multi: Add getblockchaininfo rpc.

blockchain/chain.go

@@ -8,6 +8,7 @@ package blockchain
 import (
 	"container/list"
 	"fmt"
+	"math/big"
 	"sync"
 	"time"
 
@@ -295,12 +296,16 @@ func (b *BlockChain) GetStakeVersions(hash *chainhash.Hash, count int32) ([]Stak
 	return result, nil
 }
 
+// VoteInfo represents information on agendas and their respective states for
+// a consensus deployment.
 type VoteInfo struct {
 	Agendas      []chaincfg.ConsensusDeployment
 	AgendaStatus []ThresholdStateTuple
 }
 
-// GetVoteInfo returns
+// GetVoteInfo returns information on consensus deployment agendas
+// and their respective states at the provided hash, for the provided
+// deployment version.
 func (b *BlockChain) GetVoteInfo(hash *chainhash.Hash, version uint32) (*VoteInfo, error) {
 	deployments, ok := b.chainParams.Deployments[version]
 	if !ok {
@@ -368,6 +373,17 @@ func (b *BlockChain) HaveBlock(hash *chainhash.Hash) (bool, error) {
 	return b.index.HaveBlock(hash) || b.IsKnownOrphan(hash), nil
 }
 
+// ChainWork returns the total work up to and including the block of the
+// provided block hash.
+func (b *BlockChain) ChainWork(hash *chainhash.Hash) (*big.Int, error) {
+	node := b.index.LookupNode(hash)
+	if node == nil {
+		return nil, fmt.Errorf("block %s is not known", hash)
+	}
+
+	return node.workSum, nil
+}
+
 // IsKnownOrphan returns whether the passed hash is currently a known orphan.
 // Keep in mind that only a limited number of orphans are held onto for a
 // limited amount of time, so this function must not be used as an absolute

blockchain/thresholdstate.go

@@ -80,7 +80,7 @@ type ThresholdStateTuple struct {
 	// state contains the current ThresholdState.
 	State ThresholdState
 
-	// coice is set to invalidChoice unless state is: ThresholdLockedIn,
+	// Choice is set to invalidChoice unless state is: ThresholdLockedIn,
 	// ThresholdFailed & ThresholdActive.  choice should always be
 	// crosschecked with invalidChoice.
 	Choice uint32
@@ -465,6 +465,108 @@ func (b *BlockChain) deploymentState(prevNode *blockNode, version uint32, deploy
 	return invalidState, DeploymentError(deploymentID)
 }
 
