* [NOD-700] Convert blockSet to map[*blockNode]struct{}.
* [NOD-700] Rename bluestNode to bluestBlock in bluest().
* [NOD-700] Make IsInSelectedParentChain not use the now-slower containsHash.
* [NOD-700] Rename block to node in blockset.go.
* [NOD-700] Remove containsHash and hashesEqual.
* [NOD-700] Add a comment to IsInSelectedParentChain about how it'll fail if the given blockHash is not within the block index.
* [NOD-540] Implement reachability (#545)
* [NOD-540] Begin implementing reachability.
* [NOD-540] Finish implementing reachability.
* [NOD-540] Implement TestIsFutureBlock.
* [NOD-540] Implement TestInsertFutureBlock.
* [NOD-540] Add comments.
* [NOD-540] Add comment for interval in blockNode.
* [NOD-540] Updated comments over insertFutureBlock and isFutureBlock.
* [NOD-540] Implement interval splitting methods.
* [NOD-540] Begin implementing tree manipulation in blockNode.
* [NOD-540] Implement countSubtreesUp.
* [NOD-540] Add a comment explaining an impossible condition.
* [NOD-540] Implement applyIntervalDown.
* [NOD-540] Moved the reachability tree stuff into reachability.go.
* [NOD-540] Add some comments.
* [NOD-540] Add more comments, implement isInPast.
* [NOD-540] Fix comments.
* [NOD-540] Implement TestSplitFraction.
* [NOD-540] Implement TestSplitExact.
* [NOD-540] Implement TestSplit.
* [NOD-540] Add comments to structs.
* [NOD-540] Implement TestAddTreeChild.
* [NOD-540] Fix a comment.
* [NOD-540] Rename isInPast to isAncestorOf.
* [NOD-540] Rename futureBlocks to futureCoveringSet.
* [NOD-540] Rename isFutureBlock to isInFuture.
* [NOD-540] move reachabilityInterval to the top of reachability.go.
* [NOD-540] Change "s.t." to "such that" in a comment.
* [NOD-540] Fix indentation.
* [NOD-540] Fix a potential bug involving float inaccuracy.
* [NOD-540] Wrote a more descriptive error message.
* [NOD-540] Fix error messsage.
* [NOD-540] Fix the recursive countSubtreesUp.
* [NOD-540] Rename countSubtreesUp to countSubtrees and applyIntervalDown to propagateInterval.
* [NOD-540] Implement updating reachability for a valid new block.
* [NOD-540] Implement a disk storage for reachability data.
* [NOD-540] Fix not all tree nodes being written to the database.
* [NOD-540] Implement serialization for reachabilityData.
* [NOD-540] Implement some deserialization for reachabilityData.
* [NOD-540] Implement restoring the reachabilityStore on node restart.
* [NOD-540] Made interval and remainingInterval pointers.
* [NOD-540] Rename setTreeInterval to setInterval.
* [NOD-540] Rename reindexTreeIntervals to reindexIntervals and fixed the comment above it.
* [NOD-540] Expand the comment above reindexIntervals.
* [NOD-540] Fix comment above countSubtrees.
* [NOD-540] Fix comment above countSubtrees some more.
* [NOD-540] Fix comment above split.
* [NOD-540] Fix comment above isAncestorOf.
* [NOD-540] Fix comment above reachabilityTreeNode.
* [NOD-540] Fix weird condition in addTreeChild.
* [NOD-540] Rename addTreeChild to addChild.
* [NOD-540] Fix weird condition in splitFraction.
* [NOD-540] Reverse the lines in reachabilityTreeNode.String().
* [NOD-540] Renamed f to fraction and x to size.
* [NOD-540] Fix comment above bisect.
* [NOD-540] Implement rtn.isAncestorOf().
* [NOD-540] Use treeNode isAncestorOf instead of treeInterval isAncestorOf.
* [NOD-540] Use newReachabilityInterval instead of struct initialization.
* [NOD-540] Make reachabilityTreeNode.String() use strings.Join.
* [NOD-540] Use sync.RWMutex instead of locks.PriorityMutex.
* [NOD-540] Rename thisTreeNode to newTreeNode.
* [NOD-540] Rename setTreeNode to addTreeNode.
* [NOD-540] Extracted selectedParentAnticone to a separate function.
* [NOD-540] Rename node to this.
* [NOD-540] Move updateReachability and isAncestorOf from dag.go to reachability.go.
