9111774206

package chainview

import (
        "bytes"
        "encoding/hex"
        "fmt"
        "sync"
        "sync/atomic"

        "github.com/btcsuite/btcd/btcjson"
        "github.com/btcsuite/btcd/chaincfg/chainhash"
        "github.com/btcsuite/btcd/wire"
        "github.com/btcsuite/btcwallet/chain"
        "github.com/btcsuite/btcwallet/wtxmgr"
        "github.com/lightningnetwork/lnd/blockcache"
        "github.com/lightningnetwork/lnd/channeldb"
)

// BitcoindFilteredChainView is an implementation of the FilteredChainView
// interface which is backed by bitcoind.
type BitcoindFilteredChainView struct {
        started int32 // To be used atomically.
        stopped int32 // To be used atomically.

        // bestHeight is the height of the latest block added to the
        // blockQueue from the onFilteredConnectedMethod. It is used to
        // determine up to what height we would need to rescan in case
        // of a filter update.
        bestHeightMtx sync.Mutex
        bestHeight    uint32

        // TODO: Factor out common logic between bitcoind and btcd into a
        // NodeFilteredView interface.
        chainClient *chain.BitcoindClient

        // blockEventQueue is the ordered queue used to keep the order
        // of connected and disconnected blocks sent to the reader of the
        // chainView.
        blockQueue *blockEventQueue

        // blockCache is an LRU block cache.
        blockCache *blockcache.BlockCache

        // filterUpdates is a channel in which updates to the utxo filter
        // attached to this instance are sent over.
        filterUpdates chan filterUpdate

        // chainFilter is the set of utox's that we're currently watching
        // spends for within the chain.
        filterMtx   sync.RWMutex
        chainFilter map[wire.OutPoint]struct{}

        // filterBlockReqs is a channel in which requests to filter select
        // blocks will be sent over.
        filterBlockReqs chan *filterBlockReq

        quit chan struct{}
        wg   sync.WaitGroup
}

// A compile time check to ensure BitcoindFilteredChainView implements the
// chainview.FilteredChainView.
var _ FilteredChainView = (*BitcoindFilteredChainView)(nil)

// NewBitcoindFilteredChainView creates a new instance of a FilteredChainView
// from RPC credentials and a ZMQ socket address for a bitcoind instance.
func NewBitcoindFilteredChainView(
        chainConn *chain.BitcoindConn,
        blockCache *blockcache.BlockCache) *BitcoindFilteredChainView {

        chainView := &BitcoindFilteredChainView{
                chainFilter:     make(map[wire.OutPoint]struct{}),
                filterUpdates:   make(chan filterUpdate),
                filterBlockReqs: make(chan *filterBlockReq),
                blockCache:      blockCache,
                quit:            make(chan struct{}),
        }

        chainView.chainClient = chainConn.NewBitcoindClient()
        chainView.blockQueue = newBlockEventQueue()

        return chainView
}

// Start starts all goroutines necessary for normal operation.
//
// NOTE: This is part of the FilteredChainView interface.
func (b *BitcoindFilteredChainView) Start() error {
        // Already started?
        if atomic.AddInt32(&b.started, 1) != 1 {
                return nil
        }

        log.Infof("FilteredChainView starting")

        err := b.chainClient.Start()
        if err != nil {
                return err
        }

        err = b.chainClient.NotifyBlocks()
        if err != nil {
                return err
        }

        _, bestHeight, err := b.chainClient.GetBestBlock()
        if err != nil {
                return err
        }

        b.bestHeightMtx.Lock()
        b.bestHeight = uint32(bestHeight)
        b.bestHeightMtx.Unlock()

        b.blockQueue.Start()

        b.wg.Add(1)
        go b.chainFilterer()

        return nil
}

// Stop stops all goroutines which we launched by the prior call to the Start
// method.
//
// NOTE: This is part of the FilteredChainView interface.
func (b *BitcoindFilteredChainView) Stop() error {
        // Already shutting down?
        if atomic.AddInt32(&b.stopped, 1) != 1 {
                return nil
        }