+// stateLastChanged returns the node at which the provided consensus deployment
+// agenda last changed state.  The function will return nil if the state has
+// never changed.
+//
+// This function MUST be called with the chain state lock held (for writes).
+func (b *BlockChain) stateLastChanged(version uint32, node *blockNode, checker thresholdConditionChecker, cache *thresholdStateCache) (*blockNode, error) {
+	// No state changes are possible if the chain is not yet past stake
+	// validation height and had a full interval to change.
+	confirmationInterval := int64(checker.RuleChangeActivationInterval())
+	svh := checker.StakeValidationHeight()
+	if node == nil || node.height < svh+confirmationInterval {
+		return nil, nil
+	}
+
+	// Determine the current state.  Notice that thresholdState always
+	// calculates the state for the block after the provided one, so use the
+	// parent to get the state for the requested block.
+	curState, err := b.thresholdState(version, node.parent, checker, cache)
+	if err != nil {
+		return nil, err
+	}
+
+	// Determine the first block of the current confirmation interval in order
+	// to determine block at which the state possibly changed.  Since the state
+	// can only change at an interval boundary, loop backwards one interval at
+	// a time to determine when (and if) the state changed.
+	finalNodeHeight := calcWantHeight(svh, confirmationInterval, node.height)
+	node = node.Ancestor(finalNodeHeight + 1)
+	priorStateChangeNode := node
+	for node != nil && node.parent != nil {
+		// As previously mentioned, thresholdState always calculates the state
+		// for the block after the provided one, so use the parent to get the
+		// state of the block itself.
+		state, err := b.thresholdState(version, node.parent, checker, cache)
+		if err != nil {
+			return nil, err
+		}
+
+		if state.State != curState.State {
+			return priorStateChangeNode, nil
+		}
+
+		// Get the ancestor that is the first block of the previous confirmation
+		// interval.
+		priorStateChangeNode = node
+		node = node.RelativeAncestor(confirmationInterval)
+	}
+
+	return nil, nil
+}
+
+// StateLastChangedHeight returns the height at which the provided consensus
+// deployment agenda last changed state.  Note that, unlike the ThresholdState
+// function, this function returns the information as of the passed block hash.
+//
+// This function is safe for concurrent access.
+func (b *BlockChain) StateLastChangedHeight(hash *chainhash.Hash, version uint32, deploymentID string) (int64, error) {
+	// NOTE: The requirement for the node being fully validated here is strictly
+	// stronger than what is actually required.  In reality, all that is needed
+	// is for the block data for the node and all of its ancestors to be
+	// available, but there is not currently any tracking to be able to
+	// efficiently determine that state.
+	node := b.index.LookupNode(hash)
+	if node == nil || !b.index.NodeStatus(node).KnownValid() {
+		return 0, HashError(hash.String())
+	}
+
+	// Fetch the treshold state cache for the provided deployment id as well as
+	// the condition checker.
+	var cache *thresholdStateCache
+	var checker thresholdConditionChecker
+	for k := range b.chainParams.Deployments[version] {
+		if b.chainParams.Deployments[version][k].Vote.Id == deploymentID {
+			checker = deploymentChecker{
+				deployment: &b.chainParams.Deployments[version][k],
+				chain:      b,
+			}
+			cache = &b.deploymentCaches[version][k]
+			break
+		}
+	}
+
+	if cache == nil {
+		return 0, fmt.Errorf("threshold state cache for agenda with "+
+			"deployment id (%s) not found", deploymentID)
+	}
+
+	// Find the node at which the current state changed.
+	b.chainLock.Lock()
+	stateNode, err := b.stateLastChanged(version, node, checker, cache)
+	b.chainLock.Unlock()
+	if err != nil {
+		return 0, err
+	}
+
+	var height int64
+	if stateNode != nil {
+		height = stateNode.height
+	}
+	return height, nil
+}
+
 // ThresholdState returns the current rule change threshold state of the given
 // deployment ID for the block AFTER the provided block hash.
 //

blockmanager.go

@@ -334,6 +334,11 @@ type blockManager struct {
 	// The following fields are used to filter duplicate block announcements.
 	announcedBlockMtx sync.Mutex
 	announcedBlock    *chainhash.Hash
+
+	// The following fields are used to track the height being synced to from
+	// peers.
+	syncHeightMtx sync.Mutex
+	syncHeight    int64
 }
 
 // resetHeaderState sets the headers-first mode state to values appropriate for
@@ -352,6 +357,13 @@ func (b *blockManager) resetHeaderState(newestHash *chainhash.Hash, newestHeight
 	}
 }
 
+// SyncHeight returns latest known block being synced to.
+func (b *blockManager) SyncHeight() int64 {
+	b.syncHeightMtx.Lock()
+	defer b.syncHeightMtx.Unlock()
+	return b.syncHeight
+}
+
 // findNextHeaderCheckpoint returns the next checkpoint after the passed height.
 // It returns nil when there is not one either because the height is already
 // later than the final checkpoint or some other reason such as disabled
@@ -479,6 +491,9 @@ func (b *blockManager) startSync(peers *list.List) {
 			}
 		}
 		b.syncPeer = bestPeer
+		b.syncHeightMtx.Lock()
+		b.syncHeight = bestPeer.LastBlock()
+		b.syncHeightMtx.Unlock()
 	} else {
 		bmgrLog.Warnf("No sync peer candidates available")
 	}
@@ -2307,6 +2322,9 @@ func newBlockManager(s *server, indexManager blockchain.IndexManager, interrupt
 	}
 
 	bm.lotteryDataBroadcast = make(map[chainhash.Hash]struct{})
+	bm.syncHeightMtx.Lock()
+	bm.syncHeight = best.Height
+	bm.syncHeightMtx.Unlock()
 
 	return &bm, nil
 }

dcrjson/chainsvrresults.go

@@ -89,16 +89,28 @@ type GetBlockVerboseResult struct {
 	NextHash      string        `json:"nextblockhash,omitempty"`
 }
 
