github.com/cayleygraph/cayley@v0.7.7/graph/iterator/and_optimize_test.go (about)

     1  // Copyright 2014 The Cayley Authors. All rights reserved.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package iterator_test
    16  
    17  // Tests relating to methods in and-iterator-optimize. Many are pretty simplistic, but
    18  // nonetheless cover a lot of basic cases.
    19  
    20  import (
    21  	"testing"
    22  
    23  	. "github.com/cayleygraph/cayley/graph/iterator"
    24  )
    25  
    26  func TestNullIteratorAnd(t *testing.T) {
    27  	all := newInt64(1, 3, true)
    28  	null := NewNull()
    29  	a := NewAnd(all, null)
    30  	newIt, changed := a.Optimize()
    31  	if !changed {
    32  		t.Error("Didn't change")
    33  	}
    34  	if _, ok := newIt.(*Null); !ok {
    35  		t.Errorf("Expected null iterator, got %T", newIt)
    36  	}
    37  }
    38  
    39  func TestReorderWithTag(t *testing.T) {
    40  	all := NewFixed(Int64Node(3))
    41  	all2 := NewFixed(
    42  		Int64Node(3),
    43  		Int64Node(4),
    44  		Int64Node(5),
    45  		Int64Node(6),
    46  	)
    47  	a := NewAnd()
    48  	// Make all2 the default iterator
    49  	a.AddSubIterator(all2)
    50  	a.AddSubIterator(all)
    51  
    52  	newIt, changed := a.Optimize()
    53  	if !changed {
    54  		t.Error("Expected new iterator")
    55  	}
    56  	newIt.Close()
    57  }
    58  
    59  func TestAndStatistics(t *testing.T) {
    60  	all := newInt64(100, 300, true)
    61  	all2 := newInt64(1, 30000, true)
    62  	a := NewAnd()
    63  	// Make all2 the default iterator
    64  	a.AddSubIterator(all2)
    65  	a.AddSubIterator(all)
    66  	stats1 := a.Stats()
    67  	newIt, changed := a.Optimize()
    68  	if !changed {
    69  		t.Error("Didn't optimize")
    70  	}
    71  	stats2 := newIt.Stats()
    72  	if stats2.NextCost > stats1.NextCost {
    73  		t.Error("And didn't optimize. Next cost old ", stats1.NextCost, "and new ", stats2.NextCost)
    74  	}
    75  }