        // Shutdown the rpc client, this gracefully disconnects from bitcoind's
        // zmq socket, and cleans up all related resources.
        b.chainClient.Stop()

        b.blockQueue.Stop()

        log.Infof("FilteredChainView stopping")

        close(b.quit)
        b.wg.Wait()

        return nil
}

// onFilteredBlockConnected is called for each block that's connected to the
// end of the main chain. Based on our current chain filter, the block may or
// may not include any relevant transactions.
func (b *BitcoindFilteredChainView) onFilteredBlockConnected(height int32,
        hash chainhash.Hash, txns []*wtxmgr.TxRecord) {

        mtxs := make([]*wire.MsgTx, len(txns))
        b.filterMtx.Lock()
        for i, tx := range txns {
                mtxs[i] = &tx.MsgTx

                for _, txIn := range mtxs[i].TxIn {
                        // We can delete this outpoint from the chainFilter, as
                        // we just received a block where it was spent. In case
                        // of a reorg, this outpoint might get "un-spent", but
                        // that's okay since it would never be wise to consider
                        // the channel open again (since a spending transaction
                        // exists on the network).
                        delete(b.chainFilter, txIn.PreviousOutPoint)
                }

        }
        b.filterMtx.Unlock()

        // We record the height of the last connected block added to the
        // blockQueue such that we can scan up to this height in case of
        // a rescan. It must be protected by a mutex since a filter update
        // might be trying to read it concurrently.
        b.bestHeightMtx.Lock()
        b.bestHeight = uint32(height)
        b.bestHeightMtx.Unlock()

        block := &FilteredBlock{
                Hash:         hash,
                Height:       uint32(height),
                Transactions: mtxs,
        }

        b.blockQueue.Add(&blockEvent{
                eventType: connected,
                block:     block,
        })
}

// onFilteredBlockDisconnected is a callback which is executed once a block is
// disconnected from the end of the main chain.
func (b *BitcoindFilteredChainView) onFilteredBlockDisconnected(height int32,
        hash chainhash.Hash) {

        log.Debugf("got disconnected block at height %d: %v", height,
                hash)

        filteredBlock := &FilteredBlock{
                Hash:   hash,
                Height: uint32(height),
        }

        b.blockQueue.Add(&blockEvent{
                eventType: disconnected,
                block:     filteredBlock,
        })
}

// FilterBlock takes a block hash, and returns a FilteredBlocks which is the
// result of applying the current registered UTXO sub-set on the block
// corresponding to that block hash. If any watched UTOX's are spent by the
// selected lock, then the internal chainFilter will also be updated.
//
// NOTE: This is part of the FilteredChainView interface.
func (b *BitcoindFilteredChainView) FilterBlock(blockHash *chainhash.Hash) (*FilteredBlock, error) {
        req := &filterBlockReq{
                blockHash: blockHash,
                resp:      make(chan *FilteredBlock, 1),
                err:       make(chan error, 1),
        }

        select {
        case b.filterBlockReqs <- req:
        case <-b.quit:
                return nil, fmt.Errorf("FilteredChainView shutting down")
        }

        return <-req.resp, <-req.err
}

// chainFilterer is the primary goroutine which: listens for new blocks coming
// and dispatches the relevant FilteredBlock notifications, updates the filter
// due to requests by callers, and finally is able to perform targeted block
// filtration.
//
// TODO(roasbeef): change to use loadfilter RPC's
func (b *BitcoindFilteredChainView) chainFilterer() {
        defer b.wg.Done()

        // filterBlock is a helper function that scans the given block, and
        // notes which transactions spend outputs which are currently being
        // watched. Additionally, the chain filter will also be updated by
        // removing any spent outputs.
        filterBlock := func(blk *wire.MsgBlock) []*wire.MsgTx {
                b.filterMtx.Lock()
                defer b.filterMtx.Unlock()

                var filteredTxns []*wire.MsgTx
                for _, tx := range blk.Transactions {
                        var txAlreadyFiltered bool
                        for _, txIn := range tx.TxIn {
                                prevOp := txIn.PreviousOutPoint
                                if _, ok := b.chainFilter[prevOp]; !ok {
                                        continue
                                }

                                delete(b.chainFilter, prevOp)

                                // Only add this txn to our list of filtered
                                // txns if it is the first previous outpoint to
                                // cause a match.
                                if txAlreadyFiltered {
                                        continue
                                }

                                filteredTxns = append(filteredTxns, tx.Copy())
                                txAlreadyFiltered = true
                        }
                }

                return filteredTxns
        }

        decodeJSONBlock := func(block *btcjson.RescannedBlock,
                height uint32) (*FilteredBlock, error) {
                hash, err := chainhash.NewHashFromStr(block.Hash)
                if err != nil {
                        return nil, err

