Documentation
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Index ¶
Constants ¶
const StubNodeIndex = 0
Variables ¶
This section is empty.
Functions ¶
func StackSequenceUnused ¶
func UnbalancedBitCount ¶
Returns a level at which the unbalanced node will connect to the rightmost branch. It trims from left all consequent 1's starting from (bitCount) and returns a number of remaining bits. Doesn't panic, but result is meaningless when (maxPairLevel) is not in [0, 64] or (index) >= 1<<(maxPairLevel)
Types ¶
type ForkingCalculator ¶
type ForkingCalculator struct {
StackedCalculator
}
func NewForkingCalculator ¶
func NewForkingCalculator(digester cryptkit.PairDigester, unbalancedStub cryptkit.Digest) ForkingCalculator
func (*ForkingCalculator) ForkCalculator ¶
func (p *ForkingCalculator) ForkCalculator() ForkingCalculator
func (*ForkingCalculator) ForkSequence ¶
func (p *ForkingCalculator) ForkSequence() cryptkit.ForkingDigester
type PathBuilder ¶
type PathBuilder struct {
// contains filtered or unexported fields
}
func NewPathBuilder ¶
func NewPathBuilder(leafCount uint, stubbed bool) PathBuilder
func (PathBuilder) WalkFor ¶
func (v PathBuilder) WalkFor(index uint, nodeFn PathEntryFunc)
For the given (index) WalkFor will call (nodeFn) for each level of tree that has to be included into a merkle-proof, starting from leafs. The (nodeFn) is called with a relevant index of a hash value in the merkler log, and with flags about the value - leaf-or-node and right-or-left.
NB! When stub is used, then (nodeFn) is called as (StubNodeIndex, false, _) as StackCalculator can't produce a node value at index StubNodeIndex. NB! The (nodeFn) is not called for the requested leaf itself.
type PathEntryFunc ¶
Is called in a sequence of merkle-proof items, starting from leafs. (index) is an index of a relevant entry of StackCalculator hashing log. (isLeaf) indicates is this should be a leaf value or a node value. (isRight) indicates position of this entry for a hashing operation. Either left or right.
NB! Leaf index is [0, leafCount-1], node index is [1, leafCount+N], node index = 0 means stub value.
type StackedCalculator ¶
type StackedCalculator struct {
// contains filtered or unexported fields
}
A calculator to do streaming calculation of Merkle-tree by using provided PairDigester. The resulting merkle will have same depth for all branches except for the rightmost branch.
When unbalancedStub == nil, then FinishSequence() will create the rightmost branch by recursively applying the same rule - all sub-branches will have same depth except for the rightmost sub-branch.
When unbalancedStub != nil, then FinishSequence() will create a perfect tree by using unbalancedStub once per level when a value for the rightmost sub-branch is missing.
When AddNext() was never called then FinishSequence() will return a non-nil unbalancedStub otherwise will panic.
Complexity (n - a number of added hashes):
- AddNext() is O(1), it does only upto 2 calls to PairDigester.DigestPair()
- FinishSequence() is O(log n), it does k*log(n) calls to PairDigester.DigestPair() where k ~ 1 when unbalancedStub == nil and k ~ 2 otherwise
- ForkSequence() is O(log n), but only copies memory
- Memory is O(log n)
func NewStackedCalculator ¶
func NewStackedCalculator(digester cryptkit.PairDigester, unbalancedStub cryptkit.Digest, traceFn TraceFunc) StackedCalculator
Creates a sequence digester that does merkle tree calculation. When (unbalancedStub) is empty, then the resulting merkle-tree will be closed without stubbing, otherwise with per-level stubbing with (unbalancedStub) on the right side. When (traceFn) is not nil, then StackedCalculator will call it each time when a leaf or node is added.
NB! For every AddNext() call the (traceFn) is always called twice - first time with (leafX, true) value, and then (nodeX, false), where nodeX can be nil. And during FinishSequence() - the (traceFn) can be called N < 2*log(leafCount) times with (nodeX, false), where nodeX can not be nil.
func (*StackedCalculator) AddNext ¶
func (p *StackedCalculator) AddNext(addDigest longbits.FoldableReader)
func (*StackedCalculator) Count ¶
func (p *StackedCalculator) Count() int
func (*StackedCalculator) FinishSequence ¶
func (p *StackedCalculator) FinishSequence() cryptkit.Digest
func (*StackedCalculator) GetDigestMethod ¶
func (p *StackedCalculator) GetDigestMethod() cryptkit.DigestMethod
func (*StackedCalculator) GetDigestSize ¶
func (p *StackedCalculator) GetDigestSize() int
type TraceFunc ¶
type TraceFunc func(v longbits.FoldableReader, isLeaf bool)
Source Files