[rpc blockchain] Add support for mediantime, chainwork to RPC getblock.

blockchain/chain.go

@@ -8,6 +8,7 @@ package blockchain
 import (
 	"container/list"
 	"fmt"
+	"math/big"
 	"sync"
 	"time"
 
@@ -1373,6 +1374,54 @@ func (b *BlockChain) BlockHashByHeight(blockHeight int32) (*chainhash.Hash, erro
 	return &node.hash, nil
 }
 
+// BlockAttributes desribes a Block in relation to others on the main chain.
+type BlockAttributes struct {
+	Height        int32
+	Confirmations int32
+	MedianTime    time.Time
+	ChainWork     *big.Int
+	PrevHash      *chainhash.Hash
+	NextHash      *chainhash.Hash
+}
+
+// BlockAttributesByHash returns BlockAttributes for the block with the given hash
+// relative to other blocks in the main chain. A BestState snapshot describing
+// the main chain is also returned for convenience.
+//
+// This function is safe for concurrent access.
+func (b *BlockChain) BlockAttributesByHash(hash *chainhash.Hash, prevHash *chainhash.Hash) (
+	attrs *BlockAttributes, best *BestState, err error) {
+	best = b.BestSnapshot()
+	node := b.index.LookupNode(hash)
+	if node == nil || !b.bestChain.Contains(node) {
+		str := fmt.Sprintf("block %s is not in the main chain", hash)
+		return nil, best, errNotInMainChain(str)
+	}
+
+	attrs = &BlockAttributes{
+		Height:        node.height,
+		Confirmations: 1 + best.Height - node.height,
+		MedianTime:    node.CalcPastMedianTime(),
+		ChainWork:     node.workSum,
+	}
+
+	// Populate prev block hash if there is one.
+	if node.height > 0 {
+		attrs.PrevHash = prevHash
+	}
+
+	// Populate next block hash if there is one.
+	if node.height < best.Height {
+		nextHash, err := b.BlockHashByHeight(node.height + 1)
+		if err != nil {
+			return nil, best, err
+		}
+		attrs.NextHash = nextHash
+	}
+
+	return attrs, best, nil
+}
+
 // HeightRange returns a range of block hashes for the given start and end
 // heights.  It is inclusive of the start height and exclusive of the end
 // height.  The end height will be limited to the current main chain height.

btcjson/chainsvrresults.go

@@ -77,9 +77,11 @@ type GetBlockVerboseResultBase struct {
 	VersionHex    string  `json:"versionHex"`
 	MerkleRoot    string  `json:"merkleroot"`
 	Time          int64   `json:"time"`
+	MedianTime    int64   `json:"mediantime"`
 	Nonce         uint32  `json:"nonce"`
 	Bits          string  `json:"bits"`
 	Difficulty    float64 `json:"difficulty"`
+	ChainWork     string  `json:"chainwork"`
 	PreviousHash  string  `json:"previousblockhash,omitempty"`
 	NextHash      string  `json:"nextblockhash,omitempty"`
 

rpcserver.go

@@ -1209,31 +1209,23 @@ func handleGetBlock(s *rpcServer, cmd interface{}, closeChan <-chan struct{}) (i
 		return nil, internalRPCError(err.Error(), context)
 	}
 
-	// Get the block height from chain.
-	blockHeight, err := s.cfg.Chain.BlockHeightByHash(hash)
-	if err != nil {
-		context := "Failed to obtain block height"
-		return nil, internalRPCError(err.Error(), context)
-	}
-	blk.SetHeight(blockHeight)
-	best := s.cfg.Chain.BestSnapshot()
-
-	// Get next block hash unless there are none.
-	var nextHashString string
-	if blockHeight < best.Height {
-		nextHash, err := s.cfg.Chain.BlockHashByHeight(blockHeight + 1)
-		if err != nil {
-			context := "No next block"
-			return nil, internalRPCError(err.Error(), context)
-		}
-		nextHashString = nextHash.String()
-	}
-
 	params := s.cfg.ChainParams
 	blockHeader := &blk.MsgBlock().Header
+
+	// Get further details (height, confirmations, nexthash, mediantime, etc.) from chain.
+	attrs, best, err := s.cfg.Chain.BlockAttributesByHash(hash, &blockHeader.PrevBlock)
+	if err != nil {
+		context := "Failed to obtain block details"
+		return nil, internalRPCError(err.Error(), context)
+	}
+
 	var prevHashString string
-	if blockHeight > 0 {
+	if attrs.PrevHash != nil {
-		prevHashString = blockHeader.PrevBlock.String()
+		prevHashString = attrs.PrevHash.String()
+	}
+	var nextHashString string
+	if attrs.NextHash != nil {
+		nextHashString = attrs.NextHash.String()
 	}
 
 	base := btcjson.GetBlockVerboseResultBase{
@@ -1244,13 +1236,15 @@ func handleGetBlock(s *rpcServer, cmd interface{}, closeChan <-chan struct{}) (i
 		PreviousHash:  prevHashString,
 		Nonce:         blockHeader.Nonce,
 		Time:          blockHeader.Timestamp.Unix(),
-		Confirmations: int64(1 + best.Height - blockHeight),
+		MedianTime:    attrs.MedianTime.Unix(),
-		Height:        int64(blockHeight),
+		Confirmations: int64(attrs.Confirmations),
+		Height:        int64(attrs.Height),
 		Size:          int32(len(blkBytes)),
 		StrippedSize:  int32(blk.MsgBlock().SerializeSizeStripped()),
 		Weight:        int32(blockchain.GetBlockWeight(blk)),
 		Bits:          strconv.FormatInt(int64(blockHeader.Bits), 16),
 		Difficulty:    getDifficultyRatio(blockHeader.Bits, params),
+		ChainWork:     attrs.ChainWork.Text(16),
 		NextHash:      nextHashString,
 		ClaimTrie:     blockHeader.ClaimTrie.String(),
 	}
@@ -1275,7 +1269,7 @@ func handleGetBlock(s *rpcServer, cmd interface{}, closeChan <-chan struct{}) (i
 	for i, tx := range txns {
 		rawTxn, err := createTxRawResult(params, tx.MsgTx(),
 			tx.Hash().String(), blockHeader, hash.String(),
-			blockHeight, best.Height)
+			attrs.Height, best.Height)
 		if err != nil {
 			return nil, err
 		}

rpcserverhelp.go

@@ -260,9 +260,11 @@ var helpDescsEnUS = map[string]string{
 	"getblockverboseresult-tx":                "The transaction hashes (only when verbosity=1)",
 	"getblockverboseresult-nTx":               "The number of transactions (aka, count of TX)",
 	"getblockverboseresult-time":              "The block time in seconds since 1 Jan 1970 GMT",
+	"getblockverboseresult-mediantime":        "The median block time in seconds since 1 Jan 1970 GMT",
 	"getblockverboseresult-nonce":             "The block nonce",
 	"getblockverboseresult-bits":              "The bits which represent the block difficulty",
 	"getblockverboseresult-difficulty":        "The proof-of-work difficulty as a multiple of the minimum difficulty",
+	"getblockverboseresult-chainwork":         "Expected number of hashes required to produce the chain up to this block (in hex)",
 	"getblockverboseresult-previousblockhash": "The hash of the previous block",
 	"getblockverboseresult-nextblockhash":     "The hash of the next block (only if there is one)",
 	"getblockverboseresult-strippedsize":      "The size of the block without witness data",