* [NOD-540] Add whitespace after multiline function signatures in reachability.go.
* [NOD-540] Make splitFraction return an error on empty interval.
* [NOD-540] Add a comment about rounding to splitFraction.
* [NOD-540] Replace sneaky tabs with spaces.
* [NOD-540] Rename split to splitExponential.
* [NOD-540] Extract exponentialFractions to a separate function.
* [NOD-540] Rename bisect to findIndex.
* [NOD-540] Add call to reachabilityStore.clearDirtyEntries at the end of saveChangesFromBlock.
* [NOD-540] Explain the dirty hack in reachabilityStore.init().
* [NOD-540] Split the function signature for deserializeReachabilityData to two lines.
* [NOD-540] Add a comment about float precision loss to exponentialFractions.
* [NOD-540] Corrected a comment about float precision loss to exponentialFractions.
* [NOD-540] Fixed a comment about float precision loss to exponentialFractions some more.
* [NOD-540] Added further comments above futureCoveringBlockSet.
* [NOD-540] Rename addTreeNode to setTreeNode.
* [NOD-540] Rename splitExponential to splitWithExponentialBias.
* [NOD-540] Fix object references in reachabilityData deserialization (#563)
* [NOD-540] Fix broken references in deserialization.
* [NOD-540] Fix broken references in futureCoveringSet deserialization. Also add comments.
* [NOD-540] Don't deserialize on the first pass in reachabilityStore.init().
* [NOD-540] Remove redundant assignment to loaded[hash].
* [NOD-540] Use NewHash instead of SetBytes. Rename data to destination.
* [NOD-540] Preallocate futureCoveringSet.
* [NOD-541] Implement GHOSTDAG (#560)
* [NOD-541] Implement GHOSTDAG
* [NOD-541] Replace the old PHANTOM variant with GHOSTDAG
* [NOD-541] Move dag.updateReachability to the top of dag.applyDAGChanges to update reachability before the virtual block is updated
* [NOD-541] Fix blueAnticoneSize
* [NOD-541] Initialize node.bluesAnticoneSizes
* [NOD-541] Fix pastUTXO and applyBlueBlocks blues order
* [NOD-541] Add serialization logic to node.bluesAnticoneSizes
* [NOD-541] Fix GHOSTDAG to not count the new block and the blue candidates anticone, add selected parent to blues, and save to node.bluesAnticoneSizes properly
* [NOD-541] Fix test names in inner strings
* [NOD-541] Writing TestGHOSTDAG
* [NOD-541] In blueAnticoneSize change node->current
* [NOD-541] name ghostdag return values
* [NOD-541] fix ghostdag to return slice
* [NOD-541] Split k-cluster violation rules
* [NOD-541] Add missing space
* [NOD-541] Add comment to ghostdag
* [NOD-541] In selectedParentAnticone rename past->selectedParentPast
* [NOD-541] Fix misrefernces to TestChainUpdates
* [NOD-541] Fix ghostdag comment
* [NOD-541] Make PrepareBlockForTest in blockdag package
* [NOD-541] Make PrepareBlockForTest in blockdag package
* [NOD-541] Assign to selectedParentAnticone[i] instead of appending
* [NOD-541] Remove redundant forceTransactions arguments from PrepareBlockForTEST
* [NOD-541] Add non-selected parents to anticoneHeap
* [NOD-541] add test for ghostdag
* [NOD-541] Add comments
* [NOD-541] Use adjusted time for initializing blockNode
* [NOD-541] Rename isAncestorOf -> isAncestorOfBlueCandidate
* [NOD-541] Remove params from PrepareBlockForTest
* [NOD-541] Fix TestChainHeight
* [NOD-541] Remove recursive lock
* [NOD-541] Fix TestTxIndexConnectBlock
* [NOD-541] Fix TestBlueBlockWindow
* [NOD-541] Put prepareAndProcessBlock in common_test.go
* [NOD-541] Fix TestConfirmations
* [NOD-541] Fix TestAcceptingBlock
* [NOD-541] Fix TestDifficulty
* [NOD-541] Fix TestVirtualBlock
* [NOD-541] Fix TestSelectedPath
* [NOD-541] Fix TestChainUpdates
* [NOD-541] Shorten TestDifficulty test time
* [NOD-541] Make PrepareBlockForTest use minimal valid block time
* [NOD-541] Remove TODO comment
* [NOD-541] Move blockdag related mining functions to mining.go
* [NOD-541] Use NextBlockCoinbaseTransaction instead of NextBlockCoinbaseTransactionNoLock in NextCoinbaseFromAddress
* [NOD-541] Remove useMinimalTime from BlockForMining
* [NOD-541] Make MedianAdjustedTime a *BlockDAG method
* [NOD-541] Fix ghostdag to use anticone slice instead of heap
* [NOD-541] Fix NewBlockTemplate locks
* [NOD-541] Fix ghostdag comments
* [NOD-541] Convert MedianAdjustedTime to NextBlockTime
* [NOD-541] Fix ghostdag comment
* [NOD-541] Fix TestGHOSTDAG comment
* [NOD-541] Add comment before sanity check
* [NOD-541] Explicitly initialize .blues in ghostdag
* [NOD-541] Rename *blockNode.lessThan to *blockNode.less
* [NOD-541] Remove redundant check if block != chainBlock
* [NOD-541] Fix comment
* [NOD-541] Fix comment
* [NOD-497] Add comment; General refactoring
* [NOD-497] General refactoring.