                }
                txs := make([]*wire.MsgTx, 0, len(block.Transactions))
                for _, str := range block.Transactions {
                        b, err := hex.DecodeString(str)
                        if err != nil {
                                return nil, err
                        }
                        tx := &wire.MsgTx{}
                        err = tx.Deserialize(bytes.NewReader(b))
                        if err != nil {
                                return nil, err
                        }
                        txs = append(txs, tx)
                }
                return &FilteredBlock{
                        Hash:         *hash,
                        Height:       height,
                        Transactions: txs,
                }, nil
        }

        for {
                select {
                // The caller has just sent an update to the current chain
                // filter, so we'll apply the update, possibly rewinding our
                // state partially.
                case update := <-b.filterUpdates:
                        // First, we'll add all the new UTXO's to the set of
                        // watched UTXO's, eliminating any duplicates in the
                        // process.
                        log.Tracef("Updating chain filter with new UTXO's: %v",
                                update.newUtxos)

                        b.filterMtx.Lock()
                        for _, newOp := range update.newUtxos {
                                b.chainFilter[newOp] = struct{}{}
                        }
                        b.filterMtx.Unlock()

                        // Apply the new TX filter to the chain client, which
                        // will cause all following notifications from and
                        // calls to it return blocks filtered with the new
                        // filter.
                        err := b.chainClient.LoadTxFilter(false, update.newUtxos)
                        if err != nil {
                                log.Errorf("Unable to update filter: %v", err)
                                continue
                        }

                        // All blocks gotten after we loaded the filter will
                        // have the filter applied, but we will need to rescan
                        // the blocks up to the height of the block we last
                        // added to the blockQueue.
                        b.bestHeightMtx.Lock()
                        bestHeight := b.bestHeight
                        b.bestHeightMtx.Unlock()

                        // If the update height matches our best known height,
                        // then we don't need to do any rewinding.
                        if update.updateHeight == bestHeight {
                                continue
                        }

                        // Otherwise, we'll rewind the state to ensure the
                        // caller doesn't miss any relevant notifications.
                        // Starting from the height _after_ the update height,
                        // we'll walk forwards, rescanning one block at a time
                        // with the chain client applying the newly loaded
                        // filter to each block.
                        for i := update.updateHeight + 1; i < bestHeight+1; i++ {
                                blockHash, err := b.chainClient.GetBlockHash(int64(i))
                                if err != nil {
                                        log.Warnf("Unable to get block hash "+
                                                "for block at height %d: %v",
                                                i, err)
                                        continue
                                }

                                // To avoid dealing with the case where a reorg
                                // is happening while we rescan, we scan one
                                // block at a time, skipping blocks that might
                                // have gone missing.
                                rescanned, err := b.chainClient.RescanBlocks(
                                        []chainhash.Hash{*blockHash},
                                )
                                if err != nil {
                                        log.Warnf("Unable to rescan block "+
                                                "with hash %v at height %d: %v",
                                                blockHash, i, err)
                                        continue
                                }

                                // If no block was returned from the rescan, it
                                // means no matching transactions were found.
                                if len(rescanned) != 1 {
                                        log.Tracef("rescan of block %v at "+
                                                "height=%d yielded no "+
                                                "transactions", blockHash, i)
                                        continue
                                }
                                decoded, err := decodeJSONBlock(
                                        &rescanned[0], i,
                                )
                                if err != nil {
                                        log.Errorf("Unable to decode block: %v",
                                                err)
                                        continue
                                }
                                b.blockQueue.Add(&blockEvent{
                                        eventType: connected,
                                        block:     decoded,
                                })
                        }

                // We've received a new request to manually filter a block.
                case req := <-b.filterBlockReqs:
                        // First we'll fetch the block itself as well as some
                        // additional information including its height.
                        block, err := b.GetBlock(req.blockHash)
                        if err != nil {
                                req.err <- err
                                req.resp <- nil
                                continue
                        }
                        header, err := b.chainClient.GetBlockHeaderVerbose(
                                req.blockHash)
                        if err != nil {
                                req.err <- err
                                req.resp <- nil
                                continue
                        }

                        // Once we have this info, we can directly filter the
                        // block and dispatch the proper notification.
                        req.resp <- &FilteredBlock{
                                Hash:         *req.blockHash,
                                Height:       uint32(header.Height),
                                Transactions: filterBlock(block),
                        }
                        req.err <- err

                // We've received a new event from the chain client.
                case event := <-b.chainClient.Notifications():
                        switch e := event.(type) {

