree() *graph.ResultTree
DEPRECATED Returns the ResultTree for this graph.iterator, recurses to it's subiterators.
func (*Or) Size ¶
Returns the approximate size of the Or graph.iterator. Because we're dealing with a union, we know that the largest we can be is the sum of all the iterators, or in the case of short-circuiting, the longest.
func (*Or) Stats ¶
func (it *Or) Stats() graph.IteratorStats
func (*Or) SubIterators ¶
Returns a list.List of the subiterators, in order. The returned slice must not be modified.
func (*Or) TagResults ¶
Overrides BaseIterator TagResults, as it needs to add it's own results and recurse down it's subiterators.