* [NOD-497] Use isAncestor of the tree rather than the node
* [NOD-497] Remove reachability mutex lock as it is redundant (dag lock is held so no need); General refactoring.
* [NOD-497] Update comment
* [NOD-497] Undo test blocktimestamp
* [NOD-497] Update comments; Use BlockNode.less for blockset;
* [NOD-497] Change processBlock to return boolean and not the delay duration (merge conflict)
* [NOD-497] Undo change for bluest to use less; Change blocknode less to use daghash.Less
Co-authored-by: stasatdaglabs <39559713+stasatdaglabs@users.noreply.github.com>
Co-authored-by: Dan Aharoni <dereeno@protonmail.com>
* [NOD-270] Added notifyChainChanges and related commands.
* [NOD-270] Added NTChainChanged to blockdag.
* [NOD-270] Implemented collection and sending of ChainChanged notifications.
* [NOD-270] Fixed an improperly named test.
* [NOD-270] Added a test: TestChainChangedNotification.
* [NOD-270] Fixed a couple copy+paste errors.
* [NOD-270] Added a couple of comments for TestChainChangedNotification.
* [NOD-270] Fixed formatting error.
* [NOD-270] Fixed a comment.
* [NOD-270] Uncoupled chain updates inside blockdag from the concept of a notification.
* [NOD-270] Removed intermediary ChainUpdates object from ChainChangedNotificationData.
* [NOD-269] Added a skeleton for getChainFromBlock.
* [NOD-269] Made startHash and includeBlocks optional.
* [NOD-269] Implemented chainBlock collection.
* [NOD-269] Extracted GetBlockVerboseResult building to its own method.
* [NOD-269] Implemented the IncludeBlocks part of GetChainFromBlock.
* [NOD-269] Added a comment for NewGetChainFromBlockCmd.
* [NOD-269] Made IsInSelectedPathChain return an error.
* [NOD-269] Fixed a very wrong comment.
* [NOD-269] Made SelectedPathChain allocate only the required amount of space.
* [NOD-269] Renamed pathChain to parentChain.
* [NOD-269] Split handleGetChainFromBlock to separate functions.
* [NOD-269] Fixed some grammar.
* [NOD-191] Added selectedPathChainSlice to virtualBlock.
* [NOD-191] Implemented acceptingBlock().
* [NOD-191] Implemented confirmations().
* [NOD-191] Added selectedPathChainSlice tests to TestSelectedPath.
* [NOD-191] Fixed a bug in acceptingBlock(). Written tests for confirmations().
* [NOD-191] Written tests for acceptingBlock().
* [NOD-191] Added test to make sure that acceptingBlock(tip) returns the virtual block.
* [NOD-191] Added a panic if we somehow feed a childless block that isn't the virtual to acceptingBlock.
* [NOD-191] Fixed comments.
* [NOD-191] Fixed a bug in acceptingBlock. Added red block tests for acceptingBlock.
* [NOD-191] Added red block tests for confirmations.
* [NOD-191] Fixed misleading comment and error message.