                        case chain.FilteredBlockConnected:
                                b.onFilteredBlockConnected(
                                        e.Block.Height, e.Block.Hash, e.RelevantTxs,
                                )

                        case chain.BlockDisconnected:
                                b.onFilteredBlockDisconnected(e.Height, e.Hash)
                        }

                case <-b.quit:
                        return
                }
        }
}

// UpdateFilter updates the UTXO filter which is to be consulted when creating
// FilteredBlocks to be sent to subscribed clients. This method is cumulative
// meaning repeated calls to this method should _expand_ the size of the UTXO
// sub-set currently being watched.  If the set updateHeight is _lower_ than
// the best known height of the implementation, then the state should be
// rewound to ensure all relevant notifications are dispatched.
//
// NOTE: This is part of the FilteredChainView interface.
func (b *BitcoindFilteredChainView) UpdateFilter(ops []channeldb.EdgePoint,
        updateHeight uint32) error {

        newUtxos := make([]wire.OutPoint, len(ops))
        for i, op := range ops {
                newUtxos[i] = op.OutPoint
        }

        select {

        case b.filterUpdates <- filterUpdate{
                newUtxos:     newUtxos,
                updateHeight: updateHeight,
        }:
                return nil

        case <-b.quit:
                return fmt.Errorf("chain filter shutting down")
        }
}

// FilteredBlocks returns the channel that filtered blocks are to be sent over.
// Each time a block is connected to the end of a main chain, and appropriate
// FilteredBlock which contains the transactions which mutate our watched UTXO
// set is to be returned.
//
// NOTE: This is part of the FilteredChainView interface.
func (b *BitcoindFilteredChainView) FilteredBlocks() <-chan *FilteredBlock {
        return b.blockQueue.newBlocks
}

// DisconnectedBlocks returns a receive only channel which will be sent upon
// with the empty filtered blocks of blocks which are disconnected from the
// main chain in the case of a re-org.
//
// NOTE: This is part of the FilteredChainView interface.
func (b *BitcoindFilteredChainView) DisconnectedBlocks() <-chan *FilteredBlock {
        return b.blockQueue.staleBlocks
}

// GetBlock is used to retrieve the block with the given hash. This function
// wraps the blockCache's GetBlock function.
func (b *BitcoindFilteredChainView) GetBlock(hash *chainhash.Hash) (
        *wire.MsgBlock, error) {

