support merklebtree

[bradyjoestar]

#8

Why not use google/btree

The structure of node in google/btree doesn't have parent pointer

https://github.com/google/btree/blob/be84af90a1f71c9eeac820a4cdacb863122396d6/btree.go#L244-L248

type node struct { 
 	items    items 
 	children children 
 	cow      *copyOnWriteContext 
 } 

google/btree use copyOnWriteContext whick will make it difficlut.

emirpasic/gods/btree

So I use emirpasic/gods/btree and modify the

// Node is a single element within the tree
type Node struct {
	Parent   *Node
	Entries  []*Entry // Contained keys in node
	Children []*Node  // Children nodes
}

// Entry represents the key-value pair contained within nodes
type Entry struct {
	Key   interface{}
	Value interface{}
}

to

// Node is a single element within the tree
type Node struct {
	Parent   *Node
	Contents []*Content // Contained keys in node
	Children []*Node    // Children nodes
}

type Content interface {
	// Less tests whether the current item is less than the given argument.

	// If a.Comparator(b) return
	// negative , if a < b
	// zero     , if a == b
	// positive , if a > b
	Comparator(than Content) int
}

testcase

=== RUN   TestBTreeGet1
--- PASS: TestBTreeGet1 (0.00s)
=== RUN   TestBTreeGet2
--- PASS: TestBTreeGet2 (0.00s)
=== RUN   TestBTreePut1
--- PASS: TestBTreePut1 (0.00s)
=== RUN   TestBTreePut2
--- PASS: TestBTreePut2 (0.00s)
=== RUN   TestBTreePut3
--- PASS: TestBTreePut3 (0.00s)
=== RUN   TestBTreePut4
--- PASS: TestBTreePut4 (0.00s)
=== RUN   TestBTreeRemove1
--- PASS: TestBTreeRemove1 (0.00s)
=== RUN   TestBTreeRemove2
--- PASS: TestBTreeRemove2 (0.00s)
=== RUN   TestBTreeRemove3
--- PASS: TestBTreeRemove3 (0.00s)
=== RUN   TestBTreeRemove4
--- PASS: TestBTreeRemove4 (0.00s)
=== RUN   TestBTreeRemove5
--- PASS: TestBTreeRemove5 (0.00s)
=== RUN   TestBTreeRemove6
--- PASS: TestBTreeRemove6 (0.00s)
=== RUN   TestBTreeRemove7
--- PASS: TestBTreeRemove7 (0.00s)
=== RUN   TestBTreeRemove8
--- PASS: TestBTreeRemove8 (0.00s)
=== RUN   TestBTreeRemove9
--- PASS: TestBTreeRemove9 (0.05s)
=== RUN   TestBTreeHeight
--- PASS: TestBTreeHeight (0.00s)
=== RUN   TestBTreeLeftAndRight
--- PASS: TestBTreeLeftAndRight (0.00s)
=== RUN   TestBTreeIteratorValuesAndKeys
--- PASS: TestBTreeIteratorValuesAndKeys (0.00s)
=== RUN   TestBTreeIteratorNextOnEmpty
--- PASS: TestBTreeIteratorNextOnEmpty (0.00s)
=== RUN   TestBTreeIteratorPrevOnEmpty
--- PASS: TestBTreeIteratorPrevOnEmpty (0.00s)
=== RUN   TestBTreeIterator1Next
--- PASS: TestBTreeIterator1Next (0.00s)
=== RUN   TestBTreeIterator1Prev
--- PASS: TestBTreeIterator1Prev (0.00s)
=== RUN   TestBTreeIterator2Next
--- PASS: TestBTreeIterator2Next (0.00s)
=== RUN   TestBTreeIterator2Prev
--- PASS: TestBTreeIterator2Prev (0.00s)
=== RUN   TestBTreeIterator3Next
--- PASS: TestBTreeIterator3Next (0.00s)
=== RUN   TestBTreeIterator3Prev
--- PASS: TestBTreeIterator3Prev (0.00s)
=== RUN   TestBTreeIterator4Next
--- PASS: TestBTreeIterator4Next (0.00s)
=== RUN   TestBTreeIterator4Prev
--- PASS: TestBTreeIterator4Prev (0.00s)
=== RUN   TestBTreeIteratorBegin
--- PASS: TestBTreeIteratorBegin (0.00s)
=== RUN   TestBTreeIteratorEnd
--- PASS: TestBTreeIteratorEnd (0.00s)
=== RUN   TestBTreeIteratorFirst
--- PASS: TestBTreeIteratorFirst (0.00s)
=== RUN   TestBTreeIteratorLast
--- PASS: TestBTreeIteratorLast (0.00s)
=== RUN   TestBTree_search
--- PASS: TestBTree_search (0.00s)
PASS
coverage: 94.2% of statements in ../../merkletree/...