* [NOD-42] Split checkFinalityRules and newFinalityPoint
* [NOD-42] Rename connectToDAG -> addBlock + move anything that is not actually connecting block to DAG out of connectBlock
* [NOD-42] Extract methods from PastUTXO
* [NOD-42] Give names to outputs in verifyAndBuildUTXO and propagate name
changes up the call tree
* [NOD-42] Split loop that creates UTXODiff and updates acceptance data into 2 separate methods
* [NOD-42] Removed from applyUTXOChanges any validation logic, moved in any logic related to updating the DAG and renamed to applyDAGChanges
* [NOD-42] Rename: CheckTransactionInputs -> CheckTransactionInputsAndCalculateFee
* [NOD-42] Revise some comments
* [NOD-42] Removed finalityErr constant - it's not needed
* Multiple chain -> dag corrections in comments
* [NOD-42] Removed redundant declaration of feeData
* [NOD-42] Reworded some comments
* [NOD-42] Rename MultiblockTxsAcceptanceData -> MultiBlockTxsAcceptanceData
* [DEV-234] add TxAcceptedInBlock and TxBlocks
* [DEV-234] test TxAcceptedInBlock and TxBlocks
* [DEV-234] test TxAcceptedInBlock and TxFirstBlockRegion
* [DEV-234] rename selectedPathSet to selectedPathChain
* [DEV-234] set indexers db as part of index manager initialization
* [DEV-234] remove redudant dag instance in txindex
* [DEV-234] fix TestTxIndexConnectBlock and add DAGParams as part of config in DAGSetup
* [DEV-234] TestTxIndexConnectBlock make K=1 to make calculations easier
* [DEV-234] rename TxAcceptingBlock to BlockThatAcceptedTx
* [DEV-234] update block fields names in txindex_test.go
* [DEV-234] rename selectedPathChain -> selectedPathChainSet
* [DEV-91] add TestAddrIndex
* [DEV-91] add TestFeeEstimator
* [DEV-91] rename TestFeeEstimator -> TestFeeEstimatorCfg
* [DEV-91] added TestCount
* [DEV-91] add TestExtractRejectCode in mempool_test.go
* [DEV-91] get rid of fakeErr type and defer unpatching monkey patch
* [DEV-91] use the result of monkey.patch to unpatch
* [DEV-201] In handleGetBlockDAGInfo calculate difficulty by the tip with the lowest bits
* [DEV-202] Move VirtualBlock.GetUTXOEntry to BlockDAG
* [DEV-203] Move VirtualBlock.SelectedTip() to BlockDAG
* [DEV-203] Move VirtualBlock.SelectedTip() to BlockDAG
* [DEV-204] Unexport VirtualBlock() and add CalcMedianTime method for DAG
* [DEV-204] add explanation about difficulty in CurrentBits() comment
* [DEV-204] unexport VirtualBlock type
* [DEV-169] add to BlockDAG TipHashes() and HighestTipHash() and remove Tiphashes() and SelectedTipHash from VirtualBlock
* [DEV-169] move highest node logic to separate method of blockset
* [DEV-105] use utxodiff in mempool instead of utxoview
* [DEV-105] get rid of utxoview
* [DEV-105] fix tests to use utxoset
* [DEV-105] remove utxoview type
* [DEV-105] move DagSetup to test_utils.go
* [DEV-105] add comments and add blockdag/test_utils_test.go
* [DEV-105] add restoreInputs arg to removeTransaction
* [DEV-105] give more descriptive names to vars
* [DEV-115] close txChan outside of HandleNewBlock
* [DEV-105] rename DagSetup -> DAGSetup
* [DEV-75] Removed fetchEntryByHash, which was no longer used.
* [DEV-75] Removed a few functions in manager.go that weren't used by anything.
* [DEV-75] checkConnectBlock will soon not accept a utxoViewpoint, so removed the call to view.Tip() so that it could be deleted.
* [DEV-75] Got rid of tips in UtxoViewpoint.
* [DEV-75] Added the full UTXO set to the virtual block.
* [DEV-75] Implemented UTXO-wrangling when adding a new block.
* [DEV-75] Added isCoinbase to utxoEntry creation.
* [DEV-75] Added blockHeight to utxoEntry creation.
* Implemented fetching the fullUTXOSet from the database.
* [DEV-75] Simplified DAGState because almost all of the state in it was unnecessary. Also got rid of dbDAGState.
* [DEV-75] Made the process around adding a new block, UTXO-wise, much safer.
* [DEV-75] Implemented melding the virtual UTXO diff to the database.
* [DEV-75] Fixed utxoSet loading from the wrong bucket.
* [DEV-75] Began pruning utxoviewpoint.go. Replaced FetchUtxoEntry with a fullUTXOSet-based GetUTXOEntry.
