nim-codex/codex/blockexchange/engine/engine.nim

694 lines
21 KiB
Nim

## Nim-Codex
## Copyright (c) 2021 Status Research & Development GmbH
## Licensed under either of
## * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE))
## * MIT license ([LICENSE-MIT](LICENSE-MIT))
## at your option.
## This file may not be copied, modified, or distributed except according to
## those terms.
import std/sequtils
import std/sets
import std/options
import std/algorithm
import std/sugar
import pkg/chronos
import pkg/chronicles
import pkg/libp2p/[cid, switch, multihash]
import pkg/metrics
import pkg/stint
import ../../stores/blockstore
import ../../blocktype
import ../../utils
import ../../merkletree
import ../protobuf/blockexc
import ../protobuf/presence
import ../network
import ../peers
import ./payments
import ./discovery
import ./pendingblocks
export peers, pendingblocks, payments, discovery
logScope:
topics = "codex blockexcengine"
declareCounter(codexBlockExchangeWantHaveListsSent, "codex blockexchange wantHave lists sent")
declareCounter(codexBlockExchangeWantHaveListsReceived, "codex blockexchange wantHave lists received")
declareCounter(codexBlockExchangeWantBlockListsSent, "codex blockexchange wantBlock lists sent")
declareCounter(codexBlockExchangeWantBlockListsReceived, "codex blockexchange wantBlock lists received")
declareCounter(codexBlockExchangeBlocksSent, "codex blockexchange blocks sent")
declareCounter(codexBlockExchangeBlocksReceived, "codex blockexchange blocks received")
const
DefaultMaxPeersPerRequest* = 10
DefaultTaskQueueSize = 100
DefaultConcurrentTasks = 10
# DefaultMaxRetries = 3
# DefaultConcurrentDiscRequests = 10
# DefaultConcurrentAdvertRequests = 10
# DefaultDiscoveryTimeout = 1.minutes
# DefaultMaxQueriedBlocksCache = 1000
# DefaultMinPeersPerBlock = 3
type
TaskHandler* = proc(task: BlockExcPeerCtx): Future[void] {.gcsafe.}
TaskScheduler* = proc(task: BlockExcPeerCtx): bool {.gcsafe.}
BlockExcEngine* = ref object of RootObj
localStore*: BlockStore # Local block store for this instance
network*: BlockExcNetwork # Petwork interface
peers*: PeerCtxStore # Peers we're currently actively exchanging with
taskQueue*: AsyncHeapQueue[BlockExcPeerCtx] # Peers we're currently processing tasks for
concurrentTasks: int # Number of concurrent peers we're serving at any given time
blockexcTasks: seq[Future[void]] # Future to control blockexc task
blockexcRunning: bool # Indicates if the blockexc task is running
pendingBlocks*: PendingBlocksManager # Blocks we're awaiting to be resolved
peersPerRequest: int # Max number of peers to request from
wallet*: WalletRef # Nitro wallet for micropayments
pricing*: ?Pricing # Optional bandwidth pricing
discovery*: DiscoveryEngine
Pricing* = object
address*: EthAddress
price*: UInt256
# BlockIter* = Iter[Block]
# TODO check usages
proc contains*(a: AsyncHeapQueue[Entry], b: Cid): bool =
## Convenience method to check for entry prepense
##
a.anyIt( not it.address.leaf and it.address.cid == b )
# attach task scheduler to engine
proc scheduleTask(b: BlockExcEngine, task: BlockExcPeerCtx): bool {.gcsafe} =
b.taskQueue.pushOrUpdateNoWait(task).isOk()
proc blockexcTaskRunner(b: BlockExcEngine): Future[void] {.gcsafe.}
proc start*(b: BlockExcEngine) {.async.} =
## Start the blockexc task
##
await b.discovery.start()
trace "Blockexc starting with concurrent tasks", tasks = b.concurrentTasks
if b.blockexcRunning:
warn "Starting blockexc twice"
return
b.blockexcRunning = true
for i in 0..<b.concurrentTasks:
b.blockexcTasks.add(blockexcTaskRunner(b))
proc stop*(b: BlockExcEngine) {.async.} =
## Stop the blockexc blockexc
##
await b.discovery.stop()
trace "NetworkStore stop"
if not b.blockexcRunning:
warn "Stopping blockexc without starting it"
return
b.blockexcRunning = false
for task in b.blockexcTasks:
if not task.finished:
trace "Awaiting task to stop"
await task.cancelAndWait()
trace "Task stopped"
trace "NetworkStore stopped"
proc sendWantHave(b: BlockExcEngine, address: BlockAddress, selectedPeer: BlockExcPeerCtx, peers: seq[BlockExcPeerCtx]): Future[void] {.async.} =
trace "Sending wantHave request to peers", address = $address #TODO
for p in peers:
if p != selectedPeer:
if address notin p.peerHave:
trace " wantHave > ", peer = p.id
await b.network.request.sendWantList(
p.id,
@[address],
wantType = WantType.WantHave) # we only want to know if the peer has the block
proc sendWantBlock(b: BlockExcEngine, address: BlockAddress, blockPeer: BlockExcPeerCtx): Future[void] {.async.} =
trace "Sending wantBlock request to", peer = blockPeer.id, address = $address #TODO
await b.network.request.sendWantList(
blockPeer.id,
@[address],
wantType = WantType.WantBlock) # we want this remote to send us a block
proc findCheapestPeerForBlock(b: BlockExcEngine, cheapestPeers: seq[BlockExcPeerCtx]): ?BlockExcPeerCtx =
if cheapestPeers.len <= 0:
trace "No cheapest peers, selecting first in list"
let
peers = toSeq(b.peers) # Get any peer
if peers.len <= 0:
return none(BlockExcPeerCtx)
return some(peers[0])
return some(cheapestPeers[0]) # get cheapest
# TODO think about this one
# proc requestBlock*(
# b: BlockExcEngine,
# treeCid: Cid,
# index: Natural,
# timeout = DefaultBlockTimeout
# ): Future[Block] {.async.} =
# let blockFuture = b.pendingBlocks.getWantHandle(treeCid, index, leavesCount, merkleRoot, timeout)
# if b.pendingBlocks.isInFlight(treeCid, index):
# return await blockFuture
# let peers = b.peers.selectCheapest(cid)
# if peers.len == 0:
# b.discovery.queueFindBlocksReq(@[cid])
# return await blockFuture
# else:
# b.pendingBlocks.setInFlight(treeCid, index)
# peer = peers[index mod peers.len] # round robin
# await b.sendWantBlock(treeCid, index, peer)
# await b.sendWantHave(treeCid, index, peer, toSeq(b.peers))
# return await blockFuture
# TODO think about this one
proc requestBlock(
b: BlockExcEngine,
treeReq: TreeReq,
index: Natural,
timeout = DefaultBlockTimeout
): Future[Block] {.async.} =
let
blockFuture = treeReq.getWantHandle(index, timeout)
address = BlockAddress(leaf: true, treeCid: treeReq.treeCid, index: index)
if treeReq.isInFlight(index):
return await blockFuture
let peers = b.peers.selectCheapest(treeReq.treeCid)
if peers.len == 0:
b.discovery.queueFindBlocksReq(@[treeReq.treeCid])
return await blockFuture
else:
treeReq.setInFlight(index)
let peer = peers[index mod peers.len] # round robin
await b.sendWantBlock(address, peer)
await b.sendWantHave(address, peer, toSeq(b.peers))
return await blockFuture
proc requestBlocks*(
b: BlockExcEngine,
treeCid: Cid,
leavesCount: Natural,
merkleRoot: MultiHash,
timeout = DefaultBlockTimeout
): ?!Iter[Block] =
without treeReq =? b.pendingBlocks.getOrPutTreeReq(treeCid, leavesCount, merkleRoot), err:
return failure(err)
var
iter = Iter[Block]()
index = 0
proc next(): Future[Block] =
if index < leavesCount:
inc index
if index >= leavesCount:
iter.finished = true
return b.requestBlock(treeReq, index - 1, timeout)
else:
let fut = newFuture[Block]("chronos.race()") #TODO fixit
fut.fail(newException(CodexError, "No more elements for tree with cid " & $treeCid))
return fut
iter.next = next
return success(iter)
# iterator requestBlocks*(
# b: BlockExcEngine,
# treeCid: Cid,
# leavesCount: Natural,
# merkleRoot: MultiHash,
# timeout = DefaultBlockTimeout
# ): Future[Block] {.async.} =
# ##
# ##
# without treeReq =? b.pendingBlocks.getOrPutTreeReq(treeCid, leavesCount, merkleRoot), err:
# return err
# for index in 0..<leavesCount:
# yield await b.requestBlock(treeReq, index, timeout)
proc requestBlock*(
b: BlockExcEngine,
cid: Cid,
timeout = DefaultBlockTimeout): Future[Block] {.async.} =
trace "Begin block request", cid, peers = b.peers.len
if b.pendingBlocks.isInFlight(cid):
trace "Request handle already pending", cid
return await b.pendingBlocks.getWantHandle(cid, timeout)
let
blk = b.pendingBlocks.getWantHandle(cid, timeout)
address = BlockAddress(leaf: false, cid: cid)
trace "Selecting peers who have", cid
var
peers = b.peers.selectCheapest(cid)
without blockPeer =? b.findCheapestPeerForBlock(peers):
trace "No peers to request blocks from. Queue discovery...", cid
b.discovery.queueFindBlocksReq(@[cid])
return await blk
proc blockHandleMonitor() {.async.} =
try:
trace "Monitoring block handle", cid
b.pendingBlocks.setInFlight(cid, true)
discard await blk
trace "Block handle success", cid
except CatchableError as exc:
trace "Error block handle, disconnecting peer", cid, exc = exc.msg
# TODO: really, this is just a quick and dirty way of
# preventing hitting the same "bad" peer every time, however,
# we might as well discover this on or next iteration, so
# it doesn't mean that we're never talking to this peer again.
# TODO: we need a lot more work around peer selection and
# prioritization
# drop unresponsive peer
await b.network.switch.disconnect(blockPeer.id)
# monitor block handle
asyncSpawn blockHandleMonitor()
await b.sendWantBlock(address, blockPeer)
codexBlockExchangeWantBlockListsSent.inc()
if (peers.len - 1) == 0:
trace "No peers to send want list to", cid
b.discovery.queueFindBlocksReq(@[cid])
return await blk
await b.sendWantHave(address, blockPeer, toSeq(b.peers))
codexBlockExchangeWantHaveListsSent.inc()
return await blk
proc blockPresenceHandler*(
b: BlockExcEngine,
peer: PeerId,
blocks: seq[BlockPresence]) {.async.} =
trace "Received presence update for peer", peer, blocks = blocks.len
let
peerCtx = b.peers.get(peer)
wantList = toSeq(b.pendingBlocks.wantList)
if peerCtx.isNil:
return
for blk in blocks:
if presence =? Presence.init(blk):
logScope:
address = $presence.address
have = presence.have
price = presence.price
trace "Updating precense"
peerCtx.setPresence(presence)
let
peerHave = peerCtx.peerHave
dontWantCids = peerHave.filterIt(
it notin wantList
)
if dontWantCids.len > 0:
peerCtx.cleanPresence(dontWantCids)
let
wantCids = wantList.filterIt(
it in peerHave
)
if wantCids.len > 0:
trace "Peer has blocks in our wantList", peer, count = wantCids.len
discard await allFinished(
wantCids.mapIt(b.sendWantBlock(it, peerCtx)))
# if none of the connected peers report our wants in their have list,
# fire up discovery
b.discovery.queueFindBlocksReq(
toSeq(b.pendingBlocks.wantListCids)
.filter do(cid: Cid) -> bool:
not b.peers.anyIt( cid in it.peerHaveCids ))
proc scheduleTasks(b: BlockExcEngine, blocksDelivery: seq[BlockDelivery]) {.async.} =
trace "Schedule a task for new blocks", items = blocksDelivery.len
let
cids = blocksDelivery.mapIt( it.blk.cid )
# schedule any new peers to provide blocks to
for p in b.peers:
for c in cids: # for each cid
# schedule a peer if it wants at least one cid
# and we have it in our local store
if c in p.peerWantsCids:
if await (c in b.localStore): # TODO this is cruical, though indirect
if b.scheduleTask(p):
trace "Task scheduled for peer", peer = p.id
else:
trace "Unable to schedule task for peer", peer = p.id
break # do next peer
proc resolveBlocks*(b: BlockExcEngine, blocksDelivery: seq[BlockDelivery]) {.async.} =
trace "Resolving blocks", blocks = blocksDelivery.len
b.pendingBlocks.resolve(blocksDelivery)
await b.scheduleTasks(blocksDelivery)
b.discovery.queueProvideBlocksReq(blocksDelivery.mapIt( it.blk.cid ))
proc resolveBlocks*(b: BlockExcEngine, blocks: seq[Block]) {.async.} =
await b.resolveBlocks(blocks.mapIt(BlockDelivery(blk: it, address: BlockAddress(leaf: false, cid: it.cid))))
proc payForBlocks(engine: BlockExcEngine,
peer: BlockExcPeerCtx,
blocksDelivery: seq[BlockDelivery]) {.async.} =
trace "Paying for blocks", len = blocksDelivery.len
let
sendPayment = engine.network.request.sendPayment
price = peer.price(blocksDelivery.mapIt(it.address))
if payment =? engine.wallet.pay(peer, price):
trace "Sending payment for blocks", price
await sendPayment(peer.id, payment)
proc blocksDeliveryHandler*(
b: BlockExcEngine,
peer: PeerId,
blocksDelivery: seq[BlockDelivery]) {.async.} =
trace "Got blocks from peer", peer, len = blocksDelivery.len
for bd in blocksDelivery:
if isErr (await b.localStore.putBlock(bd.blk)):
trace "Unable to store block", cid = bd.blk.cid
await b.resolveBlocks(blocksDelivery)