        return b.blockCache.GetBlock(hash, b.chainClient.GetBlock)
}

1	package chainview
2
3	import (
4	"bytes"
5	"encoding/hex"
6	"fmt"
7	"sync"
8	"sync/atomic"
9
10	"github.com/btcsuite/btcd/btcjson"
11	"github.com/btcsuite/btcd/chaincfg/chainhash"
12	"github.com/btcsuite/btcd/wire"
13	"github.com/btcsuite/btcwallet/chain"
14	"github.com/btcsuite/btcwallet/wtxmgr"
15	"github.com/lightningnetwork/lnd/blockcache"
16	"github.com/lightningnetwork/lnd/channeldb"
17	)
18
19	// BitcoindFilteredChainView is an implementation of the FilteredChainView
20	// interface which is backed by bitcoind.
21	type BitcoindFilteredChainView struct {
22	started int32 // To be used atomically.
23	stopped int32 // To be used atomically.
24
25	// bestHeight is the height of the latest block added to the
26	// blockQueue from the onFilteredConnectedMethod. It is used to
27	// determine up to what height we would need to rescan in case
28	// of a filter update.
29	bestHeightMtx sync.Mutex
30	bestHeight uint32
31
32	// TODO: Factor out common logic between bitcoind and btcd into a
33	// NodeFilteredView interface.
34	chainClient *chain.BitcoindClient
35
36	// blockEventQueue is the ordered queue used to keep the order
37	// of connected and disconnected blocks sent to the reader of the
38	// chainView.
39	blockQueue *blockEventQueue
40
41	// blockCache is an LRU block cache.
42	blockCache *blockcache.BlockCache
43
44	// filterUpdates is a channel in which updates to the utxo filter
45	// attached to this instance are sent over.
46	filterUpdates chan filterUpdate
47
48	// chainFilter is the set of utox's that we're currently watching
49	// spends for within the chain.
50	filterMtx sync.RWMutex
51	chainFilter map[wire.OutPoint]struct{}
52
53	// filterBlockReqs is a channel in which requests to filter select
54	// blocks will be sent over.
55	filterBlockReqs chan *filterBlockReq
56
57	quit chan struct{}
58	wg sync.WaitGroup
59	}
60
61	// A compile time check to ensure BitcoindFilteredChainView implements the
62	// chainview.FilteredChainView.
63	var _ FilteredChainView = (*BitcoindFilteredChainView)(nil)
64
65	// NewBitcoindFilteredChainView creates a new instance of a FilteredChainView
66	// from RPC credentials and a ZMQ socket address for a bitcoind instance.
67	func NewBitcoindFilteredChainView(
68	chainConn *chain.BitcoindConn,
69	blockCache blockcache.BlockCache) BitcoindFilteredChainView {	6✔
70		6✔
71	chainView := &BitcoindFilteredChainView{	6✔
72	chainFilter: make(map[wire.OutPoint]struct{}),	6✔
73	filterUpdates: make(chan filterUpdate),	6✔
74	filterBlockReqs: make(chan *filterBlockReq),	6✔
75	blockCache: blockCache,	6✔
76	quit: make(chan struct{}),	6✔
77	}	6✔
78		6✔
79	chainView.chainClient = chainConn.NewBitcoindClient()	6✔
80	chainView.blockQueue = newBlockEventQueue()	6✔
81		6✔
82	return chainView	6✔
83	}	6✔
84
85	// Start starts all goroutines necessary for normal operation.
86	//
87	// NOTE: This is part of the FilteredChainView interface.
88	func (b *BitcoindFilteredChainView) Start() error {	6✔
89	// Already started?	6✔
90	if atomic.AddInt32(&b.started, 1) != 1 {	6✔
91	return nil	×
92	}	×
93
94	log.Infof("FilteredChainView starting")	6✔
95		6✔
96	err := b.chainClient.Start()	6✔
97	if err != nil {	6✔
98	return err	×
99	}	×
100
101	err = b.chainClient.NotifyBlocks()	6✔
102	if err != nil {	6✔
103	return err	×
104	}	×
105
106	_, bestHeight, err := b.chainClient.GetBestBlock()	6✔
107	if err != nil {	6✔
108	return err	×
109	}	×
110
111	b.bestHeightMtx.Lock()	6✔
112	b.bestHeight = uint32(bestHeight)	6✔
113	b.bestHeightMtx.Unlock()	6✔
114		6✔
115	b.blockQueue.Start()	6✔
116		6✔
117	b.wg.Add(1)	6✔
118	go b.chainFilterer()	6✔
119		6✔
120	return nil	6✔
121	}
122
123	// Stop stops all goroutines which we launched by the prior call to the Start
124	// method.
125	//
126	// NOTE: This is part of the FilteredChainView interface.
127	func (b *BitcoindFilteredChainView) Stop() error {	6✔
128	// Already shutting down?	6✔
129	if atomic.AddInt32(&b.stopped, 1) != 1 {	6✔
130	return nil	×
131	}	×
132