+// AgendaInfo provides an overview of an agenda in a consensus deployment.
+type AgendaInfo struct {
+	Status     string `json:"status"`
+	Since      int64  `json:"since,omitempty"`
+	StartTime  uint64 `json:"starttime"`
+	ExpireTime uint64 `json:"expiretime"`
+}
+
 // GetBlockChainInfoResult models the data returned from the getblockchaininfo
 // command.
 type GetBlockChainInfoResult struct {
-	Chain                string  `json:"chain"`
-	Blocks               int32   `json:"blocks"`
-	Headers              int32   `json:"headers"`
-	BestBlockHash        string  `json:"bestblockhash"`
-	Difficulty           float64 `json:"difficulty"`
-	VerificationProgress float64 `json:"verificationprogress"`
-	ChainWork            string  `json:"chainwork"`
+	Chain                string                `json:"chain"`
+	Blocks               int64                 `json:"blocks"`
+	Headers              int64                 `json:"headers"`
+	SyncHeight           int64                 `json:"syncheight"`
+	BestBlockHash        string                `json:"bestblockhash"`
+	Difficulty           uint32                `json:"difficulty"`
+	VerificationProgress float64               `json:"verificationprogress"`
+	ChainWork            string                `json:"chainwork"`
+	InitialBlockDownload bool                  `json:"initialblockdownload"`
+	MaxBlockSize         int64                 `json:"maxblocksize"`
+	Deployments          map[string]AgendaInfo `json:"deployments"`
 }
 
 // GetBlockHeaderVerboseResult models the data from the getblockheader command when