codexBlockExchangeBlocksReceived.inc(blocksDelivery.len.int64)
let
peerCtx = b.peers.get(peer)
if peerCtx != nil:
await b.payForBlocks(peerCtx, blocksDelivery)
## shouldn't we remove them from the want-list instead of this:
peerCtx.cleanPresence(blocksDelivery.mapIt( it.address ))
proc wantListHandler*(
b: BlockExcEngine,
peer: PeerId,
wantList: WantList) {.async.} =
trace "Got wantList for peer", peer, items = wantList.entries.len
let
peerCtx = b.peers.get(peer)
if isNil(peerCtx):
return
var
presence: seq[BlockPresence]
for e in wantList.entries:
let
idx = peerCtx.peerWants.find(e)
logScope:
peer = peerCtx.id
# cid = e.cid
wantType = $e.wantType
if idx < 0: # updating entry
trace "Processing new want list entry", address = $e.address
let
have = await e.address in b.localStore
price = @(
b.pricing.get(Pricing(price: 0.u256))
.price.toBytesBE)
if e.wantType == WantType.WantHave:
codexBlockExchangeWantHaveListsReceived.inc()
if not have and e.sendDontHave:
trace "Adding dont have entry to presence response", address = $e.address
presence.add(
BlockPresence(
address: e.address,
`type`: BlockPresenceType.DontHave,
price: price))
elif have and e.wantType == WantType.WantHave:
trace "Adding have entry to presence response", address = $e.address
presence.add(
BlockPresence(
address: e.address,
`type`: BlockPresenceType.Have,
price: price))
elif e.wantType == WantType.WantBlock:
trace "Added entry to peer's want blocks list", address = $e.address
peerCtx.peerWants.add(e)
codexBlockExchangeWantBlockListsReceived.inc()
else:
# peer doesn't want this block anymore
if e.cancel:
trace "Removing entry from peer want list"
peerCtx.peerWants.del(idx)
else:
trace "Updating entry in peer want list"
# peer might want to ask for the same cid with
# different want params
peerCtx.peerWants[idx] = e # update entry
if presence.len > 0:
trace "Sending presence to remote", items = presence.len
await b.network.request.sendPresence(peer, presence)
trace "Scheduling a task for this peer, to look over their want-list", peer
if not b.scheduleTask(peerCtx):
trace "Unable to schedule task for peer", peer
proc accountHandler*(
engine: BlockExcEngine,
peer: PeerId,
account: Account) {.async.} =
let
context = engine.peers.get(peer)
if context.isNil:
return
context.account = account.some
proc paymentHandler*(
engine: BlockExcEngine,
peer: PeerId,
payment: SignedState) {.async.} =
trace "Handling payments", peer
without context =? engine.peers.get(peer).option and
account =? context.account:
trace "No context or account for peer", peer
return
if channel =? context.paymentChannel:
let
sender = account.address
discard engine.wallet.acceptPayment(channel, Asset, sender, payment)
else:
context.paymentChannel = engine.wallet.acceptChannel(payment).option
proc setupPeer*(b: BlockExcEngine, peer: PeerId) {.async.} =
## Perform initial setup, such as want
## list exchange
##
if peer notin b.peers:
trace "Setting up new peer", peer
b.peers.add(BlockExcPeerCtx(
id: peer
))
trace "Added peer", peers = b.peers.len
# broadcast our want list, the other peer will do the same
if b.pendingBlocks.len > 0:
await b.network.request.sendWantList(
peer, toSeq(b.pendingBlocks.wantList), full = true)
if address =? b.pricing.?address:
await b.network.request.sendAccount(peer, Account(address: address))
proc dropPeer*(b: BlockExcEngine, peer: PeerId) =
## Cleanup disconnected peer
##
trace "Dropping peer", peer
# drop the peer from the peers table
b.peers.remove(peer)
proc taskHandler*(b: BlockExcEngine, task: BlockExcPeerCtx) {.gcsafe, async.} =
trace "Handling task for peer", peer = task.id
# Send to the peer blocks he wants to get,
# if they present in our local store
# TODO: There should be all sorts of accounting of
# bytes sent/received here
var