133	// Shutdown the rpc client, this gracefully disconnects from bitcoind's
134	// zmq socket, and cleans up all related resources.
135	b.chainClient.Stop()	6✔
136		6✔
137	b.blockQueue.Stop()	6✔
138		6✔
139	log.Infof("FilteredChainView stopping")	6✔
140		6✔
141	close(b.quit)	6✔
142	b.wg.Wait()	6✔
143		6✔
144	return nil	6✔
145	}
146
147	// onFilteredBlockConnected is called for each block that's connected to the
148	// end of the main chain. Based on our current chain filter, the block may or
149	// may not include any relevant transactions.
150	func (b *BitcoindFilteredChainView) onFilteredBlockConnected(height int32,
151	hash chainhash.Hash, txns []*wtxmgr.TxRecord) {	347✔
152		347✔
153	mtxs := make([]*wire.MsgTx, len(txns))	347✔
154	b.filterMtx.Lock()	347✔
155	for i, tx := range txns {	353✔
156	mtxs[i] = &tx.MsgTx	6✔
157		6✔
158	for _, txIn := range mtxs[i].TxIn {	12✔
159	// We can delete this outpoint from the chainFilter, as	6✔
160	// we just received a block where it was spent. In case	6✔
161	// of a reorg, this outpoint might get "un-spent", but	6✔
162	// that's okay since it would never be wise to consider	6✔
163	// the channel open again (since a spending transaction	6✔
164	// exists on the network).	6✔
165	delete(b.chainFilter, txIn.PreviousOutPoint)	6✔
166	}	6✔
167
168	}
169	b.filterMtx.Unlock()	347✔
170		347✔
171	// We record the height of the last connected block added to the	347✔
172	// blockQueue such that we can scan up to this height in case of	347✔
173	// a rescan. It must be protected by a mutex since a filter update	347✔
174	// might be trying to read it concurrently.	347✔
175	b.bestHeightMtx.Lock()	347✔
176	b.bestHeight = uint32(height)	347✔
177	b.bestHeightMtx.Unlock()	347✔
178		347✔
179	block := &FilteredBlock{	347✔
180	Hash: hash,	347✔
181	Height: uint32(height),	347✔
182	Transactions: mtxs,	347✔
183	}	347✔
184		347✔
185	b.blockQueue.Add(&blockEvent{	347✔
186	eventType: connected,	347✔
187	block: block,	347✔
188	})	347✔
189	}
190
191	// onFilteredBlockDisconnected is a callback which is executed once a block is
192	// disconnected from the end of the main chain.
193	func (b *BitcoindFilteredChainView) onFilteredBlockDisconnected(height int32,
194	hash chainhash.Hash) {	222✔
195		222✔
196	log.Debugf("got disconnected block at height %d: %v", height,	222✔
197	hash)	222✔
198		222✔
199	filteredBlock := &FilteredBlock{	222✔
200	Hash: hash,	222✔
201	Height: uint32(height),	222✔
202	}	222✔
203		222✔
204	b.blockQueue.Add(&blockEvent{	222✔
205	eventType: disconnected,	222✔
206	block: filteredBlock,	222✔
207	})	222✔
208	}	222✔
209
210	// FilterBlock takes a block hash, and returns a FilteredBlocks which is the
211	// result of applying the current registered UTXO sub-set on the block
212	// corresponding to that block hash. If any watched UTOX's are spent by the
213	// selected lock, then the internal chainFilter will also be updated.
214	//
215	// NOTE: This is part of the FilteredChainView interface.
216	func (b BitcoindFilteredChainView) FilterBlock(blockHash chainhash.Hash) (*FilteredBlock, error) {	4✔
217	req := &filterBlockReq{	4✔
218	blockHash: blockHash,	4✔
219	resp: make(chan *FilteredBlock, 1),	4✔
220	err: make(chan error, 1),	4✔
221	}	4✔
222		4✔
223	select {	4✔
224	case b.filterBlockReqs <- req:	4✔
225	case <-b.quit:	×
226	return nil, fmt.Errorf("FilteredChainView shutting down")	×
227	}
228
229	return <-req.resp, <-req.err	4✔
230	}
231
232	// chainFilterer is the primary goroutine which: listens for new blocks coming
233	// and dispatches the relevant FilteredBlock notifications, updates the filter
234	// due to requests by callers, and finally is able to perform targeted block
235	// filtration.
236	//
237	// TODO(roasbeef): change to use loadfilter RPC's
238	func (b *BitcoindFilteredChainView) chainFilterer() {	6✔
239	defer b.wg.Done()	6✔
240		6✔
241	// filterBlock is a helper function that scans the given block, and	6✔
242	// notes which transactions spend outputs which are currently being	6✔
243	// watched. Additionally, the chain filter will also be updated by	6✔
244	// removing any spent outputs.	6✔