* [DEV-75] Removed fetchUtxos.
* [DEV-75] Moved GetUTXOEntry into the virtual block.
* [DEV-75] Updated IndexManager to not use utxoViewpoints.
* [DEV-75] Fixed some bad login in restoreUTXO involving nodeDiffs.
* [DEV-75] Got rid of the UTXO spend journal, which wasn't used anywhere.
* [DEV-75] Moved some STXO-related validation logic out of connectToDAG and into checkConnectBlock.
* [DEV-75] Renamed UtxoXxx to UTXOXxx. Removed a bunch of methods that were no longer used by anything.
* [DEV-75] Another Utxo -> UTXO rename.
* [DEV-75] Removed IsModified from UTXOView, which was not used anywhere.
* [DEV-75] Renamed nodeDiff to provisionalNode. Added a bunch of comments.
* [DEV-75] Removed the test for genesis in pastUTXO, since it can never happen.
* [DEV-75] Wrote tests for errors in pastUTXO.
* [DEV-75] Wrote tests for errors in restoreUTXO.
* [DEV-75] Improved testErrorThroughPatching.
* [DEV-75] Wrote tests for errors in verifyAndBuildUTXO.
* [DEV-75] Used TipHashes instead of tips().hashes(), fixed comments in a few places, and brought back an error return that I erroneously removed.
* [DEV-75] Removed UTXO set logs.
* [DEV-75] Recreated add/remove/contains functions for utxoCollection.
* [DEV-75] Changed newUTXOEntry to use an object initializer.
* [DEV-75] Changed the UTXO bucket version to 1.
* Added a comment that clarifies that the index is not initialized before initDAGState is called.
* [DEV-75] Renamed GetVirtualBlock to VirtualBlock.
* [DEV-75] Removed superfluous variables.
* [DEV-75] Combined connectBlockToParents with updateParentsDiffs.
* [DEV-75] Removed another superfluous variable.
* [DEV-75] In pastUTXO, first fetch transactions from the database and only then add them.
* [DEV-75] Reworded the comment for commit().
* [DEV-75] Made all the connectUTXO subfunctions not BlockDAG methods.
* [DEV-75] Updated the comment for connectUTXO.
* [DEV-75] Updated the comment explaining why we're creating provisionalNodes.
* [DEV-75] Removed a couple of unnecessary calls to toProvisionalNode.
* [DEV-75] Renamed connectUTXO to applyUTXOChanges.
* [DEV-75] Replaced allProvisionalNodes with provisionalNodeSet, an object that holds provisionalNodes for this particular call to applyUTXOChanges.
* [DEV-75] Changed createProvisionalNode to accept a boolean "withParents" instead of relying on the caller to supply the node's parents or an empty set.
* [DEV-75] Made most applyUTXOChanges subfunctions be methods on provisionalNode.
* [DEV-75] Fixed a couple of bad comments.
* [DEV-75] Added descriptive error messages to callers of applyUTXOChanges.
* [DEV-75] Fixed weird English.
* [DEV-75] Replaced DAGState with a slice of DAG tip hashes.
* [DEV-75] In createProvisionalNode, changed withParents to withRelatives to avoid certain kinds of attacks.
* [DEV-75] Renamed createdProvisionalNode to newProvisionalNode.
* [DEV-75] Added precalculating the amount of transactions inside a new block's blue set.
* [DEV-75] Pruned unnecessary variable.
* [DEV-74] Implemented and written tests for utxoIterator.
* [DEV-74] Improved utxoIterator tests.
* [DEV-74] Implemented utxoCollection tests.
* [DEV-74] Implemented utxoDiff and its tests.
* [DEV-74] Implemented utxoSet.
* [DEV -74] Added tests for fullUTXOSet.
* [DEV-74] Added some tests for diffUTXOSet.
* [DEV-74] Wrote tests for diffUTXOSet iterator.
* [DEV-74] Added a negative test for diffUTXOSet.withDiff.
* [DEV-74] Wrote tests for addTx.
* [DEV-74] Wrote a toRemove test for addTx.
* [DEV-74] Changed blockNode.utxoDiff to be of type utxoDiff.
* [DEV-74] Removed superfluous whitespace.
* [DEV-74] Renamed confusing "previousHash" to "hash".
* [DEV-74] Fixed bad test and corrected failing test.
* [DEV-74] Moved confusing "negatives" test to be part of the general utxoCollection test.