docs/json_rpc_api.md

@@ -161,38 +161,39 @@ the method name for further details such as parameter and return information.
 |5|[getaddednodeinfo](#getaddednodeinfo)|N|Returns information about manually added (persistent) peers.|
 |6|[getbestblockhash](#getbestblockhash)|Y|Returns the hash of the of the best (most recent) block in the longest block chain.|
 |7|[getblock](#getblock)|Y|Returns information about a block given its hash.|
-|8|[getblockcount](#getblockcount)|Y|Returns the number of blocks in the longest block chain.|
-|9|[getblockhash](#getblockhash)|Y|Returns hash of the block in best block chain at the given height.|
-|10|[getblockheader](#getblockheader)|Y|Returns the block header of the block.|
-|11|[getchaintips](#getchaintips)|Y|Returns information about all known chain tips the in the block tree.|
-|12|[getconnectioncount](#getconnectioncount)|N|Returns the number of active connections to other peers.|
-|13|[getdifficulty](#getdifficulty)|Y|Returns the proof-of-work difficulty as a multiple of the minimum difficulty.|
-|14|[getgenerate](#getgenerate)|N|Return if the server is set to generate coins (mine) or not.|
-|15|[gethashespersec](#gethashespersec)|N|Returns a recent hashes per second performance measurement while generating coins (mining).|
-|16|[getinfo](#getinfo)|Y|Returns a JSON object containing various state info.|
-|17|[getmempoolinfo](#getmempoolinfo)|N|Returns a JSON object containing mempool-related information.|
-|18|[getmininginfo](#getmininginfo)|N|Returns a JSON object containing mining-related information.|
-|19|[getnettotals](#getnettotals)|Y|Returns a JSON object containing network traffic statistics.|
-|20|[getnetworkhashps](#getnetworkhashps)|Y|Returns the estimated network hashes per second for the block heights provided by the parameters.|
-|21|[getpeerinfo](#getpeerinfo)|N|Returns information about each connected network peer as an array of json objects.|
-|22|[getrawmempool](#getrawmempool)|Y|Returns an array of hashes for all of the transactions currently in the memory pool.|
-|23|[getrawtransaction](#getrawtransaction)|Y|Returns information about a transaction given its hash.|
-|24|[getwork](#getwork)|N|Returns formatted hash data to work on or checks and submits solved data.<br /><br />NOTE: Since dcrd does not have the wallet integrated to provide payment addresses, dcrd must be configured via the `--miningaddr` option to provide which payment addresses to pay created blocks to for this RPC to function.|
-|25|[help](#help)|Y|Returns a list of all commands or help for a specified command.|
-|26|[ping](#ping)|N|Queues a ping to be sent to each connected peer.|
-|27|[sendrawtransaction](#sendrawtransaction)|Y|Submits the serialized, hex-encoded transaction to the local peer and relays it to the network.<br /><br />NOTE: dcrd does not yet implement the `allowhighfees` parameter, so it has no effect|
-|28|[setgenerate](#setgenerate) |N|Set the server to generate coins (mine) or not.<br/>NOTE: Since dcrd does not have the wallet integrated to provide payment addresses, dcrd must be configured via the `--miningaddr` option to provide which payment addresses to pay created blocks to for this RPC to function.|
-|29|[stop](#stop)|N|Shutdown dcrd.|
-|30|[submitblock](#submitblock)|Y|Attempts to submit a new serialized, hex-encoded block to the network.|
-|31|[validateaddress](#validateaddress)|Y|Verifies the given address is valid.  NOTE: Since dcrd does not have a wallet integrated, dcrd will only return whether the address is valid or not.|
-|32|[verifychain](#verifychain)|N|Verifies the block chain database.|
-|33|[debuglevel](#debuglevel)|N|Dynamically changes the debug logging level.|
-|34|[getbestblock](#getbestblock)|Y|Get block height and hash of best block in the main chain.|
-|35|[getcurrentnet](#getcurrentnet)|Y|Get Decred network dcrd is running on.|
-|36|[searchrawtransactions](#searchrawtransactions)|Y|Query for transactions related to a particular address.|
-|37|[node](#node)|N|Attempts to add or remove a peer. |
-|38|[generate](#generate)|N|When in simnet or regtest mode, generate a set number of blocks. |
-|39|[getstakeversions](#getstakeversions)|Y|Get stake versions per block. |
+|8|[getblockchaininfo](#getblockchaininfo)|Y|Returns information about the current state of the block chain.|
+|9|[getblockcount](#getblockcount)|Y|Returns the number of blocks in the longest block chain.|
+|10|[getblockhash](#getblockhash)|Y|Returns hash of the block in best block chain at the given height.|
+|11|[getblockheader](#getblockheader)|Y|Returns the block header of the block.|
+|12|[getchaintips](#getchaintips)|Y|Returns information about all known chain tips the in the block tree.|
+|13|[getconnectioncount](#getconnectioncount)|N|Returns the number of active connections to other peers.|
+|14|[getdifficulty](#getdifficulty)|Y|Returns the proof-of-work difficulty as a multiple of the minimum difficulty.|
+|15|[getgenerate](#getgenerate)|N|Return if the server is set to generate coins (mine) or not.|
+|16|[gethashespersec](#gethashespersec)|N|Returns a recent hashes per second performance measurement while generating coins (mining).|
+|17|[getinfo](#getinfo)|Y|Returns a JSON object containing various state info.|
+|18|[getmempoolinfo](#getmempoolinfo)|N|Returns a JSON object containing mempool-related information.|
+|19|[getmininginfo](#getmininginfo)|N|Returns a JSON object containing mining-related information.|
+|20|[getnettotals](#getnettotals)|Y|Returns a JSON object containing network traffic statistics.|
+|21|[getnetworkhashps](#getnetworkhashps)|Y|Returns the estimated network hashes per second for the block heights provided by the parameters.|
+|22|[getpeerinfo](#getpeerinfo)|N|Returns information about each connected network peer as an array of json objects.|
+|23|[getrawmempool](#getrawmempool)|Y|Returns an array of hashes for all of the transactions currently in the memory pool.|
+|24|[getrawtransaction](#getrawtransaction)|Y|Returns information about a transaction given its hash.|
+|25|[getwork](#getwork)|N|Returns formatted hash data to work on or checks and submits solved data.<br /><br />NOTE: Since dcrd does not have the wallet integrated to provide payment addresses, dcrd must be configured via the `--miningaddr` option to provide which payment addresses to pay created blocks to for this RPC to function.|
+|26|[help](#help)|Y|Returns a list of all commands or help for a specified command.|
+|27|[ping](#ping)|N|Queues a ping to be sent to each connected peer.|
+|28|[sendrawtransaction](#sendrawtransaction)|Y|Submits the serialized, hex-encoded transaction to the local peer and relays it to the network.<br /><br />NOTE: dcrd does not yet implement the `allowhighfees` parameter, so it has no effect|
+|29|[setgenerate](#setgenerate) |N|Set the server to generate coins (mine) or not.<br/>NOTE: Since dcrd does not have the wallet integrated to provide payment addresses, dcrd must be configured via the `--miningaddr` option to provide which payment addresses to pay created blocks to for this RPC to function.|
+|30|[stop](#stop)|N|Shutdown dcrd.|
+|31|[submitblock](#submitblock)|Y|Attempts to submit a new serialized, hex-encoded block to the network.|
+|32|[validateaddress](#validateaddress)|Y|Verifies the given address is valid.  NOTE: Since dcrd does not have a wallet integrated, dcrd will only return whether the address is valid or not.|
+|33|[verifychain](#verifychain)|N|Verifies the block chain database.|
+|34|[debuglevel](#debuglevel)|N|Dynamically changes the debug logging level.|
+|35|[getbestblock](#getbestblock)|Y|Get block height and hash of best block in the main chain.|
+|36|[getcurrentnet](#getcurrentnet)|Y|Get Decred network dcrd is running on.|
+|37|[searchrawtransactions](#searchrawtransactions)|Y|Query for transactions related to a particular address.|
+|38|[node](#node)|N|Attempts to add or remove a peer. |
+|39|[generate](#generate)|N|When in simnet or regtest mode, generate a set number of blocks. |
+|40|[getstakeversions](#getstakeversions)|Y|Get stake versions per block. |
 