245	filterBlock := func(blk wire.MsgBlock) []wire.MsgTx {	10✔
246	b.filterMtx.Lock()	4✔
247	defer b.filterMtx.Unlock()	4✔
248		4✔
249	var filteredTxns []*wire.MsgTx	4✔
250	for _, tx := range blk.Transactions {	12✔
251	var txAlreadyFiltered bool	8✔
252	for _, txIn := range tx.TxIn {	16✔
253	prevOp := txIn.PreviousOutPoint	8✔
254	if _, ok := b.chainFilter[prevOp]; !ok {	12✔
255	continue	4✔
256	}
257
258	delete(b.chainFilter, prevOp)	6✔
259		6✔
260	// Only add this txn to our list of filtered	6✔
261	// txns if it is the first previous outpoint to	6✔
262	// cause a match.	6✔
263	if txAlreadyFiltered {	6✔
264	continue	×
265	}
266
267	filteredTxns = append(filteredTxns, tx.Copy())	6✔
268	txAlreadyFiltered = true	6✔
269	}
270	}
271
272	return filteredTxns	4✔
273	}
274
275	decodeJSONBlock := func(block *btcjson.RescannedBlock,	6✔
276	height uint32) (*FilteredBlock, error) {	8✔
277	hash, err := chainhash.NewHashFromStr(block.Hash)	2✔
278	if err != nil {	2✔
279	return nil, err	×
280		×
281	}	×
282	txs := make([]*wire.MsgTx, 0, len(block.Transactions))	2✔
283	for _, str := range block.Transactions {	4✔
284	b, err := hex.DecodeString(str)	2✔
285	if err != nil {	2✔
286	return nil, err	×
287	}	×
288	tx := &wire.MsgTx{}	2✔
289	err = tx.Deserialize(bytes.NewReader(b))	2✔
290	if err != nil {	2✔
291	return nil, err	×
292	}	×
293	txs = append(txs, tx)	2✔
294	}
295	return &FilteredBlock{	2✔
296	Hash: *hash,	2✔
297	Height: height,	2✔
298	Transactions: txs,	2✔
299	}, nil	2✔
300	}
301
302	for {	946✔
303	select {	940✔
304	// The caller has just sent an update to the current chain
305	// filter, so we'll apply the update, possibly rewinding our
306	// state partially.
307	case update := <-b.filterUpdates:	8✔
308	// First, we'll add all the new UTXO's to the set of	8✔
309	// watched UTXO's, eliminating any duplicates in the	8✔
310	// process.	8✔
311	log.Tracef("Updating chain filter with new UTXO's: %v",	8✔
312	update.newUtxos)	8✔
313		8✔
314	b.filterMtx.Lock()	8✔
315	for _, newOp := range update.newUtxos {	20✔
316	b.chainFilter[newOp] = struct{}{}	12✔
317	}	12✔
318	b.filterMtx.Unlock()	8✔
319		8✔
320	// Apply the new TX filter to the chain client, which	8✔
321	// will cause all following notifications from and	8✔
322	// calls to it return blocks filtered with the new	8✔
323	// filter.	8✔
324	err := b.chainClient.LoadTxFilter(false, update.newUtxos)	8✔
325	if err != nil {	8✔
326	log.Errorf("Unable to update filter: %v", err)	×
327	continue	×
328	}
329
330	// All blocks gotten after we loaded the filter will
331	// have the filter applied, but we will need to rescan
332	// the blocks up to the height of the block we last
333	// added to the blockQueue.
334	b.bestHeightMtx.Lock()	8✔
335	bestHeight := b.bestHeight	8✔
336	b.bestHeightMtx.Unlock()	8✔
337		8✔
338	// If the update height matches our best known height,	8✔
339	// then we don't need to do any rewinding.	8✔
340	if update.updateHeight == bestHeight {	14✔
341	continue	6✔
342	}
343
344	// Otherwise, we'll rewind the state to ensure the
345	// caller doesn't miss any relevant notifications.
346	// Starting from the height _after_ the update height,
347	// we'll walk forwards, rescanning one block at a time
348	// with the chain client applying the newly loaded
349	// filter to each block.
350	for i := update.updateHeight + 1; i < bestHeight+1; i++ {	4✔
351	blockHash, err := b.chainClient.GetBlockHash(int64(i))	2✔
352	if err != nil {	2✔
353	log.Warnf("Unable to get block hash "+	×
354	"for block at height %d: %v",	×
355	i, err)	×
356	continue	×
357	}
358
359	// To avoid dealing with the case where a reorg
360	// is happening while we rescan, we scan one
361	// block at a time, skipping blocks that might
362	// have gone missing.
363	rescanned, err := b.chainClient.RescanBlocks(	2✔
364	[]chainhash.Hash{*blockHash},	2✔
365	)	2✔
366	if err != nil {	2✔
367	log.Warnf("Unable to rescan block "+	×
368	"with hash %v at height %d: %v",	×
369	blockHash, i, err)	×
370	continue	×
371	}
372
373	// If no block was returned from the rescan, it
374	// means no matching transactions were found.