[bradyjoestar]

Completed! Thanks for your review!
@cbergoon

Testcase coverage

=== RUN   TestBTreeGet1
--- PASS: TestBTreeGet1 (0.00s)
=== RUN   TestBTreeGet2
--- PASS: TestBTreeGet2 (0.00s)
=== RUN   TestBTreePut1
--- PASS: TestBTreePut1 (0.00s)
=== RUN   TestBTreePut2
--- PASS: TestBTreePut2 (0.00s)
=== RUN   TestBTreePut3
--- PASS: TestBTreePut3 (0.00s)
=== RUN   TestBTreePut4
--- PASS: TestBTreePut4 (0.00s)
=== RUN   TestBTreeRemove1
--- PASS: TestBTreeRemove1 (0.00s)
=== RUN   TestBTreeRemove2
--- PASS: TestBTreeRemove2 (0.00s)
=== RUN   TestBTreeRemove3
--- PASS: TestBTreeRemove3 (0.00s)
=== RUN   TestBTreeRemove4
--- PASS: TestBTreeRemove4 (0.00s)
=== RUN   TestBTreeRemove5
--- PASS: TestBTreeRemove5 (0.00s)
=== RUN   TestBTreeRemove6
--- PASS: TestBTreeRemove6 (0.00s)
=== RUN   TestBTreeRemove7
--- PASS: TestBTreeRemove7 (0.00s)
=== RUN   TestBTreeRemove8
--- PASS: TestBTreeRemove8 (0.00s)
=== RUN   TestBTreeRemove9
--- PASS: TestBTreeRemove9 (5.01s)
=== RUN   TestBTreeHeight
--- PASS: TestBTreeHeight (0.00s)
=== RUN   TestBTreeLeftAndRight
--- PASS: TestBTreeLeftAndRight (0.00s)
=== RUN   TestBTreeIteratorValuesAndKeys
--- PASS: TestBTreeIteratorValuesAndKeys (0.00s)
=== RUN   TestBTreeIteratorNextOnEmpty
--- PASS: TestBTreeIteratorNextOnEmpty (0.00s)
=== RUN   TestBTreeIteratorPrevOnEmpty
--- PASS: TestBTreeIteratorPrevOnEmpty (0.00s)
=== RUN   TestBTreeIterator1Next
--- PASS: TestBTreeIterator1Next (0.00s)
=== RUN   TestBTreeIterator1Prev
--- PASS: TestBTreeIterator1Prev (0.00s)
=== RUN   TestBTreeIterator2Next
--- PASS: TestBTreeIterator2Next (0.00s)
=== RUN   TestBTreeIterator2Prev
--- PASS: TestBTreeIterator2Prev (0.00s)
=== RUN   TestBTreeIterator3Next
--- PASS: TestBTreeIterator3Next (0.00s)
=== RUN   TestBTreeIterator3Prev
--- PASS: TestBTreeIterator3Prev (0.00s)
=== RUN   TestBTreeIterator4Next
--- PASS: TestBTreeIterator4Next (0.00s)
=== RUN   TestBTreeIterator4Prev
--- PASS: TestBTreeIterator4Prev (0.00s)
=== RUN   TestBTreeIteratorBegin
--- PASS: TestBTreeIteratorBegin (0.00s)
=== RUN   TestBTreeIteratorEnd
--- PASS: TestBTreeIteratorEnd (0.00s)
=== RUN   TestBTreeIteratorFirst
--- PASS: TestBTreeIteratorFirst (0.00s)
=== RUN   TestBTreeIteratorLast
--- PASS: TestBTreeIteratorLast (0.00s)
=== RUN   TestBTree_search
--- PASS: TestBTree_search (0.00s)
=== RUN   TestMBTreePut1
--- PASS: TestMBTreePut1 (0.00s)
=== RUN   TestMBTreePut2
--- PASS: TestMBTreePut2 (11.60s)
=== RUN   TestMBTreeRemove1
--- PASS: TestMBTreeRemove1 (0.00s)
PASS
coverage: 94.5% of statements in ../../merkletree/...
ok  	github.com/bradyjoestar/merkletree/merklebtree	16.605s	coverage: 94.5% of statements in ../../merkletree/...

webb.shi