wantsBlocks = task.peerWants.filterIt(
it.wantType == WantType.WantBlock
)
trace "wantsBlocks", peer = task.id, n = wantsBlocks.len
if wantsBlocks.len > 0:
trace "Got peer want blocks list", items = wantsBlocks.len
wantsBlocks.sort(SortOrder.Descending)
proc localLookup(e: Entry): Future[?!BlockDelivery] {.async.} =
if e.address.leaf:
(await b.localStore.getBlockAndProof(e.address.treeCid, e.address.index)).map(
(blkAndProof: (Block, MerkleProof)) =>
BlockDelivery(address: e.address, blk: blkAndProof[0], proof: blkAndProof[1])
# pb.Block(cid: blk.cid, blk.data, leaf: true, treeCid: e.treeCid, proof: proof)
)
else:
(await b.localStore.getBlock(e.address.cid)).map(
(blk: Block) => BlockDelivery(address: e.address, blk: blk)
)
let
blocksDeliveryFut = await allFinished(wantsBlocks.map(localLookup))
# Extract successfully received blocks
let
blocksDelivery = blocksDeliveryFut
.filterIt(it.completed and it.read.isOk)
.mapIt(it.read.get)
if blocksDelivery.len > 0:
trace "Sending blocks to peer", peer = task.id, blocks = blocksDelivery.len
await b.network.request.sendBlocksDelivery(
task.id,
blocksDelivery
)
codexBlockExchangeBlocksSent.inc(blocksDelivery.len.int64)
trace "About to remove entries from peerWants", blocks = blocksDelivery.len, items = task.peerWants.len
# Remove successfully sent blocks
task.peerWants.keepIf(
proc(e: Entry): bool =
not blocksDelivery.anyIt( it.address == e.address )
)
trace "Removed entries from peerWants", items = task.peerWants.len
proc blockexcTaskRunner(b: BlockExcEngine) {.async.} =
## process tasks
##
trace "Starting blockexc task runner"
while b.blockexcRunning:
let
peerCtx = await b.taskQueue.pop()
trace "Got new task from queue", peerId = peerCtx.id
await b.taskHandler(peerCtx)
trace "Exiting blockexc task runner"
proc new*(
T: type BlockExcEngine,
localStore: BlockStore,
wallet: WalletRef,
network: BlockExcNetwork,
discovery: DiscoveryEngine,
peerStore: PeerCtxStore,
pendingBlocks: PendingBlocksManager,
concurrentTasks = DefaultConcurrentTasks,
peersPerRequest = DefaultMaxPeersPerRequest
): BlockExcEngine =
## Create new block exchange engine instance
##
let
engine = BlockExcEngine(
localStore: localStore,
peers: peerStore,
pendingBlocks: pendingBlocks,
peersPerRequest: peersPerRequest,
network: network,
wallet: wallet,
concurrentTasks: concurrentTasks,
taskQueue: newAsyncHeapQueue[BlockExcPeerCtx](DefaultTaskQueueSize),
discovery: discovery)
proc peerEventHandler(peerId: PeerId, event: PeerEvent) {.async.} =
if event.kind == PeerEventKind.Joined:
await engine.setupPeer(peerId)
else:
engine.dropPeer(peerId)
if not isNil(network.switch):
network.switch.addPeerEventHandler(peerEventHandler, PeerEventKind.Joined)
network.switch.addPeerEventHandler(peerEventHandler, PeerEventKind.Left)
proc blockWantListHandler(
peer: PeerId,
wantList: WantList): Future[void] {.gcsafe.} =
engine.wantListHandler(peer, wantList)
proc blockPresenceHandler(
peer: PeerId,
presence: seq[BlockPresence]): Future[void] {.gcsafe.} =
engine.blockPresenceHandler(peer, presence)
proc blocksDeliveryHandler(
peer: PeerId,
blocksDelivery: seq[BlockDelivery]): Future[void] {.gcsafe.} =
engine.blocksDeliveryHandler(peer, blocksDelivery)
proc accountHandler(peer: PeerId, account: Account): Future[void] {.gcsafe.} =
engine.accountHandler(peer, account)
proc paymentHandler(peer: PeerId, payment: SignedState): Future[void] {.gcsafe.} =
engine.paymentHandler(peer, payment)
network.handlers = BlockExcHandlers(
onWantList: blockWantListHandler,
onBlocksDelivery: blocksDeliveryHandler,
onPresence: blockPresenceHandler,
onAccount: accountHandler,
onPayment: paymentHandler)
return engine