375	if len(rescanned) != 1 {	2✔
UNCOV 376	log.Tracef("rescan of block %v at "+	×
UNCOV 377	"height=%d yielded no "+	×
UNCOV 378	"transactions", blockHash, i)	×
UNCOV 379	continue	×
380	}
381	decoded, err := decodeJSONBlock(	2✔
382	&rescanned[0], i,	2✔
383	)	2✔
384	if err != nil {	2✔
385	log.Errorf("Unable to decode block: %v",	×
386	err)	×
387	continue	×
388	}
389	b.blockQueue.Add(&blockEvent{	2✔
390	eventType: connected,	2✔
391	block: decoded,	2✔
392	})	2✔
393	}
394
395	// We've received a new request to manually filter a block.
396	case req := <-b.filterBlockReqs:	4✔
397	// First we'll fetch the block itself as well as some	4✔
398	// additional information including its height.	4✔
399	block, err := b.GetBlock(req.blockHash)	4✔
400	if err != nil {	4✔
401	req.err <- err	×
402	req.resp <- nil	×
403	continue	×
404	}
405	header, err := b.chainClient.GetBlockHeaderVerbose(	4✔
406	req.blockHash)	4✔
407	if err != nil {	4✔
408	req.err <- err	×
409	req.resp <- nil	×
410	continue	×
411	}
412
413	// Once we have this info, we can directly filter the
414	// block and dispatch the proper notification.
415	req.resp <- &FilteredBlock{	4✔
416	Hash: *req.blockHash,	4✔
417	Height: uint32(header.Height),	4✔
418	Transactions: filterBlock(block),	4✔
419	}	4✔
420	req.err <- err	4✔
421
422	// We've received a new event from the chain client.
423	case event := <-b.chainClient.Notifications():	928✔
424	switch e := event.(type) {	928✔
425
426	case chain.FilteredBlockConnected:	347✔
427	b.onFilteredBlockConnected(	347✔
428	e.Block.Height, e.Block.Hash, e.RelevantTxs,	347✔
429	)	347✔
430
431	case chain.BlockDisconnected:	222✔
432	b.onFilteredBlockDisconnected(e.Height, e.Hash)	222✔
433	}
434
435	case <-b.quit:	6✔
436	return	6✔
437	}
438	}
439	}
440
441	// UpdateFilter updates the UTXO filter which is to be consulted when creating
442	// FilteredBlocks to be sent to subscribed clients. This method is cumulative
443	// meaning repeated calls to this method should _expand_ the size of the UTXO
444	// sub-set currently being watched. If the set updateHeight is _lower_ than
445	// the best known height of the implementation, then the state should be
446	// rewound to ensure all relevant notifications are dispatched.
447	//
448	// NOTE: This is part of the FilteredChainView interface.
449	func (b *BitcoindFilteredChainView) UpdateFilter(ops []channeldb.EdgePoint,
450	updateHeight uint32) error {	8✔
451		8✔
452	newUtxos := make([]wire.OutPoint, len(ops))	8✔
453	for i, op := range ops {	20✔
454	newUtxos[i] = op.OutPoint	12✔
455	}	12✔
456
457	select {	8✔
458
459	case b.filterUpdates <- filterUpdate{
460	newUtxos: newUtxos,
461	updateHeight: updateHeight,
462	}:	8✔
463	return nil	8✔
464
465	case <-b.quit:	×
466	return fmt.Errorf("chain filter shutting down")	×
467	}
468	}
469
470	// FilteredBlocks returns the channel that filtered blocks are to be sent over.
471	// Each time a block is connected to the end of a main chain, and appropriate
472	// FilteredBlock which contains the transactions which mutate our watched UTXO
473	// set is to be returned.
474	//
475	// NOTE: This is part of the FilteredChainView interface.
476	func (b BitcoindFilteredChainView) FilteredBlocks() <-chan FilteredBlock {	10✔
477	return b.blockQueue.newBlocks	10✔
478	}	10✔
479
480	// DisconnectedBlocks returns a receive only channel which will be sent upon
481	// with the empty filtered blocks of blocks which are disconnected from the
482	// main chain in the case of a re-org.
483	//
484	// NOTE: This is part of the FilteredChainView interface.
485	func (b BitcoindFilteredChainView) DisconnectedBlocks() <-chan FilteredBlock {	4✔
486	return b.blockQueue.staleBlocks	4✔
487	}	4✔
488
489	// GetBlock is used to retrieve the block with the given hash. This function
490	// wraps the blockCache's GetBlock function.
491	func (b BitcoindFilteredChainView) GetBlock(hash chainhash.Hash) (
492	*wire.MsgBlock, error) {	4✔
493		4✔
494	return b.blockCache.GetBlock(hash, b.chainClient.GetBlock)	4✔
495	}	4✔

lightningnetwork / lnd / 9111774206

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