 <a name="MethodDetails" />
 
@@ -335,6 +336,18 @@ the method name for further details such as parameter and return information.
 |Example Return|`[{"height": 217033, "hash": "00000000000000161bd5b120ef945faad60fc6e4c32b5caf1d4cabeae9a75346", "branchlen": 0, "status": "active"}, {"height": 213522, "hash": "0000000000000015e27658ce02ba8fa05d8d7ad9c587a5a472e3307773a9b36e", "branchlen": 1, "status": "valid-fork"}]"`|
 [Return to Overview](#MethodOverview)<br />
 
+***
+<a name="getblockchaininfo"/>
+
+|   |   |
+|---|---|
+|Method|getblockchaininfo|
+|Parameters|None|
+|Description|Returns information about the current state of the block chain.|
+|Returns|`(json object)`<br />`chain`: `(string)` The current network name.<br />`blocks`: `(numeric)` The number of blocks in the current best chain.<br />`headers`: `(numeric)` The number of validated block headers that comprise the target best chain.<br />`syncheight`: `(numeric)` The latest known block height being synced to.<br />`bestblockhash`: `(string)` The block hash of the current best chain tip.<br />`difficulty`: `(numeric)` The current network difficulty.<br />`verificationprogress`: `(numeric)` The chain verification progress estimate.<br />`chainwork`: `(string)` Hex encoded total work done for the chain.<br />`initialblockdownload`: `(boolean)` Best guess of whether this node is in the initial block download mode used to catch up the chain when it is far behind.<br />`maxblocksize`: `(numeric)` The maximum allowed block size.<br />`deployments`: `(json array of objects)` Network consensus deployments.<br />`status`: `(string)` The deployment agenda's current status.<br />`since`: `(numeric)` The blockheight of the first block to which the status applies.<br />`starttime`: `(numeric)` The start time of the voting period for the agenda.<br />`expiretime`: `(numeric)` The expiry time of the voting period for the agenda.<br /><br />`{ "chain": "name", "blocks": n, "headers": n, "syncheight": n, "bestblockhash": "hash", "difficulty": n, "verificationprogress": n, "chainwork": "n", "initialblockdownload": bool, "maxblocksize": n, "deployments": {"agenda": { "status": "status", "since": n, "starttime": n, "expiretime": n}, ...}}`|
+|Example Return|`{"chain": "simnet", "blocks": 463, "headers": 463, "syncheight": 0, "bestblockhash": "000043c89f6e227c9d90a5460aff98b662e503b9a394818942bdd60709cbb8aa", "difficulty": 520127421, "verificationprogress": 0, "chainwork": "0x23c0e40", "initialblockdownload": false, "maxblocksize": 1000000, "deployments": {"lnfeatures": {"status": "started", "since": 463, "starttime": 0, "expiretime": 9223372036854775807}, "maxblocksize": {"status": "started", "since": 463, "starttime": 0, "expiretime": 9223372036854775807}, "sdiffalgorithm": {"status": "started", "since": 463, "starttime": 0, "expiretime": 9223372036854775807}}}`|
+[Return to Overview](#MethodOverview)<br />
+
 ***
 <a name="getconnectioncount"/>