* [DEV-74] Removed utxoDiff.inverted.
* [DEV-74] Renamed blockNode.utxoDiff to blockNode.diff.
* [DEV-74] Renamed diff to diffFrom for clarity's sake.
* [DEV-74] Converted the type of utxoCollection from map[daghash.Hash]map[uint32]*wire.TxOut to map[wire.OutPoint]*UtxoEntry.
* [DEV-74] Corrected test names in utxoCollection_test.
* [DEV-74] Removed superfluous utxoCollection iterator and moved utxoIterator into utxoset.go.
* [DEV-74] Renamed variables in utxoset.go.
* [DEV-74] Renamed verifyTx to areInputsInUTXO and removed a superfulous test.
* [DEV-74] Fixed bad test logic in TestDiffUTXOSet_addTx.
* [DEV-74] Added a few comments. Added reference-equals checks to clone functions.
* [DEV-74] Moved utxoCollection and utxoDiff into utxoset.go.
* [DEV-74] Wrote explanations for utxoCollection and utxoDiff tests.
* [DEV-74] Wrote explanations for all utxoSet tests besides addTx.
* [DEV-74] Wrote explanations for TestDiffUTXOSet_addTx.
* [DEV-74] Moved the documentation for utxoDiff into utxoset.go.
* [DEV-74] Wrote an explanation on utxoSet.
* [DEV-75] Found a typo.
* [DEV-75] Renamed dag -> virtual, dagView -> virtualBlock.
* [DEV-75] Renamed newDAGView to newVirtualBlock.
* [DEV-75] Moved queries for the genesis block from virtualBlock to BlockDAG.
* [DEV-75] Got rid of chainView height and findFork.
* [DEV-75] Renamed receivers from c to v.
* [DEV-75] Updated initBlockNode to allow for virtual (headerless) nodes, updated dbDAGState to contain multiple tip hashes, implemented virtualBlock.setTips.
* [DEV-75] Got rid of virtualBlock.equals, which was not used anywhere.
* [DEV-75] Got rid of virtualBlock.tip().
* [DEV-75] Got rid of SetTip everywhere except for tests.
* [DEV-75] Got rid of Next().
* [DEV-75] Got rid of Contains().
* [DEV-75] Got rid of HeightRange(), as no one was using it.
* [DEV-75] Made verifyDAG in rpcserver.go not use block height for iteration.
* [DEV-75] Got rid of the part of Manager.Init() that handled "catching up" for side chains, which allowed me to get rid of BlockDAG.BlockByHeight().
* [DEV-75] Dropped support for the RPC command getblockhash since it was getting blocks by their height.
* [DEV-75] Dropped getnetworkhashps since it was reliant on height, fixed another couple of RPC commands to return nextHashes instead of a nextHash, and got rid of nodeByHeight in virtualBlock.
* [DEV-75] Got rid of setTip().
* [DEV-75] Moved blockLocator() out of virtualBlock and into BlockDAG. Also removed TestLocateInventory().
* [DEV-75] Implemented addTip().
* [DEV-75] Cleaned up virtualblock.go a bit.
* [DEV-75] Erased irrelevant tests in virtualblock_test.go. Moved dag-related tests into dag_test.go.
* [DEV-75] Removed unnecessary nil check.
* [DEV-75] Wrote tests for virtualBlock.
* [DEV-75] Fixed bad test, added explanations to tests.
* [DEV-89] Fixed a comment.
* [DEV-89] Fixed another comment.
* [DEV-89] Removed the section in Manager::Init that handled rolling back indexes to the main chain if their tip is an orphaned fork. This could only happen during reorg, which no longer exists. Also removed BlockDAG::MainChainHasBlock, which was no longer used by anyone.
* [DEV-89] Removed the nil check inside initBlockNode() and amended the one place that called it with nil.
* [DEV-89] Renamed the receiver param for BlockDAG from b to dag.
* [DEV-89] Moved fastLog2Floor from dag.go to btcutil/btcmath.go.
* [DEV-89] Renamed tstTip to testTip.
* [DEV-89] Renamed phanom_test.go to phantom_test.go.
* [DEV-89] Fixed comments, renamed mainChainHeight to dagHeight.
* [DEV-89] Rewrote virtualBlock.addTip().
* [DEV-89] Fixed a comment. (chain -> DAG)
* [DEV-89] Fixed another chain -> DAG comment.
